Review of the Literature on the Economics of Central Anaerobic Digesters

Minnesota can improve the utilization of manure and organic wastes via the production of biogas that can be used to produce heat and electricity. Denmark serves as a role model for Minnesota in the number of central anaerobic digesters that it supports. During anaerobic digestion methane is produced when naturally occurring anaerobic bacteria decompose organic matter in the absence of oxygen. This process produces what is called biogas, which usually is a mixture of 55 – 65 percent methane plus carbon dioxide with trace gases such as hydrogen sulfide. Co-generation using manure and other feedstocks can produce more energy than manure alone. Central digesters are more likely to process wastes from food processing plants and other sources resulting in the need for more specialized unloading facilities and larger storage spaces. Digesters can be owned by farmers or consumers cooperatives, third party/non-farming investor(s), state or municipal government, or established as a cooperative or limited liability corporation. Problems associated with centralized digester operation include capital constraints, low profitability, lower-than-expected waste availability, electricity connection and pricing, and waste disposal constraints.Livestock Production/Industries, Resource /Energy Economics and Policy,

5th Grade Veterinary Medicine Activity Book - English Edition

The objective of this book is to provide career-based activities for students in grade 5. This book incorporates Indiana Academic Standards for Math, English/Language Arts, and Science.The activities in this book are intended to educate students into considering veterinary medicine as a potential career choice.https://docs.lib.purdue.edu/vetbooks/1004/thumbnail.jp

Cryogenic Optical Packaging Using Photonic Wire Bonds

We present the required techniques for the successful low loss packaging of integrated photonic devices capable of operating down to 970 mK utilizing photonic wire bonds. This scalable technique is shown to have an insertion loss of less than 2 dB per connection between a SMF-28 single mode fibre and a silicon photonic chip at these temperatures. This technique has shown robustness to thermal cycling and is ultra-high vacuum compatible without the need for any active alignment

Tipping Points in Coastal Ecosystems

Change can happen fast in our coastal ecosystems and we often do not know what has been lost until it’s too late. Once ecological ‘tipping points’ are passed, it is difficult to reverse the state of the ecosystem.1 Often these changes creep up on us because they are caused by the cumulative impact of multiple stressors. These changes in ecosystems mean we can lose important ecosystem functions that underpin many of the things we value about out coastal ecosystems. One of the key challenges of ecosystem-based management (EBM) is therefore to identify what combination of stressors are likely to cause threshold changes and what parts of the ecosystem are most likely to be affected. A multi-institutional team of scientists from across New Zealand is conducting the science to assess the risk of passing these ‘tipping points’ in estuaries before they happen

Theology, News and Notes - Vol. 47, No. 03

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1141/thumbnail.jp

Direct measurements of ice-shelf flexure caused by surface meltwater ponding and drainage.

Global sea-level rise is caused, in part, by more rapid ice discharge from Antarctica, following the removal of the restraining forces of floating ice-shelves after their break-up. A trigger of ice-shelf break-up is thought to be stress variations associated with surface meltwater ponding and drainage, causing flexure and fracture. But until now, there have been no direct measurements of these processes. Here, we present field data from the McMurdo Ice Shelf, Antarctica, showing that the filling, to ~2 m depth, and subsequent draining, by overflow and channel incision, of four surface lakes causes pronounced and immediate ice-shelf flexure over multiple-week timescales. The magnitude of the vertical ice-shelf deflection reaches maxima of ~1 m at the lake centres, declining to zero at distances of <500 m. Our results should be used to guide development of continent-wide ice-sheet models, which currently do not simulate ice-shelf break-up due to meltwater loading and unloading.This work was supported by the U.S. National Science Foundation under award PLR-1443126 to the University of Chicago, a Leverhulme Early Career Fellowship (ECF-2014-412) and a CIRES Postdoctoral Visiting Fellowship, both awarded to A.F.B., and a NASA Earth and Space Science Fellowship (NNX15AN44H) awarded to G.J.M

Predicting the Unpredictable: Estimating Human Performance Parameters for Off-Nominal Events

A parameter meta-analysis was conducted to characterize human responses to off-nominal events. The probability of detecting an off-nominal event was influenced by characteristics of the offnominal event scenario (phase of flight, expectancy, and event location) and the presence of advanced cockpit technologies (head-up displays, highway-in-the-sky displays, datalink, and graphical route displays). The results revealed that the presence of these advanced technologies hindered event detection reflecting cognitive tunneling and pilot complacency effects

‘They Called Them Communists Then … What D'You Call ‘Em Now? … Insurgents?’. Narratives of British Military Expatriates in the Context of the New Imperialism

This paper addresses the question of the extent to which the colonial past provides material for contemporary actors' understanding of difference. The research from which the paper is drawn involved interview and ethnographic work in three largely white working-class estates in an English provincial city. For this paper we focus on ten life-history interviews with older participants who had spent some time abroad in the British military. Our analysis adopts a postcolonial framework because research participants' current constructions of an amorphous 'Other' (labelled variously as black people, immigrants, foreigners, asylum-seekers or Muslims) reveal strong continuities with discourses deployed by the same individuals to narrate their past experiences of living and working as either military expatriates or spouses during British colonial rule. Theoretically, the paper engages with the work of Frantz Fanon and Edward Said. In keeping with a postcolonial approach, we work against essentialised notions of identity based on 'race' or class. Although we establish continuity between white working-class military emigration in the past and contemporary racialised discourses, we argue that the latter are not class-specific, being as much the creations of the middle-class media and political elite

The Underpinnings of Workload in Unmanned Vehicle Systems

This paper identifies and characterizes factors that contribute to operator workload in unmanned vehicle systems. Our objective is to provide a basis for developing models of workload for use in design and operation of complex human-machine systems. In 1986, Hart developed a foundational conceptual model of workload, which formed the basis for arguably the most widely used workload measurement techniquethe NASA Task Load Index. Since that time, however, there have been many advances in models and factor identification as well as workload control measures. Additionally, there is a need to further inventory and describe factors that contribute to human workload in light of technological advances, including automation and autonomy. Thus, we propose a conceptual framework for the workload construct and present a taxonomy of factors that can contribute to operator workload. These factors, referred to as workload drivers, are associated with a variety of system elements including the environment, task, equipment and operator. In addition, we discuss how workload moderators, such as automation and interface design, can be manipulated in order to influence operator workload. We contend that workload drivers, workload moderators, and the interactions among drivers and moderators all need to be accounted for when building complex, human-machine systems

5th Grade Veterinary Medicine Activity Book - Spanish Edition

The objective of this book is to provide career-based activities for students in grade 5. This book incorporates Indiana Academic Standards for Math, English/Language Arts, and Science.The activities in this book are intended to educate students into considering veterinary medicine as a potential career choice.https://docs.lib.purdue.edu/vetbooks/1005/thumbnail.jp