Dynamic Impurity Redistributions in Kesterite Absorbers

Cu2ZnSn(S,Se)4 is a promising nontoxic earth-abundant solar cell absorber. To optimize the thin films for solar cell device performance, postdeposition treatments at temperatures below the crystallization temperature are normally performed, which alter the surface and bulk properties. The polycrystalline thin films contain relatively high concentrations of impurities, such as sodium, oxygen and hydrogen. During the treatments, these impurities migrate and likely agglomerate at lattice defects or interfaces. Herein, impurity redistribution after air annealing for temperatures up to 200 \ub0C and short heavy water treatments are studied. In addition, nonuniformities of the sodium distribution on a nanometer and micrometer scale are characterized by atom probe tomography and secondary ion mass spectrometry, respectively. Sodium and oxygen correlate to a greater extent after heat treatments, supporting strong binding between the two impurities. Redistributions of these impurities occur even at room temperature over longer time periods. Heavy water treatments confirm out-diffusion of sodium with more incorporation of oxygen and hydrogen. It is observed that the increased hydrogen content does not originate from the heavy water. The existence of an “ice-like” layer on top of the Cu2ZnSnS4 layer is proposed

31 recommendations for increased profit - reducing waste

Those companies and organizations that wish to ensure long-term profitability must successively decrease resource use in both product development and in product usage. Primarily, it is waste that must be reduced, i.e. the consumption of resources that do not add to customer value or to the organization. Waste is widespread in all operations. Even in well-functioning processes, more than half of the resource consumption can be classified as waste. One obstacle to waste elimination is that most waste is hidden. Thus, executives, middle management and specialists must prioritize efforts to uncover the waste in their operations.Building and construction activities consist of a complex system of decisions, components, organizations and processes that must be coordinated. There are therefore many explanations as to why waste arises, or does not. Based on a series of discussions with experienced builders, consultants, contractors and materials providers, five main groups of factors that characterize effective operations were found. In this report these factors are illustrated in the form of a “value pyramid”. A holistic view of long-term customer benefits is the apex of the pyramid. Structure, competence, leadership and culture act as the driving forces at each corner of the pyramid’s foundation. Should one of the corners gives way, then the pyramid risks toppling over.With the value pyramid as support, 31 recommendations for what should be done to reduce waste are presented. These are aimed at standardizing the product from an overall perspective (five recommendations), defining and standardizing processes (ten recommendations), developing the organization and its competence (seven recommendations), disciplining management (five recommendations), and driving continuous improvement work (four recommendations). Reducing uncertainties and increasing effective time utilization are the red threads, as the Swedes would say, that run through all the recommendations.Everyone who uses resources has a responsibility to reduce waste. By systematically monitoring one’s own use of time, one can gain insights that will help improve one’s work situation. However, the burden of initiating and driving improvements overall obviously lies with management. How this should be done depends on the nature and purpose of the activities as well as on the organization’s capabilities. It is to manage this progress and achieve profitability that managers are appointed. It is in the interest of all enterprises and organizations to develop the ability and an interest to detect and understand what work/task is value adding what is not. This ability will provide possibilities to develop new competitive advantages and new business concepts

Why do work sampling studies in construction? The case of plumbing work in Scandiavia

Purpose– The purpose of this paper is to identify reasons for doing work sampling studies in processes performed by temporary organisations. Specific questions consider if the technique can be used for measuring productivity and if it can be used to compare performances over time.Design/methodology/approach– A work sampling study of plumbing work in eight construction projects is compared with a similar study performed 20 years earlier. Interviews are made in order to find out how the work conditions have developed over time.Findings– Work sampling studies are of little value for measuring productivity as well as for comparing performances over time. One reason is that the conditions vary to a high extent from one situation to another. Another reason is that working conditions undergo significant development over time. On the other hand, the authors experience that data from work sampling studies are of high relevance for discussions on improvement opportunities among workers as well as among corporate managers

Why do work sampling studies in construction? The case of plumbing work in Scandiavia

Purpose– The purpose of this paper is to identify reasons for doing work sampling studies in processes performed by temporary organisations. Specific questions consider if the technique can be used for measuring productivity and if it can be used to compare performances over time.Design/methodology/approach– A work sampling study of plumbing work in eight construction projects is compared with a similar study performed 20 years earlier. Interviews are made in order to find out how the work conditions have developed over time.Findings– Work sampling studies are of little value for measuring productivity as well as for comparing performances over time. One reason is that the conditions vary to a high extent from one situation to another. Another reason is that working conditions undergo significant development over time. On the other hand, the authors experience that data from work sampling studies are of high relevance for discussions on improvement opportunities among workers as well as among corporate managers

Arbetstidens anv\ue4ndning vid VVS-montage - en fr\ue5ga om struktur och ledarskap

Most of the narratives packaged for New Orleans\u27s many tourists cultivate a desire for black culture—jazz, cuisine, dance—while simultaneously targeting black people and their communities as sources and sites of political, social, and natural disaster. In this timely book, the Americanist and New Orleans native Lynnell L. Thomas delves into the relationship between tourism, cultural production, and racial politics. She carefully interprets the racial narratives embedded in tourist websites, travel guides, business periodicals, and newspapers; the thoughts of tour guides and owners; and the stories told on bus and walking tours as they were conducted both before and after Katrina. She describes how, with varying degrees of success, African American tour guides, tour owners, and tourism industry officials have used their own black heritage tours and tourism-focused businesses to challenge exclusionary tourist representations. Taking readers from the Lower Ninth Ward to the White House, Thomas highlights the ways that popular culture and public policy converge to create a mythology of racial harmony that masks a long history of racial inequality and structural inequity