bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bismuth-based halide perovskite and perovskite-inspired light absorbing materials for photovoltaics
Authors: Ünlü Feray , Deo Meenal , Mathur Sanjay , Kirchartz Thomas , Kulkarni Ashish 
Published: October 2021

AbstractThe efficiency of organic-inorganic hybrid lead halide perovskite solar cells (PSCs) has increased over 25% within a frame of ten years, which is phenomenal and indicative of the promising potential of perovskite materials in impacting the next generation solar cells. Despite high technology readiness of PSCs, the presence of lead has raised concerns about the adverse effect of lead on human health and the environment that may slow down or inhibit the commercialization of PSCs. Thus, there is a dire need to identify materials with lower toxicity profile and comparable optoelectronic properties in regard to lead-halide perovskites. In comparison to tin-, germanium-, and copper-based PSCs, which suffer from stability issues under ambient operation, bismuth-based perovskite and perovskite-inspired materials have gained attention because of their enhanced stability in ambient atmospheric conditions. In this topical review, we initially discuss the background of lead and various lead-free perovskite materials and further discuss the fundamental aspects of various bismuth-based perovskite and perovskite-inspired materials having a chemical formula of A3Bi2X9, A2B′BiX6, B′aBibXa+3b(A = Cs+, MA+and bulky organic ligands; B′ = Ag+, Cu+; X = I−, Cl−, Br−) and bismuth triiodide (BiI3) semiconducting material particularly focusing on their structure, optoelectronic properties and the influence of compositional variation on the photovoltaic device performance and stability
Quantum shape oscillations in the thermodynamic properties of confined electrons in core–shell nanostructures
Authors: Aydin Alhun , Fransson Jonas , Sisman Altug 
Published: October 2021

Abstract
Quantum shape effect appears under the size-invariant shape transformations of strongly confined structures. Such a transformation distinctively influences the thermodynamic properties of confined particles. Due to their characteristic geometry, core–shell nanostructures are good candidates for quantum shape effects to be observed. Here we investigate the thermodynamic properties of non-interacting degenerate electrons confined in core–shell nanowires consisting of an insulating core and a GaAs semiconducting shell. We derive the expressions of shape-dependent thermodynamic quantities and show the existence of a new type of quantum oscillations due to shape dependence, in chemical potential, internal energy, entropy and specific heat of confined electrons. We provide physical understanding of our results by invoking the quantum boundary layer concept and evaluating the distributions of quantized energy levels on Fermi function and in state space. Besides the density, temperature and size, the shape per se also becomes a control parameter on the Fermi energy of confined electrons, which provides a new mechanism for fine tuning the Fermi level and changing the polarity of semiconductors.
Non-contact, automated adjustment procedure for capacitive displacement sensors
Authors: Daul Lars , Tao Jin , Busch Ingo , Koenders Ludger , Meeß Rudolf , Wolff Helmut 
Published: October 2021

Abstract
Capacitive sensors enable non-contact displacement measurements in the micrometer range with sub-nanometer resolution. To achieve this, a proper alignment of capacitive sensors is necessary. In this work, a non-contact, automated and intrinsic adjustment procedure is presented which is based on determining the extrema of slope error and nonlinearity. After the final adjustment step, the remaining tilt is less than 1.5 mrad. A measurement routine is used to evaluate the adjustment procedure by applying tilt around the final adjustment position and measuring the global slope error and the global nonlinearity. The combination of adjustment procedure and measurement routine enables the investigation of capacitive displacement sensors with higher accuracy in order to establish a comprehensive uncertainty budget and to explore improvements in capacitive sensor technology.
Transition metal nitrides and their mixed crystals for spintronics
Authors: Ito Keita , Honda Syuta , Suemasu Takashi 
Published: October 2021

Abstract
Anti-perovskite transition metal nitrides exhibit a variety of magnetic properties—such as ferromagnetic, ferrimagnetic, and paramagnetic—depending on the 3d transition metal. Fe4N and Co4N are ferromagnetic at room temperature (RT), and the minority spins play a dominant role in the electrical transport properties. However, Mn4N is ferrimagnetic at RT and exhibits a perpendicular magnetic anisotropy caused by tensile strain. Around the magnetic compensation in Mn4N induced by impurity doping, researchers have demonstrated ultrafast current-induced domain wall motion reaching 3000 m s−1 at RT, making switching energies lower and switching speed higher compared with Mn4N. In this review article, we start with individual magnetic nitrides—such as Fe4N, Co4N, Ni4N, and Mn4N; describe the nitrides’ features; and then discuss compounds such as Fe4−x
A
x
N (A = Co, Ni, and Mn) and Mn4−x
B
x
N (B = Ni, Co, and Fe) to evaluate nitride properties from the standpoint of spintronics applications. We pay particular attention to preferential sites of A and B atoms in these compounds, based on x-ray absorption spectroscopy and x-ray magnetic circular dichroism.
Surprisingly good thermoelectric performance of monolayer C3N
Authors: Jiao W Y , Hu R , Han S H , Luo Y F , Yuan H M , Li M K , Liu H J 
Published: October 2021

Abstract
The rapid emergence of graphene has attracted numerous efforts to explore other two-dimensional materials. Here, we combine first-principles calculations and Boltzmann theory to investigate the structural, electronic, and thermoelectric transport properties of monolayer C3N, which exhibits a honeycomb structure very similar to graphene. It is found that the system is both dynamically and thermally stable even at high temperature. Unlike graphene, the monolayer has an indirect band gap of 0.38 eV and much lower lattice thermal conductivity. Moreover, the system exhibits obviously larger electrical conductivity and Seebeck coefficients for the hole carriers. Consequently, the ZT value of p-type C3N can reach 1.4 at 1200 K when a constant relaxation time is predicted by the simple deformation potential theory. However, such a larger ZT is reduced to 0.6 if we fully consider the electron–phonon coupling. Even so, the thermoelectric performance of monolayer C3N is still significantly enhanced compared with that of graphene, and is surprisingly good for low-dimensional thermoelectric materials consisting of very light elements.
Spectral analysis of heart sounds associated with coronary artery disease
Authors: Larsen Bjarke Skogstad , Winther Simon , Nissen Louise , Diederichsen Axel , Bøttcher Morten , Jan Struijk Johannes , Christensen Mads Græsbøll , Schmidt Samuel Emil 
Published: October 2021

Abstract

Objective. The aim of this study was to find spectral differences of diagnostic interest in heart sound recordings of patients with coronary artery disease (CAD) and healthy subjects. Approach. Heart sound recordings from three studies were pooled, and patients with clear diagnostic outcomes (positive: CAD and negative: Non-CAD) were selected for further analysis. Recordings from 1146 patients (191 CAD and 955 Non-CAD) were analyzed for spectral differences between the two groups using Welch’s spectral density estimate. Frequency spectra were estimated for systole and diastole segments, and time-frequency spectra were estimated for first (S1) and second (S2) heart sound segments. An ANCOVA model with terms for diagnosis, age, gender, and body mass index was used to evaluate statistical significance of the diagnosis term for each time-frequency component. Main results. Diastole and systole segments of CAD patients showed increased energy at frequencies 20–120 Hz; furthermore, this difference was statistically significant for the diastole. CAD patients showed decreased energy for the mid-S1 and mid-S2 segments and conversely increased energy before and after the valve sounds. Both S1 and S2 segments showed regions of statistically significant difference in the time-frequency spectra. Significance. Results from analysis of the diastole support findings of increased low-frequency energy from previous studies. Time-frequency components of S1 and S2 sounds showed that these two segments likely contain heretofore untapped information for risk assessment of CAD using phonocardiography; this should be considered in future works. Further development of features that build on these findings could lead to improved acoustic detection of CAD.
Enhancing the directivity of a radiating array element for an optical true-time-delay network
Authors: Zarezadeh Esmail , Ghorbani Ayaz 
Published: October 2021

Abstract
The directivity of a horn antenna as a true-time-delay array element of an optical beam-forming network is enhanced by using a graded index dielectric lens. The proposed refractive index distribution of the lens is designed to mitigate the phase error at the antenna aperture while keeping the antenna reflectionless. Ray-tracing-based optimization is carried out to achieve the best design parameters and modify the horn’s body. Realization of the lens is also demonstrated by discretizing the refractive index of the lens into several layers. The half-power beamwidth value of an example horn antenna is divided by four using the proposed lens. The functionality of the proposed lens is verified by conducting ray-tracing and full-wave simulations using COMSOL.
3D mapping in optical trapping of polystyrene particles applying the Gerchberg–Saxton modified with 2D Legendre polynomials
Authors: Arriaga Hernández J A , Cuevas Otahola B , Oliveros Oliveros J , Morín Castillo M 
Published: October 2021

Abstract
We are focused on the phase retrieval and 3D profiles of microparticles (MP), analyzed in optical trapping. To this aim, we use several image segmentation procedures of MP from an optical trapping video. Moreover, we implement different procedures to remove several errors in the segmented image by means of algorithms based on the Legendre polynomials to enhance the MP image quality, as well as the errors caused by the drift inducing a shift in the MP (considering different MP with drift by shift, static, trapped and untrapped). Once the image corrections are conducted considering these errors, we propose some processes to recover the irradiance distribution of the MP in the image, from which it is possible to retrieve the MP phase to show their 3D profiles as 3D objects. Finally, we analyze the image in gray tones and use different retrieval methods with 2D Legendre polynomials, Gerchberg–Saxton (GS), Goldstein, and Quality Guided. We propose some modifications to such algorithms using Legendre polynomials, resulting in the deformation re-scaling iterative algorithm, ModI-LP, and a modified GS using the 2D-LP code to optimize our results.
Study on the effect of tin and antimony oxide interlayer on the performance of titanium-based manganese dioxide anode
Authors: Du Bo-Yan , Wang San-Fan , Yu Sheng-San 
Published: October 2021

AbstractTin-antimony interlayer and manganese dioxide active catalytic coating were prepared on titanium plate by coating and thermal decomposition. The load of interlayer and calcination temperature were selected as the influencing factors for univariate experiment. The seen morphology of the electrode was explored by SEM. The electrocatalytic performance and oxygen evolution mechanism were analyzed by testing the cyclic voltammetry curve, oxygen evolution polarization curve and AC impedance graph, the optimal preparation conditions of the Ti-Mno2anode interlayer were obtained.
Crystal structure, Curie temperature, and electromagnetic absorption properties in FexCo30Ni60−xSi5Al5 (x = 30, 35, 40, 45) high entropy alloys
Authors: Zhang Chen , Yuan Jianhui , Wang Xin , Zheng Guangzhi 
Published: October 2021

Abstract
In order to meet the requirements of future national defense for high temperature electromagnetic (EM) absorbing performance, a series of FexCo30Ni60−xSi5Al5 (x = 30, 35, 40, 45) high-entropy alloys (HEAs) powders was prepared and their Curie temperatures (TC) were measured by a self-made Wheatstone bridge. According to the results, varying the Fe/Ni ratio affected the crystal structure, Curie temperature, oxidation resistance, and electromagnetic absorbing properties of the above compounds. Since Fe has a BCC structure and is thus easier to form the solid solutions with Si and Al, the crystal structure of the alloy has changed from FCC toward BCC with increasing Fe dopant content. In turn, the Curie temperature (TC) decreased from 473.68 °C to 358.07 °C, being lower than their initial oxidation temperature (>800 °C). The reflection losses (RL) of powders at room temperature and high temperatures (≤500 °C) were calculated as well. It was found that the flake powders after ball milling gained a larger aspect ratio, resulting in the better absorption effect, which was due to high toughness and low strength characteristics of the initial FCC structure. Furthermore, the permittivity and permeability of alloys upon heating reached impedance matching at a certain temperature, thus achieving the greater RLmax value. Finally, the high-temperature EM absorption characteristics of HEAs were shown to merit a thorough study.
Deep learning-based thoracic CBCT correction with histogram matching
Authors: Qiu Richard L J , Lei Yang , Shelton Joseph , Higgins Kristin , Bradley Jeffrey D , Curran Walter J , Liu Tian , Kesarwala Aparna H , Yang Xiaofeng 
Published: October 2021

Abstract
Kilovoltage cone-beam computed tomography (CBCT)-based image-guided radiation therapy (IGRT) is used for daily delivery of radiation therapy, especially for stereotactic body radiation therapy (SBRT), which imposes particularly high demands for setup accuracy. The clinical applications of CBCTs are constrained, however, by poor soft tissue contrast, image artifacts, and instability of Hounsfield unit (HU) values. Here, we propose a new deep learning-based method to generate synthetic CTs (sCT) from thoracic CBCTs. A deep-learning model which integrates histogram matching (HM) into a cycle-consistent adversarial network (Cycle-GAN) framework, called HM-Cycle-GAN, was trained to learn mapping between thoracic CBCTs and paired planning CTs. Perceptual supervision was adopted to minimize blurring of tissue interfaces. An informative maximizing loss was calculated by feeding CBCT into the HM-Cycle-GAN to evaluate the image histogram matching between the planning CTs and the sCTs. The proposed algorithm was evaluated using data from 20 SBRT patients who each received 5 fractions and therefore 5 thoracic CBCTs. To reduce the effect of anatomy mismatch, original CBCT images were pre-processed via deformable image registrations with the planning CT before being used in model training and result assessment. We used planning CTs as ground truth for the derived sCTs from the correspondent co-registered CBCTs. The mean absolute error (MAE), peak signal-to-noise ratio (PSNR), and normalized cross-correlation (NCC) indices were adapted as evaluation metrics of the proposed algorithm. Assessments were done using Cycle-GAN as the benchmark. The average MAE, PSNR, and NCC of the sCTs generated by our method were 66.2 HU, 30.3 dB, and 0.95, respectively, over all CBCT fractions. Superior image quality and reduced noise and artifact severity were seen using the proposed method compared to the results from the standard Cycle-GAN method. Our method could therefore improve the accuracy of IGRT and corrected CBCTs could help improve online adaptive RT by offering better contouring accuracy and dose calculation.
70 Availability of Personal Protective Equipment in NHS Hospitals During COVID-19: A National Survey
Authors: Mantelakis A , Spiers H , Lee C W , Chambers A , Joshi A 
Published: October 2021

Abstract

Introduction
The continuous supply of personal protective equipment (PPE) in the National Health Service (NHS) is paramount in order to sustain a safe level of staffing and to reduce transmission of COVID-19 to patients, public and staff.

Method
A 16-question survey was created to assess the availability and personal thoughts of healthcare professionals regarding PPE supply in England. The survey was distributed via social media (Facebook © and Twitter ©) to all UK COVID-19 healthcare professional groups, with responses collected over 3 weeks in March 2020 during the beginning of the pandemic.

Results
A total of 121 responses from physicians in 35 different hospitals were collected (105 inpatient wards, 16 from intensive care units). In inpatient wards, eye and face protection were unavailable to 19.1% of respondents. Masks were available to 97.7% of respondents and gloves in all respondents (100%). Body protection was available primarily as a plastic apron (83.8%). All of respondents working in intensive care had access to full-body PPE, except FFP3 respirator masks (available in 87.5%). PPE is ‘Always’ available for 29.8% of all respondents, and ‘Never’ or ‘Almost Never’ in 11.6%. There was a statistically significant difference between London and non-London responders that ‘Always’ had PPE available (43.9% versus 19.0%, p = 0.003).

Conclusions
This is the first survey to evaluate PPE supply in England during the COVID-19 pandemic. Our survey demonstrated an overall lack of PPE volume supply in the UK, with preferential distribution in London. Eye and full body protection are in most lack of supply.
118 Trauma in COVID-19: A comparison analysis of trauma calls at a Major Trauma Centre in the UK during the CoVID pandemic restrictions
Authors: Naseem S , Lee J 
Published: October 2021

Abstract

Aim
Varying restrictions placed on the UK public to manage the COVID-19 Pandemic impacted on the day-to-day lives of most people and changed the presentation and nature of trauma presenting at our UK Major Trauma Centre. Trauma activity during the November and March 2020 lockdown periods were compared and the changes in trauma activity were used to inform workforce planning. During the most restrictive period, March 2020, trauma activity initially decreased compared with 6 weeks preceding lockdown, before returning and then exceeding beyond pre-lockdown levels.

Method
Prospective data was collected for all ED trauma calls and regional referrals to the Major Trauma Service. We compared the initial 27-day lockdown periods in November to March 2020; specifically comparing trends in code red calls, silver trauma, road traffic collisions and injuries resulting from deliberate self-harm.

Results
There were a similar number of RTCs (18 vs 16) in both periods. There was a 28% increase in the number of trauma calls (103 vs 80), and a 4-fold increase in Code RED calls (8 vs 2) and injuries due to deliberate self-harm (8 vs 2). There were almost double the number of silver trauma patients. Interestingly, there was a 30% decrease in alcohol related trauma alerts.

Conclusions
Our results reflected the level of restrictions in place; a higher incidence of trauma calls including code reds and RTCs in November. The higher incidence of self-harm noticed in the second lockdown may reflect the psychological impact of the pandemic and change in restrictions over time.
165 Impact of COVID-19 on management of Foreign Bodies in Otolaryngology
Authors: Mahmood S , Mair M , Hussain M , Conboy P 
Published: October 2021

Abstract

Aim
The primary aim was to assess safety of Ear, nose and throat foreign body extraction during the coronavirus pandemic as this procedure is considered a potential aerosol generating procedure. The secondary aim was to evaluate the potential risks to patients if foreign body removal was delayed.

Method
A prospective study of 50 patients presenting to our unit with foreign bodies between March 2020 and August 2020 during the COVID-19 pandemic was performed. All patients were seen within 1 week of referral. The sites and types of foreign bodies were studied and correlated with complications where present. We assessed the circumstances under which foreign body removal was performed and its effect on health care professionals.

Results
The most common age group was the paediatric age group (52%). The most frequent sites of foreign bodies were the Ears at 78%(39 patients), followed by the nose at 12% (26 patients). Non-organic foreign bodies (52%) were more prevalent than organic foreign bodies (48%). Removal was performed in 31 (62%) patients either in clinic or in theatre. However, 19 patients (38%) were managed conservatively adhering to the British Association for Paediatric Otolaryngology guidance. Only 2 patients developed complications secondary to retained non-organic aural foreign bodies. None of the patients with organic foreign bodies developed complications. No infection rates among medical staff managing these patients were identified.

Conclusions
Contrary to normal practice, it is safe to manage selective ENT foreign bodies in a semi-urgent manner allowing time to implement ample precautions to reduce infection risks.
217 Covid-19 And Femoral Neck Fracture: A Retrospective Review
Authors: Morris R , Elbadri Z , Patel V , Azam A 
Published: October 2021

Abstract

Aim
Covid-19 has dominated healthcare over the past year. It most severely affects the elderly, a population whom also commonly present following falls, sustaining femoral neck fractures. Our aim was to retrospectively evaluate the effects of concomitant covid-19 infection in patients presenting acutely with femoral neck fractures.

Method
We conducted a retrospective review of all patients with femoral neck fractures during the ‘first wave’ of the coronavirus pandemic in Ysbyty Gwynedd (Bangor, UK), between April 2020 to June 2020. We noted each patient’s covid-19 status within 14 days of presentation with their acute femoral neck fracture and compared length of stay, discharge destination and mortality rate between covid and non-covid groups.

Results
There was a total of 75 femoral neck fractures in the 3-month period studied. 4 patients had incomplete data and were excluded from analysis. Of the remaining 71 patients, 15 (21%) were covid-positive within 14 days of admission, 47 patients (66%) were confirmed covid-negative and 9 patients (13%) received no coronavirus testing. The average age of patients was 88 in the covid-positive group and 84 in the covid-negative group. Those who developed covid-19 infection had an increased length of hospital stay (33 days covid-positive versus 14 days covid-negative; p = 0.25) and significantly increased in-hospital mortality rate (47% covid-positive versus 6% covid-negative; p = 0.001).

Conclusions
These results show that concomitant infection with covid-19 shortly after femoral neck fracture is associated with a significant increase in hospital mortality. They highlight the importance of trying to prevent covid-19 infection in this patient group.