Food waste composting

The objective of this thesis was to increase our knowledge of issues relevant to process problems in large-scale composting. The investigations focused on acid-related process inhibition and the relationships between temperature, aeration, evaporation and the scale of the process. Three manuscripts are summarised in the thesis proper. The first investigated composting at different scales; at full-scale, in a 2 m high reactor and in a one-litre vessel. The process in the reactor resembled the full-scale process, but the theoretical calculations showed that the heat losses from the reactor were large. About 0.45 m of glass wool would be necessary to produce similar thermal properties in the reactor as in the full scale plant. Accumulation of acids was studied in the second investigation. Different amounts of active compost were used as a starting culture in rotating three-litre reactors, which were fed daily with fresh waste and water. In reactors with a large amount of starting culture, more than four times the daily feed, a well-functioning process with high temperature, high CO2 production and high pH was established. In reactors with a starting culture less than twice the daily feed, the composting process failed. The temperature was below 42 °C and the CO2 production was small. In these reactors the pH was low and organic acids accumulated. It was concluded that acid inhibition of fed-batch processes can be avoided if sufficient amounts of a good starting culture are used. In the third investigation, the combined effects of temperature and pH on the degradation were studied. Small samples of compost from the initial acidic phase were treated with sodium hydroxide to raise the pH. This resulted in high respiratory activity in samples at all pH levels at 36 °C and in those with pH over 6.5 at 46 °C. However, at 46 °C the activity was very low in samples with pH below 6.0. This shows that a combination of high temperature and low pH can inhibit the composting process. The influence of the composting temperature on the evaporation was also analysed. Simulations showed that the difference in evaporation at different temperatures was very small for the same degradation, although there were large variations in airflow. Finally, addition of water to compost is discussed. It is often necessary to add water when composting energy-rich substrates, since otherwise the process may be halted due to drying before the compost has stabilised

Distribution-free factor analysis - Estimation theory and applicability to high-dimensional data

We here provide a distribution-free approach to the random factor analysis model. We show that it leads to the same estimating equations as for the classical ML estimates under normality, but more easily derived, and valid also in the case of more variables than observations ($p>n$). For this case we also advocate a simple iteration method. In an illustration with $p=2000$ and $n=22$ it was seen to lead to convergence after just a few iterations. We show that there is no reason to expect Heywood cases to appear, and that the factor scores will typically be precisely estimated/predicted as soon as $p$ is large. We state as a general conjecture that the nice behaviour is not despite $p>n$, but because $p>n$.Comment: 12 pages, 2 figure

Advances in solid state switchgear technology for large space power systems

High voltage solid state remote power controllers (RPC's) and the required semiconductor power switches to provide baseline technology for large, high power distribution systems in the space station, all electric airplane and other advanced aerospace applications were developed. The RPC's were developed for dc voltages from 28 to 1200 V and ac voltages of 115, 230, and 440 V at frequencies of 400 Hz to 20 kHz. The benefits and operation of solid state RPC's and highlights of several developments to bring the RPC to technology readiness for future aerospace needs are examined. The 28 V dc Space Shuttle units, three RPC types at 120 V dc, two at 270/300 V dc, two at 230 V ac and several high power RPC models at voltages up to 1200 V dc with current ratings up to 100 A are reviewed. New technology programs to develop a new family of (DI)2 semiconductor switches and 20 kHz, 440 V ac RPC's are described

Civil air transport: A fresh look at power-by-wire and fly-by-light

Power-by-wire (PBW) is a key element under subsonic transport flight systems technology with potential savings of over 10 percent in gross take-off-weight and in fuel consumption compared to today's transport aircraft. The PBW technology substitutes electrical actuation in place of centralized hydraulics, uses internal starter-motor/generators and eliminates the need for variable engine bleed air to supply cabin comfort. The application of advanced fiber optics to the electrical power system controls, to built-in-test (BITE) equipment, and to fly-by-light (FBL) flight controls provides additional benefits in lightning and high energy radio frequency (HERF) immunity over existing mechanical or even fly-by-wire controls. The program plan is reviewed and a snapshot is given of the key technologies and their benefits to all future aircraft, both civil and military

Advanced Launch System (ALS): Electrical actuation and power systems improve operability and cost picture

To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrical power system and controls for all actuation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a specific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military and civilian aircraft, lunar/Martian vehicles, and a multitude of commercial applications

The Peahen’s Tale, or Dressing Our Parts at Work

However, there may ultimately be no logical way to reconcile decisions that prohibit employers from requiring women to wear revealing outfits and others that permit employers to require them to wear makeup,20 or decisions that prohibit penalizing a woman for being insufficiently feminine and others that permit penalizing a man for being insufficiently masculine.21 In addition, the increasing judicial acceptance of the sex stereotyping theory of sex discrimination under Title VII is in substantial tension with recent cases that insist that sex-differentiated dress and grooming requirements that merely 22 conform to existing social gender norms do not amount to impermissible sex discrimination. Because dress is so crucial a characteristic in sexually dimorphic species, and because it is so closely tied to sexual attractiveness, choice, and power dynamics, employers should be prohibited from requiring women to dress in gender normative ways that reflect those traits even if they believe that such dress codes do not amount to intentional sex stereotyping.223 Where, as here, so many threads come together to demonstrate that sex differences in dress are likely to affect the way that individuals are treated by others, employers should not be permitted to mandate differences that implicate notions of attractiveness or power

The ac power system testbed

The object of this program was to design, build, test, and deliver a high frequency (20 kHz) Power System Testbed which would electrically approximate a single, separable power channel of an IOC Space Station. That program is described, including the technical background, and the results are discussed showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment was completed and delivered and is being operated as part of the Space Station Power System Test Facility

Absorptive Capacity and Achieving the MDGs

aid, absorptive capacity, Millennium Development Goals

The Justice of Unequal Pay in the UFC: An In-Depth Analysis of the Fighters’ Antitrust Class Action Lawsuit Against the UFC and the Misplaced Support of the Proposed Muhammad Ali Expansion Act

In 2016, the Ultimate Fighting Championships (“UFC”) set the record for the largest sale in sports history. The UFC, the primary promotion company of the once fringe sport of mixed martial arts (“MMA”) had matured into a mammoth 4 billion dollar promotion, but not without some growing pains. The league is replete with controversy, mostly dealing with disgruntled athletes over compensation. Athletes of the UFC feel that they are being financially exploited and they may be correct. The athletes are choosing different routes to remedy their pay disparities but they are misguided. The first course of action chosen by the fighters is litigation, as a group of former UFC fighters have filed a class action antitrust suit against the UFC. Fighters are also lobbying for legislation in an attempt to expand the Muhammad Ali Act to regulate MMA as another method of resolution. While both will ultimately fail to appease the aggrieved athletes, the process may injure the UFC brand, something fighters may want to avoid. By reviewing similar antitrust disputes in sports and entertainment, the failure of the lawsuit against the UFC becomes apparent. As for the legislation, the Muhammad Ali Act fell short in protecting fighters in boxing as it was intended and will have the same ineffectualness in MMA. When the UFC was purchased in 2016 by WME-IMG, an immense international entertainment conglomerate, it is not likely the company was ignorant to these unsettled issues. This leads to the conclusion that the league’s prospects are still bright. It is in the fighters’ and the league’s best interests to quell their innate divisive temperaments and negotiate a compromise internally. Part II of this paper discusses the history of MMA, the sport of mixed martial arts. It also evaluates the evolution and current state of the UFC, the premier league that arranges and promotes the competition of elite MMA athletes. After a brief explanation of relevant antitrust laws, Part III analyzes the merits of the class action lawsuit against the UFC. Part IV explores the distinct nature of MMA and why antitrust enforcement will have varying results from what the athletes hope to achieve. Part V addresses possible effects of the proposed federal legislation amending the Muhammad Ali Act. Finally, Part VI summarizes that the antitrust litigation and proposed regulation will fail to redress the fighters’ affliction of their income but may injure the UFC brand. Thus, imploring the league to be proactive in resolving this issue