bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Space Protection and Renewal of Historic City Wall Landscape Belt in Modern City
Authors: Liu Qiming , Wang Yingqi
Published: March 2023

Historical blocks play a very important role in the inheritance of a city’s context. The ancient city wall has always been a witness of the history and culture of various countries and nationalities, but it still stands despite the weather. For China, after the devastating destruction of the city demolition movement in the last century, there are not many relatively complete ancient city walls left. Ancient city walls played a military role in protecting towns in ancient times. In today’s world, ancient buildings bring people more spiritual culture and symbolic culture. It is more important to combine the development of historical blocks with modern cities. The significance of this combination to our contemporary social culture and social development is worth studying.

Taking the design of “Suocheng” ancient town in Yantai City, Shandong Province as an example, this paper analyzes the existing situation, the structure of the ancient city wall and the surrounding environment of the ancient town by means of on-the-spot investigation and literature research. Without destroying its essential spirit, it gives the meaning of the new era, digs more possibilities and functions, forms a complete spatial combination with landscape design, makes full use of new materials, combines new forms with ancient building forms, and makes efforts to repair the old, protect and protect it.
Research on symbiosis of man, ecology and industry based on catalyst theory
Authors: Wang Xiaoshi , Feng Yaru
Published: March 2023

Tianjin’s industrial heritage has witnessed the development of China’s modern industry and carries the city’s memory. Focusing on the symbiosis of man, ecology and industry, we analyze the current situation of industrial heritage protection in Tianjin and apply the catalyst theory to the conservation and renewal of industrial heritage. Taking the Tianjin Steel Mill and Tianjin Medium Plate Mill in Tianjin as an example, based on the results of the questionnaire and the catalyst properties of the site, a research framework of industrial heritage based on catalyst theory is constructed according to the characteristics of the site. We focus on how to guide the catalytic effect to make the industrial symbiosis with ecology and man, and finally achieve the sustainable development of itself and the area. The research on the symbiosis model of man, ecology and industry of industrial heritage based on catalyst theory is actively explored.
Study on the evolution process of drying-wetting cycle cracks in compacted loess based on DIC technology
Authors: Hu Changming , Hu Tingting , Yuan Yili , Wang Fangfang , Tian Minghui , Hou Xuhui
Published: March 2023

Loess cracks and expands easily under the condition of drying-wetting cycles, which will seriously affect the mechanical properties of loess in geotechnical engineering applications and lead to a large number of engineering accidents. Taking the loess in Yan ’an area as the research object, the drying-wetting cycles crack experimental of compacted loess was carried out by a self-made device. The surface crack of loess samples was quantitatively analyzed by using the PCAS system, and the relationship between the surface displacement, strain, and crack evolution during the drying-wetting cycles was analyzed by the digital correlation method (DIC). The results show that loess surface crack development can be divided into three stages: slow growth stage, rapid growth stage, and sluggish development stage. The displacement and strain distribution of loess surfaces are different at different positions, and the development degree of surface cracks varies with the number of drying-wetting cycles. DIC technology can be used for rapid and nondestructive detection of the displacement field and strain field on the surface of loess samples, and dynamic display of the temporal and spatial evolution characteristics of the generation and evolution of loess cracks.
Construction technology on dismantlement and reconstruction of point supported glass curtain wall for airport terminal building
Authors: Li Jian , Hong Jian , Liu Shiyao , Zhou Yuzai , Wang Guangbo , Xu Chengxiang
Published: March 2023

Based on the corridor channel curtain wall reconstruction project at Wuhan Tianhe airport T2-T3 terminal building, the structural system of point supported glass curtain wall with cable structure 18 years ago was analyzed, the technical difficulties of curtain wall glass panel removal and bearing cable removal were studied, and technical measures for the dismantlement and reconstruction of point supported glass curtain wall with cable structure were reasonably proposed. During the construction process of the dismantlement and reconstruction, the curtain wall structure was dynamically monitored, the deformation of the monitoring points were small, and the construction process was in a safe state. Due to the success in the dismantlement and reconstruction control technology of the point supported glass curtain wall with cable structure in this project, it not only ensured the construction safety, but also improved the construction quality, which could provide a reference for other similar projects.
Evaluation of green transportation development based on pressure-state-response model
Authors: Wang Wei , Meng Weiwei , Yuan Guozhu
Published: March 2023

In order to promote the green and low-carbon development of transportation in China and provide scientific guidance for green transportation construction, this paper adopts the pressure-state-response theory to construct a PSR model applicable to the development of urban green transportation system, and uses the statistical data of Tianjin, China, and assigns weights to each index with the help of entropy value method, which reasonably and accurately reflects the importance of evaluation indexes. And provides some suggestions for Tianjin transportation development.
Research on the risk of Metro PPP projects based on DEMATEL-ANP
Authors: Wu Ping , Liu Xiaoyan , Wang Hongxiao
Published: March 2023

The risk of metro PPP project has the characteristics of complexity and diversity, and the introduction of social capital in the project further aggravates the complexity of metro PPP project. Based on the particularity of metro PPP projects, this paper identifies 27 indicators suitable for the risk research of such projects; the internal relationship between risk indicators is established by using Decision Making Trial and Evaluation Laboratory (DEMATEL), the weight of risk indicators is determined by using analytic network process (ANP), and a risk research model based on ANP is proposed; the risk of metro PPP project is realized according to typical case. The results show that policy is the indicator with both the highest centrality and influence, while geological conditions is the indicator with the highest causality, and the most easily affected factor is construction cost; construction cost and project overdue are the most important indicators among the 27 indicators.
Nonpharmacological Methods to Reduce Pain During Active Labor in A Real-life Setting
Authors: Silva Clarissa Bernardes de Oliveira , Rodrigues Karine Mendonça Davi , Zoldan Camila , Nomura Roseli Mieko Yamamoto , Araujo Júnior Edward , Peixoto Alberto Borges
Published: March 2023

Objective To evaluate the association between pain intensity in the active phase of the first stage of labor with the use or not of nonpharmacological methods for pain relief in a real-life scenario.

Methods This was an observational cross-sectional study. The variables analyzed were obtained by a questionnaire with the mothers (up to 48 hours postpartum) to investigate the intensity of pain during labor using the visual analog scale (VAS). The nonpharmacological pain relief methods routinely used in obstetric practice were evaluated by consulting medical records. The patients were separated into two groups: Group I – patients who did not use nonpharmacological methods for pain relief and Group II –patients who used these methods.

Results A total of 439 women who underwent vaginal delivery were included; 386 (87.9%) used at least 1 nonpharmacological method and 53 (12.1%) did not. The women who did not use nonpharmacological methods had significantly lower gestational age (37.2 versus 39.6 weeks, p < 0.001) and shorter duration of labor (24 versus 114 min, p < 0.001) than those who used the methods. There was no statistically significant difference in the pain scale score using the VAS between the group that used nonpharmacological methods and the group that did not (median 10 [minimum 2–maximum 10] versus 10 [minimum 6–maximum 10] p = 0.334).

Conclusion In a real-life setting, there was no difference in labor pain intensity between the patients who used nonpharmacological methods and those who did not use them during the active phase of labor.
Maternal Near Miss in Patients with Systemic Lupus Erythematosus
Authors: Silva Arlley Cleverson Belo da , Sun Sue Yazaki , Campanharo Felipe Favorette , Morooka Letícia Tiemi , Cecatti José Guilherme , Mattar Rosiane
Published: March 2023

Objective Systemic lupus erythematosus (SLE) may cause irreversible organ damage. Pregnancy with SLE may have severe life-threatening risks. The present study aimed to determine the prevalence of severe maternal morbidity (SMM) in patients with SLE and analyze the parameters that contributed to cases of greater severity.

Methods This is a cross-sectional retrospective study from analysis of data retrieved from medical records of pregnant women with SLE treated at a University Hospital in Brazil. The pregnant women were divided in a control group without complications, a group with potentially life-threatening conditions (PLTC), and a group with maternal near miss (MNM).

Results The maternal near miss rate was 112.9 per 1,000 live births. The majority of PLTC (83.9%) and MNM (92.9%) cases had preterm deliveries with statistically significant increased risk compared with the control group (p = 0.0042; odds ratio [OR]: 12.05; 95% confidence interval [CI]: 1.5–96.6 for the MNM group and p = 0.0001; OR: 4.84; 95%CI: 2.2–10.8 for the PLTC group). Severe maternal morbidity increases the risk of longer hospitalization (p < 0.0001; OR: 18.8; 95%CI: 7.0–50.6 and p < 0.0001; OR: 158.17; 95%CI: 17.6–1424,2 for the PLTC and MNM groups, respectively), newborns with low birthweight (p = 0.0006; OR: 3.67; 95%CI: 1.7–7.9 and p = 0.0009; OR: 17.68; 95%CI: 2–153.6) for the PLTC and MNM groups, respectively] as well as renal diseases (PLTC [8.9%; 33/56; p = 0.0069] and MNM [78.6%; 11/14; p = 0.0026]). Maternal near miss cases presented increased risk for neonatal death (p = 0.0128; OR: 38.4; 95%CI: 3.3–440.3]), and stillbirth and miscarriage (p = 0.0011; OR: 7.68; 95%CI: 2.2–26.3]).

Conclusion Systemic lupus erythematosus was significantly associated with severe maternal morbidity, longer hospitalizations, and increased risk of poor obstetric and neonatal outcomes.
Imaging Recommendations for Diagnosis, Staging, and Management of Small Bowel and Colorectal Malignancies
Authors: Bansal Abhinav , Baheti Akshay D , Goyal Ankur , Chandramohan Anuradha , Eapen Anu , Gupta Pankaj , Sen Saugata , Ankathi Suman K , Agarwal Archi , Saklani Avanish , Mittal Rohin , Parshad Rajinder , Sharma Raju
Published: March 2023

Small bowel malignancies are rare, though colorectal cancers are common. This article reviews the current imaging recommendations for small bowel and colorectal malignancies. Contrast-enhanced computed tomography (CT) is the imaging modality of choice for diagnosis/staging/response evaluation/follow-up of the small bowel and colonic tumors. Magnetic resonance imaging of the pelvis with high-resolution T2-weighted images in sagittal, oblique axial, and coronal planes is the imaging modality of choice for staging/response evaluation of anorectal tumors. CT colonography may be utilized as a tumor screening modality, alternative to colonoscopy.
Imaging Recommendations for Diagnosis, Staging, and Management of Cervical Cancer
Authors: Popat Palak Bhavesh , Maheshwari Amita , Manchanda Smita , Renganathan Rupa , Sen Saugata , Dhamija Ekta , Thakur Meenakshi , Deodhar Kedar , Chopra Supriya , Kanteti Aditya Pavan Kumar , Ghosh Jaya , Shah Sneha , Sable Nilesh , Baheti Akshay , Chauhan Sonal , Gala Kunal , Kulkarni Suyash
Published: March 2023

Cervical cancer is the fourth most common cancer in women globally and the second most common cancer in Indian women, more common in lower socioeconomic strata. Improvement in survival and decrease in morbidity reflect the earlier detection with screening and imaging, as well as multifactorial multimodality therapy integrating surgery, and concurrent chemoradiation therapy providing superior therapeutic benefits. Imaging plays a vital role in assessing the extent of disease and staging of cervical cancer. The appropriateness criteria of a modality are different from its availability based on infrastructure, medical facilities, and resource status. Although in an ideal situation, magnetic resonance imaging (MRI) would be of greatest value in locoregional assessment of extent of disease and fluorodeoxyglucose positron emission tomography-computed tomography for distant staging; often, an ultrasonography, chest radiograph, and bone scans are utilized, with contrast-enhanced computed tomography representing a fair superior diagnostic accuracy, and can be reported as per the RECIST 1.1 criteria. MRI is also of good utility in the assessment of residual disease, predicting response and detecting small volume recurrence. MRI offers the highest diagnostic accuracy in determining parametrial invasion and hence surgical planning; so also, MRI-guided radiation planning helps in more accurate graded radiation dose planning in radiation therapy. Stage and therapy-based surveillance imaging should be encouraged and recommended.
Imaging Recommendations for Diagnosis, Staging, and Management of Renal Tumors
Authors: Das Chandan J , Aggarwal Ankita , Singh Prabhjot , Nayak B , Yadav Taruna , Lal Anupam , Gorsi Ujjwal , Batra Atul , Shamim Shamim Ahmed , Duara Bijit Kumar , Arulraj Kevin , Kaushal Seema , Seth Amlesh
Published: March 2023

Renal cell carcinomas accounts for 2% of all the cancers globally. Most of the renal tumors are detected incidentally. Ultrasound remains the main screening modality to evaluate the renal masses. A multi -phase contrast enhanced computer tomography is must for characterizing the renal lesions. Imaging plays an important role in staging, treatment planning and follow up of renal cancers. In this review , we discuss the imaging guidelines for the management of renal tumors.
A bibliometric analysis of cultural heritage research in the humanities: The Web of Science as a tool of knowledge management
Authors: Vlase Ionela , Lähdesmäki Tuuli
Published: March 2023

Substantial research on the topic of cultural heritage has been conducted over the past two decades. At the same time, the overall output volume of journals and citation metrics have become important parameters in assessing and ranking researchers’ performance. Even though the scholarly interest in cultural heritage has recently increased world-wide, a comprehensive analysis of the publication output volume and its correlation to the shift in the cultural heritage regime starting in 2003 is still lacking. The article aims to understand the role of Web of Science (WOS) as a tool of knowledge management in academia by drawing on the scholarly output volume, the patterns displayed by this volume, and the intellectual structure of cultural heritage research based on WOS-indexed journal articles. The data include 1843 journal articles published between 2003 and 2022 and indexed in the WOS Core Collection. The article draws on a bibliometric analysis by using WOS tools and employing VOSviewer software to map and visualize hidden patterns of research collaboration and avenues of knowledge progress. The cultural heritage research indexed in WOS was found to be Eurocentric, corresponding to the increasing funding provided by European national and supranational agencies for research funding. Although the indexed research has grown significantly, the bulk of studies on cultural heritage in WOS is concentrated in a reduced number of European institutions and countries, written by a small number of prolific authors, with relatively poor collaborative ties emerging across time between authors, institutions, and countries. The central themes reflect the development of digital technologies and increased participatory emphasis in cultural heritage care. This article brings new insights into the analysis of the cultural heritage research in correlation with the emergence of international heritage governance with new institutional actors, professional networks, and international agreements, which are all constitutive elements of scientific production. The article seeks to critically assess and discuss the results and the role of WOS as a tool of knowledge management in academia.
Power relations are central to shaping collaborative governance of the urban sharing economy
Authors: Cao Jun , Prior Jason , Giurco Damien , Gu Dasong
Published: March 2023

Since its rise in the early 2000s, the sharing economy has expanded and developed rapidly worldwide. While the sharing economy can boost resource-use efficiency and encourage sustainable urban living, it also challenges urban governance. Recently, a collaborative governance (CG) approach involving public and private partnerships has been adopted in various global cities to address these governance dilemmas. However, the influence of stakeholder power relations on the CG of the sharing economy remains inadequately explored in the literature. This article argues that multi-actor collaboration can be enhanced by clarifying how power relations shape effective governance, actor engagement, shared motivation, and capacity for joint actions. This article draws on practical insights by discussing examples of the governance practices of urban bike-sharing programs to demonstrate how the nature of public-private power relations can result in specific (and quite different) forms of CG. This article will help CG researchers, policymakers, urban planners, and communities understand CG practices in the new era of shared cities and global cities.
Comparison of decomposition levels for wavelet transform based energy management in multi-fuel cell system
Authors: Chen Yang , Liang YiFan , Qiao Liang , Li MengJie , Xiong JingYang
Published: March 2023

In a hybrid energy storage system consisting of multi-fuel cell systems and super-capacitors, the wavelet transform is adopted to decompose the load power into multiple levels and assign the low-frequency component for fuel cell (FC) systems to reduce the impact caused by frequent variations in power demand. Two strategies—wavelet-based direct strategy and wavelet-quadratic strategy—are simulated in order to explore the system output characteristics with an increasing decomposition level. It is shown that the wavelet-quadratic strategy decreases the frequency of FC fluctuations as the decomposition level increases, which facilitates delayed degradation. The direct strategy improves the efficiency but sacrifices the FC stack health due to frequent load changes.
Correlating properties of alloys with constituent phases and their Raman spectra
Authors: Karar N. , Jain Vipin
Published: March 2023

Microstructure in alloys decides their physical properties; however, microstructure variations in metallic alloys are never quantitative. This applies to ferrous and non-ferrous alloys. Therefore, a correlative methodology is proposed for their indirect quantification using x-ray diffraction (XRD) and Raman spectroscopy. As a representative case, 16 different iron-based alloys with slight variations in composition and microstructure are considered. Changes to their properties and microstructure are correlated with XRD and Raman spectroscopy. Thermal treatments also have a role in such variation. Every x-ray peak position and FWHM was analyzed and correlated with corresponding Raman spectra and FWHM. The objective is the development of a reliable database and secondary testing methodology for fast performance estimation of different ferrous and non-ferrous alloys during production and for checking repeatability, other than by their microstructure and tensile strength, which is done at present.
Flexible Pb(Zr0.52,Ti0.48)O3 thin film acoustic emission sensor for monitoring partial discharge in power cable
Authors: Wu Ming , Yan Yu , Xiao Yanan , Liu Yongbin , Li Huaqiang , Zhong Lisheng , Lou Xiaojie , Gao Jinghui
Published: March 2023

Piezoelectric acoustic emission sensors can be used detect the sound emitted by the target structure when it is damaged and have important applications in the field of structure health monitoring. However, due to the mismatch of the interface acoustic impedance, it is hard for the conventional ultrasonic sensor to monitor the acoustic emission in a pipe structure. In this work, a flexible sensor by the deposition of a Pb(Zr0.52,Ti0.48)O3 thin film on a mica substrate was fabricated, and the acoustic emission generated by the partial discharge of a 110 kV power cable was detected by using the flexible sensor. The flexible sensor was designed with an electromagnetic shielding structure and, therefore, can screen most of the electromagnetic interference. The flexible sensor shows a relatively flat response in the frequency range from 100 to 1000 kHz with a sensitivity over 47.5 dB, which is beneficial for pattern recognition studies of acoustic emission. This work not only provides a flexible, anti-electromagnetic interference and broadband sensor for acoustic emission detection but also promotes the development and application of flexible ferroelectric materials.
Impeller design and performance characteristics of a side channel pump
Authors: Appiah Desmond , Adu-Poku Kofi Asamoah , Zhang Fan , Chen Ke , Yuan Shouqi
Published: March 2023

Flow non-uniformity inherent at the impeller passages is realized to have pronounced effects in hydraulic pumps, which leads to severe operational challenges. Cutting the blade tip has emerged as a research hotspot, which is deemed to be a feasible and viable approach to mitigate flow-induced problems. Therefore, this paper reveals more insight into the inner flow phenomena in a side channel pump under different impeller geometry. First, five models of impeller blades are designed with different tip cutting angles ranging from 10° to 50°. Based on the experimental data and the reliable shear stress transport k-ω model, the turbulent flow nature of the pump was established by numerical simulations. The performance curves revealed that impeller model 2 attained the highest efficiency of 37.13% at the best efficiency point, although registering 26.9% and 32.9% at part-load and over-load conditions, respectively. At over-load conditions, the efficiency of model 2 improved by 3.46%, 3.13%, 2.21%, and 8.72% compared to models 1, 3, 4, and 5, respectively. The pressure distribution at the impeller passage was higher compared to the side channel of all the impeller models. Noticeably, each type of vortex structure occupies nearly all the impeller passages of the impeller models justifying the complicated flow in the side channel pump. Impeller models 1, 2, and 3 produced better flow exchanges with the higher mass flow in and out, hence stimulating improved energy conversion. The conclusion can provide a physical foundation for designers in selecting a reasonable tip angle for specific tasks from engineering perspectives.
Isogeometric analysis based investigation on material filling of coin cavities
Authors: Li Jing , Yan Tingyu , Wang Qingyun , Xu Jiangping , Wang Fei
Published: March 2023

The coining technology produces a wide variety of commemorative coins with exquisite patterns. However, it often encounters defects such as insufficient filling, flash lines, light bands, and so on. Process engineers usually perform multiple tryouts to avoid the above-mentioned problems in actual production. This is not only time-consuming and laborious but also ineffective. The virtual tryout of the finite element method (FEM) could assist engineers to avoid the defects in the coining process with a great improvement in product quality. In order to exactly describe complex patterns of commemorative coins, a large number of elements are employed in the classical FEM. Even then, the three dimensional elements, which come in early contact with the reliefs of the punch/die, undergo large deformation and become distorted. Errors of contact judgment between the tools and the workpiece in the FEM occur during the simulation process. Taking into account the advantage of Non-Uniform Rational B-Spline (NURBS) basis functions when accurately describing complex boundaries or surfaces, isogeometric analysis (IGA) is developed for studying the material filling of coin cavities. Six numerical examples involving elastic and plastic analyses with/without contact issues are considered by the presented IGA frameworks and show good performance of the present method in simulating the cavity filling compared with ABAQUS. In addition, numerical findings also indicate that the proposed method exhibits excellent contact detection and strong anti-mesh distortion in large deformation of the coining process. These encouraging observations motivate us to explore the NURBS description of complicated reliefs of coins and the corresponding IGA framework for the coining process.
Modelling nitrous oxide emissions: comparing algorithms in six widely used agro-ecological models
Authors: Xing Hongtao , Smith Chris. J. , Wang Enli , Macdonald Ben , Wårlind David
Published: March 2023

Agricultural soils are the most important anthropogenic source of nitrous oxide (N2O) emissions. This occurs via two main pathways: (1) from microbial-mediated oxidation of ammonium to nitrite and nitrate; and (2) denitrification. Most agro-ecological models explicitly deal with these two pathways albeit with different degrees of process understanding and empiricism. Models that integrate the impact of multiple environmental factors on N2O emissions can provide estimates of N2O fluxes from complex agricultural systems. However, uncertainties in model predictions arise from differences in the algorithms, imperfect quantification of the nitrification and denitrification response to edaphic conditions, and the spatial and temporal variability of N2O fluxes resulting from variable soil conditions. This study compared N2O responses to environmental factors in six agro-ecological models. The comparisons showed that environmental factors impact nitrification and denitrification differently in each model. Reasons include the inability to apportion the total N2O flux to the specific N transformation rates used to validate and calibrate the simplifications represented in the model algorithms, and incomplete understanding of the multiple interactions between processes and modifying factors as these are generally not quantified in field experiments. Rather, N2O flux data is reported as total or net N2O emissions without attributing emissions to gross and/or net rates for specific N processes, or considering changes that occur between production and emissions. Additional measurements that quantify all processes understand the multiple interactions that affect N2O emissions are needed to improve model algorithms and reduce the error associated with predicted emissions.
Analysis of sampling methods for imaging a periodic layer and its defects
Authors: Boukari Yosra , Haddar Houssem , Jenhani Nouha
Published: March 2023

We revisit the differential sampling method introduced in (Haddar and Nguyen 2017 Comput. Math. Appl.
74 2831–55) for the identification of a periodic domain and some local perturbation. We provide a theoretical justification of the method that avoids assuming that the local perturbation is also periodic. Our theoretical framework uses functional spaces with continuous dependence with respect to the Floquet–Bloch variable. The corner stone of the analysis is the justification of the generalized linear sampling method in this setting for a single Floquet–Bloch mode.
Innovations in nanosynthesis: emerging techniques for precision, scalability, and spatial control in reactions of organic molecules on solid surfaces
Authors: Lipton-Duffin Josh , MacLeod Jennifer
Published: March 2023

The surface science-based approach to synthesising new organic materials on surfaces has gained considerable attention in recent years, owing to its success in facilitating the formation of novel 0D, 1D and 2D architectures. The primary mechanism used to date has been the catalytic transformation of small organic molecules through substrate-enabled reactions. In this Topical Review, we provide an overview of alternate approaches to controlling molecular reactions on surfaces. These approaches include light, electron and ion-initiated reactions, electrospray ionisation deposition-based techniques, collisions of neutral atoms and molecules, and superhydrogenation. We focus on the opportunities afforded by these alternative approaches, in particular where they may offer advantages in terms of selectivity, spatial control or scalability.
25.7% efficient PERC solar cell using double side silicide on oxide electrostatically doped (SILO-ED) carrier selective contacts: process and device simulation study
Authors: Kashyap Savita , Pandey Rahul , Madan Jaya
Published: March 2023

Passivating contacts have recently considered as a superior carrier-selective contact approach for high-efficiency silicon-based photovoltaic devices. However, the conversion efficiencies of the silicon-based passivated emitter and rear cell (PERC) are limited by contact recombination losses that reduce their performance. Therefore, we investigated a new manufacturable silicide on oxide-based electrostatically doped (SILO-ED) carrier-selective contact to suppress the contact recombination losses and reduce the saturation current density (j
0). For the first time, double side electrostatic doping is introduced to the PERC devices to form the carrier selective passivating contacts. First, a conventional PERC device was designed and the effects of surface recombination velocity (SRV) at both contacts were studied. After that, single and double SILO-ED based contacts are introduced into the device and a systematic analysis is performed to understand the tunneling phenomena and improve the conversion efficiency compared to existing PERC cells. The front SILO-ED based device with back contact SRV of 10 cm s−1 showed a power conversion efficiency of 25.4% with j
0 (14.3 fA·cm−2). In contrast, the double SILO-ED device delivered 25.7% conversion efficiency by further suppressing the j
0 to 11.8 fA·cm−2 by implementing SILO-ED approach with two different metal silicides such as erbium silicide (ErSi2) and palladium silicide (Pd2Si) on front and rear contact surface. The champion double SILO-ED PERC solar cell delivered a conversion efficiency of 25.7% with an open circuit voltage (V
OC) of 742 mV. The results reported in this study would help to develop superior passivating contact-based PERC solar cells for higher efficiencies.
Self-sensing synchronized switch damping based on zero-crossing detection with voltage decay compensation
Authors: Zhang Lin , Li Ming , Deng Pengcheng , Cheng Wei
Published: March 2023

Synchronized switch damping (SSD) techniques have been developed for structural vibration suppression in recent years. In SSD control, a self-sensing approach can invert the voltage on piezoelectric materials at displacement extrema without sensors or real-time controllers. However, tracing extrema from the voltage on piezoelectric materials has become challenging since the voltage generated by the vibration of controlled mode is minor compared with noises as the increase of damping performance. Furthermore, the voltage decay caused by the current leakage is dominant when the host structure vibrates at a low frequency. This paper proposes a self-sensing approach based on the zero-crossing detection technique with voltage decay compensation. The switching delay and voltage decay are considered in the electromechanical model of the SSD system. Accordingly, a band-limited proportional-differential circuit is implemented to offset the voltage decay and generate zero-crossings at displacement extrema simultaneously. Experiments show that the proposed method is still effective when the voltage decay in the SSD control is dominant.
Experimental study on the critical pressure of converging ferrofluid seal with alternating pole teeth
Authors: Yang Xiaolong , Jiang Lei , Li Decai
Published: March 2023

For the improvement of pressure capability in ferrofluid seal with a small gap, a structure of converging ferrofluid seal (CFS) with alternating pole teeth is proposed in this study. Distribution of magnetic field in this structure is analyzed by using finite element method, and then theoretical values of withstanding gas pressure are calculated. The influence of ferrofluid volume, sizes of radial and axial sealing gap, numbers of radial and axial pole teeth on the critical pressure of CFS with alternating pole teeth is studied on the test bench. Then experimental results are compared and analyzed with the experimental pressure resistance of ordinary stepped ferrofluid seal. It is demonstrated that the calculated value of pressure resistance of the CFS with alternating pole teeth fits well with the experimental data. The volume of the injected ferrofluid can reach saturation. The sealing performance of CFS with alternating pole teeth is related not only to the clearance between pole teeth and stepped shaft, but also to the number of radial and axial pole teeth. The sealing performance of CFS with alternating pole teeth is better than that of ordinary stepped ferrofluid seal.
Discriminate primary gammas (signal) from the images of hadronic showers by cosmic rays in the upper atmosphere (background) with machine learning
Authors: Malakouti Seyed Matin
Published: March 2023

The grid search approach was used in this article to tune the hyperparameters of the Light Gradient Boosting Machine, Random Forest, Gradient Boosting, Extra Tree, Ada Boost, and Linear Discriminant Analysis algorithms for Gamma and Hadron classification. The findings of ROC and Precision-Recall curves were also discussed to assess the performance of algorithms in the Gamma and Hadron classification. with the light gradient boosting machine, it took 33 s to get an AUC value of 0.94 for the Gamma and Hardon classification. Also, the results of the Random Forest, the light gradient boosting machine, and the Linear Discriminant Analysis were all about the same.
Halo-independent bounds on the non-relativistic effective theory of WIMP-nucleon scattering from direct detection and neutrino observations
Authors: Kang Sunghyun , Kar Arpan , Scopel Stefano
Published: March 2023

We combine experimental constraints from direct detection searches and from neutrino
telescopes looking for WIMP annihilations in the Sun to derive halo-independent bounds on each of
the 28 WIMP-proton and WIMP-neutron couplings of the effective non-relativistic Hamiltonian
that drives the scattering process off nuclei of a WIMP of spin 1/2. The method assumes that the
velocity distribution is normalized to one and homogeneous at the the solar system scale, as well
as equilibrium between WIMP capture and annihilation in the Sun, and requires to fix the WIMP
annihilation channels (we assume bb̅). We consider a single non-vanishing coupling at a
time, and find that for most of the couplings the degree of relaxation of the halo-independent
bounds compared to those obtained by assuming the Standard Halo Model is with few exceptions
relatively moderate in the low and high WIMP mass regimes, where it can be as small as a factor of
≃ 2, while in the intermediate mass range between 10 GeV and 200 GeV it can be as large as
∼ 103. An exception to this general pattern, with more moderate values of the bound
relaxation, is observed in the case of spin-dependent WIMP-proton couplings with no or a
comparatively small momentum suppression, for which WIMP capture is strongly enhanced because it
is driven by scattering events off 1H
, which is the most abundant target in the Sun. Within
this class of operators the relaxation is particularly small for interactions that are driven by
only the velocity-dependent term, for which the solar capture signal is enhanced compared to the
direct detection one, thanks to the highest speed of scattering WIMPs within the Sun due to the
larger gravitational acceleration.
Anatomy of single-field inflationary models for primordial black holes
Authors: Karam Alexandros , Koivunen Niko , Tomberg Eemeli , Vaskonen Ville , Veermäe Hardi
Published: March 2023

We construct an analytically solvable simplified model that captures the essential
features for primordial black hole (PBH) production in most models of single-field inflation. The
construction makes use of the Wands duality between the constant-roll (or slow-roll) and the
preceding ultra-slow-roll phases and can be realized by a simple inflaton potential of two joined
parabolas. Within this framework, it is possible to formulate explicit inflationary scenarios
consistent with the CMB observations and copious production of PBHs of arbitrary mass. We quantify
the variability of the shape of the peak in the curvature power spectrum in different inflationary
scenarios and discuss its implications for probing PBHs with scalar-induced gravitational wave
backgrounds. We find that the COBE/Firas μ-distortion constraints exclude the production of
PBHs heavier than 104
M
⊙ in single-field inflation.
Back to the features: assessing the discriminating power of future CMB missions on inflationary models
Authors: Braglia Matteo , Chen Xingang , Kumar Hazra Dhiraj , Pinol Lucas
Published: March 2023

Future Cosmic Microwave Background (CMB) experiments will deliver extremely accurate measurements of the E-modes pattern of the CMB polarization field.
Given the sharpness of the E-modes transfer functions, such surveys make for a powerful detector of high-frequency signals from primordial features that may be lurking in current data sets.
With a handful of toy models that increase the fit to the latest Planck data, but are of marginal statistical significance, we use a state-of-the-art forecast pipeline to illustrate the promising prospects to test primordial features in the next decade.
Not only will future experiments allow us to detect such features in data, but they will also be able to discriminate between models and narrow down the physical mechanism originating them with high statistical significance.
On the other hand, if the anomalies in the currently measured CMB spectra are just statistical fluctuations, all the current feature best fit candidates will be ruled out. Either way, our results show that primordial features are a clear target of forthcoming CMB surveys beyond the detection of tensor modes.
Nova neutrinos in the multi-messenger era
Authors: Guetta Dafne , Hillman Yael , Della Valle Massimo
Published: March 2023

The recently discovered high energy emission from the recurrent nova RS Ophiuchi by Fermi-LAT (> 100 MeV), H.E.S.S. and MAGIC (>100 GeV), hints towards a possible hadronic origin of this radiation component.
From the observed high energy photon flux we derive the expected number of neutrino events that could be detected by present and future neutrino telescopes in the different energy ranges.

Preliminary estimates indicate that with the “next-generation” instrument IceCube-Gen2, the expected number of neutrino detections from Galactic novae, admittedly with large uncertainty, should not exceed 1 event per decade.
The impact of inlet mach number and domain shape on subsonic nozzle flow via small disturbance equation
Authors: Qian Xuehui
Published: March 2023

Computational fluid dynamics (CFD) is a cross-disciplinary field that combines mathematics, fluid dynamics, and computer programming to simulate and analyze fluid flow problems using numerical methods. Nowadays, the use of CFD to conduct numerical simulations rather than costly and time-consuming ignition experiments has become an essential aspect of nozzle design. Therefore, it is significant to study the nozzle by numerical simulation. In this paper, a numerical method called small disturbance equation (SDE) is adopted to investigate the impact of inlet Mach number and domain shape on subsonic nozzle flow. Conducting the small disturbance equation via python code, the impact of the inlet Mach number and domain shape is revealed by comparing the different errors of the method, streamlines of the nozzle flow, velocity fields. It is found that with the increase of inlet Mach number, the error of the SDE method grows, and the velocity in x-direction increases while the velocity in y-direction stays the same. Besides, with the shrink of the domain shape, the error of the SDE method gets larger, meanwhile, the maximum of the velocity in each direction increases while the minimum of the velocity decreases. This research would make advantages to identify the optimal designs of a subsonic nozzle.
Numerical Simulation of the Two-phase Flow of a Constant-pressure Rear-spray Low Recoil Weapon with Two Chambers
Authors: Li Zijian , Qiu Ming , Song Jie , Yang Liang , Liao Zhenqiang
Published: March 2023

To study the effect of a constant-pressure rear-spray low recoil weapon with two chambers on weapon launch performance, based on two-phase flow theory, the valve-spring type constant-pressure rear-spray low recoil weapon firing process with two chambers was studied numerically. Considering the movement of the valve-spring system, a mathematical model of the weapon launch process combining the two-phase flow of gas and solid in the front and back chambers, the movement of the projectile and the transient flow of gas in the lateral rear nozzle is established. Using a 30 mm chain gun as an example, numerical simulation was carried out, and the distribution law of the flow field in the two chambers and the lateral rear nozzle during the firing of the weapon was obtained and compared with the internal flow field of the traditional weapon chamber. The results show that by reasonably matching parameters to control the flow of gunpowder gas in the two chambers, the recoil impulse can be reduced by 81.58% under the premise that the initial velocity of the projectile does not decrease, and the purpose of making full use of gunpowder gas energy to greatly reduce arms recoil is realized.
The Effects of Roadside Buildings Roof Shapes and Tree Plantings on the Vehicle Exhaust Gas Pollution Dispersion in the Urban Street
Authors: Hsu Frances , Bennett Ajanae
Published: March 2023

In this study, the effects of roadside building roof shapes and roadside tree plantings on the dispersion of vehicle exhaust gas pollution in the urban street have been carefully explored. Three typical roof shapes, i.e., flat, triangle and round shapes, are considered in the present work. Firstly, the numerical simulations of air pollution transport in the atmospheric turbulent boundary layer with/without the vegetation canopy have been performed using Computational Fluid Dynamics (CFD). Secondly, the mean flow patterns and the distribution of turbulent kinetic energy (TKE) are then examined. Finally, the concentrations of the air pollution have been carefully explored. It is found that the triangle roof could result in a lower concentration of air pollution in the street canyon. The existence of the roadside trees could decrease the air pollution concentration, although its influence is much weaker than the roof shape. It is also found that the concentration of air pollution is quite related to the flow pattern and TKE distribution. This study could provide helpful guidance on the urban planners on the design of the urban street in the future.
Numerical study of different micro-channel structures on fluid flow and heat transfer performance
Authors: Chen Zijian
Published: March 2023

This research mainly proposed three new types of micro-channel heat sink structures. Numerical simulations and simulation calculations were carried out on the heat sink structure. The three groups of inlet flow rates were used as the main variables to analyse the three new types of heat sinks, model flow characteristics and heat transfer performance. In addition, it was compared with the traditional rectangular micro-channel heat sink (RT-MCHS). Based on and compared with RT-MCHS, three new microchannel heat sinks, reverse concave microchannel heat sink (RC-MCHS), co-directional concave microchannel heat sink (CC-MCHS) and convex reverse concave microchannel heat sink (CRC-MCHS), were designed and studied numerically. The comparative analysis of MCHS design performance includes fluid flow characteristics, fluid heat transfer performance and heat transfer efficiency. The effects of inlet velocity on the Darcy friction coefficient, pressure drop, Nusselt number, average outlet temperatures and efficiency factors were studied numerically as inlet velocity from 1 m·s-1 to 5 m·s-1. The results show that the optimal strategy in the new design is the CRC-MCHS, which can hinder the flow of fluid and enable sufficient heat exchange between the liquid and the substrate. In addition, at the optimal inlet flow rate of 3 m·s-1, the outlet water temperature of CC-MCHS is the lowest, indicating the heat transfer performance of the electronic components is the best.
Numerical simulation of two-phase evaporation and condensation
Authors: Chang Wei , Zhang Fangju , Fang Kun , Tan Gongli , Fan Pengjie
Published: March 2023

The evaporation and condensation mechanism of two-phase flow is studied. The Euler-Euler pattern is used to express the evaporation and condensation properties of two-phase flow. The research shows that the tracking program can accurately track the interface. The thermal resistance on the confluence of the condensation part and insulation part becomes larger. The working fluids have significant influence of two-phase.
Approximation properties of some Bernstein-Schurer type operators
Authors: Lian Boyong
Published: March 2023

This paper mainly studies the approximation properties of Bernstein-Schurer operators based on a non-negative real parameter λ. By analysis techniques and the method to make the kernel estimation, the author studies the convergence order of this Schurer operators for the function class θBV[0,1 + p]. Our conclusion expands the research results of Çetin.
Differences among IllustrisTNG series and a Brief Comparison with the Illustris Project
Authors: Dai Zhengyu , Dong Jinao , Liao Runyu , Yue Qiwei
Published: March 2023

The IllustrisTNG project is one of the most advanced cosmological gravity and magnetohydrodynamical models that simulates the formation and evolution of galaxies. It focuses on figuring out the physical processes involved based on the moving-mesh code AREPO. This project consists of three series (TNG50, TNG100, TNG300) with different box sizes, resolution, and physical parameters while each series also contains sub-simulations with lower resolution (TNG50-2, TNG50-3, TNG100-2, TNG100-3, TNG300-2, TNG300-3). The purpose of this paper is to illuminate the major differences and connections among different series of the IllustrisTNG project by analysing the data and carrying out corresponding visualization. Moreover, since the IllustrisTNG project is built upon the previous Illustris project, the improvements of the new model have been compared to the former one. Based on the analysis, different IllustrisTNG series differ in physical and numerical parameters, research areas, quantity of sample and so on. In the meantime, there are a lot of connections especially among the sub-simulations and we draw several figures, which provide a clear insight. The situation between the new model and the old one is very similar while the former introduces new methods and includes new physics which make the simulation process much more accurate. These results help to understand the ongoing problems and offer a guideline to enable the establishment of a future simulation model.