Improving Monolithic Perovskite Silicon Tandem Solar Cells From an Optical Viewpoint

Perovskite silicon tandem solar cells are the most promising concept for a future photovoltaic technology. We report on recent progress from an optical viewpoint and disucss how we achieved more than 25 device efficienc

A digital definition method for manufacturing model of aircraft integral panel

The manufacturing model of aircraft integral panel is presented based on the analysis of its structure and manufacturing process. The manufacturing model for each key process consists of model for processing and model for workpiece to bridge digital design and fabricating. Model for workpiece is used to express the target part information at the end of some operation. Model for processing is used to describe the intermediate state information, and it aims to attain but is different the workpiece because of process factors. The definition flow of the manufacturing model is given. The modeling approach of integral panel part blank from shot peen forming part model orienting to NC cutting is proposed and exemplified. It is analyzed that the approaches above can define the models accurately and totally to meet the needs of process planning , NC fabricating and inspecting

Organic Agriculture and Food Utilization

SUMMARY OF FINDINGS 90. Food safety: Many aspects of organic agriculture reduce the risks of pathogens (zoonoses), mycotoxins, bacterial toxins and industrial toxic pollutants, compared to conventional agriculture. However, some other aspects potentially increase them. Reduced resistance to antibiotics in zoonotic pathogens indicates a better prognosis for patients if an infection does occur. For natural plant toxins, the content in plants appears to systematically be 10 to 50 percent higher than in conventional plants. However, this is in a range of concentrations where these compounds have no toxic effect and may even benefit human health. 91. Pesticide poisoning: This is an area where very substantial health problems have been documented, especially among farmers and their families. Pesticide poisoning causes some 20 000 deaths per year globally and an average of 11 days wages lost due to illness, per farmer per incidence, in some areas. Even symptom-free workers often exhibit biomarker changes indicating increased risk of diseases, including Parkinson’s disease. With the present level of knowledge, elimination of such horrible conditions, which can be achieved on a short timescale, is the quantitatively single most important benefit of organic farming in terms of human health. Still, long-term occupational exposure to copper also increases the risk of Parkinson’s disease, but not as much as exposure to synthetic pesticides. 92. Pesticide residues: The levels in organic products are consistently 4 to 5 times lower than in conventional products. However, no definitive causal connection with harm to consumers has ever been demonstrated for food produced in accordance with general (conventional) food safety rules. Errors and accidents can cause contamination with harmful levels of pesticides, but this risk is eliminated when no pesticides are present. Across the different safety risks in both systems, the best managers achieve much better standards than the average producers, and the occurrence of serious hazards is so low that no significant differences have been demonstrated between production systems. 93. Food quality: Consumers generally appreciate that food is authentic and trustworthy and produced with care for them and the environment. So reduced food additives and pesticide residues, good traceability and emphasis on animal welfare all support the perception of organic food as being of high-quality. Differences in taste between organic and conventional food products are strongly affected by interaction with local aspects and therefore show few general trends. Only poultry (broiler) produced according to the organic standards results in a clearly differentiated taste compared with mainstream conventional products. 94. Nutritional adequacy: In developing countries, organic agriculture has several advantages for the provision of nutrients, such as higher Zn/phytate ratio and better amino acid composition in cereals. Also, a more balanced diet due to the greater diversity of organic rotations, including legumes and various types of vegetables, and the need for animals on each farm provide important nutritional benefits. In developed countries, nutritional value is much more difficult to determine. However, the higher levels of plant secondary metabolites and conjugated fatty acids in milk may provide important protection against cardiovascular disease, cancer and other diseases known to be influenced by diet. 95. Human health: Epidemiological studies have shown better health scores among consumers of organic food for immunological characteristics and weight control, and similar benefits have been reproduced in animal studies, supporting a possible causal role of the food production system. 96. Post-harvest operations: Higher activity of plant defense mechanisms in organic plants reduces the losses during transport and storage. The preference for local products and short supply chains also reduce the loss of quality during transport. 97. Pollution of drinking water: Organic farmers have substantially higher economic incentives than conventional farmers to establish and maintain sufficient capacity for collection, composting and incorporation of animal and human wastes as valuable fertilizer. This is particularly important in areas where sanitation is not provided or standards not enforced by the authorities. Such measures will also substantially reduce contamination with nitrates and phosphorus. There is little evidence that these minerals have any harmful effects on humans, if the drinking water is free of pathogens, except by promoting blooms of toxic algae. 98. Pollution of the environment: Persistent pesticides (such as DDT) have damaged wildlife globally and are still being used in many developing countries. Organic agriculture protects the local environment against all types of pesticides and has potential to benefit the global situation if the proportion of land under organic management becomes large enough to reduce the total use. Pollution with nitrate and phosphorus are major causes of eutrophication. Organic farms leach lower levels of phosphorus into drainage water than conventional ones. For nitrate, the loss from organic farms tends to be slightly lower than conventional, except when comparing organic outdoor pig production with conventional indoor production. However, recent data indicate that organically managed soil may be more efficient at denitrification, releasing most of the nitrate into the atmosphere as harmless N2. If this is a general trend, the benefits of organic farming are much larger than previously estimated

A Framework for Evaluating Model-Driven Self-adaptive Software Systems

In the last few years, Model Driven Development (MDD), Component-based Software Development (CBSD), and context-oriented software have become interesting alternatives for the design and construction of self-adaptive software systems. In general, the ultimate goal of these technologies is to be able to reduce development costs and effort, while improving the modularity, flexibility, adaptability, and reliability of software systems. An analysis of these technologies shows them all to include the principle of the separation of concerns, and their further integration is a key factor to obtaining high-quality and self-adaptable software systems. Each technology identifies different concerns and deals with them separately in order to specify the design of the self-adaptive applications, and, at the same time, support software with adaptability and context-awareness. This research studies the development methodologies that employ the principles of model-driven development in building self-adaptive software systems. To this aim, this article proposes an evaluation framework for analysing and evaluating the features of model-driven approaches and their ability to support software with self-adaptability and dependability in highly dynamic contextual environment. Such evaluation framework can facilitate the software developers on selecting a development methodology that suits their software requirements and reduces the development effort of building self-adaptive software systems. This study highlights the major drawbacks of the propped model-driven approaches in the related works, and emphasise on considering the volatile aspects of self-adaptive software in the analysis, design and implementation phases of the development methodologies. In addition, we argue that the development methodologies should leave the selection of modelling languages and modelling tools to the software developers.Comment: model-driven architecture, COP, AOP, component composition, self-adaptive application, context oriented software developmen

Integrated product relationships management : a model to enable concurrent product design and assembly sequence planning

The paper describes a novel approach to product relationships management in the context of concurrent engineering and product lifecycle management (PLM). Current industrial practices in product data management and manufacturing process management systems require better efficiency, flexibility, and sensitivity in managing product information at various levels of abstraction throughout its lifecycle. The aim of the proposed work is to manage vital yet complex and inherent product relationship information to enable concurrent product design and assembly sequence planning. Indeed, the definition of the product with its assembly sequence requires the management and the understanding of the numerous product relationships, ensuring consistency between the product and its components. This main objective stresses the relational design paradigm by focusing on product relationships along its lifecycle. This paper gives the detailed description of the background and models which highlight the need for a more efficient PLM approach. The proposed theoretical approach is then described in detail. A separate paper will focus on the implementation of the proposed approach in a PLM-based application, and an in-depth case study to evaluate the implementation of the novel approach will also be given

Agricultural Sustainability - Progress and Prospects in Crop Research

Agricultural Sustainability: Progress and Prospects in Crop Research, covers different aspects of sustainability in a holistic manner and presents a wide range of subject areas by agricultural experts from across the world. The book offers different points of view including important topics in agrobiodiversity, biotechnology, marginal crops, industrial approaches, resource conservation, nutritional enhancement of crops and crop products, and explores economic and political issues

Optimization viewpoint on Kalman smoothing, with applications to robust and sparse estimation

In this paper, we present the optimization formulation of the Kalman filtering and smoothing problems, and use this perspective to develop a variety of extensions and applications. We first formulate classic Kalman smoothing as a least squares problem, highlight special structure, and show that the classic filtering and smoothing algorithms are equivalent to a particular algorithm for solving this problem. Once this equivalence is established, we present extensions of Kalman smoothing to systems with nonlinear process and measurement models, systems with linear and nonlinear inequality constraints, systems with outliers in the measurements or sudden changes in the state, and systems where the sparsity of the state sequence must be accounted for. All extensions preserve the computational efficiency of the classic algorithms, and most of the extensions are illustrated with numerical examples, which are part of an open source Kalman smoothing Matlab/Octave package.Comment: 46 pages, 11 figure