Silicon MINP solar cells

The MINP solar cell concept refers to a cell structure designed to be a base region dominated device. Thus, it is desirable that recombination losses are reduced to the point that they occur only in the base region. The most unique feature of the MINP cell design is that a tunneling contact is utilized for the metallic contact on the front surface. The areas under the collector grid and bus bar are passivated by a thin oxide of tunneling thickness. Efforts must also be taken to minimize recombination at the surface between grid lines, at the junction periphery and within the emitter. Results of both theoretical and experimental studies of silicon MINP cells are given. Performance calculations are described which give expected efficiencies as a function of base resistivity and junction depth. Fabrication and characterization of cells are discussed which are based on 0.2 ohm-cm substrates, diffused emitters on the order of 0.15 to 0.20 microns deep, and with Mg MIS collector grids. A total area AM 1 efficiency of 16.8% was achieved. Detailed analyses of photocurrent and current loss mechanisms are presented and utilized to discuss future directions of research. Finally, results reported by other workers are discussed

Memory for Emotional Simulations: Remembering a Rosy Future

Mental simulations of future experiences are often concerned with emotionally arousing events. Although it is widely believed that mental simulations enhance future behavior, virtually nothing is known about the mnemonic fate of these simulations over time or whether emotional simulations are especially well-remembered. We used a novel paradigm, combining recently developed methods for generating future event simulations and well-established memory testing procedures, to examine the retention of positive, negative, and neutral simulations over multiple delays. We found that with increasing delay, details associated with negative simulations become more difficult to remember than details associated with positive and neutral simulations. We suggest that these delay-by-emotion interactions reflect the mnemonic influence of fading affect bias, where negative reactions fade more quickly than positive ones, resulting in a tendency to remember a rosy simulated future. We also discuss implications for affective disorders such as depression and anxiety.Psycholog

Remembering the Past and Imagining the Future in the Elderly

Recent research has demonstrated commonalities between remembering past events and imagining future events. Behavioral studies have revealed that remembering the past and imagining the future depend on shared cognitive processes, whereas neuropsychological and neuroimaging studies have shown that many of the same brain regions are involved in both remembering the past and imagining the future. Here, we review recent cognitive and neuroimaging studies that examine remembering the past and imagining the future in elderly adults. These studies document significant changes in elderly adults’ capacities to imagine future events that are correlated with their memory deficits; most strikingly, older adults tend to remember the past and imagine the future with less episodic detail than younger adults. These findings are in line with the constructive episodic simulation hypothesis [Schacter and Addis: Phil Trans R Soc B 2007;362:773-786], which holds that that past and future events draw on similar information and rely on similar underlying processes, and that episodic memory supports the construction of future events by extracting and recombining stored information into a simulation of a novel event. At the same time, however, recent data indicate that non-episodic factors also contribute to age-related changes in remembering the past and imagining the future. We conclude by considering a number questions and challenges concerning the interpretation of age-related changes in remembering and imagining, as well as functional implications of this research for everyday concerns of older adults.Psycholog

Remembering what could have happened: Neural correlates of episodic counterfactual thinking

Recent evidence suggests that our capacities to remember the past and to imagine what might happen in the future largely depend on the same core brain network that includes the middle temporal lobe, the posterior cingulate/retrosplenial cortex, the inferior parietal lobe, the medial prefrontal cortex, and the lateral temporal cortex. However, the extent to which regions of this core brain network are also responsible for our capacity to think about what could have happened in our past, yet did not occur (i.e., episodic counterfactual thinking), is still unknown. The present study examined this issue. Using a variation of the experimental recombination paradigm (Addis, Pan, Vu, Laiser, & Schacter, 2009. Neuropsychologia. 47: 2222–2238), participants were asked both to remember personal past events and to envision alternative outcomes to such events while undergoing functional magnetic resonance imaging. Three sets of analyses were performed on the imaging data in order to investigate two related issues. First, a mean-centered spatiotemporal partial least square (PLS) analysis identified a pattern of brain activity across regions of the core network that was common to episodic memory and episodic counterfactual thinking. Second, a non-rotated PLS analysis identified two different patterns of brain activity for likely and unlikely episodic counterfactual thoughts, with the former showing significant overlap with the set of regions engaged during episodic recollection. Finally, a parametric modulation was conducted to explore the differential engagement of brain regions during counterfactual thinking, revealing that areas such as the parahippocampal gyrus and the right hippocampus were modulated by the subjective likelihood of counterfactual simulations. These results suggest that episodic counterfactual thinking engages regions that form the core brain network, and also that the subjective likelihood of our counterfactual thoughts modulates the engagement of different areas within this set of regions.Psycholog

Re-imagining the future:repetition decreases hippocampal involvement in future simulation

Imagining or simulating future events has been shown to activate the anterior right hippocampus (RHC) more than remembering past events does. One fundamental difference between simulation and memory is that imagining future scenarios requires a more extensive constructive process than remembering past experiences does. Indeed, studies in which this constructive element is reduced or eliminated by “pre-imagining” events in a prior session do not report differential RHC activity during simulation. In this fMRI study, we examined the effects of repeatedly simulating an event on neural activity. During scanning, participants imagined 60 future events; each event was simulated three times. Activation in the RHC showed a significant linear decrease across repetitions, as did other neural regions typically associated with simulation. Importantly, such decreases in activation could not be explained by non-specific linear time-dependent effects, with no reductions in activity evident for the control task across similar time intervals. Moreover, the anterior RHC exhibited significant functional connectivity with the whole-brain network during the first, but not second and third simulations of future events. There was also evidence of a linear increase in activity across repetitions in right ventral precuneus, right posterior cingulate and left anterior prefrontal cortex, which may reflect source recognition and retrieval of internally generated contextual details. Overall, our findings demonstrate that repeatedly imagining future events has a decremental effect on activation of the hippocampus and many other regions engaged by the initial construction of the simulation, possibly reflecting the decreasing novelty of simulations across repetitions, and therefore is an important consideration in the design of future studies examining simulation

The Future of Memory: Remembering, Imagining, and the Brain

During the past few years, there has been a dramatic increase in research examining the role of memory in imagination and future thinking. This work has revealed striking similarities between remembering the past and imagining or simulating the future, including the finding that a common brain network underlies both memory and imagination. Here we discuss a number of key points that have emerged during recent years, focusing in particular on the importance of distinguishing between temporal and non-temporal factors in analyses of memory and imagination, the nature of differences between remembering the past and imagining the future, the identification of component processes that comprise the default network supporting memory- based simulations, and the finding that this network can couple flexibly with other networks to support complex goal-directed simulations. This growing area of research has broadened our conception of memory by highlighting the many ways in which memory supports adaptive functioning.Psycholog

Do Women in Anxiety Support Groups Demonstrate Less Anxiety Than Those Who Are Not in Support Groups?

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An overview of historical and contemporary concrete shells, their construction and factors in their general disappearance

Only through understanding why concrete shells’ loss in popularity over the course of modern history can designers be equipped with the skills to create and apply this type of construction. Through modifications to design processes, construction stages, material understanding and relevant formwork improvements will architects and designers be able to meet the demands of the 21st century and beyond. To understand why concrete shells are no longer commonly built is to understand its construction process. An amorphous material, the fundamental relationship between formwork and the resultant concrete shell needs to be raised, appreciated, understood and analyzed for a holistic understanding of concrete shells. Through understanding this, issues and factors affecting concrete shells can be tackled and designed out in reviving this type of structures because they can be efficient in structural performance, economical in cost and provide high aesthetic value. This paper discusses concrete shells as an architectural solution by asking the question to what constituted their popularity and factors that led to their demise in the modern age of technological advancement, construction process and environmental concerns. This paper presents a cultural perspective and an overview of seminal, historical and contemporary concrete shells so as to bring about a renaissance of such structures in our built environment once again because of all the benefits it can offer.</p

Horseplay, care and hands on hard work: gendered strategies of a project manager on a construction site

The discourse of managerial expertise favours rational analysis and masculine ideals but contemporary management literature also recognises the value of well-being and employee voice in the workplace. Drawing upon narrative analysis of interview data, we share unique insights into the lived experiences of Laura, one female project manager who recently managed a construction site in the Midlands in the UK. In contrast to previous research which indicates that female managers tend to conform to quite a traditional set of gender behaviours, Laura embraces a range of workplace appropriate gendered strategies, such as hard work and horseplay, together with sensitivity and caring. She draws from this mix of gendered strategies in negotiating between two different discourses of construction; one professional and one tough and practical. Her behaviour both reproduces the masculine ideals (through horseplay and heroic management) and opens up possibilities for modernising construction management (by caring). It is this combination of strategies that is at the heart of tacit expertise for Laura. Theoretically, the discussion adds to the development of a more nuanced understanding of management expertise as situated and person specific knowledge that draws on both the explicit and tacit. Specifically, the centrality of gendered strategies beyond the masculine ideals to success on site is highlighted