general validity
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2021 ◽  
Author(s):  
Blandine Ribotta ◽  
Miguel Alejandro A. Silan ◽  
Olivier Dujols ◽  
Ronan Bellemin ◽  
Hans IJzerman

Central to interventions to improve the quality of romantic relationships is its measurement. Yet, to what degree is the concept of relationship quality well-defined, and, importantly, well-measured? In the present article, the authors conducted a comprehensive search of instruments measuring relationship quality in ProQuest, Web of Science, and Scopus finding a total of 599 scales, with 26 meeting our definition of romantic relationship quality. When the authors investigated the 26 scales’ overlap of item-content, they identified 25 distinct categories among 754 items (with our database of items on the OSF: https://osf.io/v964p/). The mean overlap between scales was weak (Jaccard Index correlation coefficient = 0.39), indicating that these scales were very heterogeneous. The authors then assessed to what extent researchers reported internal validity in 43 scale development-validation articles. They found that Cronbach’s Alpha was most often reported (in 91% of the articles). Other aspects were reported far less often, with 55% reporting exploratory factor analyses, 26% reporting confirmatory factor analyses, 23% reporting test-retest reliability, 7% reporting measurement invariance. The heterogeneity of measures and lack of reported general validity of romantic relationship quality points to the need for concept-driven work on the assessment of romantic relationship quality.


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4094
Author(s):  
Yu-Ho Wen ◽  
Chen-Chieh Wang ◽  
Guo-Sian Cyue ◽  
Rong-Hao Kuo ◽  
Chia-Hsiang Hsu ◽  
...  

For highly viscous polymer melts, considerable fluid temperature rises produced by viscous heating can be a disturbing factor in viscosity measurements. By scrutinizing the experimental and simulated capillary pressure losses for polymeric liquids, we demonstrate the importance of applying a viscous heating correction to the shear viscosity, so as to correct for large errors introduced by the undesirable temperature rises. Specifically, on the basis of a theoretical derivation and 3-D nonisothermal flow simulation, an approach is developed for retrieving the equivalent shear viscosity in capillary rheometry, and we show that the shear viscosity can be evaluated by using the average fluid temperature at the wall, instead of the bulk temperature, as previously assumed. With the help of a viscous Cross model in analyzing the shear-dominated capillary flow, it is possible to extract the viscous heating contribution to capillary pressure loss, and the general validity of the methodology is assessed using the experiments on a series of thermoplastic melts, including polymers of amorphous, crystalline, and filler-reinforced types. The predictions of the viscous model based on the equivalent viscosity are found to be in good to excellent agreement with experimental pressure drops. For all the materials studied, a near material-independent scaling relation between the dimensionless temperature rise (Θ) and the Nahme number (Na) is found, Θ ~ Na0.72, from which the fluid temperature rise due to viscous heating as well as the resultant viscosity change can be predicted.


Author(s):  
Julio Alcantara

The study of plant community dynamics has a long tradition. However, this field has barely incorporated the tools developed in the modern study of ecological networks. Key for this incorporation is the availability of a theoretical model able to incorporate field data about plant-plant interactions. In this study I introduce the Recruitment and Replacement (R&R) model that explicitly incorporates empirical networks of plant-plant interactions that occur during recruitment. The R&R model is built on fundamental demographic rates and incorporates competition for space between adults, intra- and inter-specific effects of established plants on recruitment and the colonization of vacant space. The basic analysis of the model provides predictions regarding different aspects of plant community dynamics, like the environmental conditions and species properties under which facilitation of recruitment is more likely to occur, the effect of recruitment facilitation on invasion, the effects of plant-plant interactions on equilibrium abundances and community stability, and the network properties that should relate to species equilibrium abundances. Many of these predictions agree with findings from published meta-analyses, supporting the general validity of the recruitment networks framework as a general approach to integrate the study of plant community dynamics into the study of ecological networks.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6841
Author(s):  
Giovanna De Luca ◽  
Franz Bianco Mauthe Degerfeld ◽  
Ilaria Ballarini ◽  
Vincenzo Corrado

The recently issued EN ISO 52016-1 technical standard provides a new simplified dynamic method for the building energy performance assessment. Since an extensive validation of the EN ISO 52016-1 hourly method is still missing, the present work investigates the effect of the main modelling assumptions—related to the heat balance on the outdoor and the indoor envelope surfaces—on the building thermal behaviour. The model validation was carried out by assessing the accuracy variation consequent to the application of the EN ISO 52016-1 modelling assumptions to a detailed dynamic calculation tool (EnergyPlus). To guarantee a general validity of the outcomes, two buildings, two levels of thermal insulation, and two Italian climatic zones were considered, for a total of eight case studies. To explore different applications of the standard method, the analysis was performed both under a free-floating condition—to evaluate the accuracy of the model in predicting the indoor operative temperatures—and to assess the annual energy needs for space heating and cooling. Results show that the assumptions related to the definition of the external convective and the shortwave (solar) radiation heat transfer lead to non-negligible inaccuracies in the EN ISO 52016-1 hourly model.


Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1252
Author(s):  
Ha V. Le ◽  
Vy B. Nguyen ◽  
Hai H. Pham ◽  
Khoa D. Nguyen ◽  
Phuoc H. Ho ◽  
...  

A series of mixed oxides of CuO, CeO2, and SiO2 were prepared by gel combustion and employed for the first time as efficient solid catalysts in a solvent-less liquid-phase cross-dehydrogenative coupling. The facile one-pot catalyst synthesis resulted in highly porous materials presenting large specific surface areas and strong metal–support interactions. The interaction with highly dispersed CeO2 enhanced the redox properties of the CuO species. The CuO-CeO2-SiO2 composites exhibited excellent catalytic performance for the selective coupling between 1,1-diphenylethylene and tetrahydrofuran with a yield up to 85% of 2-(2,2-diphenylvinyl)-tetrahydrofuran in the presence of di-tert-butyl peroxide (DTPB) and KI. Albeit both CuO and CeO2 species are proved to be responsible for the catalytic conversion, a great synergistic improvement in the catalytic activity was obtained by extended contact between the oxide phases by high porosity in comparison with the reactions using individual Cu or Ce catalysts. The activity of the composite catalyst was shown to be highly stable after five successive reaction cycles. Furthermore, the study scope was extended to the synthesis of different derivatives via composite-catalyzed coupling of C(sp2)-H with C(sp3-H) adjacent to a heteroatom. The good yields recorded proved the general validity of this composite for the cross-dehydrogenative coupling reaction rarely performed on solid catalysts.


Author(s):  
Marioara Iordan ◽  
Ion Ghizdeanu ◽  
Alexandra Patricia Braica

Abstract Convergence and economic and social cohesion remain priorities for the EU, beyond failures to achieve the objectives of the ‘Europe 2020’ strategy. Convergence and territorial cohesion, as a prerequisite for sustainable and durable development, have been the fundamental objectives that generated and developed the strategic planning in the EU, including through the two global strategies, ‘Lisbon’ and ‘Europe 2020’. The sustainability of these processes, even in periods of high economic growth, is questionable since real national convergence is based in many countries, including Romania, on large and widening divergences between regions and counties. In recent years, Romania has seen one of the most enhanced improvements in convergence compared to the EU average, from 60% in 2016 to 69% of the European average in 2019 respectively. During the same period, disparities between regions and counties have deepened. More than 10 years after EU accession and participation in the Community cohesion policy, there is still a third of the counties with less than 70% of the national average of gross domestic product per capita. The health crisis has deeply affected economic activity, but in a differentiated way, depending on the specific territorial economic structures. As a result, the objective of improved and sustainable real convergence, by bringing regions and counties closer together in terms of their level of development, is receding. The economic situation in the counties in 2020 indirectly provides support for assessing the impact of the pandemic on the territorial cohesion process. The implicit conclusion revealed by the latest statistical data is that the level of development has been the support for better resilience to the health crisis. Although the restrictions on international movement and the closure of tourist and industrial capacities have had general validity, the counties with a higher degree of disparity have been more affected.


2021 ◽  
Vol 9 (10) ◽  
pp. 2073
Author(s):  
Sophie Rabouille ◽  
Benjamin Randall ◽  
Amélie Talec ◽  
Patrick Raimbault ◽  
Thierry Blasco ◽  
...  

Marine nitrogen (N2) fixation was historically considered to be absent or reduced in nitrate (NO3−) rich environments. This is commonly attributed to the lower energetic cost of NO3− uptake compared to diazotrophy in oxic environments. This paradigm often contributes to making inferences about diazotroph distribution and activity in the ocean, and is also often used in biogeochemical ocean models. To assess the general validity of this paradigm beyond the traditionally used model organism Trichodesmium spp., we grew cultures of the unicellular cyanobacterium Crocosphaera watsonii WH8501 long term in medium containing replete concentrations of NO3−. NO3− uptake was measured in comparison to N2 fixation to assess the cultures’ nitrogen source preferences. We further measured culture growth rate, cell stoichiometry, and carbon fixation rate to determine if the presence of NO3− had any effect on cell metabolism. We found that uptake of NO3− by this strain of Crocosphaera was minimal in comparison to other N sources (~2–4% of total uptake). Furthermore, availability of NO3− did not statistically alter N2 fixation rate nor any aspect of cell physiology or metabolism measured (cellular growth rate, cell stoichiometry, cell size, nitrogen fixation rate, nitrogenase activity) in comparison to a NO3− free control culture. These results demonstrate the capability of a marine diazotroph to fix nitrogen and grow independently of NO3−. This lack of sensitivity of diazotrophy to NO3− suggests that assumptions often made about, and model formulations of, N2 fixation should be reconsidered.


Author(s):  
Hyobin Julianne Lim ◽  
Haejin Yoon ◽  
Hyeyeon Kim ◽  
Yun-Won Kang ◽  
Ji-Eun Kim ◽  
...  

Extracellular vesicles (EVs) are membranous structures containing bioactive molecules, secreted by most cells into the extracellular environment. EVs are classified by their biogenesis mechanisms into two major subtypes: ectosomes (enriched in large EVs; lEVs), budding directly from the plasma membrane, which is common in both prokaryotes and eukaryotes, and exosomes (enriched in small EVs; sEVs) generated through the multivesicular bodies via the endomembrane system, which is unique to eukaryotes. Even though recent proteomic analyses have identified key proteins associated with EV subtypes, there has been no systematic analysis, thus far, to support the general validity and utility of current EV subtype separation methods, still largely dependent on physical properties, such as vesicular size and sedimentation. Here, we classified human EV proteomic datasets into two main categories based on distinct centrifugation protocols commonly used for isolating sEV or lEV fractions. We found characteristic, evolutionarily conserved profiles of sEV and lEV proteins linked to their respective biogenetic origins. This may suggest that the evolutionary trajectory of vesicular proteins may result in a membership bias toward specific EV subtypes. Protein–protein interaction (PPI) network analysis showed that vesicular proteins formed distinct clusters with proteins in the same EV fraction, providing evidence for the existence of EV subtype-specific protein recruiters. Moreover, we identified functional modules enriched in each fraction, including multivesicular body sorting for sEV, and mitochondria cellular respiration for lEV proteins. Our analysis successfully captured novel features of EVs embedded in heterogeneous proteomics studies and suggests specific protein markers and signatures to be used as quality controllers in the isolation procedure for subtype-enriched EV fractions.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5502
Author(s):  
Pietro Croce

Cables are typically used in engineering applications as tensile members. Relevant examples are the main cables of suspension bridges, the stays of cable-stayed bridges, the load-bearing and stabilizing cables of tensile structures, the anchor cables of floating mooring structures, the guy-ropes for ship masts, towers, and wind turbines, the copper cables of electrical power lines. Since cables are characterized by non-linear behavior, analysis of cable structures often requires advanced techniques, like non-linear FEM, able to consider geometric non-linearity. Nevertheless, a traditional simplified approach consists in replacing the cable with an equivalent tie rod, characterized by a suitable non-linear constitutive law. Currently used equivalent constitutive laws have been derived by Dischinger, Ernst and Irvine. Since the equivalence is restricted to taut cables, characterized by small sag to chord ratios, these traditional formulae are not appropriate for uniformly loaded sagging cables: the main cables of suspension bridges are a particularly emblematic case. Despite some recent attempts to find more refined solutions, the problem is still open, since closed form solutions of general validity are not available. In the paper, general analytical formulae of the non-linear constitutive law of the equivalent tie rod are proposed, distinguishing two relevant cases, according as the length of the cable can vary or not. The expressions, derived by applying the general form of the theorem of virtual work, can be applied independently on the material, on the sag to chord ratio, on the load intensity and on the stress level, so allowing the replacement of the whole cable with a single equivalent tie rod. The expressions are critically discussed referring to a wide parametric study also in comparison with the existing formulae, stressing the influence of the most relevant parameters.


Electricity ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 342-358
Author(s):  
Marco Landini ◽  
Giovanni Mazzanti ◽  
Riccardo Mandrioli

The verification of the limits of the population’s exposure to the magnetic field generated by double-circuit power lines from field measurements carried out on site is not trivial. It requires knowledge of the power line current instant values during the measurement period, the determination of the relationship between current and field at the measurement points (made more complex by the double-circuit overhead line configuration) and the use of that relationship to extrapolate the field values. Nevertheless, the verification of exposure limits for double-circuit power lines from on-site measurements is often conducted with rough, or not particularly stringent, procedures. A practical and straightforward procedure of general validity for non-optimized double-circuit lines is proposed here. No specific measurement position or conductors disposition knowledge is required as well as no complex three-dimensional finite element method code is necessary. The procedure, potentially also applicable to high- and extra-high-voltage lines, is validated on a medium-voltage (15 kV) double-circuit overhead power line study case. Exposure limits assessment suggests that if the line is operated at its rated capacity (230/285 A), the 3 μT quality target is missed. Results are provided with a 95% confidence interval ranging from ±100 nT to ±140 nT in all the cases.


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