Is Dark Matter made up of Massive Quark Objects?

We suggest that dark matter is made up of massive quark objects that have survived from the Big Bang, representing the ground state of ``baryonic'' matter. Hence, there was no overall phase transition of the original quark matter, but only a split-up into smaller objects. We speculate that normal hadronic matter comes about through enforced phase transitions when such objects merge or collide, which also gives rise to the cosmic gamma-ray bursts.Comment: 8 pages Latex, no figures; to be published in the Proceedings of Dark '98, Heidelberg, July 199

Development of large fish farm numerical modeling techniques with in situ mooring tension comparisons

Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Aquacultural Engineering 36 (2007): 137-148, doi:10.1016/j.aquaeng.2006.10.001.A study is conducted to validate a numerical model for calculating mooring system tensions of a large fish farm containing 20 net pens in the absence of waves. The model is forced using measured current velocity values obtained outside of the farm. Mooring line tensions calculated with the numerical model are compared with load cell field data sets. The approach considers current velocity reduction and load characteristics that occur through the net pen system for both clean and fouled net conditions. Without accounting for the reduction, the numerical model produces excessively conservative results. With reduction, a substantial improvement occurs. Understanding these differences will help to establish appropriate safety factors when designing large marine fish farms using the model. Additional validation studies should be conducted with wave and current forcing to investigate the modeling large fish farms for exposed or open ocean sites.The authors would also like to express sincere thanks the National Oceanic and Atmospheric Administration for funding this project through the Saltonstall-Kennedy program under Grant NAO3NMF4270183

Gamma-Ray Bursts from Primordial Quark Objects in Space

We investigate the possibility that gamma-ray bursts originate in a concentric spherical shell with a given average redshift and find that this is indeed compatible with the data from the third BATSE (3B) catalog. It is also shown that there is enough freedom in the choice of unknown burst properties to allow even for extremely large distances to the majority of bursts. Therefore, we speculate about an early, and very energetic, origin of bursts, and suggest that they come from phase transitions in massive objects of pure quark matter, left over from the Big Bang.Comment: 11 pages, Latex, 3 postscript figures, to be publ in the Proc of the Joint Meeting of the Networks 'The Fundamental Structure of Matter' and 'Tests of the Electroweak Symmetry Breaking', Ouranoupolis, Greece, May 199

The Chandrasekhar limit for quark stars

The Chandrasekhar limit for quark stars is evaluated from simple energy balance relations, as proposed by Landau for white dwarfs or neutron stars. It has been found that the limit for quark stars depends on, in addition to the fundamental constants, the Bag constant.Comment: LateX fil

A Quark-Matter Dominated Universe

We present a new scenario for the development of the Universe after the Big Bang, built on the conjecture that a vast majority of the primordial quark matter did not undergo a phase transition to normal nuclear matter, but rather split up into massive quark objects that remained stable. Hence, such primordial quark matter would make up the so-called dark matter. We discuss, mostly in qualitative terms, the consequences for galaxy formation, the origin of normal matter, the occurrence of massive black-holes in galactic centres and the cosmic gamma-ray bursts.Comment: 32 pages Latex, 3 postscipt figure

Diquark condensation effects on hot quark star configurations

The equation of state for quark matter is derived for a nonlocal, chiral quark model within the mean field approximation.We investigate the effects of a variation of the formfactors of the interaction on the phase diagram of quark matter. Special emphasis is on the occurrence of a diquark condensate which signals a phase transition to color superconductivity and its effects on the equation of state under the condition of beta- equilibrium and charge neutrality. We calculate the quark star configurations by solving the Tolman- Oppenheimer- Volkoff equations and obtain for the transition from a hot, normal quark matter core of a protoneutron star to a cool diquark condensed one a release of binding energy of the order of Delta M c^2 ~ 10^{53} erg. We find that this energy could not serve as an engine for explosive phenomena since the phase transition is not first order. Contrary to naive expectations the mass defect increases when for a given temperature we neglect the possibility of diquark condensation.Comment: 24 pages, 2 tables, 8 figures, references added, figures and text improve

Deployment of the northern fish cage and mooring, University of New Hampshire — Open Ocean Aquaculture Program summer 2000

The University of New Hampshire - Open Ocean Aquaculture (UNH-OOA) program has worked for the past few years on developing the technology to deploy and maintain fish cages in open, exposed northern waters. In June 1999, two Sea Station octagonal net cages by Ocean Spar Technologies were deployed with their UNH designed and constructed moorings. In June 2000 the Northern Cage and its mooring were retrieved, examined and repaired , and readied for redeployment. This was a complex operation, initiated by a team of UNH ocean engineers lead by Dr. Barbaros Celikkol. This year's effort was expanded with the addition of a Program Manager (Michael Chambers), the Fishing Vessel Nobska, and researchers from the Woods Hole Oceanographic Institution (WHOI). During the week of 21 to 25 August 2000, the cage and mooring were assembled and deployed at the UNH-OOA site seven miles offshore the New Hampshire coast, south of the Isle of Shoals. This collaborative effort involved members of the UNH Mechanical Engineering Dept., UNH divers, members of the WHOI Applied Ocean Physics & Engineering Dept. and the Captain and crew of the FV Nobska. Ship support for the deployment was provided by the R/V Gulf Challenger and Galen J. (UNH) and the FV Nobska (a 100 foot fishing vessel based at Woods Hole, MA). The work was favored by light wind and sea conditions. The endeavor resulted in the successful placement of the North Cage and its complex mooring system with load cells and environmental sensors. Unexpected and unexplained tangling of the mooring system, in particular near its grid corner points, was encountered and corrected.Fudning was provided by the National Oceanic and Atmospheric Adminstration for the Open Ocean Aquaculture Project under Contract No. NA86RG0016 to the Univesity of New Hampshire and under Subcontracts 00-394 and 01-442 to the Woods Hole Oceanographic Institution

Spectra of Baryons Containing Two Heavy Quarks in Potential Model

In this work, we employ the effective vertices for interaction between diquarks (scalar or axial-vector) and gluon where the form factors are derived in terms of the B-S equation, to obtain the potential for baryons including a light quark and a heavy diquark. The concerned phenomenological parameters are obtained by fitting data of $B^{(*)}-$mesons instead of the heavy quarkonia. The operator ordering problem in quantum mechanics is discussed. Our numerical results indicate that the mass splitting between $B_{3/2}(V), B_{1/2}(V)$ and $B_{1/2}(S)$ is very small and it is consistent with the heavy quark effective theory (HQET).Comment: 16 page

Reflections and Experiences of a Co-Researcher involved in a Renal Research Study

Background Patient and Public Involvement (PPI) is seen as a prerequisite for health research. However, current Patient and public involvement literature has noted a paucity of recording of patient and public involvement within research studies. There have been calls for more recordings and reflections, specifically on impact. Renal medicine has also had similar criticisms and any reflections on patient and public involvement has usually been from the viewpoint of the researcher. Roles of patient and public involvement can vary greatly from sitting on an Advisory Group to analysing data. Different PPI roles have been described within studies; one being a co-researcher. However, the role of the co-researcher is largely undefined and appears to vary from study to study. Methods The aims of this paper are to share one first time co-researcher's reflections on the impact of PPI within a mixed methods (non-clinical trial) renal research study. A retrospective, reflective approach was taken using data available to the co-researcher as part of the day-to-day research activity. Electronic correspondence and documents such as meeting notes, minutes, interview thematic analysis and comments on documents were re-examined. The co-researcher led on writing this paper. Results This paper offers a broad definition of the role of the co-researcher. The co-researcher reflects on undertaking and leading on the thematic analysis of interview transcripts, something she had not previously done before. The co-researcher identified a number of key themes; the differences in time and responsibility between being a coresearcher and an Advisory Group member; how the role evolved and involvement activities could match the co-researchers strengths (and the need for flexibility); the need for training and support and lastly, the time commitment. It was also noted that it is preferable that a co-researcher needs to be involved from the very beginning of the grant application. Conclusions The reflections, voices and views of those undertaking PPI has been largely underrepresented in the literature. The role of co-researcher was seen to be rewarding but demanding, requiring a large time commitment. It is hoped that the learning from sharing this experience will encourage others to undertake this role, and encourage researchers to reflect on the needs of those involved.Peer reviewedFinal Published versio

Comparative system dynamic modeling of a conventional and hybrid electric powertrain

© 2017 Taylor & Francis Group, London. Hybrid Electric Vehicles (HEVs) provide many known benefits over conventional vehicles, including reduced emissions, increased fuel economy, and performance. The high cost of HEVs has somewhat limited their widespread adoption, especially in developing countries. Conversely, it is these countries that would benefit most from the environmental benefits of HEV technology. As part of our ongoing project to develop a cost-effective and viable mild HEV for these markets, dynamic simulations are required to ensure that the proposed designs are to achieve their desired targets. In this paper, mathematical models of the powertrain are used to analyze and compare the dynamics of both a conventional power train and one with the addition of components required for the Mild Hybrid system. Using Matlab and Simulink, simulations of both powertrains under particular driving conditions are performed to observe the advantages of the MHEV over conventional drivetrains. These benefits include torque-hole filling between gear changes, increased fuel efficiency and performance