bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neonatal outcomes during the COVID-19 pandemic in New York City
Authors: Richter Felix , Strasser Arielle S. , Suarez-Farinas Mayte , Zhao Shan , Nadkarni Girish N. , Jabs Ethylin Wang , Guttmann Katherine , Glicksberg Benjamin S. 
Published: December 2020

ABSTRACTWe explored rates of premature births and neonatal intensive care unit (NICU) admissions at the Mount Sinai Hospital after the implementation of COVID-19 lockdown measures (March 16, 2020) and phase one reopening (June 8, 2020), comparing them to those of the same time periods from 2012-2019. Mount Sinai Hospital is in New York City (NYC), an early epicenter of COVID-19 in the United States, which was heavily impacted by the pandemic during the study period. Among 43,963 singleton births, we observed no difference in either outcome after the implementation of lockdown measures when compared to the same trends in prior years (p=0.09-0.35). Of interest, we observed a statistically significant decrease in premature births after NYC phase one reopening compared to those of the same time period in 2012-2019 across all time windows (p=0.0028-0.049), and a statistically significant decrease in NICU admissions over the largest time window (2.75 months) compared to prior years (p=0.0011).
Changes in hospital prescribing activity at a specialist children’s hospital during the COVID-19 pandemic - an observational study
Authors: Vestesson Emma , Alonso Carlos , Booth John , Sebire Neil J , Steventon Adam , Tomlin Steve , Standing Joseph F 
Published: December 2020

AbstractObjectiveTo compare hospital activity, patient casemix and medication prescribing and administration before and during the COVID-19 emergency.DesignRetrospective observational studySettingA specialist children’s hospital in the UKPatientsInpatients aged 25 and younger treated at a specialist children’s hospital between 29 April 2019 and 6 September 2020ResultsThere were 21,471 day cases and inpatients treated during the 16 month study period. Day cases (no overnight stay) dropped by around 37% per week. Both admissions and discharges for inpatients (at least one overnight stay) decreased leading to a small reduction in hospital bed days but no reduction in hospital bed nights. The effect on hospital activity on different patient groups varied substantially with some groups such as medical oncology day cases increasing by 13%. As a result, the patient case mix in the hospital was very different during the pandemic. Overall weekly medication administrations decreased for day cases and inpatients, but weekly medication administrations per bed day increased by 10% for day cases and 6% for inpatients.ConclusionsDespite not being badly affected by the disease itself, specialist paediatric hospital services have been greatly affected by the pandemic. The average number of medications per inpatient bed day increased, likely reflecting changes to the patient population, with only those children with severe conditions being treated during the pandemic. These data demonstrate the complex pattern of implications on specialist services and provide evidence for planning the impact of future emergencies and resolution strategies.
The semi-leptonic form factors of $$\Lambda _{b}\rightarrow \Lambda _{c}$$ and $$\Xi _{b}\rightarrow \Xi _{c}$$ in QCD sum rules
Authors: Zhao Zhen-Xing , Li Run-Hui , Shen Yue-Long , Shi Yu-Ji , Yang Yan-Sheng 
Published: December 2020

AbstractIn this work, the full leading order results of the form factors for $$\Xi _{b}\rightarrow \Xi _{c}$$

Ξ
b

→

Ξ
c

and $$\Lambda _{b}\rightarrow \Lambda _{c}$$

Λ
b

→

Λ
c

are obtained in QCD sum rules. Contributions from up to dimension-5 have been considered. For completeness, we also study the two-point correlation function to obtain the pole residues of $$\Xi _{Q}$$

Ξ
Q

and $$\Lambda _{Q}$$

Λ
Q

, and higher accuracy is achieved. For the three-point correlation function, since stable Borel regions cannot be found, about $$20\%$$

20
%

uncertainties are introduced for the form factors of $$\Xi _{b}\rightarrow \Xi _{c}$$

Ξ
b

→

Ξ
c

and $$\Lambda _{b}\rightarrow \Lambda _{c}$$

Λ
b

→

Λ
c

. Our results for the form factors are consistent with those of the lattice QCD within errors.
The Effects of Non-Ideal, Lithiation-Based Active Material Volume Change on Mechano-Electrochemical Pouch Cell Simulation
Authors: Pereira Drew Joseph , Fernandez Miguel , Streng Kathryn Corine , Hou Xu Xian , Gao Jay , Garrick Taylor R. , Weidner John W. 
Published: December 2020

Automotive battery manufacturers are working to improve individual cell and overall pack design by increasing their performance, durability, and range, while reducing cost; and active material volume change is one of the more complex aspects that needs to be considered during this process. In the study presented here, thermodynamically non-ideal (non-linear), lithiation-based volume change behavior for the anode and cathode active materials were incorporated into a previously developed mechano-electrochemical model.(1-4) Before, an ideal (linear) relationship between active material volume change and state-of-lithiation was assumed.
Using the non-ideal active material volume change behavior, the changing thickness of an automotive relevant, large-format pouch cell was predicted while simulating cell discharge. Measurements were taken using an experimental setup capable of simultaneous mechanical and electrochemical operation and observation. Figure 1 shows that the mechano-electrochemical measurements prove to agree well with simulation when using non-ideal lithiation-based volume change as opposed to the previously assumed ideal volume change behavior.
The resulting model was used to simulate other mechano-electrochemical phenomena including the effects of anode/cathode capacity ratio and changing pressure/porosity during cell discharge. This mechano-electrochemical model shows promise to help define operational parameters to mitigate negative effects from active material volume change and may act as a tool for developers to reduce the extensive electrochemical and mechanical testing required for the design of promising new batteries.

References

T. R. Garrick, K. Higa, S.-L. Wu, Y. Dai, X. Huang, V. Srinivasan and J. W. Weidner, Journal of The Electrochemical Society, 164, E3592 (2017).

T. R. Garrick, X. Huang, V. Srinivasan and J. W. Weidner, Journal of The Electrochemical Society, 164, E3552 (2017).

T. R. Garrick, K. Kanneganti, X. Huang and J. W. Weidner, Journal of The Electrochemical Society, 161, E3297 (2014).

D. J. Pereira, J. W. Weidner and T. R. Garrick, Journal of The Electrochemical Society, 166, A1251 (2019).

D. J. Pereira, M. A. Fernandez, K. C. Streng, X. X. Hou, X. Gao, J. W. Weidner, and T. R. Garrick, Journal of The Electrochemical Society, 167, 080515 (2020).

Figure 1. Experimentally measured data and simulations using ideal and non-ideal active material volume change behavior for a NMC/LMO:Graphite pouch cell strain as a function of cell state-of-charge.

Figure 1
Modeling Capacity and Power Fade of Cylindrical NCA-Si Graphite Battery Cell in Electric Vehicles
Authors: Ko Jing Ying , Benavente Fabian Andres , Ekström Henrik , Lindbergh Göran 
Published: December 2020

The energy storage device in most electric vehicles today are lithium-ion batteries. Particularly, Tesla electric vehicles uses the lithium ion chemistry of nickel cobalt aluminum oxide (NCA) and graphite electrodes. Their aging and lifetime are critical issues that must be addressed for a successful large-scale commercialization of electrified vehicles. Therefore, the present work focus on the study of possible aging mechanisms that contribute to the capacity fade and impedance increase of NCA and Si-graphite battery cells in a modeling framework. The batteries are subjected to partial cycling at different state-of-charge (SOC) ranges to imitate different driving behaviors. By predicting the aging parameters from separated electrodes through model, it is possible to understand the responsible aging mechanisms in such applications.
The NCA/Si-graphite cylindrical cells were calendar-aged and cycle-aged between SOC of 20-50 %, 35-65 %, 60-90 % and 20-95 % until end of test (EOT) is reached. The cells electrochemical characterization methods include electrochemical impedance spectroscopy (EIS) at 100-cycle interval to measure the impedance behavior and slow cycle discharge to measure the capacity available.
We use two models in analyzing the aging behavior through fitting and validation with experimental data – time-based model for capacity fade and frequency-based model for impedance increase. They are physics-based Doyle-Fuller-Newman (DFN) model, which is based on porous electrode theory. The models account for (electrochemical) aging processes within the electrode. Specifically, the solid-electrolyte interface (SEI) build-up, surface and particle cracking; and electrolyte oxidation on the cathode particle interface. These lead to the loss of lithium inventory (LLI) and loss of active material (LAM), contributing to the capacity fade. The same aging mechanisms are represented in the impedance model in the form of charge transfer resistance, interfacial resistance and diffusion time constant. The challenge in modeling the full cell impedance is the superimposition of aging parameters of roughly the same time constants, making it quite hard for the deconvolution of anode and cathode aging. The deduced aging mechanisms from the modeling work are supported by experimental observation, e.g. scanning electron microscope (SEM). For example, micro-cracks and isolation of particles observed from SEM explain the high possibility of increase in LAM and structural change. Overall, modeling of the battery’s capacity and power fade can deepen our understanding of aging processes, allow lifetime prediction, or optimal battery design.
(Invited) Nanoarray Cathode Design for Durable Zn Batteries
Authors: Fan Hong Jin , Tan Hua , Wang Zhe 
Published: December 2020

Rechargeable aqueous zinc battery, as a novel promising candidate for grid-scale energy storage, has drawn tremendous attention recently. Our group has been actively working in design nanostructured electrode materials for metal-ion batteries (Na, K, Zn) and electrocatalysts for metal-air batteries. In this talk, I will present our latest results on cathode materials for both Zn-ion battery and Zn-air battery. Specifically, we developed layered ZnOV nanosheets that are directly grown on a 3D graphite current collector. Meanwhile, the anode is also 3D Zn nanosheet array obtained by electro-deposition. As for the Zn-air battery cathode, we employed 3D conductive MOF and Ni-based LDH hybrid materials on conductive carbon support as the electrode both for aqueous alkaline and all-solid-state Zn-battery. The whole material system has a high conductivity, sufficient active sites and low transition energy that render highly reversible redox reaction and inhibition of dendrite formation, as well as extremely soft feature so that it can be appropriate for the application of flexible devices. The all-solid-state Zn-based batteries using CMNC@CC and Zn@CC as the electrodes displays outstanding performance when compared with most of the aqueous oxy/hydroxy or pristine MOFs based energy storage devices.
We appreciate the financial support from Agency for Science, Technology, and Research (A*STAR) by AME Individual Research Grant (A1983c0026) and from Singapore MOE AcRF Tier 2 Grant (MOE2017-T2-1-073).
Data-Driven Discovery of New Materials for Solid-State Batteries
Authors: Mo Yifei 
Published: December 2020

All-solid-state Li-ion battery based on solid electrolytes is a promising next-generation battery technology with high energy density, intrinsic safety, long cycle life, and wide operational temperatures. However, the lack of solid electrolyte materials that satisfy multiple requirements, such as high ionic conductivity, good stability, and interfacial compatibility with the electrode, are impeding the development of this new battery technology. To resolve these materials challenges, we develop and leverage an array of data-driven computation techniques including machine learning to discover and design novel solid-state Li-ion conductors as solid electrolytes for all-solid-state batteries. The data-driven approach enables rapid searching over a large materials space of tens of thousands of materials with highly diverse structures and chemistries. Dozens of novel solid-state conductors are discovered through our data-driven materials search. Our data-driven analyses provide unique insights into the fundamental understanding about solid-state Li-ion conductors beyond traditional physical mechanistic studies. Our study demonstrates a new paradigm of using machine learning techniques for materials discovery that overcome the data-scarcity challenges.
Zhang et al., “Unsupervised Discovery of Solid-State Lithium Ion Conductors”, Nature Communications, 10, 5260 (2019) DOI: 10.1038/s41467-019-13214-1
He et al., “Crystal Structural Framework of Lithium Super-Ionic Conductors”, Advanced Energy Materials 9, 1902078 (2019) DOI: 10.1002/aenm.201902078
Nolan et al., “Computation-Accelerated Design of Materials and Interfaces for All-Solid-State Lithium-Ion Batteries”, Joule, 2, 2016-2046 (2018) DOI: 10.1016/j.joule.2018.08.017
Development of Multivalent Electrolytes with a Wide Electrochemical Window and Their Applications
Authors: Liao Chen , Yang Mengxi , Lau Ka-Cheong , Leon Noel , Kwon Bob Jin , Key Baris , Vaughey John T. , Ingram Brian J. 
Published: December 2020

Multivalent (MV) ion batteries have been under intense scrutiny because the modeling effort predicted that a high Mg2+ diffusion mobility in spinel cathodes and a higher specific energy density can be achieved. Recently new cathodes have been tested against Mg, with novel cathodes such as layered oxides MoO2.8F0.2,1 MgCr2-xVxO4,2 and conversion-type cathodes.3

Previously chloride containing electrolytes4 were dominant in multivalent ion batteries because of their facile deposition and high Coulombic efficiency towards the anode. However, the corrosion issue of Cl- limits their application. Here we report the development of chloride-free multivalent salts with a weakly coordinating anion that shows exceptional electrochemical properties. Moreover, the passivation-free properties of these anions make them efficient in assessing the Mg2+ mobility inside a solid solution electrode. Further development on other multivalent cations will also be demonstrated. Together with cathodes, these electrolyte developments would pave the way for a holistic approach towards high energy density multivalent batteries.
References

T. Incorvati, L. F. Wan, B. Key, D. Zhou, C. Liao, L. Fuoco, M. Holland, H. Wang, D. Prendergast, K. R. Poeppelmeier, Chemistry of Materials 2015, 28, 17-20.

J. Kwon, K.-C. Lau, H. Park, Y. A. Wu, K. L. Hawthorne, H. Li, S. Kim, I. L. Bolotin, T. T. Fister, P. Zapol, R. F. Klie, J. Cabana, C. Liao, S. H. Lapidus, B. Key, J. T. Vaughey, Chemistry of Materials 2019. DOI:10.1021/acs.chemmater.9b04206

Pan, J. Huang, Z. Feng, L. Zeng, M. He, L. Zhang, J. T. Vaughey, M. J. Bedzyk, P. Fenter, Z. Zhang, C. Liao, Advanced Energy Materials 2016, 6.

Pan, J. Huang, N. Sa, S. M. Brombosz, J. T. Vaughey, L. Zhang, A. K. Burrell, Z. Zhang, C. Liao, * Journal of The Electrochemical Society 2016, 163, A1672-A1677.

-C. Lau, T. J. Seguin, E. V. Carino, N. T. Hahn, J. G. Connell, B. J. Ingram, K. A. Persson, K. R. Zavadil, C. Liao, * J. Electrochem. Soc. 2019, 166, A1510-A1519.
A GaAs/Si X-Ray Pixel Detector Based on Low Temperature Covalent Wafer Bonding
Authors: Razek Nasser , Prieto Ivan , Neves Jorge , Le Corre Philippe , von Känel Hans 
Published: December 2020

Low temperature wafer bonding of silicon to various materials is a key technology for many applications requiring a low temperature budget, such as monolithic CMOS integrated pixel detectors, optoelectronic devices and high-speed electronics. We present a pixel detector comprising a gallium arsenide (GaAs) absorber wafer bonded to a CMOS readout wafer, both 8-inch in size. The 700 µm thick absorber wafer is semi-insulating (ρ = 5 × 108 Ωcm) whereas the CMOS readout wafer, thinned to 50 µm, has a resistivity of 1 kΩcm, as indicated in Fig. 1a). The oxide-free, covalent bonding process was performed at room temperature and under high vacuum.
The surface preparation combines wet etching of the native oxide on the wafer surfaces with the removal of the hydrogen passivation layer by a low-energy plasma prior to bonding. The infrared (Fig. 1b) and scanning acoustic images (Fig. 1c), 1d)) show that the bonded interface is of high quality (no outgassing, no visible voids). After thermal annealing at 200°C the bond strength proved to be sufficiently strong to permit post-bonding processing, including carrier wafer removal and dicing into individual detector chips.
These first prototype GaAs on Si X-ray detectors fabricated by our novel wafer bonding approach are going to be tested for X-ray imaging in the near future.

Figure 1
A Viologen-Based Anolyte with a Very Negative Redox Potential for Neutral Aqueous Redox Flow Batteries
Authors: Bahari Meisam , D. Watt Gerald , Harb John N. 
Published: December 2020

Redox flow batteries have been recognized as a promising option for energy-storage purposes, mitigating the intermittency of renewable sources of energy such as solar, wind, and hydroelectric power. In particular, aqueous redox flow batteries (ARFBs) are very attractive owing to high conductivity, relatively low cost, and safe nature of aqueous electrolytes. Performance of ARFBs can be further improved with developing new electroactive species. Viologens are a group of organic compounds with great tunability, making them appealing for flow battery applications. In this study, a viologen-based electroactive compound called MMV is proposed with the potential of improving performance of aqueous flow batteries.
The potential of MMV as an anolyte was investigated for developing a neutral aqueous flow battery. MMV required a simple synthesis procedure with inexpensive starting materials, resulting in a low cost. MMV showed solubility of almost 3 M that is relatively high compared to other organic electroactive compounds, such as quinones, especially in neutral electrolytes. The electrochemical reaction of MMV involved the transfer of one electron at fast kinetics. Additionally, MMV demonstrated a redox potential of -1.05 V vs. SCE that is one of the most negative redox potentials reported for organic electroactive species under neutral conditions. These characteristics indicated that MMV is a promising anolyte candidate. Such a very negative redox potential and high solubility provide MMV the potential to significantly improve performance of a flow battery in terms of capacity, energy density, and cell potential. Despite these interesting properties, MMV exhibited a poor cycling performance. MMV underwent irreversible reactions at elevated concentrations. Signs of dimerization and also precipitation were observed during cycling. The irreversible reactions led to a high capacity fade rate (2.1%/cycle). Approaches to improve the cycling performance include synthesizing MMV-derivatives that possess a higher charge compared to that of MMV to possibly limit the extent of both dimerization and precipitation.
(Invited) Intercalation-Type Cathode Materials for Nonaqueous Calcium-Ion Batteries
Authors: Hong Seung-Tae 
Published: December 2020

Calcium-ion batteries (CIBs) represent a promising alternative to the current lithium-ion batteries (LIBs). Calcium ions can transfer two electrons per ion. Thus, in principle, the capacity of a host material can double due to the divalency of calcium, provided the host material can release and accept the transferred electrons. The final battery product is expected to be cost-effective, owing to the earth-abundance of calcium reserves. The redox potential of calcium is close to that of lithium, enabling a high cell voltage. The larger ionic radius of calcium (1.0 Å) compared to those of other divalent ions (0.60–0.74 Å) could be a disadvantage because a narrow diffusion pathway sufficient for smaller ions will not allow the passage of larger Ca ions. However, the larger ionic radius ensures a lower effective intercalant-ion charge density, which can be rather advantageous for the diffusion in the host materials as well as in the electrolytes.
Recent discoveries of reversible plating or alloying of calcium provoked considerable interest in calcium-based rechargeable batteries. Theoretical calculations also predict that the energy barriers for Ca diffusion are lower than other multivalent ions in some structures, and the development of positive materials are anticipated. However, only a few cathode materials have been reported so far, only to exhibit low energy-storage capability and poor cyclability. In this talk, the synthesis, structural and electrochemical properties of new cathode materials for nonaqueous CIBs will be presented, which were recently developed in our group. Some examples include NASICON-type NaV2(PO4)3, FeV3O9∙1.2H2O, Ca0.13MoO3·(H2O)0.41. These stimulating discoveries will lead to the development of new strategies for obtaining high energy density CIBs.
(Invited) Atomic Layer Deposited Amorphous Igzo Semiconductor with Vertical Composition Engineering for High Mobility Field Effect Transistor
Authors: Sheng Jiazhen , Hong Tae-Hyun , Jeong Hyun-Jun , Park Jin-Seong 
Published: December 2020

Amorphous oxide semiconductors have been widely studied for the potential use in flat-panel displays such as active matrix liquid crystal display (LCD) and Organic light emitting didoes (OLEDs). Since reporting amorphous InGaZnO semiconductor thin film transistor (TFT) in 2003 & 2004, many multi-component oxide semiconductors have been intensively investigated and developed by physical vapor deposition (PVD) method. Very recently, the sputtered InGaZnO TFTs are already adopted in mass-production to fabricate AMOLED TVs. Also, semiconductor industries have looked at metal oxide semiconductor thin films as an alternative Si channel layer because this semiconductor exhibited extremely low-off current level (below 10-18A/um). It is the unique property to decrease power consumption for various semiconductor devices. However, there remain several problems such as enhancing field effect mobility, composition uniformity, bias-temperature stability, and p-type oxide semiconductor in order to go further for the future device applications.
In this talk, I will introduce various oxide semiconductor materials with atomic layer deposition (ALD) methods. Unlike PVD, ALD method has unique properties, including controlling atomic-level-thickness, manipulating atomic-level-composition control, and depositing impurity-free & uniform films. The key materials such In2O3, ZnO, SnO2, and Ga2O3 will be summarized and then I will show the combinatorial research works in terms of amorphous InGaZnO semiconductor thin film transistors. Generally, electrical properties of amorphous oxide semiconductors are strongly dependent on each element composition. The indium (In) rich InGaZnO exhibited a high mobility of 50cm2/V.sec. However, the In-rich InGaZnO TFTs have the demerit of negative threshold voltage owing to intrinsically high carrier density. I will present that In-rich IGZO TFTs with vertical stacked InOx, ZnOx and GaOx atomic layers show excellent performances such as saturation mobility of ~ 74cm cm2/V.sec, threshold voltage of -1.3V, on/off ratio of 8.9 × 108, subthreshold swing of 0.26V/decade, and hysteresis of 0.2V, while keeping a reasonable carrier density of ~1017 cm-3. Flexible ALD InGaZnO TFTs on polymer substrates were also discussed depending on gate insulator materials, in terms of device performances. ALD technique will be a very promising candidate to improve oxide semiconductor materials as well as various device applications (Display & Semiconductor Industry) because it has not only unique nano-growth mechanism but also ultimate uniform property.