bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoredox‐Catalyzed 1,4‐Dichloromethyldimerization of Alkenes with Chloroform: Access to Polychlorinated Vicinal Diaryl Alkanes
Authors: Qian Zhu‐Ming , Yang Ming‐Lin , Guan Zhi , Huang Chu‐Sheng , He Yan‐Hong 
Published: January 2025

AbstractA visible‐light‐mediated strategy is reported for the direct synthesis of polychlorinated vicinal diaryl alkanes from aryl alkenes and chloroform. In this approach, two haloalkyl radicals generated from chloroform via halogen atom transfer (XAT) and direct single electron transfer (SET) within the same photoredox catalysis cycle enable the 1,4‐dichloromethyldimerization of alkenes. Besides chloroform, this strategy is applicable to carbon tetrachloride, bromotrichloromethane, and α‐bromo carboxylic esters, yielding corresponding 1,4‐disubstituted vicinal diaryl alkanes. Diverse polychlorinated structures containing highly congested vicinal quaternary carbon centers are effectively synthesized by this method. The potential of this reaction in late‐stage drug modification is highlighted by the successful transformation of olefins with pharmaceutical structures.
A Chiral Porous Organic Polymer Used as the Stationary Phase for High‐Resolution Gas Chromatography Separations
Authors: Wang Wei , Wang Zhen , Wang Yuwei , Sun Liquan , Zhang Jiangjiang , Zhang Yukui , Luo Aiqin 
Published: January 2025

ABSTRACTA chiral porous organic polymer (cPOP) was synthesized through nucleophilic substitution polymerization between dichloromaleimide and aromatic amine. This cPOP was used as a new chiral stationary phase (CSP) for gas chromatography (GC) chiral separation. In this work, we first used this cPOP as the CSP for gas chromatography to investigate its ability to separate racemic mixtures, including amino acid derivatives, chiral alcohols, aldehydes, alkanes, ketones, esters, and organic acids. The results showed that the column can effectively separate various racemic mixtures and achieve baseline separation of threonine (Rs = 1.91). Furthermore, the separation mechanism was elucidated by density functional theory (DFT) simulation. Additionally, the cPOP column demonstrated good repeatability and stability. The relative standard deviations (RSDs) for intraday were 0.11%–0.12% (n = 3) for the retention time of n‐butyl glycidyl ether, 0.1%–0.34% (n = 3) for interday, and 2.25%–3.37% (n = 3) for column to column. This work shows that cPOP has good potential as chiral stationary phases in gas chromatography.
Organic alkalis as potential additives in hot water flooding for enhancing heavy oil recovery
Authors: Du Xuan , Xi Changfeng , Zhou You , Shen Dehuang , Wang Bojun , Liu Tong , Zhao Fang , Zhao Jiu , Qi Zongyao , Lin Lixing , Istratescu Georgeta , Babadagli Tayfun , Li Huazhou Andy 
Published: January 2025

AbstractAlkali–surfactant–polymer (ASP) flooding is a chemical enhanced oil recovery method; its working mechanisms include mobility control, wettability alteration, and in‐situ emulsification. However, conventional alkalis used in the ASP flooding could cause some serious issues, including scaling, formation damage, and pipe corrosion. In this study, we investigated the feasibility of incorporating organic alkalis as chemical additives in hot water flooding to enhance heavy oil recovery. The focus was on studying the interfacial properties, that is, interfacial tension (IFT) and wettability, emulsification mechanisms, thermal stability of alkalis, and recovery efficiency through coreflooding experiments. Three organic alkalis, including diethylamine (DEA), ethanolamine (ETA), and triethlymine (TEA), were selected to evaluate their potentials in enhancing heavy oil recovery and investigate their recovery mechanisms. Coreflooding experiments were conducted at 50°C and 2 MPa with sandpacks saturated with a high total‐acid‐number (TAN) heavy oil sample. The measurement results demonstrated that all three organic alkalis could effectively reduce the IFT between water and heavy oil from 22.7 to 1.6 mN/m and favourably alter the wettability of rock surface. ETA exhibited good thermal stability up to 100°C in hot water applications. The interaction between organic alkalis and heavy oil could generate either water‐in‐oil or oil‐in‐water emulsions, depending on the water–oil ratio (WOR). The coreflooding experiments showed a significant increase (16%–17.5%) in heavy oil recovery using ETA for two distinct injection strategies. IFT reduction, wettability alteration, and emulsification were found to be the main recovery mechanisms when organic alkalis are utilized as chemical additives for hot water flooding.
Bubble size and rise velocity, gas holdup, and frother concentration in flotation
Authors: Zhou Joe Z. 
Published: January 2025

AbstractIt was revealed from the literature that although Sauter mean bubble diameter, d32, remained virtually unchanged after critical coalescence concentration (CCC), gas holdup kept rising without reaching a maximum plateau. In addition, for a given d32, different gas holdups were obtained for different types of frothers, contrary to conventional belief regarding bubbly columns. A brief analysis was given in this Note, by considering the effect of different hydrodynamic environment surrounding a bubble in a swarm from a single bubble alone on dynamic frother adsorption. Based on the balance between hydrodynamic drag and surface tension gradient force acting on a bubble, it was speculated that frother adsorption density or compactness in the dynamic adsorption layer on a bubble would be lower in swarms than in single bubble systems of the same size. This could allow further frother adsorption after CCC and CMV (concentration at minimum/terminal velocity for single bubbles). Consequently gas holdup might continue to rise. Moreover, the overlap of adsorption layers between adjacent bubbles caused stronger molecular interactions among frothers of longer hydrocarbon chains, or larger molecular weights with different head groups, and interfered bulk free water flow through the channels of rising bubbles, leading to their stronger drag to slow bubbles thereby higher gas holdups for a given bubble size. It appeared that bubble surfaces in real flotation systems may not be totally immobilized.
Deep learning models for forecasting sour gas generation in a petroleum refinery
Authors: Dharmalingam Balakrishnan , Arul Jesu Gnanaprakasam , Marimuthu Thirumarimurugan 
Published: January 2025

AbstractSour water stripping is a critical process in petroleum refineries, essential for the safe handling and disposal of wastewater that contains hazardous components such as hydrogen sulphide (H₂S) and ammonia (NH₃). Effective management of sour gas, the product of sour water stripping, is crucial to minimize environmental impacts of release of pollutants like sulphur dioxide (SO₂) and nitrogen oxides (NOₓ). This study explores the application of advanced deep learning models for forecasting sour gas generation in a refinery setting. Utilizing a comprehensive dataset from a sour water stripper unit, various deep learning architectures, such as recurrent neural networks (RNNs), long short‐term memory networks (LSTMs), bidirectional LSTMs (BiLSTMs), one dimensional convolutional neural network (1D‐CNN), and few hybrid models were employed to predict sour gas output. The evaluation metrics indicate that the 1D‐CNN and two‐layer LSTM models outperformed the other models, whereas the CNN‐LSTM encoder–decoder model did not result in good prediction among all the models studied. These findings underscore the capability of deep learning techniques to improve predictive accuracy and enhance operational efficiency in refinery sour gas management.
Self‐Reported Oral Health‐Related Quality of Life and Orofacial Esthetics Among Young Adults With Treated Dental Trauma
Authors: Odersjö Mari Louise , Johansson Lina , Robertson Agneta , Sabel Nina 
Published: January 2025

ABSTRACTObjectivesThis study aimed to explore how young adults with a history of dental trauma and restored teeth perceive their oral health–related quality of life (OHRQoL) and orofacial esthetics, with a focus on gender‐based differences.Materials and MethodsThis pilot study is a retrospective case–control study. Young adults experiencing dental trauma and consequently receiving dental treatment were asked to answer CPQ11‐14, Oral Esthetic Scale (OES), and some complimentary questions concerning the esthetics of their teeth. A control group was recruited. t‐Test was used to analyze the scores of CPQ11‐14 and OES, comparing both the study group and the control group, as well as assessing differences between the genders. Regression analysis ANOVA was used to examine the relationship between the OES questions and CPQ11‐14 domains.ResultsThe study group comprised 74 individuals (mean age = 23 years, SD 2.8), including 48 females and 26 males, with an equivalent number in the control group (mean age = 23 years, SD 3.4), with 49 females and 25 males. The mean score of the CPQ11‐14 was 8.8 (SD 7.2) for the study group and 8.0 (SD 6.8) for the control group. Within the emotional well‐being domain, the study group exhibited a higher mean score (3.4, SD 3.6) compared to the control group (1.5, SD 2.6) (p < 0.001 t‐test). Females in the study group scored higher in the emotional well‐being domain (4.0, SD 3.7) compared to females in the control group (1.8, SD 2.7), (p < 0.01 independent t‐test). The study group, who reported low satisfaction with their tooth color or alignment in the OES, also scored higher in the social well‐being domain of CPQ11‐14 (p < 0.026, ANOVA). This was not observed in the control group.ConclusionsYoung adults with treated dental trauma trend to report a negative impact on their oral health‐related quality of life and oral esthetics, particularly females.
Environmental Sustainability Award Winners: Do They Communicate Their Environmental Performance Without Potential Greenwashing?
Authors: Marrucci Luca , Iovino Roberta , Iraldo Fabio 
Published: January 2025

ABSTRACTSustainability awards are often seen as a mark of credibility and can help companies attract new customers, investors and partners. However, there is some question as to whether the companies that win sustainability awards—and therefore who ought to be genuinely committed to sustainability—correctly communicate their environmental performances according to internationally recognised principles for the fair use of environmental labels and claims such as those set by ISO standards. This study examined the web communication practices of a sample of 100 Italian companies that had won a sustainability award. Our findings showed that, while most of these companies boasted their environmental performance in several ways, they did not always follow the above‐mentioned communication principles. This suggests that companies need further training and education on how to communicate their environmental performance correctly and in a substantiated manner, thus preventing the risk of greenwashing.
A 0.5–5 Gb/s Wide Range, 160 fJ/Pulse Fully Integrated 13th‐Order CMOS IR‐UWB Transmitter for Wireless Capsule Endoscopy Systems
Authors: Akuri Naga Ganesh , Kumar Kunal , Kumar Sandeep , Nikhil K. S. , Song Hanjung 
Published: January 2025

ABSTRACTThis paper proposes a novel technique based fully integrated 13th‐order derivative CMOS impulse‐radio ultrawideband (IR‐UWB) transmitter with wide range of adaptive data rates for wireless capsule endoscopy systems (WCE). The proposed IR‐UWB transmitter involves BPSK modulator‐integrated RF power amplifier (PA) approach for WCE in first time as per author's best knowledge. The CMOS BPSK modulator with resonator technique generates 13th‐order Modulated Gaussian pulse without the pulse generator. It has a peak‐to‐peak value of 25 mV and PSD level of −72.60 dBm/MHz, data rate variability from 500 Mbps to 5 Gbps. The BPSK modulator with resonator is designed by time constant analysis in first time. In addition, a proposed CMOS PA is designed using four stacked transistors, which achieves a high output power as well as high efficiency for entire frequency band of operation from 3 to 16 GHz and wide impedance matching. The PA achieved an excellent gain of 16.55 dB with gain ripple of 0.25 dB only. Moreover, the PA achieved the saturated output power of 18.2 to 19.3 dBm with OP1dB of 15.96 to 16.72 dBm across entire bandwidth. Without violating FCC guidelines, PA strengths both peak‐to‐peak values, and PSD level of BPSK modulated signal to 80 mV and −46.42 dBm/MHz. An IR‐UWB transmitter has been implemented and fabricated using 65‐nm CMOS Process, which consumes of only 160 fJ/pulse for generating Gaussian pulses order ranging from third‐order to more than 13th‐order at various data rates.
Three‐Port Bidirectional DC–DC Converter for Application in Renewable Energy Systems
Authors: de Alencar Juliana Carvalho , Berrehil El Kattel Menaouar , Pinheiro Gabriel José Oliveira , Torrico‐Bascopé Grover Victor , Torrico‐Bascopé René Pastor 
Published: January 2025

ABSTRACTThis paper proposes a new three‐port bidirectional DC–DC converter designed for integration into photovoltaic systems with battery energy storage. The proposed topology features three ports: two for power supply (one powered by batteries and the other by photovoltaic panels) and a third for the load. Due to its bidirectional characteristics, this converter facilitates power flow both from the batteries and/or photovoltaic panels to the load, as well as from the photovoltaic panels to the batteries. The converter operates in open loop, and this paper presents qualitative and quantitative analyses of the converter operating in continuous conduction mode (CCM) for two power flow scenarios. Additionally, an illustrative design is detailed for a nominal power of 1.5 kW, a switching frequency of 30 kHz, a battery voltage of 48 V, a photovoltaic panel voltage of 142 V, and a load bus voltage of 250 V. The theoretical analysis is validated through experimental results. Some of the main highlights include operating the inductor at twice the switching frequency, significantly reducing both the inductor's size and the input current ripple. Furthermore, the optimal battery current ripple occurs at a duty cycle close to 50%, where it is practically zero. The converter efficiency was analyzed in all power flow scenarios at various operating points, reaching up to 97.33%. Furthermore, a supplementary video showcasing its functionality is included with this manuscript.
Forecasting Gold Volatility in an Uncertain Environment: The Roles of Large and Small Shock Sizes
Authors: Zhang Li , Wang Lu , Ji Yu , Pan Zhigang 
Published: January 2025

ABSTRACTIn a complex and volatile macroeconomic environment, precious metals, which have the functions of preservation, appreciation, and hedging, play an important role in investment risk management. Therefore, this study adopts the extended GARCH‐MIDAS model to investigate the underlying connection between gold price volatility and different uncertain shocks. In this paper, we consider five uncertainty indicators and then decompose them into different states to capture their shock sizes. Next, we introduce uncertainty shocks into the MIDAS structure to test whether they contain relevant and valid information about gold price volatility forecasts. Specifically, parameter significance suggests a positive association between uncertain indicators and gold price volatility, but variability in the influence of their shock sizes on gold price volatility. Out‐of‐sample results present that the extended model that includes asymmetric shock sizes outperforms other competitive models. Besides, the model that includes large shock sizes exhibits better predictive performance than the model that includes small shocks. Finally, based on the empirical analyses, this paper provides new insights for the gold industry, futures exchanges, government regulators, and investors engaged in futures hedging to achieve risk control and financial stability in response to uncertain shocks.
Estimation of Constrained Factor Models for High‐Dimensional Time Series
Authors: Liu Yitian , Pan Jiazhu , Xia Qiang 
Published: January 2025

ABSTRACTThis article studies the estimation of the constrained factor models for high‐dimensional time series. The approach is based on the eigenanalysis of a nonnegative definite matrix constructed from the autocovariance matrices. The convergence rate of the estimator for loading matrix and the asymptotic normality of the estimated factor score are explored under regularity conditions set for the proposed model. Our estimation for the constrained factor models can achieve the optimal rate of convergence even in the case of weak factors. The finite sample performance of our approach is examined and compared with the existing methods by Monte Carlo simulations. Our methodology is illustrated and supported by a real data example.
Economic Conditions and Predictability of US Stock Returns Volatility: Local Factor Versus National Factor in a GARCH‐MIDAS Model
Authors: S alisu Afees A. , Liao Wenting , Gupta Rangan , Cepni Oguzhan 
Published: January 2025

ABSTRACTThe aim of this paper is to utilize the generalized autoregressive conditional heteroscedasticity–mixed data sampling (GARCH‐MIDAS) framework to predict the daily volatility of state‐level stock returns in the United States (US), based on the weekly metrics from the corresponding broad economic conditions indexes (ECIs). In light of the importance of a common factor in explaining a large proportion of the total variability in the state‐level economic conditions, we first apply a dynamic factor model with stochastic volatility (DFM‐SV) to filter out the national factor from the local components of weekly state‐level ECIs. We find that both the local and national factors of the ECI generally tend to affect state‐level volatility negatively. Furthermore, the GARCH‐MIDAS model, supplemented by these predictors, surpasses the benchmark GARCH‐MIDAS model with realized volatility (GARCH‐MIDAS‐RV) in a majority of states. Interestingly, the local factor often assumes a more influential role overall, compared with the national factor. Moreover, when the stochastic volatilities associated with the local and national factors are integrated into the GARCH‐MIDAS model, they outperform the GARCH‐MIDAS‐RV in over 80% of the states. Our findings have important implications for investors and policymakers.
Reduced White Matter Damage and Lower Neuroinflammatory Potential of Microglia and Macrophages in Hri/Eif2ak1−/− Mice After Contusive Spinal Cord Injury
Authors: Saraswat Ohri Sujata , Myers Scott A. , Rood Benjamin , Brown Brandon L. , Chilton Paula M. , Slomnicki Lukasz , Liu Yu , Wei George Z. , Andres Kariena R. , Mohan Divya , Howard Russell M. , Whittemore Scott R. , Hetman Michal 
Published: January 2025

ABSTRACTCellular stressors inhibit general protein synthesis while upregulating stress response transcripts and/or proteins. Phosphorylation of the translation factor eIF2α by one of the several stress‐activated kinases is a trigger for such signaling, known as the integrated stress response (ISR). The ISR regulates cell survival and function under stress. Here, germline knockout mice were used to determine contributions by three major ISR kinases, HRI/EIF2AK1, GCN2/EIF2AK4, and PKR//EIF2AK2, to pathogenesis of moderate contusive spinal cord injury (SCI) at the thoracic T9 level. One‐day post‐injury (dpi), reduced levels of peIF2α were found in Hri−/− and Gcn2−/−, but not in Pkr−/− mice. In addition, Hri−/− mice showed attenuated expression of the downstream ISR transcripts, Atf4 or Chop. Such differential effects of SCI‐activated ISR correlated with a strong or moderate enhancement of locomotor recovery in Hri−/− or Gcn2−/− mice, respectively. Hri−/− mice also showed reduced white matter loss, increased content of oligodendrocytes (OL) and attenuated neuroinflammation, including decreased lipid accumulation in microglia/macrophages. Cultured neonatal Hri−/− OLs showed lower ISR cytotoxicity. Moreover, cell autonomous reduction in neuroinflammatory potential was observed in microglia and bone marrow‐derived macrophages derived from Hri−/− mice. These data identify HRI as a major positive regulator of SCI‐associated secondary injury. In addition, targeting HRI may enable multimodal neuroprotection to enhance functional recovery after SCI.
Team Diversity as a Safety Asset: A Field Investigation of Language Diversity and Occupational Safety
Authors: Lacerenza Christina N. , Johnson Stefanie K. , Schwatka Natalie V. , Beldon Marissa A. , Dennerlein Jack T. 
Published: January 2025

ABSTRACTDespite significant progress in understanding how situational factors influence safety compliance, the effects of team diversity—particularly language diversity—on safety outcomes remain underexplored. This is particularly concerning given the prevalence of language diversity in teams operating in hazardous environments and the disparities in accident rates, injuries, and fatalities among workers from diverse linguistic and racial‐ethnic backgrounds. In this study, we examine how language diversity affects occupational safety, and therefore begin to resolve an unsettled deliberation of whether diversity is a detractor or catalyst of safety outcomes. Integrating social identity theory and work on leader member exchange differentiation, we develop and test a model hypothesizing that team language diversity is positively related to safety compliance and that this relationship can be explained by leaders' relationships with followers. Analysis of survey data from over 1,000 construction workers (162 teams) showed that our hypotheses were generally supported; that team language diversity was positively related to safety compliance. Further, we found that this relationship can be explained by the process of leader‐member exchange differentiation, but only when leaders also exhibit safety‐specific transformational leadership (SSTL). We discuss these results in detail and implications for scientists and human resource practitioners are presented.
How Does the Visibility of LGBTQ+ Directors Influence Firm Value? The Mediating Role of Environmental, Social, and Governance Performance
Authors: Federo Ryan , Aguilera Ruth V. 
Published: January 2025

ABSTRACTBoard directors who identify as lesbian, gay, bisexual, transgender, queer, and other identities (LGBTQ+) are now more visible at the corporate apex, as the attainment of diversity, equity, and inclusion at the upper echelons is a goal for many organizations, researchers, and policymakers worldwide. The visibility of LGBTQ+ directors implies the shift toward truly diverse boards that demonstrate commitment to the provision of equal career opportunities and empowerment for all types of individuals. However, we still lack knowledge regarding the relationship between LGBTQ+ board representation and firm outcomes. Drawing on upper echelons and signaling theories, we examine a sample of Fortune 500 companies to identify how LGBTQ+ directors influence their firm values. Our OLS regressions on an unbalanced panel dataset of 441 firms in 2021–2022 reveal that the visibility of LGBTQ+ directors is positively associated with enterprise value, and this relationship is mediated by environmental, social, and governance performance, which can be attributed to corporate social performance. Our research contributes to the literature by showing how the visibility of LGBTQ+ status in the boardroom can matter on firms.