366 research outputs found
Toward Carbon-Neutral Electric Power Systems in the New York State: a Novel Multi-Scale Bottom-Up Optimization Framework Coupled with Machine Learning for Capacity Planning at Hourly Resolution
In
this work, we propose a novel multi-scale bottom-up optimization
framework for the carbon-neutral transition planning of the electric
power sector, which incorporates hourly time scale and electricity
storage to address the reliability and energy balance issues of the
future deep-decarbonized power systems. In addition to the technology
and capacity information for each facility, the proposed framework
also accounts for facility ages, which are usually omitted in the
literature, without significantly increasing the computational demand.
To reduce the computational requirement of simultaneously optimizing
capacity planning and hourly systems operations over the next few
decades, a reduced model is developed based on representative days,
using a novel approach that integrates multiple machine learning techniques.
Based on the optimal transition pathways, hourly operational simulations
are conducted for every year within the planning horizon to obtain
detailed optimization results. To illustrate the applicability of
the proposed framework, a case study for the New York State is presented
through two cases, with and without electricity storage capacity expansion.
The proposed approach using principal component analysis coupled with
K-means outcompetes multiple conventional approaches of using clustering
techniques directly. The transition planning results show that the
total generation capacity for the case with electricity capacity expansion
is 39% higher than the other case, while the latter case has 200%
more generation capacity from non-intermittent sources. Detailed hourly
operational simulation results indicate that offshore wind, hydro,
and utility solar are the primary power sources by 2040 for the case
with electricity storage capacity expansion, while hydro, offshore
wind, and nuclear are the main electricity sources for the other case
Regression results of mechanism analysis.
Based on empirical analysis of Chinese listed companies from 2010 to 2018, we demonstrate that enterprise digital transformation has a significant impact on improving capacity utilization. Digital transformation is a significant driving force behind enterprise-specific production and innovation. Furthermore, enterprise innovation and enterprise-specialized production play a mediating role in the impact of enterprise digital transformation on capacity utilization. Based on these baseline findings, heterogenous analysis reveals that the impact of digital transformation on capacity utilization is significant for firms with larger capital scales or poor governance and manufacturing abilities. However, it is less important for enterprises with small- and medium-sized capital scales or with more standardized governance, as well as non-manufacturing (service) enterprises.</div
Variable definitions.
Based on empirical analysis of Chinese listed companies from 2010 to 2018, we demonstrate that enterprise digital transformation has a significant impact on improving capacity utilization. Digital transformation is a significant driving force behind enterprise-specific production and innovation. Furthermore, enterprise innovation and enterprise-specialized production play a mediating role in the impact of enterprise digital transformation on capacity utilization. Based on these baseline findings, heterogenous analysis reveals that the impact of digital transformation on capacity utilization is significant for firms with larger capital scales or poor governance and manufacturing abilities. However, it is less important for enterprises with small- and medium-sized capital scales or with more standardized governance, as well as non-manufacturing (service) enterprises.</div
Collecting data.
Based on empirical analysis of Chinese listed companies from 2010 to 2018, we demonstrate that enterprise digital transformation has a significant impact on improving capacity utilization. Digital transformation is a significant driving force behind enterprise-specific production and innovation. Furthermore, enterprise innovation and enterprise-specialized production play a mediating role in the impact of enterprise digital transformation on capacity utilization. Based on these baseline findings, heterogenous analysis reveals that the impact of digital transformation on capacity utilization is significant for firms with larger capital scales or poor governance and manufacturing abilities. However, it is less important for enterprises with small- and medium-sized capital scales or with more standardized governance, as well as non-manufacturing (service) enterprises.</div
Descriptive statistics results.
Based on empirical analysis of Chinese listed companies from 2010 to 2018, we demonstrate that enterprise digital transformation has a significant impact on improving capacity utilization. Digital transformation is a significant driving force behind enterprise-specific production and innovation. Furthermore, enterprise innovation and enterprise-specialized production play a mediating role in the impact of enterprise digital transformation on capacity utilization. Based on these baseline findings, heterogenous analysis reveals that the impact of digital transformation on capacity utilization is significant for firms with larger capital scales or poor governance and manufacturing abilities. However, it is less important for enterprises with small- and medium-sized capital scales or with more standardized governance, as well as non-manufacturing (service) enterprises.</div
Heterogeneity analysis results.
Based on empirical analysis of Chinese listed companies from 2010 to 2018, we demonstrate that enterprise digital transformation has a significant impact on improving capacity utilization. Digital transformation is a significant driving force behind enterprise-specific production and innovation. Furthermore, enterprise innovation and enterprise-specialized production play a mediating role in the impact of enterprise digital transformation on capacity utilization. Based on these baseline findings, heterogenous analysis reveals that the impact of digital transformation on capacity utilization is significant for firms with larger capital scales or poor governance and manufacturing abilities. However, it is less important for enterprises with small- and medium-sized capital scales or with more standardized governance, as well as non-manufacturing (service) enterprises.</div
Results of robustness tests.
Based on empirical analysis of Chinese listed companies from 2010 to 2018, we demonstrate that enterprise digital transformation has a significant impact on improving capacity utilization. Digital transformation is a significant driving force behind enterprise-specific production and innovation. Furthermore, enterprise innovation and enterprise-specialized production play a mediating role in the impact of enterprise digital transformation on capacity utilization. Based on these baseline findings, heterogenous analysis reveals that the impact of digital transformation on capacity utilization is significant for firms with larger capital scales or poor governance and manufacturing abilities. However, it is less important for enterprises with small- and medium-sized capital scales or with more standardized governance, as well as non-manufacturing (service) enterprises.</div
Benchmark regression results.
Based on empirical analysis of Chinese listed companies from 2010 to 2018, we demonstrate that enterprise digital transformation has a significant impact on improving capacity utilization. Digital transformation is a significant driving force behind enterprise-specific production and innovation. Furthermore, enterprise innovation and enterprise-specialized production play a mediating role in the impact of enterprise digital transformation on capacity utilization. Based on these baseline findings, heterogenous analysis reveals that the impact of digital transformation on capacity utilization is significant for firms with larger capital scales or poor governance and manufacturing abilities. However, it is less important for enterprises with small- and medium-sized capital scales or with more standardized governance, as well as non-manufacturing (service) enterprises.</div
Cell Chemistry of Sodium–Oxygen Batteries with Various Nonaqueous Electrolytes
Development
of the nonaqueous Na–O<sub>2</sub> battery with
a high electrical energy efficiency requires the electrolyte stable
against attack of highly oxidative species such as nucleophilic anion
O<sub>2</sub><sup>•–</sup>. A combined evaluation method
was used to investigate the Na–O<sub>2</sub> cell chemistry
with various solvents, including ethylene carbonate/propylene carbonate
(EC/PC)-, <i>N</i>-methyl-<i>N</i>-propylpiperidinium
bis(trifluoromethansulfonyl) imide (PP13TFSI)-, and tetraethylene
glycol dimethyl ether (TEGDME)-based electrolytes. It is found that
the TEGDME-based electrolytes have the best stability with the predominant
yield of NaO<sub>2</sub> upon discharge and the largest electrical
energy efficiency (approaching 90%). Both EC/PC- and PP13TFSI-based
electrolytes severely decompose during discharge, forming a large
amount of side products. Analysis of the acid dissociation constant
(p<i>K</i><sub>a</sub>) of these electrolyte solvents reveals
that the TEGDME has the relatively large value of p<i>K</i><sub>a</sub>, which correlates with good stability of the electrolyte
and high round-trip energy efficiency of the battery
Table_1_Comprehensive bioinformatics analysis reveals common potential mechanisms, progression markers, and immune cells of coronary virus disease 2019 and atrial fibrillation.DOCX
ObjectivesAtrial fibrillation (AF) is the most common arrhythmia in coronary virus disease 2019 (COVID-19) patients, especially in severe patients. A history of AF can exacerbate COVID-19 symptoms. COVID-19 Patients with new-onset AF have prolonged hospital stays and increased death risk. However, the mechanisms and targets of the interaction between COVID-19 and AF have not been elucidated.Materials and methodsWe used a series of bioinformatics analyses to understand biological pathways, protein-protein interaction (PPI) networks, gene regulatory networks (GRNs), and protein-chemical interactions between COVID-19 and AF and constructed an AF-related gene signature to assess COVID-19 severity and prognosis.ResultsWe found folate and one-carbon metabolism, calcium regulation, and TFG-β signaling pathway as potential mechanisms linking COVID-19 and AF, which may be involved in alterations in neutrophil metabolism, inflammation, and endothelial cell function. We identified hug genes and found that NF-κb, hsa-miR-1-3p, hsa-miR-124-3p, valproic acid, and quercetin may be key regulatory molecules. We constructed a 3-gene signature consisting of ARG1, GIMAP7, and RFX2 models for the assessment of COVID-19 severity and prognosis, and found that they are associated with neutrophils, T cells, and hematopoietic stem cells, respectively.ConclusionOur study reveals a dysregulation of metabolism, inflammation, and immunity between COVID-19 and AF, and identified several therapeutic targets and progression markers. We hope that the results will reveal important insights into the complex interactions between COVID-19 and AF that will drive novel drug development and help in severity assessment.</p
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