4,699 research outputs found
Comparative Analysis of Web of Science and Scopus on the Energy Efficiency and Climate Impact of Buildings
Although the body of scientific publications on energy efficiency and climate mitigation from buildings has been growing quickly in recent years, very few previous bibliometric analysis studies exist that analyze the literature in terms of specific content (trends or options for zero‐energy buildings) or coverage of different scientific databases. We evaluate the scientific literature published since January 2013 concerning alternative methods for improving the energy efficiency and mitigating climate impacts from buildings. We quantify and describe the literature through a bibliometric approach, comparing the databases Web of Science (WoS) and Scopus. A total of 19,416 (Scopus) and 17,468 (WoS) publications are analyzed, with only 11% common documents. The literature has grown steadily during this time period, with a peak in the year 2017. Most of the publications are in English, in the area of Engineering and Energy Fuels, and from institutions from China and the USA. Strong links are observed between the most published authors and institutions worldwide. An analysis of keywords reveals that most of research focuses on technologies for heating, ventilation, and air‐conditioning, phase change materials, as well as information and communication technologies. A significantly smaller segment of the literature takes a broader perspective (greenhouse gas emissions, life cycle, and sustainable development), investigating implementation issues (policies and costs) or renewable energy (solar). Knowledge gaps are detected in the areas of behavioral changes, the circular economy, and some renewable energy sources (geothermal, biomass, small wind). We conclude that i) the contents of WoS and Scopus are radically different in the studied fields; ii) research seems to focus on technological aspects; and iii) there are weak links between research on energy and on climate mitigation and sustainability, the latter themes being misrepresented in the literature. These conclusions should be validated with further analyses of the documents identified in this study. We recommend that future research focuses on filling the above identified gaps, assessing the contents of several scientific databases, and extending energy analyses to their effects in terms of mitigation potentials.This work was funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018‐
093849‐B‐C31), by ICREA under the ICREA Academia programme, and by the foundation SIVL
Engineering calculations for communications satellite systems planning
The final phase of a satellite synthesis project is described. Several methods for generating satellite positionings with improved aggregate carrier to interference characteristics were studied. Two general methods for modifying required separation values are presented. Also, two methods for improving aggregate carrier to interference (C/I) performance of given satellite synthesis solutions are presented. A perturbation of the World Administrative Radio Conference (WARC) synthesis is presented
Chemical Models for Aqueous Biodynamical Processes
The University of Kansas has long historical connections with Central America and the many Central
Americans who have earned graduate degrees at KU. This work is part of the Central American Theses
and Dissertations collection in KU ScholarWorks and is being made freely available with permission of the
author through the efforts of Professor Emeritus Charles Stansifer of the History department and the staff of
the Scholarly Communications program at the University of Kansas Libraries’ Center for Digital Scholarship.The proton inventory method was applied to the study of three
processes: the viscous flow of water, the neutral hydrolysis of
esters, and the exchange reaction between aqueous sodium ion and the
carboxylic exchanger Amberlite CG-50®.
The fluidity (1/viscosity; of mixtures of protium and deuterium
oxides at 298.16 K can be described by the equation (1 ~ n + 0.90n)
J ^ n o
This result indicates that two protons contribute equally to the overall
isotope effect. The proposed mechanism for momentum transfer involves
an interstitial water molecule linked to "flowing" molecular sheaths.
The rate constants of neutral hydrolysis of ethyl trifluoroacetate
at 298.16 K can be described by the equation k = k (l-n+0.47n) (l-n+0. 78«)
n o .
This result suggests a catalytic entity with 67% hydronium ion character
which we have called the poena -hydronium ion.
The rate of exchange of the reaction Na(aq)+ + Arnberlite CG-50®
4.
was found to be independent of a) [Na ] / (resin) ; b) hydrodynamic condi-
4- -j- -ftions;
c) nature of cation (Li , Na , K ) . The solvent isotope effect
for Na and K exchange was found to be 3.06 ± 0.17 and 3.31 i 0.38,
respectively. These results suggest that diffusion of the newly exchanged
hydronium ion through the polymeric matrix is rate determining. The
reaction rate constants for sodium exchange in mixtures of H20~D20 at
298.16 K can be described by the equation k = k (1 - n + 0. 70n)3 which
n o
supports the proposed mechanism.
Fractionation factors were measured for four geminal hydroxylic
compounds as models for the tetrahedral intermediate in the hydrolysis
of carboxylic acid derivatives. The values are 1.23 ± 0.08 for chloral
hydrate; 1.24 ± 0.20 for ninhydrin; 1-28 ± 0.17 for D-glucose; and
1.23 ± 0.02 for D-fructose. These values indicate that hydrogens are
more tightly bound in these molecules than in bulk water. A theoretical
calculation of deuterium isotope effects was made on a gem-diol model.
The isotope effect K.JK^ increases with an increase in the hydroxylic
D li
torsional force constant. An extensive table of isotopic fractionation
factors is given.
v
Group and individual differences in the neural representation of described and experienced risk
NGC 6309, a Planetary Nebula that Shifted from Round to Multipolar
We present new narrow-band Ha, [N II], and [O III] high-resolution images of
the quadrupolar planetary nebula (PN) NGC 6309 that show in great detail its
bipolar lobes and reveal new morphological features. New high- and
low-dispersion long-slit spectra have been obtained to help in the
investigation of the new nebular components. The images and spectra unveil two
diffuse blobs, one of them located at 55 arcsec from the central star along the
NE direction (PA= +71) and the other at 78 arcsec in the SW direction (PA=
-151). Therefore, these structures do not share the symmetry axes of the inner
bipolar outflows. Their radial velocities relative to the system are quite low:
+3 and -4 km/s, respectively. Spectroscopic data confirm a high [O III] to Ha
ratio, indicating that the blobs are being excited by the UV flux from the
central star. Our images convincingly show a spherical halo 60 arcsec in
diameter encircling the quadrupolar nebula. The expansion velocity of this
shell is low, 66 km/s. The software SHAPE has been used to construct a
morpho-kinematic model for the ring and the bipolar flows that implies an age
of 4,000 yrs, the expansion of the halo sets a lower limit for its age 46,000
yrs, and the very low expansion of the blobs suggests they are part of a large
structure corresponding to a mass ejection that took place 150,000 yrs ago. In
NGC 6309 we have direct evidence of a change in the geometry of mass-loss, from
spherical in the halo to axially-symmetric in the two pairs of bipolar lobes.Comment: 8 pages, 7 figures, Accepted for publication in MNRA
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Winning the Oil Lottery: The Impact of Natural Resource Extraction on Growth
This paper provides evidence on the causal impact of oil discoveries on local development. Novel data on the drilling of 20,000 oil wells in Brazil allows us to exploit a quasi-experiment: municipalities where oil was discovered constitute the treatment group while municipalities with drilling but no discovery are the control group. The results show that oil discoveries significantly increase per capita GDP and urbanization. We find positive spillovers to non-oil sectors, specifically an increase in services GDP which stems from higher labor productivity. The results are consistent with greater local demand for non-tradable services driven by highly paid oil workers
Risk management of bored piling construction on sandy soils with real-time cost control
UIDP/GEO/04035/2020In a global society, in which geotechnical projects are increasingly designed in a country other than the one where construction takes place, geotechnical risk management must be extended to cover infrastructure works, which are smaller than dams and tunnels, for example, since there is a significant impact on works budget imponderables. Therefore, a risk management methodology based on the likelihood of the occurrence of certain events and their economic consequences is proposed, which is applicable to bored piles (Kelly drilled) in coarse soils, easy to use, and simple to implement since the initial stage of construction. Of 12 case studies of construction works involving bored piles (Kelly drilled) carried out in Luanda (Angola), two selected examples involving the proposed risk methodology on sandy soil layers with interbedded clays are discussed. Subsequently, whether the overall foundation contract budget is affected by assessed risk is determined, and what influence it has on the budget in the light of mitigating factors and associated real costs. This method intended to encourage the adaptation of sustainable risk management in bored piles construction by the site project managers, involving risk analysis concurrently with budgetary review. Though the level of assessed technical risk may be acceptable, overall costs associated with the contract in question may not be acceptable.publishersversionpublishe
Comparing phrase-final patterns across speech styles and groups in European Portuguese
Le présent travail se propose d’étudier les effets phonétiquesphonologiques et les types de tons présents à la frontière d’unités intonatives majeures et mineures (indices de rupture 4 et 3 du système ToBI), en comparant la parole spontanée et la parole préparée (non lue) produites par des adolescents et par des adultes à l’école. Le corpus analysé est constitué d’un relevé de 1041 unités intonatives extraites de 18 présentations orales faites par 6 élèves (14-15 ans) et 3 professeurs (un sous-ensemble du corpus CPE-FACES). Les résultats montrent que les indices phonétiques et prosodiques en fin d’unités intonatives varient en fonction (i) du style de parole et (ii) de l’âge/statut des locuteurs
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