625 research outputs found
Droplets formation inside a venturi liquid mixer
The formation of a coarse photographic emulsion by entraining a hot oil phase into a cooler aqueous phase by a Venturi device is considered. The main focus is on understanding the mechanism and site of droplet formation in the device, as well as the time-scale of heat flow, to see if it is feasible to feed this emulsion directly to a homogenizer in a continuous process
Changes in population structure and body dimensions of two xanthid crabs: A long-term study in a single boulder-shore
Two xanthid crab species were studied during 29 months over a period of 14 years between 1986 and 1999 all in exactly the same boulder shore. One of the crab species studied was the xanthid, Eriphia verrucosa (Forskall, 1775) with 60 specimens, the other species, Xantho poressa (Olivi, 1792), with 155 specimens. A significant change in numbers of both males and females of E. verrucosa was noticeable between 1986 and 1996 with a marked drop in numbers between these years. In 1997 male numbers increased again to almosttheir previous numbers in the population during 1986. The population of X. poressa declined significantly towards the end of the study period. Numbers of both genders peaked in spring and again, in summer. There was generally a decline in numbers of both crab species during autumn and winter. Thus, the average capture during the seasons was highest in spring for males of both E. verrucosa, and X. poressa. The body dimensions: mass, carapace length (CL) and width (CW) were measured in both xanthids. The aim of this long-term study was to determine whether temporal changes in the population structure and allometric changes in the dimensions of these crabs took place. Only such long-term observations could reveal these changes in population
Deformation of liquid drops containing ions in the presence of an electric field
Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.The deformation and breakup of a conducting water drop
immersed in hexadecane in the presence of an electric field is
investigated using a numerical tool for a range of field strengths
and ion concentrations. At low electric field strengths, the drop
deformation is a linear function of the electric capillary
number. For high electric field strengths, the dependence is no
longer linear, and significant drop deformation occurs. The
drop deformation increases with increasing ion concentration,
due to a separation of ions within the drop, leading to a
redistribution of charge at either end of the drop.dc201
Experimental assessment of mixed-mode partition theories for generally laminated composite beams
NOTICE: this is the author’s version of a work that was accepted for publication in Composite Structures. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version will be subsequently published in Composite Structures.Three different approaches to partitioning mixed-mode delaminations are assessed for their ability to predict the interfacial fracture toughness of generally laminated composite beams. This is by using published data from some thorough and comprehensive experimental tests carried out by independent researchers (Davidson et al., 2000 and 2006). Wang and Harvey’s (2012) Euler beam partition theory is found to give very accurate prediction of interfacial fracture toughness for arbitrary layups, thickness ratios and loading conditions. Davidson et al.’s (2000) non-singular-field partition theory has excellent agreement with Wang and Harvey’s Euler beam partition theory for unidirectional layups. Although Davidson et al.’s partition theory predicts the interfacial fracture toughness of multidirectional layups reasonably well, overall Wang and Harvey’s Euler beam partition theory is found to give better predictions. In general, the singular-field approach based on 2D elasticity and the finite element method gives poor predictions of fracture toughness
Macroscopic Car Condensation in a Parking Garage
An asymmetric exclusion process type process, where cars move forward along a
closed road that starts and terminates at a parking garage, displays dynamic
phase transitions into two types of condensate phases where the garage becomes
macroscopically occupied. The total car density and the exit
probability are the two control parameters. At the transition, the
number of parked cars diverges in both cases, with the length of the road
, as with . Towards the transition, the
number of parked cars vanishes as with ,
or being the
distance from the transition. The transition into the normal phase represents
also the onset of transmission of information through the garage. This gives
rise to unusual parked car autocorrelations and car density profiles near the
garage, which depend strongly on the group velocity of the fluctuations along
the road.Comment: 12 pages including 15 figures; published version in PR
An Emerging Natural History in the Development, Mechanisms and Worldwide Prevalence of Major Mental Disorders
Conciliating recent findings from molecular genetics, evolutionary biology, and clinical observations together point to new understandings regarding the mechanism, development and the persistent worldwide prevalence of major mental disorders (MMDs),
which should be considered the result of an evolutionary downside trade off. Temperamental/trait variability, by facilitating choices
for individual and group responses, confers robustness flexibility and resilience crucial to success of our species. Extreme temperamental variants, originating evolutionarily from the asocial aspect of human nature, also constitute the premorbid personality
of the disorders. The latter create vulnerable individuals out of whom some will develop MMDs but at much higher rate to that of the general population. Significantly, similar temperamental “lopsidedness� enables many of these vulnerable individuals, if intelligent, tenacious, and curious, to be creative and contribute to our survival while some may also develop MMDs. All have a common neural-developmental origin and share characteristics in their clinical expression and pharmacological responses also expressed as mixed syndromes or alternating ones over time. Over-pruning of synaptic neurons may be considered the trigger of such occurrences
or conversely, the failure to prevent them in spite of it. The symptoms of the major mental disorders are made up of antithetical substitutes as an expression of a disturbed over-all synchronizing property of brain function for all higher faculties previously unconsidered in their modeling. The concomitant presence of psychosis is a generic common occurrence
Choosing how to choose : Institutional pressures affecting the adoption of personnel selection procedures
The gap between science and practice in personnel selection is an ongoing concern of human resource management. This paper takes Oliver´s framework of organizations´ strategic responses to institutional pressures as a basis for outlining the diverse economic and social demands that facilitate or inhibit the application of scientifically recommended selection procedures. Faced with a complex network of multiple requirements, practitioners make more diverse choices in response to any of these pressures than has previously been acknowledged in the scientific literature. Implications for the science-practitioner gap are discussed
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