bluuebunny/crossref_metadata_2025 huggingface dataset:
On-chip parallel processing of quantum frequency comb
Authors: Zhang Liang , Cui Chaohan , Yan Jianchang , Guo Yanan , Wang Junxi , Fan Linran
Published: June 2023

The frequency degree of freedom of optical photons has been recently explored for efficient quantum information processing. Significant reduction in hardware resources and enhancement of quantum functions can be expected by leveraging the large number of frequency modes. Here, we develope an integrated photonic platform for the generation and parallel processing of quantum frequency combs (QFCs). Cavity-enhanced parametric down-conversion with Sagnac configuration is implemented to generate QFCs with identical spectral distributions. On-chip quantum interference of different frequency modes is simultaneously realized with the same photonic circuit. High interference visibility is maintained across all frequency modes with the identical circuit setting. This enables the on-chip reconfiguration of QFCs. By deterministically separating QFCs without spectral filtering, we further demonstrate high-dimensional Hong-Ou-Mandel effect. Our work provides the critical step for the efficient implementation of quantum information processing with integrated photonics using the frequency degree of freedom.
Interaction of fatty acid quality indices and genes related to lipid homeostasis on mental health among overweight and obese women
Authors: Rasaei Niloufar , Khadem Alireza , masihi Lilit Sardari , Mirzaei Khadijeh
Published: June 2023

The aim of this study is to investigate the interaction of fatty acid quality indices and genes related to lipid homeostasis on mental health among overweight and obese women. This cross-sectional study included 279 overweight and obese women for N6/N3 ratio and 378 overweight and obese women for CSI aged 18–58 years. Mental health were evaluated using Depression Anxiety Stress Scales (DASS-21). The anthropometric indices, biochemical parameters, body composition and dietary fat quality were measured. MC4R (rs17782313) and Caveolin-1 (CAV-1) (rs3807992) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) technique. The results of the study showed that after adjusting for age, energy intake, thyroid disease, physical activity, and BMI, a positive interaction between TC genotype of MC4R and CSI on depression (β = 0.39, CI = 0.12, 0.66, P = 0.004), and DASS-21 (β = 0.074, CI = 0.04, 1.44, P = 0.036). Also, there were a marginal significant interactions between AG genotype of CAV-1 and N6/N3 ratio on depression in adjustment model1 (β = 16.83, CI = − 0.19, 33.85, P = 0.053). Our findings showed that increasing adherence to fatty acid quality indices by considering genes related to lipid homeostasis was related to increasing depression in our population.
Altered functional brain network patterns in patients with migraine without aura after transcutaneous auricular vagus nerve stimulation
Authors: Rao Yuyang , Liu Wenting , Zhu Yunpeng , Lin Qiwen , Kuang Changyi , Huang Huiyuan , Jiao Bingqing , Ma Lijun , Lin Jiabao
Published: June 2023

Transcutaneous auricular vagus nerve stimulation (taVNS) shows excellent effects on relieving clinical symptoms in migraine patients. Nevertheless, the neurological mechanisms of taVNS for migraineurs remain unclear. In recent years, voxel-wise degree centrality (DC) and functional connectivity (FC) methods were extensively utilized for exploring alterations in patterns of FC in the resting-state brain. In the present study, thirty-five migraine patients without aura and thirty-eight healthy controls (HCs) were recruited for magnetic resonance imaging scans. Firstly, this study used voxel-wise DC analysis to explore brain regions where abnormalities were present in migraine patients. Secondly, for elucidating neurological mechanisms underlying taVNS in migraine, seed-based resting-state functional connectivity analysis was employed to the taVNS treatment group. Finally, correlation analysis was performed to explore the relationship between alterations in neurological mechanisms and clinical symptoms. Our findings indicated that migraineurs have lower DC values in the inferior temporal gyrus (ITG) and paracentral lobule than in healthy controls (HCs). In addition, migraineurs have higher DC values in the cerebellar lobule VIII and the fusiform gyrus than HCs. Moreover, after taVNS treatment (post-taVNS), patients displayed increased FC between the ITG with the inferior parietal lobule (IPL), orbitofrontal gyrus, angular gyrus, and posterior cingulate gyrus than before taVNS treatment (pre-taVNS). Besides, the post-taVNS patients showed decreased FC between the cerebellar lobule VIII with the supplementary motor area and postcentral gyrus compared with the pre-taVNS patients. The changed FC of ITG-IPL was significantly related to changes in headache intensity. Our study suggested that migraine patients without aura have altered brain connectivity patterns in several hub regions involving multisensory integration, pain perception, and cognitive function. More importantly, taVNS modulated the default mode network and the vestibular cortical network related to the dysfunctions in migraineurs. This paper provides a new perspective on the potential neurological mechanisms and therapeutic targets of taVNS for treating migraine.
Critically raw materials as potential emerging environmental contaminants, their distribution patterns, risks and behaviour in floodplain soils contaminated by heavy metals
Authors: Kanianska Radoslava , Drimal Marek , Varga Jozef , Komárek Michael , Ahado Samuel Kudjo , Šťastná Milada , Kizeková Miriam , Jančová Ľubica
Published: June 2023

The expanding demand for new critical raw materials can lead to their increased release to the environment in the form of emerging environmental contaminants (EECs). However, there has never been a comprehensive study that takes into account the total EEC content, the content of various EEC fractions, their behaviour in floodplain soils, and potential ecological and human health risks. The occurrence, fractions, and influencing factors of the seven EECs (Li, Be, Sr, Ba, V, B, Se) originating from historical mining in floodplain soils of various ecosystems (arable lands, grasslands, riparian zones, contaminated sites) were investigated. Based on the evaluation of the overall levels of EECs (potentially toxic elements) in comparison to the soil guideline values set by European legislation for Be, Ba, V, B, and Se, it was found that only Be did not exceed the recommended limits. Among the elements analyzed, Li had the highest average contamination factor (CF) of 5.8, followed by Ba with 1.5 and B with 1.4. Particularly concerning was the discovery of a potential serious health risk associated with Li exposure for children, as indicated by hazard quotients ranging from 0.128 to 1.478. With the exception of Be and Se, the partitioning of the EECs into the different fractions revealed that the EECs are primarily bound with the residual fraction. Be (13.8%) had the highest percentage of exchangeable fraction as the most bioavailable in the first soil layer, followed by Sr (10.9%), Se (10.2%), Ba (10.0%), and B (2.9%). The most frequently observed correlations were between EEC fractions and pH/KCl, followed by soil organic carbon and manganese hydrous oxides. Variance analyses confirmed the impact of different ecosystems on EEC total content and fractions.
Mechanism of remodeling and local effects in vivo of a new injectable cosmetic filler
Authors: Sun Likui , Sun Xiaoxia , Ruan Wenting , Che Guoxi , Zhu Fuyu , Liu Chenghu , Wan Min
Published: June 2023

By studying the local effects of a new type of injectable cosmetic filler implanted into the animal to explore the mechanism of remodeling and cosmetic effect of this kind of product. Take 12 rabbits and select 4 implantation points on both sides of the spine, respectively, and implant the test sample (PLLA) and negative control sample (HDPE) into the subcutaneous tissues on both sides. In the same way, take another 12 rabbits and implant the marketing control sample (cross-linked sodium hyaluronate) and negative control sample (HDPE) into the subcutaneous tissues on both sides. The animals were executed at 1 week, 4 weeks, 13 weeks and 52 weeks respectively, and Hematoxylin–Eosin staining, Masson trichrome staining and immunofluorescence staining were performed to characterize the local effects in vivo and the expression of type I collagen (Col. I), type III collagen (Col.III) and matrix metalloproteinase 9 (MMP-9). Good histocompatibility of the test sample and the marketing control sample were found. The foreign body reaction of marketing control sample was more intense than that of the test sample after 13 weeks. The foreign body reaction of testing sample was more intense after 52 weeks, while that of the marketing control sample was more stable. With the process of tissue repair, the collagen fibers of test samples and marketing control samples gradually increased after implantation. Type I collagen was mainly found inside the fiber capsule, while type III collagen was mainly found outside. The positive expression of matrix metalloproteinase 9 gradually increased, the positive expression of test samples increased significantly after 52 weeks, while that of marketing control samples did not change significantly. Good histocompatibility of PLLA filler is found. Matrix metalloproteinase 9 participates in foreign body reaction and collagen formation, which can reflect the process of tissue remodeling.
Improved GBS-YOLOv5 algorithm based on YOLOv5 applied to UAV intelligent traffic
Authors: Liu Haiying , Duan Xuehu , Lou Haitong , Gu Jason , Chen Haonan , Bi Lingyun
Published: June 2023

As the road traffic situation becomes complex, the task of traffic management takes on an increasingly heavy load. The air-to-ground traffic administration network of drones has become an important tool to promote the high quality of traffic police work in many places. Drones can be used instead of a large number of human beings to perform daily tasks, as: traffic offense detection, daily crowd detection, etc. Drones are aerial operations and shoot small targets. So the detection accuracy of drones is less. To address the problem of low accuracy of Unmanned Aerial Vehicles (UAVs) in detecting small targets, we designed a more suitable algorithm for UAV detection and called GBS-YOLOv5. It was an improvement on the original YOLOv5 model. Firstly, in the default model, there was a problem of serious loss of small target information and insufficient utilization of shallow feature information as the depth of the feature extraction network deepened. We designed the efficient spatio-temporal interaction module to replace the residual network structure in the original network. The role of this module was to increase the network depth for feature extraction. Then, we added the spatial pyramid convolution module on top of YOLOv5. Its function was to mine small target information and act as a detection head for small size targets. Finally, to better preserve the detailed information of small targets in the shallow features, we proposed the shallow bottleneck. And the introduction of recursive gated convolution in the feature fusion section enabled better interaction of higher-order spatial semantic information. The GBS-YOLOv5 algorithm conducted experiments showing that the value of mAP@0.5 was 35.3$$\%$$%and the mAP@0.5:0.95 was 20.0$$\%$$%. Compared to the default YOLOv5 algorithm was boosted by 4.0$$\%$$%and 3.5$$\%$$%, respectively.
Correction for attenuation and visual response in digital radiography.
Authors: Welande U , Yoshiura K , Li G , Sällström P , McDavid W D
Published: June 2023

OBJECTIVES

To derive a method to correct for the exponential attenuation adding visual linearization for digital radiography and to perform an experimental test to study effects on observer performance.

METHOD

A theoretical analysis was performed and expressions were derived to correct radiographic data for the attenuation. An experiment was performed exposing an aluminum step wedge with holes of increasing depths behind each step plus soft tissue simulation. Seven original images were created with a digital intraoral X-ray sensor and a further 14 transformed images produced. Ten observers examined the images in a randomized order reporting the number of holes seen per wedge step. The results were analysed by One Way ANOVA.

RESULTS

It was possible to correct for attenuation and the response of the human visual system to light intensities from a computer monitor. Perception was significantly improved in all recalculated radiographs that took both attenuation and the response of the eye into account (P-values ranged from <0.0001 to <0.0286).

CONCLUSIONS

The transforms may be useful for improved perception when viewing digital radiographs.
Survey of dental radiographic services in private dental clinics in Damascus, Syria.
Authors: Salti L , Whaites E J
Published: June 2023

OBJECTIVES

To perform a radiographic survey of private dental clinics in Damascus, Syria using a postal questionnaire to produce recommendations for improving the quality of dental radiographic services and education in Syria.

METHODS

Three hundred private dental clinics in Damascus were surveyed using a postal questionnaire (in English and Arabic) containing 27 questions on demographic information, equipment, techniques, selection criteria, frequency of examinations, and undergraduate/ postgraduate education.

RESULTS

Two hundred and two (67%) dentists responded of which 95% graduated in Syria. The results showed a general lack of knowledge and understanding of dental radiography. Sixty four per cent did not know the kVp setting of their equipment, 73% used D-speed film, 57% did not use film holders and beam aiming devices, 25% did not use a viewing box. In addition, 45% of known equipment operated at 50 kVp or less and 16% was over 20 years old. No meaningful selection criteria existed with a wide variation in type and frequency of radiographs used for different clinical conditions. Syrian undergraduate training in dental radiology was minimal and there was no postgraduate education in the speciality.

CONCLUSIONS

Several areas of the radiographic service in Damascus fall short of current recommendations on good practice. Recommendations are made to improve the service, the quality of undergraduate education and to establish postgraduate education.
Supramolecular presentation of bioinstructive peptides on soft multilayered nanobiomaterials stimulates neurite outgrowth
Authors: Lopes Maria , Torrado Marília , Barth Daryl , Santos Sofia D. , Sever-Bahcekapili Melike , Tekinay Ayse B. , Guler Mustafa O. , Cleymand Franck , Pêgo Ana P. , Borges João , Mano João F.
Published: June 2023

The supramolecular presentation of bioinstructive peptides on multilayered nanofilms enabled self-assembled nanofibers with high laminin-derived IKVAV epitope density, enhancing neuronal cell adhesion, viability, morphology and neurite outgrowth.
Effect of a magnetic field/electrostatic field on the quality attributes of green bell peppers during cool chain transportation
Authors: Feng Tianlin , Zhang Min , Mujumdar Arun S. , Zhang Lihui
Published: June 2023

The use of magnetic/electric field treatment reduced quality deterioration of green bell pepper during transportation. Electrostatic treatment at 4 °C and 5 kV cm−1 effectively reduced the loss of nutrients during transportation of pepper.
A wearable colorimetric sweat pH sensor-based smart textile for health state diagnosis
Authors: Ha Ji-Hwan , Jeong Yongrok , Ahn Junseong , Hwang Soonhyong , Jeon Sohee , Kim Dahong , Ko Jiwoo , Kang Byeongmin , Jung Young , Choi Jungrak , Han Hyeonseok , Gu Jimin , Cho Seokjoo , Kim Hyunjin , Bok Moonjeong , Park Su A. , Jeong Jun-Ho , Park Inkyu
Published: June 2023

The proposed diagnostic clothing incorporates a curcumin/thermoplastic polyurethane composite fiber-based colorimetric pH sensor. It can serve as a diagnostic tool to assess the deterioration of symptoms associated with cystic fibrosis.
Nanoceramics of metastable ε-Fe2O3: effect of sintering on the magnetic properties and sub-terahertz electron resonance
Authors: Gorbachev Evgeny A. , Alyabyeva Liudmila N. , Soshnikov Miroslav V. , Lebedev Vasily A. , Morozov Anatolii V. , Kozlyakova Ekaterina S. , Ahmed Asmaa , Eliseev Artem A. , Trusov Lev A.
Published: June 2023

Nanoceramics of metastable ε-Fe2O3 were obtained by sintering at 700 °C. Temperature dependencies of the static and dynamic magnetic properties were investigated before and after sintering. The nanoceramics is more hard-magnetic at low temperatures.
Influence of bridge structure manipulation on the electrochemical performance of π-conjugated molecule-bridged silicon quantum dot nanocomposite anode materials for lithium-ion batteries
Authors: Choi Young-Hwa , Bang Jiyoung , Lee Sunyoung , Jeong Hyun-Dam
Published: June 2023

To assess the impact of bridge structure manipulation on the electrochemical performance of π-conjugated molecule-bridged Si QD nanocomposite (SQNC) anode materials, we prepared two SQNCs via Sonogashira cross-coupling and hydrosilylation reactions.
Synthesis of N-functionalized 2,3-disubstituted benzofurans/naphthofurans from para-quinone methides and isocyanides via the [4 + 1] annulation pathway
Authors: Kale Someshwar B. , Kumar Manish , Shinde Dinesh R. , Krishna Gamidi Rama , Das Utpal
Published: June 2023

Synthesis of 2-amino substituted benzo- and naphtho-furans via [4 + 1] cycloaddition of 2-hydroxy-substituted p-QMs and various alkyl/aryl isocyanides has been achieved by using Sc(OTf)3 as the catalyst.
Dual role of BrCF2CO2Et: difluorocarbene-enabled access to α-trifluoromethyl ketones from sulfoxonium ylides
Authors: Wu Chun-Yan , Chen Xiang-Long , Wang Huai-Yu , Yang Dong-Sheng , Zhuang Shi-Yi , Zhou You , Yu Zhi-Cheng , Wu Yan-Dong , Geng Xiao , Wu An-Xin
Published: June 2023

A transition metal and external fluorine anion-free method has been developed for the efficient trifluoromethylation of sulfoxonium ylides with BrCF2CO2Et to afford α-trifluoromethyl ketones.
Fe/S cluster catalyzed cascade cyclization of N,S-1,6-enynes for the synthesis of thieno[3,4-b]indoles
Authors: Liu Zhuqing , Sun Shaobin , Lou Jiang
Published: June 2023

Fe/S cluster catalyzed radical cascade cyclization of alkylthio-functionalized o-anilide-embedded N,S-1,6-enynes to afford thieno[3,4-b]indoles is developed.
Semiconductor and topological phases in lateral heterostructures constructed from germanene and AsSb monolayers
Authors: Ha Chu Viet , Nguyen Thi Bich Ngoc , Trang Pham Quynh , Ponce-Pérez R. , Kim Lien Vu Thi , Guerrero-Sanchez J. , Hoat D. M.
Published: June 2023

New lateral heterostructures formed by stitching germanene and AsSb monolayers are investigated using density functional theory.
Correction: Infrared sensitive mixed phase of V7O16 and V2O5 thin-films
Authors: Rana Anchal , Yadav Aditya , Gupta Govind , Rana Abhimanyu
Published: June 2023

Correction for ‘Infrared sensitive mixed phase of V7O16 and V2O5 thin-films’ by Anchal Rana et al., RSC Adv., 2023, 13, 15334–15341, https://doi.org/10.1039/D3RA00752A.
Size-dependent bending of a rectangular polymer film
Authors: Liu Yin , Fu Xuemei , Yang Ruochen , Liu Jun , Tee Benjamin Chee Keong , Liu Zhuangjian
Published: June 2023

The phase diagram reveals how the bending of a rectangular bilayer is influenced by its size, specifically in terms of length, width, and thickness.
Origin and predictive principle for selective products of electrocatalytic carbon dioxide reduction
Authors: Gong Lele , Wang Xiaowei , Daiyan Rahman , Zhu Xiaofeng , Leverett Joshua , Duan Zhiyao , Zhang Lipeng , Amal Rose , Dai Liming , Xia Zhenhai
Published: June 2023

A computational method, based on DFT and electrical double-layer interface models with explicit hydrogen bonding, is developed to accurately predict potential-dependent reaction pathways, catalytic activity, and product selectivity of CO2 reduction.
“One stone three birds” of a synergetic effect between Pt single atoms and clusters makes an ideal anode catalyst for fuel cells
Authors: Li He , Wang Xian , Gong Xue , Liu Cong , Ge Junjie , Song Ping , Xu Weilin
Published: June 2023

Scheme for the newly revealed unique synergetic “one stone three birds” effect containing one “win–win” mode for the HOR and two “lose–lose” modes for the poisonings of both O2 and CO between individual Pt atoms and the neighboring Pt clusters.
A fluoroalkyl iodide additive for Li–O2 battery electrolytes enables stable cycle life and high reversibility
Authors: Jeong Min-Gi , Lee Hyun Ho , Shin Hyeon-Ji , Jeong Yeseul , Hwang Jang-Yeon , Kwak Won-Jin , Oh Gwangseok , Kim Wonkeun , Ryu Kyounghan , Yu Seungho , Lim Hee-Dae , Lee Minah , Jung Hun-Gi
Published: June 2023

The introduction of CF3(CF2)2I into the electrolyte leads to the simultaneous formation of LiI as a redox mediator and LiF as a protective layer. This enables long cycle life and high reversibility even at high areal capacity (∼5 mA h cm−2).
Machine learning-assisted design of AlN-based high-performance piezoelectric materials
Authors: Jing Huirong , Guan Chaohong , Yang Yu , Zhu Hong
Published: June 2023

A ML model capable of rapidly predicting the piezoelectric coefficient of AlN-based materials, guiding the design of promising piezoelectric materials.
Improving the oxidative stability of gel polymer electrolytes for lithium metal batteries
Authors: Cha JinHyeok , Nam Kyungju , Baek Jihye , Seo Samuel , Kwak Kyuju , Kim Ji-Wan , Kim Wonkeun , Ryu Kyoung Han , Kim Dong-Won , Kwon Eunji
Published: June 2023

Research progress to clarify the mechanism of the changes in the behaviors of free organic molecules after the addition of polymers impacting on oxidative stability of the electrolyte using quantum and molecular dynamics simulations.
UV-robust and efficient perovskite solar cells enabled by interfacial photocatalysis suppression and defect passivation
Authors: Zhu Jingwei , Hu Xumeng , Liu Zhuoyan , Guo Minghuang , Zhang Ying , Li Yafeng , Li Junming , Wei Mingdeng
Published: June 2023

A UV absorber, 4,4′-oxybisbenzoic acid, was first utilized as a modification layer between TiO2 and perovskite solar cells. An impressive stability under extreme UV irradiation was achieved, and a PCE of up to 22.14% was obtained.
Electron transfer driving force as the criterion for efficient n-doping of organic semiconductors with DMBI-H derivatives
Authors: Xu Chunlin , Wang Dong
Published: June 2023

The electron affinity (EA) of OSCs and the ionization energy (IE) of dopant radicals (D˙s) are two molecular descriptors for the n-doping reaction with DMBI-H derivatives, and EA(OSC) − IE(D·) > 1.0 eV is proposed as a criterion for efficient doping.
Ultrahigh sensitivity upconversion low temperature sensorsviamanipulating the non-thermally coupled levels of Er3+ions
Authors: Ying Weitao , He Jingyi , Fan Xuemei , Xu Shiqing , Gu Jianmin , Liu Shimin
Published: June 2023

The GC material produces excellent blue UC emission under 980 nm or 1550 nm excitation, where the blue emission level (2H9/2) could form a novel NTCL (2H11/2–2H9/2) with other energy levels, realizing ultrahigh sensitivity low temperature sensing.
Hydrogel-integrated optical fiber sensors and their applications: a comprehensive review
Authors: Sadeque Md. Sazid Bin , Chowdhury Hussain Kawsar , Rafique Muzaffar , Durmuş Mehmet Atıf , Ahmed Md. Kawsar , Hasan Md. Mehdi , Erbaş Aykut , Sarpkaya İbrahim , Inci Fatih , Ordu Mustafa
Published: June 2023

Hydrogel-integrated optical fiber sensors have garnered momentous interest due to their optical properties, biocompatibility, and biodegradability.
Tunable valley-selective circular polarization in vdW multilayers consisting of inversion-symmetric monolayers
Authors: Ma Xikui , Li Weifeng , Li Yangyang , Liu Xiangdong , Zhao Xian , Zhao Mingwen
Published: June 2023

Valley manipulation via valley selective circular dichroism is beneficial for information encoding and processing.
Channel characteristics analysis of millimetre‐wave bands in Hyperloop scenarios based on ray‐tracing
Authors: Wang Kai , Liu Liu , Zhang Jiachi , Liu MeiLu , Zhou Tao , Ai Bo
Published: June 2023

A reliable train‐to‐ground wireless communication system is proposed for the foundation of the safe operation of Hyperloop. The wireless channel characteristics of Hyperloops at millimetre‐wave (mmWave) bands are analysed based on the ray‐tracing method. Considering the reflection paths and line of sight path, the channel transfer function expression is derived for each multipath and then the channel impulse response is obtained. On this basis, the investigation and analysis of the large‐scale and small‐scale channel characteristics, including the path loss, shadow fading, delay spread, and angular spread of 4 different mmWave frequency carriers, that is, 28/38/45/60 GHz, are conducted. Simulation results show that the path loss increases as the frequency increases while the time delay spread and angular spread almost keep unchanged. The relevant research results will contribute to the design of future Hyperloop wireless communication systems.
Competitive relationship between electrical degradation and healing in self‐healing dielectric polymers
Authors: Han Lu , Xie Jiaye , Li Qi , He Jinliang
Published: June 2023

The concept of self‐healing dielectric polymers has been heatedly discussed, with the expectation of high damage resistance and longer service time. However, there is still a lack of analysis on the competitive relationship between electrical degradation and self‐healing. The authors discussed this relationship in two stages: the design of self‐healing strategies and the operation of self‐healing polymers. Since the requirements for excellent insulating or mechanical properties are not consistent with the demands for high self‐healing capability, trade‐offs are necessary during the design of self‐healing polymeric systems. In the operation stage of dielectric polymers, some key factors that affect the service lifetime of non‐autonomous self‐healing dielectric polymers are analysed, including the efficiency and repeatability of self‐healing, and the frequency of healing maintenance. For autonomous self‐healing dielectrics, the simultaneous processes of ageing and healing are investigated using a self‐healing epoxy resin based on microcapsules and in situ‐generated radicals. A quicker recovery of insulating properties, in terms of partial discharge magnitude, was observed under appropriate healing voltages. However, the self‐healing ability might vanish when the voltage was too high, verifying the competitive relationship between electrical degradation and self‐healing.
Non‐linear modelling and distortion compensation in optical Fast‐orthogonal frequency division multiplexing systems
Authors: Vieira Luis Carlos , Ozan Waseem , Mitchell John , Darwazeh Izzat
Published: June 2023

Fast‐OFDM‐based intensity‐modulation and direct‐detection (IM/DD) has been proposed for deployment of cost‐efficient optical access networks, due to its implementation simplicity and high spectral efficiency. In this article, the accuracy of the generalised memory polynomial (GMP) for the non‐linear modelling of optical Fast‐OFDM links is studied, including memory effects and considering different model parameters. After model validation using measured data of a 10 km single mode fibre link, the GMP is used for performance investigations of a distortion compensation approach to optical Fast‐OFDM, for up to 16PAM modulation formats and different number of Fast‐OFDM subcarriers. This study firstly reports the performance results of optical 16PAM‐Fast‐OFDM systems using either 2PAM‐ or 4PAM‐based training signals for digital post‐distortion and FFT‐based channel estimation, and firstly investigates the influence of the zero padding (ZP) length on the performance of optical Fast‐OFDM. Excellent performance improvements are achieved using the proposed distortion compensation scheme, relative to conventional system implementation.
Unraveling the formation histories of the first supermassive black holes with the Square Kilometre Array’s pulsar timing array
Authors: Padmanabhan Hamsa , Loeb Abraham
Published: June 2023

Galaxy mergers at high redshifts trigger activity of their central supermassive black holes, eventually also leading to their coalescence as well as a potential source of low-frequency gravitational waves detectable by the Square Kilometre Array’s pulsar timing array (SKA PTA). Two key parameters related to the fueling of black holes are the Eddington ratio of quasar accretion,ηEdd, and the radiative efficiency of the accretion process,ϵ(which affects the so-called active lifetime of the quasar,tQSO). Here, we forecast the regime of detectability of gravitational wave events with SKA PTA. We find the associated binaries to have orbital periods of the order of weeks to years, observable via relativistic Doppler velocity boosting and/or optical variability of their light curves. Combining the SKA regime of detectability with the latest observational constraints on high-redshift black hole mass and luminosity functions, as well as theoretically motivated prescriptions for the merger rates of dark matter halos, we forecast the number of active counterparts of SKA PTA events expected as a function of primary black hole mass atz ≳ 6. We find that the quasar counterpart of the most massive black holes will be uniquely localizable within the SKA PTA error ellipse atz ≳ 6. We also forecast the number of expected counterparts as a function of the quasars’ Eddington ratios and active lifetimes. Our results show that SKA PTA detections can place robust constraints on the seeding and growth mechanisms of the first supermassive black holes.
Astrochemical models of interstellar ices: History matters
Authors: Clément A. , Taillard A. , Wakelam V. , Gratier P. , Loison J.-C. , Dartois E. , Dulieu F. , Noble J. A. , Chabot M.
Published: June 2023

Context. Ice is ubiquitous in the interstellar medium. As soon as it becomes slightly opaque in the visible, it can be seen for visual extinctions (AV) above ~1.5. The James Webb Space Telescope (JWST) will observe the ice composition toward hundreds of lines of sight, covering a broad range of physical conditions in these extinct regions.

Aims. We model the formation of the main constituents of interstellar ices, including H2O, CO2, CO, and CH3OH. We strive to understand what physical or chemical parameters influence the final composition of the ice and how they benchmark to what has already been observed, with the aim of applying these models to the preparation and analysis of JWST observations.

Methods. We used the Nautilus gas-grain model, which computes the gas and ice composition as a function of time for a set of physical conditions, starting from an initial gas phase composition. All important processes (gas-phase reactions, gas-grain interactions, and grain surface processes) are included and solved with the rate equation approximation.

Results. We first ran an astrochemical code for fixed conditions of temperature and density mapped in the cold core L429-C to benchmark the chemistry. One key parameter was revealed to be the dust temperature. When the dust temperature is higher than 12 K, CO2 will form efficiently at the expense of H2O, while at temperatures below 12 K, it will not form. Whatever hypothesis we assumed for the chemistry (within realistic conditions), the static simulations failed to reproduce the observed trends of interstellar ices in our target core. In a second step, we simulated the chemical evolution of parcels of gas undergoing different physical and chemical situations throughout the molecular cloud evolution and starting a few 107 yr prior to the core formation (dynamical simulations). We obtained a large sample of possible ice compositions. The ratio of the different ice components seems to be approximately constant for AV > 5, and in good agreement with the observations. Interestingly, we find that grain temperature and low AV conditions significantly affect the production of ice, especially for CO2, which shows the highest variability.

Conclusions. Our dynamical simulations satisfactorily reproduce the main trends already observed for interstellar ices. Moreover, we predict that the apparent constant ratio of CO2/H2O observed to date is probably not true for regions of low AV, and that the history of the evolution of clouds plays an essential role, even prior to their formation.
A CO funnel in the Galactic centre: Molecular counterpart of the northern Galactic chimney
Authors: Veena V. S. , Riquelme D. , Kim W.-J. , Menten K. M. , Schilke P. , Sormani M. C. , Banda-Barragán W. E. , Wyrowski F. , Fuller G. A. , Cheema A.
Published: June 2023

We report the discovery of a velocity coherent, funnel-shaped 13CO emission feature in the Galactic centre (GC) using data from the SEDIGISM survey. The molecular cloud appears as a low-velocity structure (VLSR = [ − 3.5,   + 3.5] km s−1) with an angular extent of 0.95° ×1°, extending towards positive Galactic latitudes. The structure is offset from Sgr A* towards negative Galactic longitudes; it spatially and morphologically correlates well with the northern lobe of the 430 pc radio bubble, believed to be the radio counterpart of the multiwavelength GC chimney. Spectral line observations in the frequency range of 85–116 GHz have been carried out using the IRAM 30-m telescope towards 12 positions along the funnel-shaped emission. We examine the 12C/13C isotopic ratios using various molecules and their isotopologues. The mean 12C/13C isotope ratio (30.6 ± 2.9) is consistent with the structure located within inner 3 kpc of the Galaxy and possibly in the GC. The velocity of the molecular funnel is consistent with previous radio recombination line measurements of the northern lobe of radio bubble. Our multiwavelength analysis suggests that the funnel-shaped structure extending over 100 pc above the Galactic plane is the molecular counterpart of the northern GC chimney.
Dwell time in contact-free creep tests plays an age-dependent role in the viscoelastic behavior of in vivo human skin
Authors: Abellan Marie-Angèle , Ayadh Meriem , Bergheau Jean-Michel , Zahouani Hassan
Published: June 2023

The experimental characterization of human skin in vivo may be highly dependent on the experimental protocol and on the procedure employed for analyzing the experimental data. One way of overcoming these drawbacks is the contact-free indenter at the Laboratoire de Tribologie et Dynamique des Systèmes, Lyon, France. However, it is still necessary to determine the possible influence of the experimental protocol in terms of the dwell time chosen. This paper describes a coupled theoretical/experimental/numerical study on the viscoelastic responses of the human skin at two different ages during contact-free creep tests with dwell times of 0.1 s, 0.5 s, 1 s, 2 s and 100 s, respectively. The 3-D finite element simulations are conducted with the SYSTUS® software. The numerical results point to different behaviors for the young and elderly subjects. The young subject does not appear influenced by dwell times during the numerical creep tests. On the contrary, the response of the elderly subject is highly dependent on dwell time.
Rapid Prototyping and Tooling Technology to Assist the Development of Low-Cost Dies
Authors: Shehbaz Muhammad , Sajid Muhammad , Ahmad Wasim , Hussain Salman , Jahanzaib Mirza
Published: June 2023

This case study aims toward the importance of the application of rapid prototyping and tooling technology in die design and manufacturing. Many conventional machining processes of die manufacturing, including computer numeric control (CNC) machining and electric discharge machining (EDM), are used by the local manufacturers of die, but these processes are time-consuming and expensive. There is a need to explore opportunities to reduce die manufacturing costs. This paper aims to assist the development of low-cost dies through the application of rapid prototyping and tooling technology. For this purpose, solid works software was used to design the die of a 4-hole Lego Block. 3D printing was incorporated in the existing capability of investment casting process for die manufacturing. A proper gating system design consideration was taken into account to ensure the accurate flow of casting material for achieving fine surface finish. From the results, it has been observed that gating system design with four ingates gives the optimum value of surface finish (~3.4156μm). The proposed rapid prototyping and tooling technology makes the practitioners (tool makers) capable of making dies with complex shapes, superior surface finishes, and dimensional accuracy in less or no time.
Design and Fabrication of Small-Scale Urban Air Purification Tower
Authors: Nadeem Abdullah Umer , Khan Maroofi Imad , Hammad Baig Mirza , Shayan Ahmed Syed
Published: June 2023

Air pollution has become a significant environmental issue in the twenty-first century, causing a negative impact on the quality of life and human health. Various international organizations have been working to address air pollution issues and provide potential solutions. One of the primary tools used to measure air quality is the Air Quality Index (AQI), which ranges from 0 to 500, indicating levels of different air pollutants in the ambient air. Particulate matter (PM) is one of the most hazardous air pollutants. Outdoor air purification towers are a promising technology to address air quality issues, and this project aims to design and fabricate an air purification tower for Karachi, biggest city of Pakistan and an industrial hub with significant air pollution issues. The lack of air purification devices throughout the country is a significant motivation behind this project, and the main objectives include observing the current situation of ambient air quality in Karachi, testing the performance of the air purification tower, and evaluating the feasibility of the project to be replicated on a larger scale. The project’s methodology includes a review of existing literature and engineering knowledge, followed by design calculations based on heat losses, velocities, and volume flow rates. A parametric study and economic analysis were used to select feasible dimensions, and a CAD model was developed. The report outlines the project’s chronology, including an introduction, literature review, assessment of air quality in Karachi, heat loss coefficient, velocity and flow rate calculations, and a parametric study to reach optimal dimensions for the model used in fabrication. The project’s significance lies in addressing air pollution issues and providing a solution for Karachi’s air quality problems. The success of this project could inspire further replication of air purification towers on a larger scale in Pakistan and other countries facing similar air pollution issues.
Actuation and Flow Control in Paper-Based Microfluidics by Varying Thickness of Storage Reservoir
Authors: Abbas Hamza , Ali Mubashar , Ullah Hammas , Jafry Ali Turab
Published: June 2023

This paper discusses the potential of paper-based microfluidic devices for affordable diagnostics, and the importance of flow control. We have explored the variation of the width of paper, effect of 2D flow, and altering the surface wettability of paper to increase the resistance to fluid flow by physicochemical barriers. We used Whatman filter paper No. 40 and No. 1, mustard oil, and oleic acid, to examine the fluid flow due to capillary forces. Moreover, the effect of increase in thickness of the storage reservoir to decrease flow rate in the paper was also investigated. The experiments provide valuable insights into the behavior of fluid flow in porous media, and the findings have important applications in biomedical diagnostics and environmental monitoring.
The Performance and Cost Analysis on Bio Fuel Blends for Internal Combustion Engine
Authors: Khan Abdul Manan , Askari Ghulam Hassan , Ahmed Zaheer
Published: June 2023

Petrol, Diesel or CNG are useful fuels in most of auto-mobile industry. Increment in fuel prices and its highly demands created a need of research to make its use optimistic, cost effective and its burning gases environment friendly by considering its environment degradation effect. Bio-Ethanol Fuel is best replacement as a solution same as renewable energy resource. To measure the impact of several kinds of mixtures of ethanol-gasoline on spark ignited single cylinder engine an experimental investigation was performed. To perform investigation analysis, test bench was prepared first as a CAD model and then a proper experimental setup made with mild steel structure on which engine was mounted with all additional devices like fuel measuring device, gas analyzer, tachometer, stopwatch and dynamometer. Several kinds of ethanol-gasoline blends i.e. E-0, E-2, E-4, E-6, E-8, E-9, E-10, E-12 and E-14 were considered for investigation. The digits 0 to 14 represent the percentage of ethanol in gasoline. Gasoline Outcomes were analyzed after assessments from test results to find out best conditions in which it operates optimal. Cost Economic Analysis were performed to check the economical values of the blends, it becomes clear that the running cost of ethanol gasoline blend E10 is lower than the running cost of hi-octane gasoline.
A hybrid sentiment based stock price prediction model using machine learning
Authors: Mehmood Awais , Khurram Ali Muhammad
Published: June 2023

Accurate stock market prediction is highly desirable to corporations and investors. In this study a deep learning model based on LSTM, BiLSTM with attention mechanism used to predict stocks closing price for next 30 days of two banks listed in Pakistan Stock Exchange. For accurate stock price prediction, it is necessary to consider volatile factors such as news sentiments along with historical data. This study covers that aspect by incorporating news sentiments along with historical stock data that is distributed over a span of ten years from Jan 2011 to July 2021. Preprocessing and sentiment analysis of data was performed using python NLTK module. After that we built a univariate deep learning model based on four layers of LSTM and one dense layer to combine all layers and performed a prediction on train and test data followed by a multivariate deep learning model based on BiLSTM with self-attention mechanism and found out that incorporation of news sentiments really improved the prediction accuracy by reducing the values of mean squared error. Finally, we did the prediction for next 30 days of stock closing price of two banks and compared those predicted prices with actual prices and got quite accurate results.
Fabrication of Intumescent Fire-Retardant Coating for Structural Applications
Authors: Ali Kazmi Muhammad , Hassan Askari Ghulam , Ali Nasir Muhammad , Asim Pasha Riffat , Parveen Amina
Published: June 2023

Applicability of materials limited by the effect of flammability in case of any sudden incident. Worldwide protection of any structure from the fire is covered through intumescent fire resistant coatings since many past years. Purpose of this study is to prepare and to fabricate several intumescent fire retardant coatings (IFRC) using different proportions of materials per unit weight. Also to find most optimistic formulations and analyse the performance of intumescent fire retardant coatings (IFRC). On the basis of background studies 5 different materials were considered to prepare several formulations i-e Titanium dioxide (TiO2), Ammonium polyphosphate (APP), Zinc borate, Epoxy hardener, Kaolinite (Clay), Melamine (MEL) and Expandable Graphite (EG). IFRC formulations were applied on Mild Steel plates after its preparation Each formulation was subjected to a temperature of 700°C for a period of five minutes. The results revealed that the coatings, Out of 5 formulations of IFRC, IFRC-4 exhibited promising performance. It demonstrated excellent stability and adhesion at the elevated temperature, lasting for over five minutes. Additionally, its coating expanded up to four times the initial thickness. Heat Transfer rate was completely reduced.
Ernährungsumstellung bei metabolischem Syndrom
Authors: Römmele Petra
Published: June 2023

Das metabolische Syndrom kann durch die Lebensstiländerung, die diätetische Interventionen umfasst, positiv beeinflusst werden. Erfolgreiche Ernährungsstrategien fokussieren sich zunächst auf das Erreichen einer negativen Energiebilanz und Gewichtsverlust. Langfristig muss eine individuell passende neue Ernährungsweise gefunden und verfestigt werden. Je nach Präferenz kann die zeitlich begrenzte Nahrungsaufnahme, der Verzicht auf hochverarbeitete Lebensmittel oder die Umstellung auf beispielsweise eine mediterrane Ernährungsweise als Lebensstiländerung hilfreich sein. Gesunde Ernährungsmuster zeichnen sich durch eine Lebensmittelauswahl mit geringer Energie- und hoher Nährstoffdichte aus.
Heilstollentherapie – ein traditionelles Naturheilmittel für Atemwegserkrankungen
Authors: Schwarz Joachim
Published: June 2023

Die Heilstollen- oder Heilhöhlentherapie (Speläotherapie) ist ein traditionelles Naturheilverfahren, dessen wissenschaftliche Aufarbeitung erst Mitte des 20. Jahrhunderts begann. Wichtigstes Kennzeichen der 12 zertifizierten Kaltluftheilstollen in Deutschland ist die kalte, feuchte Luft, die nahezu frei von Staub, Pollen und Allergenen ist. Ein weiteres Merkmal ist die außergewöhnliche Stille unter Tage. Salzheilstollen zeichnen sich durch die hohe Salzkonzentration, Radonheilstollen durch ihre hohe Radonkonzentration in der Luft aus. Hauptindikationen sind Erkrankungen der Atemwege in Kaltluft- und Salzheilstollen, entzündliche Erkrankungen des Bewegungsapparats in Radonheilstollen. Die klimatischen Bedingungen in Heilstollen und die bisherigen Erfahrungen mit Long-Covid-Patienten machen die Therapie von Long Covid durch Heilstollenaufenthalte zu einer sinnvollen Ergänzung.
Fast protodeboronation of arylboronic acids and esters with AlCl3 at room temperature
Authors: Yuan Zhijun , Liang Yunshi , He Yiting , Deng Huiying , Wu Haiting , Lin Bohong , Zhang Jing
Published: June 2023

AlCl3-mediated protodeboronation of arylboronic acids and esters is reported herein. This method features mild reaction conditions, high reaction yields, as well as short reaction times. Mechanistic studies based on 11B NMR spectroscopy suggest that it might proceed through initial boron activation by coordination of AlCl3 to the oxygen atom of arylboronic acid or ester groups.
Post-wildfire contamination of soils and sediments by polycyclic aromatic hydrocarbons in north-central British Columbia, Canada
Authors: Kieta K. A. , Owens P. N. , Petticrew E. L.
Published: June 2023

Background The Nechako River Basin (NRB) is a large, regulated basin in north-central British Columbia, Canada that has been impacted by numerous landscape disturbances, including a severe wildfire in 2018. Aims The aims of this study were to quantify the post-wildfire temporal and spatial extent of contamination by polycyclic aromatic hydrocarbons (PAHs) of both soils and riverine sediments, and to identify the primary sources of PAHs in the watershed. Methods Soil samples were collected at burned and unburned sites in 2018 and at the burned sites in 2020 and 2021. Sediment samples were collected at three tributaries impacted by wildfire and three Nechako River mainstem (i.e. main channel) sites from 2018 to 2021. Samples were analysed for parent PAHs. Key results PAH concentrations decreased in soil samples from 2018 to 2021 but are not below the concentrations found in unburned samples. Tributary sediment samples showed higher concentrations immediately post-fire relative to the mainstem Nechako River, but in the years since, that trend has reversed. Conclusions PAHs persist in terrestrial and aquatic environments for years following wildfire, but at concentrations below various quality guidelines. PAHs were primarily derived from the wildfires, with some mixed sources at the downstream sites. Implications Wildfires are an important source of environmental contamination of terrestrial and aquatic environments.