356 research outputs found
Circular entrepreneurial ecosystems: a Quintuple Helix Model approach
Purpose: The shift toward a circular economy (CE) represents a collaborative endeavor necessitating the presence of efficient frameworks, conducive contexts and a common comprehension. This research serves as a pivotal stride towards this goal, presenting an exclusive prospect for the investigation and fusion of these frameworks, with particular emphasis on the Quintuple Helix Model (5HM), into a unified theoretical framework that underscores the core principles of the CE. This study is centered on three pivotal questions aimed at decoding the CE transition in specific regional settings.
Design/methodology/approach: Adopting an abductive approach firmly anchored in a two-stage qualitative process, this study specifically merges the foundational principles from institutional theory, entrepreneurship literature and CE frameworks to provide insights into the dynamics of circular ecosystems, with a specific focus on the Huelva region in Spain.
Findings: The findings demonstrate significant potential in the CE, ranging from the integration of product and service systems to innovations in eco-industrial practices. Yet, a notable deficiency exists: the absence of institutional entrepreneurs, highlighting the essential role that universities can play. As recognized centers of innovation, universities are suggested to be key contributors to the transformation toward a CE, aligning with their societal and economic responsibilities.
Practical implications: This study highlights the importance of managing relationships with entities like SMEs and policymakers or academia for effective CE adoption. Policymakers can refine strategies based on the research’s insights, while the impact of university-driven circular ecosystems on sustainable societies is another crucial area for research.
Originality/value: The sustainability models cited in CE literature may not be comprehensive enough to prevent problem shifting, and it can be argued that they lack a sound theoretical and conceptual basis. Furthermore, the connections between sustainability objectives and the three levels of the CE operating system remain vague. Additionally, there is insufficient information on how regions foster the involvement of the environment in fivefold helix cooperation and how this impacts the CE.The authors thank the companies for their role as key partners in the production of primary data for
this paper. Special thanks to the interviewed. This research is supported by Nazarbayev University
Grants No. 11022021FD2913 and No. 11022021CRP1510Departamento de Dirección de Empresas y Marketin
The properties of penumbral microjets inclination
We investigate the dependence of penumbral microjets inclination on the
position within penumbra. The high cadence observations taken on 10 November
2006 with the Hinode satellite through the \ion{Ca}{ii} H and G--band filters
were analysed to determine the inclination of penumbral microjets. The results
were then compared with the inclination of the magnetic field determined
through the inversion of the spectropolarimetric observations of the same
region. The penumbral microjet inclination is increasing towards the outer edge
of the penumbra. The results suggest that the penumbral microjet follows the
opening magnetic field lines of a vertical flux tube that creates the sunspot.Comment: 4 pages, 4 figures, A&A Letter in pres
Detection of Gravitational Redshift on the Solar Disk by Using Iodine-Cell Technique
With an aim to examine whether the predicted solar gravitational redshift can
be observationally confirmed under the influence of the convective Doppler
shift due to granular motions, we attempted measuring the absolute spectral
line-shifts on a large number of points over the solar disk based on an
extensive set of 5188-5212A region spectra taken through an iodine-cell with
the Solar Domeless Telescope at Hida Observatory. The resulting heliocentric
line shifts at the meridian line (where no rotational shift exists), which were
derived by finding the best-fit parameterized model spectrum with the observed
spectrum and corrected for the earth's motion, turned out to be weakly
position-dependent as ~ +400 m/s near the disk center and increasing toward the
limb up to ~ +600 m/s (both with a standard deviation of sigma ~ 100 m/s).
Interestingly, this trend tends to disappear when the convectiveshift due to
granular motions (~-300 m/s at the disk center and increasing toward the limb;
simulated based on the two-component model along with the empirical
center-to-limb variation) is subtracted, finally resulting in the averaged
shift of 698 m/s (sigma = 113 m/s). Considering the ambiguities involved in the
absolute wavelength calibration or in the correction due to convective Doppler
shifts (at least several tens m/s, or more likely up to <~100 m/s), we may
regard that this value is well consistent with the expected gravitational
redshift of 633 m/s.Comment: 28 pages, 12 figures, electronic materials as ancillary data (table3,
table 4, ReadMe); accepted for publication in Solar Physic
Universal linear-temperature dependence of static magnetic susceptibility in iron-pnictides
A universal linear-temperature dependence of the uniform magnetic
susceptibility has been observed in the nonmagnetic normal state of
iron-pnictides. This non-Pauli and non-Curie-Weiss-like paramagnetic behavior
cannot be understood within a pure itinerant picture. We argue that it results
from the existence of a wide antiferromagnetic fluctuation window in which the
local spin-density-wave correlations exist but the global directional order has
not been established yet.Comment: 4 pages, 2 figure
ORIGIN OF THE LA CABAÑA FREATOMAGMATIC DEPOSIT, LOWER BASIN OF THE CHINCHINÁRIVER, CALDAS-COLOMBIA
El depósito piroclástico de La Cabaña aflora al Oeste de Manizales (Departamento de Caldas, Colombia), entre los RíosChinchiná y Guacaica en la zona de La Cabaña, Tres Puertas y La Manuela, en un área de aproximadamente 6 Km2. Ladistancia aproximada recorrida por la corriente de densidad piroclástica que lo generó desde la probable fuente, el VolcánNevado del Ruiz, hasta el Río Cauca (probable límite de la zona de influencia del flujo) es de 50 Km.; esta corriente presentóun alto grado de fluidización y un comportamiento dinámico turbulento de una fase menos densa de la corriente piroclástica,lo cual evitó su confinamiento a lo largo de los valles de los drenajes principales. Comparando los resultados de losparámetros del software SFT, fracción (k) y del factor de fragmentación (φm/γ) contra la moda de cada subpoblación de éstedepósito, se concluye que todas las subpoblaciones se ubican en el campo freatomagmático, según gráficos presentados porWohletz (1983), y aunque éste es el principal mecanismo de fragmentación no involucra volúmenes de agua importantes. Seencontró que la tendencia de la moda con respecto al factor gamma, promedio ponderado de la dispersión entre la TobaNapolitana Amarilla (Campi Flegrei, Italia) y el depósito piroclástico de La Cabaña son muy similares, lo que induce apensar en un origen común asociado con una caldera, propuesta que se puede relacionar con los resultados de Londoño &Sudo (2002) donde una estructura caldérica es predefinida en el volcán Nevado del Ruiz. La creciente acumulación de grandescantidades de gas en algunas áreas (especialmente alrededor del Cráter Arenas-Volcán Nevado del Ruiz) a profundidadessomeras puede producir la inestabilidad del sistema volcánico–magmático– hidrotermal y podría disparar erupciones freáticaso freatomagmáticas, similares a las que originaron el depósito piroclástico de La Cabaña.
Palabras clave: Caldera, corriente de densidad piroclástica, freatomagmatismo, Volcán Nevado del Ruiz.
The pyroclastic deposit of La Cabaña outcropping to the west of Manizales (Department of Caldas, Colombia) betweenChinchiná and Guacaica rivers in the area of La Cabaña, Tres Puertas and La Manuela, shows an areal distribution ofabout 6 Km2. The approximated distance runout by pyroclastic density current, which generated it, from the probablesource, the Ruiz Volcanic Massif area, to the Cauca river (probable limit to the influence area) is 50 Km.; this pyroclasticdensity current attained a high degree of fluidization and turbulence of a less dense phase, avoiding the confinement alongthe major drainages valleys. Comparing the estimates of the parameters fraction (k) and fragmentation factor (φm/γ),obtained from SFT software, with the mode of each subpopulation from this deposit, we concluded that all subpopulationsare located in the phreatomagmatic field, according to Wohletz (1983), and although the fragmentation mechanism wasmainly phreatomagmatic, this involved little amounts of water. We found that the tendency of the Mode with respect togamma factor, weighted average of the dispersion between the Neapolitan Yellow Tuff (Campi Flegrei, Italia) and thepyroclastic deposit of La Cabaña are very similar; from this is possible to infer a common origin associated with a caldera.This proposal could be relate with Londoño & Sudo (2002), whose conclusions predefined a calderic structure in theNevado del Ruiz volcano. The increasing accumulation of enormous gas volumes in some areas (mainly around of theCrater Arenas–Nevado del Ruiz Volcano) at shallow depths, could produce instability in the volcanic–magmatic–hydrothermal system and could trigger phreatic or phreatomagmatic eruptions, in a similar way to the ones that gaveorigin to the pyroclastic deposit of La Cabaña.
Key words: Caldera, phreatomagmatism, pyroclastic density current, Nevado del Ruiz Volcano
ORIGIN OF THE LA CABAÑA FREATOMAGMATIC DEPOSIT, LOWER BASIN OF THE CHINCHINÁRIVER, CALDAS-COLOMBIA
El depósito piroclástico de La Cabaña aflora al Oeste de Manizales (Departamento de Caldas, Colombia), entre los RíosChinchiná y Guacaica en la zona de La Cabaña, Tres Puertas y La Manuela, en un área de aproximadamente 6 Km2. Ladistancia aproximada recorrida por la corriente de densidad piroclástica que lo generó desde la probable fuente, el VolcánNevado del Ruiz, hasta el Río Cauca (probable límite de la zona de influencia del flujo) es de 50 Km.; esta corriente presentóun alto grado de fluidización y un comportamiento dinámico turbulento de una fase menos densa de la corriente piroclástica,lo cual evitó su confinamiento a lo largo de los valles de los drenajes principales. Comparando los resultados de losparámetros del software SFT, fracción (k) y del factor de fragmentación (φm/γ) contra la moda de cada subpoblación de éstedepósito, se concluye que todas las subpoblaciones se ubican en el campo freatomagmático, según gráficos presentados porWohletz (1983), y aunque éste es el principal mecanismo de fragmentación no involucra volúmenes de agua importantes. Seencontró que la tendencia de la moda con respecto al factor gamma, promedio ponderado de la dispersión entre la TobaNapolitana Amarilla (Campi Flegrei, Italia) y el depósito piroclástico de La Cabaña son muy similares, lo que induce apensar en un origen común asociado con una caldera, propuesta que se puede relacionar con los resultados de Londoño &Sudo (2002) donde una estructura caldérica es predefinida en el volcán Nevado del Ruiz. La creciente acumulación de grandescantidades de gas en algunas áreas (especialmente alrededor del Cráter Arenas-Volcán Nevado del Ruiz) a profundidadessomeras puede producir la inestabilidad del sistema volcánico–magmático– hidrotermal y podría disparar erupciones freáticaso freatomagmáticas, similares a las que originaron el depósito piroclástico de La Cabaña.
Palabras clave: Caldera, corriente de densidad piroclástica, freatomagmatismo, Volcán Nevado del Ruiz.
The pyroclastic deposit of La Cabaña outcropping to the west of Manizales (Department of Caldas, Colombia) betweenChinchiná and Guacaica rivers in the area of La Cabaña, Tres Puertas and La Manuela, shows an areal distribution ofabout 6 Km2. The approximated distance runout by pyroclastic density current, which generated it, from the probablesource, the Ruiz Volcanic Massif area, to the Cauca river (probable limit to the influence area) is 50 Km.; this pyroclasticdensity current attained a high degree of fluidization and turbulence of a less dense phase, avoiding the confinement alongthe major drainages valleys. Comparing the estimates of the parameters fraction (k) and fragmentation factor (φm/γ),obtained from SFT software, with the mode of each subpopulation from this deposit, we concluded that all subpopulationsare located in the phreatomagmatic field, according to Wohletz (1983), and although the fragmentation mechanism wasmainly phreatomagmatic, this involved little amounts of water. We found that the tendency of the Mode with respect togamma factor, weighted average of the dispersion between the Neapolitan Yellow Tuff (Campi Flegrei, Italia) and thepyroclastic deposit of La Cabaña are very similar; from this is possible to infer a common origin associated with a caldera.This proposal could be relate with Londoño & Sudo (2002), whose conclusions predefined a calderic structure in theNevado del Ruiz volcano. The increasing accumulation of enormous gas volumes in some areas (mainly around of theCrater Arenas–Nevado del Ruiz Volcano) at shallow depths, could produce instability in the volcanic–magmatic–hydrothermal system and could trigger phreatic or phreatomagmatic eruptions, in a similar way to the ones that gaveorigin to the pyroclastic deposit of La Cabaña.
Key words: Caldera, phreatomagmatism, pyroclastic density current, Nevado del Ruiz Volcano
Volumetric quantification in ovarian pathology using abdomino-pelvic computed tomography
Pathological ovary is categorized into cystic tumors, solid tumors and mixed,
according to the content of the affected ovary. Accordingly, the degree of benignity or
malignity thereof is established. The imaging study for the preliminary morphological
assessment of PO is ultrasound, in its pelvic and transvaginal modalities, for which wellestablished
criteria are available. Once the ultrasound findings suggest malignancy,
complementary studies such as abdominal-pelvic tomography images and tumor markers are
requested. This type of images has challenging problems called noise, artifacts and low
contrast. In this paper, in order to address these problems, a computational technique is
proposed to characterize a pathological ovary. To do this, a thresholding and the median and
gradient magnitude filters are applied, preliminarily, to complete the preprocessing stage.
Then, during the segmentation, the algorithm of region growing is used to extract the threedimensional
morphology of the pathological ovary. Using this morphology, the volume of the
pathological ovary is calculated and it allows selecting the surgical-medical behavior to
approach this kind of ovary. The validation of the proposed technique indicates that the results
are promising. This technique can be useful in the detection and monitoring the diseases linked
to pathological ovary
Spectral Inversion of Multi-Line Full-Disk Observations of Quiet Sun Magnetic Fields
Spectral inversion codes are powerful tools to analyze spectropolarimetric
observations, and they provide important diagnostics of solar magnetic fields.
Inversion codes differ by numerical procedures, approximations of the
atmospheric model, and description of radiative transfer. Stokes Inversion
based on Response functions (SIR) is an implementation widely used by the solar
physics community. It allows to work with different atmospheric components,
where gradients of different physical parameters are possible, e.g., magnetic
field strength and velocities. The spectropolarimetric full-disk observations
were carried out with the Stokesmeter of the Solar Telescope for Operative
Predictions (STOP) at the Sayan Observatory on 3 February 2009, when neither an
active region nor any other extended flux concentration was present on the Sun.
In this study of quiet Sun magnetic fields, we apply the SIR code
simultaneously to 15 spectral lines. A tendency is found that weaker magnetic
field strengths occur closer to the limb. We explain this finding by the fact
that close to the limb, we are more sensitive to higher altitudes in an
expanding flux tube, where the field strength should be smaller since the
magnetic flux is conserved with height. Typically, the inversions deliver two
populations of magnetic elements: (1) high magnetic field strengths (1500-2000
G) and high temperatures (5500-6500 K) and (2) weak magnetic fields (50-150 G)
and low temperatures (5000-5300 K).Comment: 10 pages, 6 figures, accepted for Solar Physic
Family Discussions About Contraception And Family Planning: A Qualitative Exploration Of Black Parent and Adolescent Perspectives
Parent-adolescent communication is associated with increased adolescent contraceptive use. However, studies of this association are limited by their lack of examination of the communication process, reliance on cross-sectional designs and infrequent comparison of parent and adolescent perspectives. Examining communication in black families is particularly important, given the high pregnancy rate among black adolescents
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