9,815 research outputs found
Challenges of Primary Frequency Control and Benefits of Primary Frequency Response Support from Electric Vehicles
As the integration of wind generation displaces conventional plants, system inertia provided by rotating mass declines, causing concerns over system frequency stability. This paper implements an advanced stochastic scheduling model with inertia-dependent fast frequency response requirements to investigate the challenges on the primary frequency control in the future Great Britain electricity system. The results suggest that the required volume and the associated cost of primary frequency response increase significantly along with the increased capacity of wind plants. Alternative measures (e.g. electric vehicles) have been proposed to alleviate these concerns. Therefore, this paper also analyses the benefits of primary frequency response support from electric vehicles in reducing system operation cost, wind curtailment and carbon emissions
On determination of the geometric cosmological constant from the OPERA experiment of superluminal neutrinos
The recent OPERA experiment of superluminal neutrinos has deep consequences
in cosmology. In cosmology a fundamental constant is the cosmological constant.
From observations one can estimate the effective cosmological constant
which is the sum of the quantum zero point energy
and the geometric cosmological constant . The
OPERA experiment can be applied to determine the geometric cosmological
constant . It is the first time to distinguish the contributions of
and from each other by experiment. The
determination is based on an explanation of the OPERA experiment in the
framework of Special Relativity with de Sitter space-time symmetry.Comment: 7 pages, no figure
Superconductivity at 36 K in Gadolinium-arsenide Oxides GdOFFeAs
In this paper we report the fabrication and superconducting properties of
GdOFFeAs. It is found that when x is equal to 0.17,
GdOFFeAs is a superconductor with the onset transition
temperature T 36.6K. Resistivity anomaly near 130K was
observed for all samples up to x = 0.17, such a phenomenon is similar to that
of LaOFFeAs. Hall coefficient indicates that
GdOFFeAs is conducted by electron-like charge carriers.Comment: 3 pages, 4 figure
Pressure Effect on the superconducting properties of LaO_{1-x}F_{x}FeAs(x=0.11) superconductor
Diamagnetic susceptibility measurements under high hydrostatic pressure (up
to 1.03 GPa) were carried out on the newly discovered Fe-based superconductor
LaO_{1-x}F_{x}FeAs(x=0.11). The transition temperature T_c, defined as the
point at the maximum slope of superconducting transition, was enhanced almost
linearly by hydrostatic pressure, yielding a dT_c/dP of about 1.2 K/GPa.
Differential diamagnetic susceptibility curves indicate that the underlying
superconducting state is complicated. It is suggested that pressure plays an
important role on pushing low T_c superconducting phase toward the main
(optimal) superconducting phase.Comment: 7 pages, 4 figure
The co-creation of social ventures through bricolage, for the displaced, by the displaced
Purpose
Although scholars have investigated how social entrepreneurs create and develop social enterprises in the penurious stable environment, how they are created in the penurious unstable environment has yet been overlooked. The purpose of this paper is to address this research gap by exploring how internally displaced individuals, despite the lack of resources, create and develop a social enterprise to serve the other displaced population in the war and conflict zones.
Design/methodology/approach
Underpinned by a biographical research design, in-depth interviews with internally displaced individuals who have created social enterprises in the war and conflict zones were undertaken. Three social entrepreneurs were chosen for this study from three different social enterprises that are created by internally displaced individuals to serve the other internally displaced people of three different countries, namely, Pakistan, Afghanistan and Syria.
Findings
The single and cross-case analysis found that internally displaced individuals deploy bricolage strategy, for example, reconfiguration of pre-existing resources and competencies (both internal and external), to start up a social venture in the war and conflict zones. They utilise pre-existing internal resources, mainly human capital, and external resources, through a frugal approach towards resources acquisitions. The authors also found that the displaced social entrepreneurs utilise resources of other displaced individuals, for example, networks, volunteers, local knowledge and financial supports mainly from older arrivals, and develop their own enterprise ecosystem within the host location to co-create and co-develop social enterprise and social values for all of them.
Research limitations/implications
The findings show that internally displaced individuals utilise bricolage strategies to create and develop socially entrepreneurial venture to serve other internally displaced individuals in the war and conflict zones. As the findings are based on three case studies, for confirmatory approach, a quantitative study with a large sample size is necessary. Furthermore, as the differences in economic, cultural and linguistic in between the home and host locations can have impact on the creation and the development of a social venture, they should be considered in the future studies.
Originality/value
This study contributes to the limited literature and studies on social entrepreneurship, specifically, to the context of unstable penurious environment. It also contributes to the literature on bricolage by extending its application from penurious stable environment to the penurious unstable environment. By exploring what and how internal and external resources are utilised to create and develop a socially entrepreneurial venture in a war and conflict zones, this study has added value to the literature on not only bricolage but also entrepreneurship in war and conflict zones
Peran Panti Sosial Dalam Membina Dan Meningkatkan Life Skills Anak Terlantar
The aim of this research was to explain the role of the orphanage in building and increasing the life skills for homeless children. The method used in this research was descriptive method with quantitative approach. The samples of this research were 50 children. The data were analyzed by using Chi quadrate and Questionnaire. The result showed that: there was a role of the orphanage to build and increase the life skills for homeless children in PSBR Radin Intan. This research proved that when the role of the orphanage more higher, so in building and increasing the life skills for homelsess children will be higher too.Tujuan penelitian ini untuk menjelaskan peran panti sosial dalam membina dan meningkatkan life skills anak kurang mampu dan terlantar di Pelayanan Sosial Bina Remaja (PSBR) Radin Intan. Metode penelitian yang digunakan dalam penelitian ini adalah metode deskriptif dengan pendekatan kuantitatif.Sampel dalam penelitian ini 50 orang. Analisis data menggunakan Chi Kuadrat dan teknik pengumpulan data menggunakan Angket. Hasil penelitian menunjukkan bahwa: terdapat peran panti sosial dalam membina dan meningkatkan life skills anak kurang mampu dan terlantar di Pelayanan Sosial Bina Remaja (PSBR) Radin Intan. Hal ini menunjukkan bahwa semakin tinggi peran panti sosial maka dalam membina dan meningkatkan life skills semakin tinggi juga
Transverse Velocity Field Measurement in High-Resolution Solar Images Based on Deep Learning
To address the problem of the low accuracy of transverse velocity field
measurements for small targets in high-resolution solar images, we proposed a
novel velocity field measurement method for high-resolution solar images based
on PWCNet. This method transforms the transverse velocity field measurements
into an optical flow field prediction problem. We evaluated the performance of
the proposed method using the Ha and TiO datasets obtained from New Vacuum
Solar Telescope (NVST) observations. The experimental results show that our
method effectively predicts the optical flow of small targets in images
compared with several typical machine- and deep-learning methods. On the Ha
dataset, the proposed method improves the image structure similarity from
0.9182 to 0.9587 and reduces the mean of residuals from 24.9931 to 15.2818; on
the TiO dataset, the proposed method improves the image structure similarity
from 0.9289 to 0.9628 and reduces the mean of residuals from 25.9908 to
17.0194. The optical flow predicted using the proposed method can provide
accurate data for the atmospheric motion information of solar images. The code
implementing the proposed method is available on
https://github.com/lygmsy123/transverse-velocity-field-measurement.Comment: 14 pages, 10 figures, 4 tables. Accepted for publication in Research
in Astronomy and Astrophysic
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