A prototype printer for laser driven micro-transfer printing

This paper demonstrates a new mode of automated micro transfer printing called laser micro transfer printing (LμTP). As a process, micro-transfer printing provides a unique and critical manufacturing route to extracting active microstructures from growth substrates and deterministically assembling them into a variety of functional substrates ranging from polymers to glasses and ceramics and to metallic foils to support applications such as flexible, large-area electronics, concentrating photovoltaics and displays. Laser transfer printing extends micro-transfer printing technology by providing a non-contact approach that is insensitive to the preparation and properties of the receiving substrate. It does so by exploiting the difference in the thermo-mechanical responses of the microstructure and transfer printing stamp materials to drive the release of the microstructure or ‘ink’ from the stamp and its transfer to substrate. This paper describes the process and the physical phenomena that drive it. It focuses on the use of this knowledge to design and test a print head for the process. The print head is used to demonstrate the new printing capabilities that LμTP enables.     

The value of cooperation in resolving international river basin disputes

This paper reviews the phenomenon of international river basins, and concludes that the sharing of river basins between and among countries is the rule rather than the exception for the major river systems of the world. The growth of the nation state with rivers as agreed-upon boundaries, as cease-fire lines and as natural defensive lines has led to the carving up of most river basins around the world. More than 200 river basins, accounting for more than 50% of the land area of the Earth, are shared by two or more countries. When population densities were low, there was plenty of water for all and major conflicts were avoided. With the rapid population and economic growth experienced in the past few decades, conflicts over use of water are becoming more important. It is expected that in the near future such conflicts will become much more severe. The paper reviews the literature on attempts to analyse river basin conflicts and negotiate solutions. Some rudimentary game models are examined, and some tentative conclusions, based upon various game theory concepts of stability, are applied to the Ganges-Brahmaputra basin. The paper ends with suggestions on how to plan Pareto-Admissible outcomes for international basins.     

Real-time measurements of jet aircraft engine exhaust

Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations.     

A social–ecological framework and toolbox to help strengthening functional agrobiodiversity-supported ecosystem services at the landscape scale

Functional agrobiodiversity (FAB) has severely declined during the last decades. Current efforts to reinforce FAB are mainly focused on single-actor, parcel-based measures, whereas multi-actor landscape approaches are supposed to be more effective. In this paper, we propose a social–ecological framework that structures how different land users at both the parcel and landscape level interact with FAB as a natural resource. Furthermore, we introduce 1 m² FAB gardens as an interactive multipurpose measurement tool to gather data on ecosystem services in collaboration with land users. The presented action research approach provides new insights on motivations and interests of different land users in FAB and how knowledge exchange can result in a higher motivation to invest in FAB. Using a case study in Flanders, we illustrate the FAB-garden concept and highlight its strengths and necessary considerations to properly complement other research approaches in this social–ecological system.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01382-0) contains supplementary material, which is available to authorized users.     

Western Land Managers will Need all Available Tools for Adapting to Climate Change,Including Grazing: A Critique of Beschta et al.

In a previous article, Beschta et al. (Environ Manag 51(2):474–491, 2013) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a challenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO₂ and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20–50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing.     

Use of fecundity measured directly throughout the breeding season to test a source-sink demographic model

Populations of landbirds (bird species that occupy terrestrial habitats for most of their life cycle) are declining throughout North America (north of Mexico) and Europe, yet little is known about how demography is driving this trend. A recent model of 5 geographically separated populations of Cerulean Warblers (Dendroica cerulea) that was based on within-season sampling of nest survival and fledgling success shows that all populations are sinks (annual reproduction is consistently less than annual adult mortality). I tested this indirect model by directly measuring fecundity (number of female fledglings/female) during the breeding season for 2 years in a Cerulean Warbler population occupying a mature forest in southwestern Michigan (U.S.A.) I determined territories of male birds on the basis of male plumage characters and phases of the nesting cycle (2007) and on uniquely color-banded males (2008). I transferred locations of identified males to topographic maps. I counted all fledglings in territories from May to July each year. The model I tested may apply only to single-brooded species; therefore, I searched the literature to estimate the percentage of single-brooded species in North America. The breeding season of Cerulean Warblers was short- nearly all nests were initiated from mid-May to late June. Nest predation and brood parasitism were primary and rare causes of nest failure, respectively. Significantly fewer Cerulean Warblers fledged from parasitized than from nonparasitized nests. Fledgling survival required to maintain the population size was well above previously published values for Neotropical migrants. Single-brooded species comprise 62% of North American breeding bird species for which the number of broods per year is known; I believe my results may apply to these species. The consistency between identification of populations as sources or sinks on the basis of either model estimates or direct measurements suggests that a demographic model relying on within-season sampling of fecundity is adequate to determine population status of single-brooded avian populations. In addition, on the basis of results of previous studies, annual adult survival rate of the Cerulean Warbler is typical of parulid warblers that are not declining. Thus, low fecundity, here determined with different quantitative methods, can drive status of landbird species with high-observed survival.     

Bayesian networks make LOPA more effective,QRA more transparent and flexible,and thus safety more definable!

Quantitative risk analysis is in principle an ideal method to map one’s risks, but it has limitations due to the complexity of models, scarcity of data, remaining uncertainties, and above all because effort, cost, and time requirements are heavy. Also, software is not cheap, the calculations are not quite transparent, and the flexibility to look at various scenarios and at preventive and protective options is limited. So, the method is considered as a last resort for determination of risks. Simpler methods such as LOPA that focus on a particular scenario and assessment of protection for a defined initiating event are more popular. LOPA may however not cover the whole range of credible scenarios, and calamitous surprises may emerge.In the past few decades, Artificial Intelligence university groups, such as the Decision Systems Laboratory of the University of Pittsburgh, have developed Bayesian approaches to support decision making in situations where one has to weigh gains and costs versus risks. This paper will describe details of such an approach and will provide some examples of both discrete random variables, such as the probability values in a LOPA, and continuous distributions, which can better reflect the uncertainty in data.     

The Precautionary Principle for Environmental Management: A Defensive-expenditure Application

The Precautionary Principle has emerged in response to the need for an effective method for dealing with risks and uncertainties in environmental management. In essence, the Principle requires action to prevent serious and irreversible damage even before harm can be scientifically demonstrated or economically assessed. Proponents argue that the Principle should be applied in situations where both the probability and value of irreversible damage are unknown. The lack of these particular data prevent a full cost–benefit analysis, but permit application of the Principle through the defensive-expenditure approach. How much would the community be required to pay to fund alternatives to maintain the environment and so defend existing levels of utility? Through the application of risk analysis and the stochastic dominance technique, a range of options and outcomes can be examined incorporating the using available information within a framework consistent with economic rationality. An extended risk simulation is applied to an environmental issue where there is a risk of serious and irreversible damage to the environment, namely, protection of the Barmah-Millewa forest-wetland in Australia.     

Experimental studies in the electrostatic precipitation of high-resistivity particulate

A pulsed charging system is described that eliminates reverse ionization inelectrostatic precipitation. The motivating concept is a purely electrical approach. The fundamental characteristic of this method is the relaxation time of the precipitated particulate. Laboratory studies indicate that this powering concept could increase precipitator performance on high-resistivity particulate by more than two orders of magnitude. Pilot results are also presented.