Suchergebnisse

Production of medium chain carboxylic acids (MCCA) as renewable feedstock bio-chemicals, from food waste (FW), requires complicated reactor configurations and supplementation of chemicals to achieve product selectivity. This study evaluated the manipulation of organic loading rate in an un-supplemented, single stage stirred tank reactor to steer an anaerobic digestion (AD) microbiome towards acidogenic fermentation (AF), and thence to chain elongation. Increasing substrate availability by switching to a FW feedstock with a higher COD stimulated chain elongation. The MCCA species n-caproic (10.1 ± 1.7 g L−1) and n-caprylic (2.9 ± 0.8 g L−1) acid were produced at concentrations comparable to more complex reactor set-ups. As a result, of the adjusted operating strategy, a more specialised microbiome developed containing several MCCA-producing bacteria, lactic acid-producing Olsenella spp. and hydrogenotrophic methanogens. By contrast, in an AD reactor that was operated in parallel to produce biogas, the retention times had to be doubled when fed with the high-COD FW to maintain biogas production. The AD microbiome comprised a diverse mixture of hydrolytic and acidogenic bacteria, and acetoclastic methanogens. The results suggest that manipulation of organic loading rate and food-to-microorganism ratio may be used as an operating strategy to direct an AD microbiome towards AF, and to stimulate chain elongation in FW fermentation, using a simple, un-supplemented stirred tank set-up. This outcome provides the opportunity to repurpose existing AD assets operating on food waste for biogas production, to produce potentially higher value MCCA products, via simple manipulation of the feeding strategy. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 665992

"Communism must kill what it cannot control. So for a century, it has killed artists, writers, musicians, and even dancers. It kills them secretly, using bioweapons and poison to escape accountability. Among its victims was Anna Pavlova, history's greatest dancer, who was said to have God-given wings and feet that never touched the ground. But she defied Stalin, and for that she had to die. Her sudden death in Paris in 1931 was a mystery until now. The Dancer and the Devil traces Marxism's century-long fascination with bioweapons, from the Soviets' leak of pneumonic plague in 1939 that nearly killed Stalin to leaks of anthrax at Kiev in 1972 and Yekaterinburg in 1979; from the leak of a flu in northeast China in 1977 that killed millions to the catastrophic COVID-19 leak from biolabs in Wuhan, China. Marxism's dark past must not be a parent to the world's dark future."--Provided by publisher

After reading Jack Shafer's review of Rahul Sagar's Secrets and Leaks ('Live and Let Leak,' March/April 2014), it strikes me as important to distinguish between the United States' security classification system itself and an individual's decision to breach his obligation of confidentiality. Adapted from the source document.

Experiences with an advanced spent nuclear fuel management in Slovakia are presented in this paper. The evaluation and monitoring procedures are based on practices at the Slovak wet interim spent fuel storage facility in NPP Jaslovské Bohunice. Since 1999, leak testing of WWER-440 fuel assemblies are provided by special leak tightness detection system "Sipping in pool" delivered by Framatomeanp with external heating for the precise defects determination. In 2006, a new inspection stand "SVYP-440" for monitoring of spent nuclear fuel condition was inserted. This stand has the possibility to open WWER-440 fuel assemblies and examine fuel elements. Optimal ways of spent fuel disposal and monitoring of nuclear fuel condition were designed. With appropriate approach of conservativeness, new factor for specifying spent fuel leak tightness is introduced in the paper. By using computer simulations (based on SCALE 4.4a code) for fission products creation and measurements by system "Sipping in pool," the limit values of leak tightness were established.

Front -- Cartoonists -- Introduction -- Anton Emdin -- Reg Lynch -- Ron Tandberg -- Jon Kudelka -- Alan Moir -- Jon Kudelka -- Cathy Wilcox -- Rod Clement -- Christopher Downes -- Andrew Dyson -- Jim Pavlidis -- Chris Kelly -- Matt Golding -- Andrew Dyson -- Ron Tandberg -- Bill Leak -- Mark Knight -- Peter Broelman -- Bruce Petty -- Geoff Pryor -- Mark Knight -- Andrew Dyson -- Peter Lewis -- Andrew Dyson -- Matt Golding -- Jon Kudelka -- Ron Tandberg -- David Pope -- David Pope -- Peter Broelman -- Jon Kudelka -- David Pope -- Judy Horacek -- Jon Kudelka -- Dean Alston -- David Pope -- Alan Moir -- David Rowe -- Bill Leak -- Glen Le Lievre -- Mark Knight -- Ron Tandberg -- Cathy Wilcox -- Bruce Petty -- Matt Golding -- Alan Moir -- Ron Tandberg -- Eric Löbbecke -- Jon Kudelka -- Bruce Petty -- Cathy Wilcox -- David Rowe -- Jim Pavlidis -- David Pope -- Warren Brown -- Peter Lewis -- Cathy Wilcox -- First Dog on the Moon -- Geoff Pryor -- Geoff Pryor -- Matt Golding -- Peter Nicholson -- David Rowe -- Eric Löbbecke -- Warren Brown -- John Spooner -- Dean Alston -- Matt Golding -- John Spooner -- Pat Campbell -- John Spooner -- Andrew Dyson -- Paul Zanetti -- David Rowe -- Ron Tandberg -- Fiona Katauskas -- David Rowe -- Jon Kudelka -- John Spooner -- Fiona Katauskas -- Christopher Downes -- Pat Campbell -- Oslo Davis -- Judy Horacek -- Andrew Weldon -- First Dog on the Moon -- Jon Kudelka -- Bill Leak -- Peter Nicholson -- Mark Knight -- Jon Kudelka -- Bill Leak -- Neil Matterson -- Ron Tandberg -- Glen Le Lievre -- Bill Leak -- Greg Smith -- Bruce Petty -- Andrew Dyson -- John Spooner -- Reg Lynch -- First Dog on the Moon -- Jon Kudelka -- Bill Leak -- Ron Tandberg -- Eric Löbbecke -- First Dog on the Moon -- Rod Clement -- Paul Zanetti -- Peter Broelman -- Glen Le Lievre -- Geoff Pryor -- Jos Valdman -- Dean Alston -- First Dog on the Moon.

A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air‐conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air‐conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air‐conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air‐conditioning systems, absent a means of mitigating exposure.

This dissertation is composed of three unrelated chapters, all of which are theoretical.In Chapter 1, co-authored with Kristóf Madarász, we develop a model in which people experience standard consumption utility as well as anticipatory utility, defined as the weighted sum of independently anticipated consumption "episodes" or "dimensions". The weights on these dimensions correspond to the attention that the person pays to the dimension. We assume attention on a dimension increases when expected consumption utility in the dimension differs from expected consumption utility under the default action or the prior belief. We show that the decision maker will pay more for information about dimensions with high expected consumption utility, and the willingness to pay may be negative when expected consumption utility is low. Additionally, when expected consumption utility is sufficiently low, but not when it is high, the decision maker will follow the default action even if it is suboptimal from a consumption standpoint. Furthermore, given the decision maker's current beliefs and preferences in a dimension, he will consume more in that dimension if he just received information. We then consider an advertisement application in which a monopolist decides whether to certifiably reveal the quality of various exogenous attributes of a good to a consumer who may choose to buy or not. There exists a sequential equilibrium for which the monopolist will not disclose information for attributes in which the consumer's utility with the highest quality good is sufficiently worse than not buying the good. Competition increases disclosure.The purpose of the Chapter 2 is to connect the literature on industrial self-regulation with the literature on political revolutions by showing that these seemingly different situations are, from a strategic perspective, different cases of the same basic game. I construct a simple two-player extensive game of complete information in which two players have preferences over the realization of a policy in one dimension. The first mover has a marginal cost to change the policy and the second player has a fixed cost. The first mover may placate the second mover from taking action or provoke the second mover to take action. In equilibrium, the second mover may benefit from having preferences that diverge more from the first player, and may benefit by having higher fixed costs. The equilibria are robust even when there are multiple first movers. Many applications are discussed and incorporated into the framework.In Chapter 3 I study the interaction where an informed party wants an uninformed party to believe that the state of the world is as high as possible. A fraction of the time the informed party exogenously "leaks" the true state of the world, and a fraction of the time the informed party can strategically choose a "decoy" that is indistinguishable from the exogenous leak. Despite preferences being similar to those in Crawford and Sobel (1982) with maximum bias, strategic senders do not babble. Instead they trade-off exaggeration for credibility. In equilibrium, all messages received below a threshold will be leaks and will be believed by the receiver, while all messages above the threshold will induce an identical expectation. The model applies to many applications. In particular we motivate the model with a political interpretation in which leaks represent transparency within a political administration.

AbstractThis essay revisits the saga of Cold War era stealth development programs—classified but curiously public efforts to build airplanes that eluded radar detection—to explore how leaks work and the work leaks do when designing complex technical systems. Stealth programs are aging examples of an increasingly visible phenomenon: disclosures about large, closely guarded design, manufacturing, and administrative efforts before their official unveiling. Rather than simply policing the boundary between the secret and the public, in "big" design, in collective efforts to produce knowledge and things at scale, the article argues that leaks have a more subtle purpose: they help govern the uncertain terrain between knowing and knowing enough.

How does information affect foreign policy? This dissertation explores the political dynamic of disclosure of classified information about national security and defense policy and its effects on foreign policymaking.In Chapter 1, I introduce the subsequent chapters by discussing their research questions.Chapter 2 confirms the prevalence of disclosure of classified information by anonymous sources in foreign policy reporting; 43.8 percent of all quotes in a corpus of news articles about drone strikes are attributed to anonymous individuals. Chapter 2 also shows that most of anonymously-sourced information is either neutral or supportive of the government's policies.Chapter 3 analyzes the puzzling credibility of disclosure of pro-government classified information (a "helpful leak"). I argue that credibility of unverifiable information leaked by anonymous sources stems from the perception that they may be leakers who reveal the truth and from the government's stronger incentive to punish leakers of true than false information. The mechanism hinges on a trade-off that the government faces between allowing positive information to leak irrespective of its veracity and the need to assert bureaucratic control by prosecuting unauthorized disclosures. I show that this trade-off causes the government to prosecute some, but not all, truthful leaks of pro-government information.Chapter 4 illustrates a dilemma for the government when punishing bureaucrats who disclose politically detrimental and classified information ("harmful leaks"). I argue the government's dilemma over bureaucratic and political incentives drives the government's sporadic punishment of harmful leaks. Although criminal punishment of harmful leakers establishes bureaucratic discipline, it deprives the government of maintaining plausible deniability of the damaging information. I show that this tradeoff between internal credibility and external credibility results in limited enforcement of secrecy.Chapter 5 examines a political consequence of harmful leaks. I argue that these harmful leakers can effect a change in public opinion about foreign policy when they reveal their own identity. The revelation strengthens the public's belief in the credibility of anti-government information provided by the leaker. This renders the government's policy proposal unpopular among the public.I conclude in Chapter 6.