bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular simulation on the effect of formation depth on methane adsorption by clay minerals
Authors: Deng Yijie , Wang Dongbo , Han Yixiao
Published: January 2023

Shale gas is an unconventional natural gas with large reserves. Recently, its production has increased rapidly, significantly impacting the international gas market and global energy landscape. In addition to organic matter and quartz, clay minerals constitute the majority of shale, and their production activities are effectively guided by evaluating their shale gas adsorption capabilities. To explore shale gas reserves and model their distribution, the variation in shale gas content with formation depth should be investigated. Currently, experimental methods are used to evaluate the effect of formation depth on shale gas adsorption, the data are substituted into a theoretical model, and the resulting mathematical model is used to estimate the variation in methane adsorption with formation depth, considering only temperature and pressure. However, the experimental method is flawed, and the true adsorption content cannot be obtained. The absolute methane adsorption amount was calculated using molecular dynamics and the grand-canonical Monte Carlo method for the corresponding temperature and pressure conditions. The supercritical Dubinin–Radushkevich (SDR) equation was fitted, yielding a temperature-dependent equation for the SDR parameter. Shale gas adsorption can be predicted using the developed mathematical model based on formation depth and temperature–pressure gradient.
Tuning the Q-factor of nanomechanical string resonators by torsion support design
Authors: Li Zichao , Xu Minxing , Norte Richard A. , Aragón Alejandro M. , van Keulen Fred , Alijani Farbod , Steeneken Peter G.
Published: January 2023

In recent years, the Q-factor of Si3N4 nanomechanical resonators has significantly been increased by soft-clamping techniques using large and complex support structures. To date, however, obtaining similar performance with smaller supports has remained a challenge. Here, we make use of torsion beam supports to tune the Q-factor of Si3N4 string resonators. By design optimization of the supports, we obtain a 50% Q-factor enhancement compared to the standard clamped–clamped string resonators. By performing experimental and numerical studies, we show that further improvement of the Q-factor is limited by a trade-off between maximizing stress and minimizing torsional support stiffness. Thus, our study also provides insight into dissipation limits of high-stress string resonators and outlines how advanced designs can be realized for reaching ultimate f0×Q product while maintaining a small footprint.
A core drain current model for β-Ga2O3 power MOSFETs based on surface potential
Authors: Zhou Kai , Miao Songming , Zhou Xuanze , Xu Guangwei , Wang Lingfei , Long Shibing
Published: January 2023

For the first time, a core drain current model based on surface potential without any implicit functions is developed for beta-phase gallium oxide (β-Ga2O3) power metal-oxide-semiconductor field-effect transistors (MOSFETs). The surface potential solution is analytically deduced by solving the Poisson equation with appropriate simplification assumptions in accumulation, partial-depletion, and full-depletion modes. Then, the drain current expression is analytically derived from the Pao–Sah integral as a function of the mobile charge density obtained from the surface potential at the source and drain terminals. In addition, nonlinear resistors in the source/drain access region are considered. It continuously predicts the characteristics of β-Ga2O3 power MOSFETs in all operation modes, including accumulation mode, partial-depletion mode, and full-depletion mode. Furthermore, the validity of the model is verified by comparing the results of the model with the numerical simulations carried out with the technology computer-aided design (TCAD) tool ATLAS Device Simulator from Silvaco. Good agreement between the proposed model and TCAD simulations is shown for β-Ga2O3 power MOSFETs with different intrinsic channel lengths, channel doping concentrations, and channel thicknesses. Ultimately, the Gummel symmetry test and the harmonic balance simulation test are performed to validate the model’s robustness and convergence.
Large-signal dynamics of resonant-tunneling diodes
Authors: Ourednik P. , Picco G. , Tuan Nguyen D. , Spudat C. , Feiginov M.
Published: January 2023

A model for analyzing dynamic large-signal characteristics of double-barrier resonant-tunneling diodes (RTDs) is presented. The model is based on the analysis of dynamical trajectories in phase space, defined by the RTD bias and electron density in the RTD quantum well. We show that an accurate dynamic model can be reformulated in an approximate way, relying only on a directly measurable DC I–V curve and on few other RTD parameters, which could be easily estimated with simple DC calculations. We further demonstrate that a simple equivalent circuit, composed of a capacitor, inductor, and two resistors (RLRC), accurately describes the large-signal admittance of RTDs. The circuit elements can be described in terms of relaxation time, geometrical RTD capacitance, and low- and high-frequency resistors. The circuit has the very same structure as that previously derived for small-signal RTD admittance, although with deviating parameters, which are now dependent on the AC-signal amplitude. We show that the large-signal RTD relaxation time can be shorter and longer than the small-signal one. In the context of RTD oscillators, a shorter RTD relaxation time allows one to get higher output power at high frequencies. The availability of an accurate, general, but rather simple, physics-based model for analyzing large-signal RTD dynamics removes one of the major hindrances to the further development of sub-THz and THz RTD oscillators.
On the identification of cross-flow mode in three-dimensional boundary layers
Authors: Liu Zhiyong
Published: January 2023

Parametric zones are obtained where the cross-flow instability can be identified as a mode in the three-dimensional boundary layers with the Mach number ranging from 0 to 10. Although the term cross-flow mode is widely used in the investigations on boundary-layer instability, the previous work [Z. Liu, Phys. Fluids 34, 094110 (2022)] has demonstrated that a cross-flow mode cannot be designated in certain circumstances. The identification of the cross-flow mode is significant not only in the justifiable use of the term but also in judging whether a disturbance is more inclined to a cross-flow type or not. In this work, a criterion is built to identify the cross-flow mode based on the growth-rate peak and disturbance shape. By means of extensive calculations and identifications, parametric zones are presented for the unstable cross-flow mode. It is found that the cross-flow mode cannot be identified at large local sweep or at Mach numbers larger than 1.6. In parametric zones, the cross-flow mode can be distinguished from the Tollmien–Schlichting mode, or identified as the solely dominant mode. Based on the identifications, the maximum growth rates of the cross-flow mode, the Tollmien–Schlichting mode, and the Mack modes in the three-dimensional boundary layers are provided. The dominant mode can be determined at different Mach numbers. The cross-flow mode is revealed to dominate the boundary-layer instability at low Mach numbers. Under large cross-flow strengths, the second mode could not be the dominant mode in the hypersonic boundary layers, which contrasts sharply with the two-dimensional case.
The dynamics of burning activity on degraded peatland in two villages in Central Kalimantan, Indonesia
Authors: Robb Samuel , Asi Nion Yanetri , Anggreini Trisna , Richards Russell , Abdul Aziz Ammar , Joseph Stephen , Dargusch Paul
Published: January 2023

Background Recurring wildfires on degraded peatlands throughout Central Kalimantan have resulted in severe economic and social impacts for local people along with globally significant environmental impacts. The interdependence between the livelihoods of local villagers and wildfire is not well understood in areas of degraded peat in proximity to urban environments. Aims The aim of the study was to consider fire hotspots in two villages close to the regional capital of Palangka Raya. These were Kalampangan, a Javanese transmigrant farming village, and Tumbang Nusa, a Dayaknese fishing village. Methods A system dynamics model was constructed to study the factors contributing to greenhouse gas emissions and wildfire extent resulting from long-term peatland degradation. The model was used to analyse existing policy scenarios where degraded peatlands are cultivated in perpetuity, and then consider hypothetical future policy scenarios where efforts are made to rewet and rehabilitate peatland while alternative livelihoods are enabled. Conclusions Analysis reveals that the assumption within the model of unconstrained alternative livelihoods is insufficient to facilitate full rewetting where the incumbent livelihood is reliant on drained peatland. Implications Only when livelihood alternatives displace drained peatland cultivation is full rewetting and sustained reduction in fire risk achievable in both villages.
Climate-driven changes of global marine mercury cycles in 2100
Authors: Wang Yujuan , Wu Peipei , Zhang Yanxu
Published: January 2023

Human exposure to monomethylmercury (CH
3
Hg), a potent neurotoxin, is principally through the consumption of seafood. The formation of CH
3
Hg and its bioaccumulation in marine food webs experience ongoing impacts of global climate warming and ocean biogeochemistry alterations. Employing a series of sensitivity experiments, here we explicitly consider the effects of climate change on marine mercury (Hg) cycling within a global ocean model in the hypothesized twenty-first century under the business-as-usual scenario. Even though the overall prediction is subjected to significant uncertainty, we identify several important climate change impact pathways. Elevated seawater temperature exacerbates elemental Hg (Hg
0
) evasion, while decreased surface wind speed reduces air–sea exchange rates. The reduced export of particulate organic carbon shrinks the pool of potentially bioavailable divalent Hg (Hg
II
) that can be methylated in the subsurface ocean, where shallower remineralization depth associated with lower productivity causes impairment of methylation activity. We also simulate an increase in CH
3
Hg photodemethylation potential caused by increased incident shortwave radiation and less attenuation by decreased sea ice and chlorophyll. The model suggests that these impacts can also be propagated to the CH
3
Hg concentration in the base of the marine food web. Our results offer insight into synergisms/antagonisms in the marine Hg cycling among different climate change stressors.
Neighbor-specific gene expression revealed from physically interacting cells during mouse embryonic development
Authors: Kim Junil , Rothová Michaela Mrugala , Madan Esha , Rhee Siyeon , Weng Guangzheng , Palma António M. , Liao Linbu , David Eyal , Amit Ido , Hajkarim Morteza Chalabi , Vudatha Vignesh , Gutiérrez-García Andrés , Moreno Eduardo , Winn Robert , Trevino Jose , Fisher Paul B. , Brickman Joshua M. , Gogna Rajan , Won Kyoung Jae
Published: January 2023

Development of multicellular organisms is orchestrated by persistent cell–cell communication between neighboring partners. Direct interaction between different cell types can induce molecular signals that dictate lineage specification and cell fate decisions. Current single-cell RNA-seq technology cannot adequately analyze cell–cell contact-dependent gene expression, mainly due to the loss of spatial information. To overcome this obstacle and resolve cell–cell contact-specific gene expression during embryogenesis, we performed RNA sequencing of physically interacting cells (PIC-seq) and assessed them alongside similar single-cell transcriptomes derived from developing mouse embryos between embryonic day (E) 7.5 and E9.5. Analysis of the PIC-seq data identified gene expression signatures that were dependent on the presence of specific neighboring cell types. Our computational predictions, validated experimentally, demonstrated that neural progenitor (NP) cells upregulateLhx5andNkx2-1genes, when exclusively interacting with definitive endoderm (DE) cells. Moreover, there was a reciprocal impact on the transcriptome of DE cells, as they tend to upregulateRaxandGscwhen in contact with NP cells. Using individual cell transcriptome data, we formulated a means of computationally predicting the impact of one cell type on the transcriptome of its neighboring cell types. We have further developed a distinctive spatial-t-distributed stochastic neighboring embedding to display the pseudospatial distribution of cells in a 2-dimensional space. In summary, we describe an innovative approach to study contact-specific gene regulation during embryogenesis.
Human ERG oncoprotein represses
a Drosophila
LIM domain binding protein–coding gene
Chip
Authors: Bharti Mahima , Bajpai Anjali , Rautela Umanshi , Manzar Nishat , Ateeq Bushra , Sinha Pradip
Published: January 2023

Human
E
TS
R
elated
G
ene, ERG, a master transcription factor, turns oncogenic upon its out-of-context activation in diverse developmental lineages. However, the mechanism underlying its lineage-specific activation of Notch (N), Wnt, or EZH2—three well-characterized oncogenic targets of ERG—remains elusive. We reasoned that deep homology in genetic tool kits might help uncover such elusive cancer mechanisms in
Drosophila
. By heterologous gain of human ERG in
Drosophila
, here we reveal
Chip,
which codes for a transcriptional coactivator, LIM-domain-binding (LDB) protein, as its novel target. ERG represses
Drosophila Chip
via its direct binding and, indirectly, via E(z)-mediated silencing of its promoter. Downregulation of
Chip
disrupts LIM–HD complex formed between Chip and Tailup (Tup)—a LIM–HD transcription factor—in the developing notum. A consequent activation of N-driven Wg signaling leads to notum-to-wing transdetermination. These fallouts of ERG gain are arrested upon a simultaneous gain of Chip, sequestration of Wg ligand, and, alternatively, loss of
N
signaling or
E(z)
activity. Finally, we show that the human
LDB1
, a homolog of
Drosophila Chip
, is repressed in ERG-positive prostate cancer cells. Besides identifying an elusive target of human ERG, our study unravels an underpinning of its lineage-specific carcinogenesis.
Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna
Authors: Cassemiro Fernanda A. S. , Albert James S. , Antonelli Alexandre , Menegotto André , Wüest Rafael O. , Cerezer Felipe , Coelho Marco Túlio P. , Reis Roberto E. , Tan Milton , Tagliacollo Victor , Bailly Dayani , da Silva Valéria F. B. , Frota Augusto , da Graça Weferson J. , Ré Reginaldo , Ramos Telton , Oliveira Anielly G. , Dias Murilo S. , Colwell Robert K. , Rangel Thiago F. , Graham Catherine H.
Published: January 2023

Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes—the most species-rich continental vertebrate fauna on Earth—to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of in situ diversification, which led to it being an important source of species dispersing to other regions. All regional biotic interchanges were associated with documented hydrogeographic events and the formation of biogeographic corridors, including the Early Miocene (c. 23 to 16 Ma) uplift of the Serra do Mar and Serra da Mantiqueira and the Late Miocene (c. 10 Ma) uplift of the Northern Andes and associated formation of the modern transcontinental Amazon River. The combination of high diversification rates and extensive biotic interchange associated with Western Amazonia yielded its extraordinary contemporary richness and phylogenetic endemism. Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish faunas.
Circadian regulator BMAL1::CLOCK promotes cell proliferation in hepatocellular carcinoma by controlling apoptosis and cell cycle
Authors: Qu Meng , Zhang Guoxin , Qu Han , Vu Alexander , Wu Raymond , Tsukamoto Hidekazu , Jia Zhenyu , Huang Wendong , Lenz Heinz-Josef , Rich Jeremy N. , Kay Steve A.
Published: January 2023

Hepatocellular carcinoma (HCC) remains a global health challenge whose incidence is growing worldwide. Previous evidence strongly supported the notion that the circadian clock controls physiological homeostasis of the liver and plays a key role in hepatocarcinogenesis. Despite the progress, cellular and molecular mechanisms underpinning this HCC-clock crosstalk remain unknown. Addressing this knowledge gap, we show here that although the human HCC cells Hep3B, HepG2, and Huh7 displayed variations in circadian rhythm profiles, all cells relied on the master circadian clock transcription factors, BMAL1 and CLOCK, for sustained cell growth. Down-regulating
Bmal1
or
Clock
in the HCC cells induced apoptosis and arrested cell cycle at the G
2
/M phase. Mechanistically, we found that inhibiting
Bmal1
/
Clock
induced dysregulation of the cell cycle regulators
Wee1
and
p21
which cooperatively contribute to tumor cell death.
Bmal1
/
Clock
knockdown caused downregulation of
Wee1
that led to apoptosis activation and upregulation of
p21
which arrested the cell cycle at the G
2
/M phase. Collectively, our results suggest that the circadian clock regulators BMAL1 and CLOCK promote HCC cell proliferation by controlling
Wee1
and
p21
levels, thereby preventing apoptosis and cell cycle arrest. Our findings shed light on cellular impact of the clock proteins for maintaining HCC oncogenesis and provide proof-of-principle for developing cancer therapy based on modulation of the circadian clock.
Heterotypic electrostatic interactions control complex phase separation of tau and prion into multiphasic condensates and co-aggregates
Authors: Rai Sandeep K. , Khanna Roopali , Avni Anamika , Mukhopadhyay Samrat
Published: January 2023

Biomolecular condensates formed via phase separation of proteins and nucleic acids are thought to perform a wide range of critical cellular functions by maintaining spatiotemporal regulation and organizing intracellular biochemistry. However, aberrant phase transitions are implicated in a multitude of human diseases. Here, we demonstrate that two neuronal proteins, namely tau and prion, undergo complex coacervation driven by domain-specific electrostatic interactions to yield highly dynamic, mesoscopic liquid-like droplets. The acidic N-terminal segment of tau interacts electrostatically with the polybasic N-terminal intrinsically disordered segment of the prion protein (PrP). We employed a unique combination of time-resolved tools that encompass several orders of magnitude of timescales ranging from nanoseconds to seconds. These studies unveil an intriguing symphony of molecular events associated with the formation of heterotypic condensates comprising ephemeral, domain-specific, short-range electrostatic nanoclusters. Our results reveal that these heterotypic condensates can be tuned by RNA in a stoichiometry-dependent manner resulting in reversible, multiphasic, immiscible, and ternary condensates of different morphologies ranging from core-shell to nested droplets. This ternary system exhibits a typical three-regime phase behavior reminiscent of other membraneless organelles including nucleolar condensates. We also show that upon aging, tau:PrP droplets gradually convert into solid-like co-assemblies by sequestration of persistent intermolecular interactions. Our vibrational Raman results in conjunction with atomic force microscopy and multi-color fluorescence imaging reveal the presence of amorphous and amyloid-like co-aggregates upon maturation. Our findings provide mechanistic underpinnings of overlapping neuropathology involving tau and PrP and highlight a broader biological role of complex phase transitions in physiology and disease.
Translation of allusive literary text in both directions
Authors: Ren Haimeng
Published: January 2023

The translation of culture-specific expressions has received considerable attention in translation studies in recent decades; however, the translation of allusion and allusive text has rarely been touched upon. This article reports an eye-tracking study which aims to answer the following question: What factors influence the allocation of cognitive efforts (CE) in L1 and L2 translation of allusive text? Results from a generalised linear mixed model revealed that for the 30 Chinese student translators who participated in this study, the impact of allusion type was significant in L1 but not L2 translation. Allusion familiarity, the source context length and typing speed have no significant relationship with the amount of CE in all areas of interest (AOIs). Meanwhile, Skopoi and the visits to the external resources correlated with the CE in both directions of the translation process.
How and when need for cognitive closure impacts attitudes towards women managers (Cómo y cuándo la necesidad de cierre influye en las actitudes hacia las mujeres directivas)
Authors: Viola Marta , Baldner Conrad , Pierro Antonio
Published: January 2023

In recent decades, a new line of research has found associations between specific individual differences with prejudice against female leaders. In three studies collected in Italy with heterogeneous samples (Total N = 391), we investigated the relationship between self-reported need for cognitive closure (NCC) and attitudes towards women as managers. In Study 1a we used a sample of Italian students and hypothesized that higher NCC is associated with more negative attitudes towards women managers and that this relationship is mediated by benevolence, but not by hostility, towards men. In Study 1b we used a sample of Italian employees and hypothesized that employees with higher NCC had less (vs. more) negative attitudes towards women managers when they had a female (vs. male) superior. In Study 2 we tested the model including both mediators and moderator from the previous two preliminary studies on a sample of Italian employees. The findings support the hypotheses. Our work increases knowledge about the individual-level antecedents of prejudice against women managers, as well as the conditions under which it can be reduced.
Parameter estimation of gravitational waves with a quantum metropolis algorithm
Authors: Escrig Gabriel , Campos Roberto , Casares Pablo A M , Martin-Delgado M A
Published: January 2023

After the first detection of a gravitational wave in 2015, the number of successes achieved by this innovative way of looking through the Universe has not stopped growing. However, the current techniques for analyzing this type of events present a serious bottleneck due to the high computational power they require. In this article we explore how recent techniques based on quantum algorithms could surpass this obstacle. For this purpose, we propose a quantization of the classical algorithms used in the literature for the inference of gravitational wave parameters based on the well-known quantum walks technique applied to a Metropolis–Hastings algorithm. Finally, we develop a quantum environment on classical hardware, implementing a metric to compare quantum versus classical algorithms in a fair way. We further test all these developments in the real inference of several sets of parameters of all the events of the first detection period GWTC-1 and we find a polynomial advantage in the quantum algorithms, thus setting a first starting point for future algorithms.
Stellar instability from parametric resonance
Authors: Maier Rodrigo
Published: January 2023

In this paper we examine the stability of stellar configurations in which the interior solution is described by a closed Friedmann-Lemaître-Robertson-Walker (FLRW) geometry sourced with a charged pressureless fluid and radiation. An interacting vacuum component and a conformally coupled massive scalar field are also included. Given a simple factor for the energy transfer between the pressureless fluid and the vacuum component we obtain bounded interior oscillatory solutions. We show that in proper domains of the parameter space the interior dynamics is highly unstable so that the break of the Kolmogorov–Arnold–Moser (KAM) tori leads to a disruptive ejection of mass. For such configurations the interior solution asymptotically matches an exterior Reissner–Nordström–de Sitter spacetime.
Dual-band valley topological refraction materials for bulk elastic waves manipulation
Authors: Huo Shao-Yong , Li Hong-Kang , Chen Cong-Ying , Deng Jian , Yao Long-Chao , Fu Chun-Ming , Huang Hong-Bo , Qu Wei
Published: January 2023

Valley topological refraction material (TRM) of elastic wave and its direction signal transmittance with robustness against structural disturbance is crucial for various applications such as communication, navigation and detection devices for medical and industrial purpose. However, the existing TRM is limited by the single topological band, which obviously hinders the exploration of the multi-band topological ultrasonic devices to guarantee its efficiency and stability. Here, we demonstrate the dual-band valley TRM for elastic waves, in which the valley edge states and their robustness are investigated. Furthermore, the topological refractions of the valley edge states from the interface into the free space at zigzag termination in two frequency bands are explored, where the mode conversion of the bulk elastic wave occurs at interface termination. Interestingly, the full mode conversion from longitudinal to transverse waves is revealed in the low frequency band while the non-full mode conversion between the longitudinal and transverse takes place in the high frequency band. The researched dual-band elastic TRM could facilitate the potential applications in multi-band and multi-directional devices.
Crystalline texture of cobalt nanowire arrays probed by the switching field distribution and FORC diagrams
Authors: Lobo Guerrero A , Encinas A , Araujo E , Piraux L , de la Torre Medina J
Published: January 2023

The crystalline texture of arrays of low diameter Co nanowires (NWs) synthesized by electrodeposition using electrolytes with different acidities (pH in the range 2.0–6.6) was studied by the switching field distribution (SFD) and first order reversal curve (FORC) diagrams. Particularly, the SFD determined as the derivative

d
M

/

d
H

of the descending part of the major hysteresis loop has proven to be a reliable and powerful method for the identification of different crystalline textures in the NWs and the quantification of their corresponding texture percentages. The presence of the face centered cubic-like texture at low pH values and hexagonal close packed textures with the c-axis perpendicular and parallel to the NWs axis at higher pH values have been identified by performing multiple Gaussian fits to the SFD by virtue of their different magnetic behavior observed during reversal of the magnetization. The field position and size of each curve in the multiple Gaussian fit provide information about the corresponding magnetic contribution and volumetric texture percentage of each crystalline texture in the NWs, respectively. The analysis of the SFD has been complemented and validated with FORC diagram measurements, showing that the width of the coercive field distribution is in good agreement with the width of the SFD. Also, it has been found that the different branches observed in the FORC diagrams along the interaction axis provide further insight on the interaction between magnetocrystalline fields. This work provides a novel methodology for the use of magnetometry as a reliable technique for the study of the interplay between the microstructure and magnetic behavior of arrays of NWs.
A VMD-PE-SG denoising method based on K–L divergence for satellite atomic clock
Authors: Yifeng Liang , Jiangning Xu , Fangneng Li , Miao Wu
Published: January 2023

The time scale of the global navigation satellite system (GNSS) is the core element for its position, navigation and timing services. A highly stable atomic clock is essential to ensure the reliability of the GNSS time scale. This study proposed a novel hybrid denoising model combining variational mode decomposition (VMD), K–L divergence, permutation entropy (PE), and Savitzky–Golay (SG) filter for satellite atomic clocks. Firstly, the key parameter of VMD is solved efficiently by taking the minimum sum of K–L divergence of decomposed modes as the constraint condition, and the optimised parameters are applied to the decomposition process. On this basis, the PE algorithm is used to determine the modes decomposed by VMD into signal-dominant and noise-dominant components by searching for the mutation of PE value at two adjacent points. Finally, the noise-dominant components are denoised by the SG filter and then reconstructed with the signal-dominant components to form the denoised signal. The analysis of the simulated signal shows that the method can effectively remove noise from the simulated signal, and the resulting denoised signal is similar to the pure signal. Compared with commonly used ensemble empirical mode decomposition and wavelet denoising methods, the signal-noise ratio of the proposed method is improved by 21.2% and 28.9%, and the root mean square error is improved by 24.1% and 29.8%, respectively. The results of experimental data testify that the K–L VMD-PE-SG-based denoising method can significantly reduce the dominant noise within one day, thus effectively improving the short to medium-term frequency stability. Compared with the original signal, the stability of the smoothing time within 76 800 s is generally improved, and the degree of improvement depends on the type of atomic clock and the smoothing time.
Time transfer with BDS-3 signals: CV, PPP and IPPP
Authors: Ren Zhiling , Gong Hang , Lyu Daqian , Peng Jing , Guo Yu , Sun Guangfu
Published: January 2023

The third phase of BeiDou navigation satellite system (BDS-3) was officially commissioned on 31 July 2020. In this study, we make a comprehensive evaluation of BDS-3 time transfer with the B1I, B3I, B1C and B2a measurements. The multi-path (MP) errors and noises of different BDS-3 ranging signals are analyzed to illustrate characteristic of the code observations firstly. Then dual-frequency ionosphere-free linear combinations of BDS-3 B1I&B3I and B1C&B2a measurements are used to achieve time transfer. Using Multi-GNSS Experiment station observations, we evaluate the performance of BDS-3 time transfer with common-view (CV), precise point positioning (PPP) and integer ambiguity PPP (IPPP) techniques. Analysis results show that BDS-3 B1C&B2a CV time transfer links show a better performance than GPS L1P&L2P links, whereas BDS-3 B1I&B3I links are worse than GPS links. For the PPP time transfer, GPS links show the best performance, followed by BDS-3 B1C&B2a links and B1I&B3I links. Furthermore, frequency stability of BDS-3 IPPP time transfer is more stable than PPP solutions at the long average interval time. And the long-term frequency stability of BDS-3 IPPP is comparable with GPS IPPP.
Adaptive fractionation at the MR-linac
Authors: Pérez Haas Y , Ludwig R , Dal Bello R , Tanadini-Lang S , Unkelbach J
Published: January 2023

Objective. Fractionated radiotherapy typically delivers the same dose in each fraction. Adaptive fractionation (AF) is an approach to exploit inter-fraction motion by increasing the dose on days when the distance of tumor and dose-limiting organs at risk (OAR) is large and decreasing the dose on unfavorable days. We develop an AF algorithm and evaluate the concept for patients with abdominal tumors previously treated at the MR-linac in 5 fractions. Approach. Given daily adapted treatment plans, inter-fractional changes are quantified by sparing factors δ

t
defined as the OAR-to-tumor dose ratio. The key problem of AF is to decide on the dose to deliver in fraction t, given δ

t
and the dose delivered in previous fractions, but not knowing future δ

t
s. Optimal doses that maximize the expected biologically effective dose in the tumor (BED10) while staying below a maximum OAR BED3 constraint are computed using dynamic programming, assuming a normal distribution over δ with mean and variance estimated from previously observed patient-specific δ

t
s. The algorithm is evaluated for 16 MR-linac patients in whom tumor dose was compromised due to proximity of bowel, stomach, or duodenum. Main Results. In 14 out of the 16 patients, AF increased the tumor BED10 compared to the reference treatment that delivers the same OAR dose in each fraction. However, in 11 of these 14 patients, the increase in BED10 was below 1 Gy. Two patients with large sparing factor variation had a benefit of more than 10 Gy BED10 increase. For one patient, AF led to a 5 Gy BED10 decrease due to an unfavorable order of sparing factors. Significance. On average, AF provided only a small increase in tumor BED. However, AF may yield substantial benefits for individual patients with large variations in the geometry.
River Islands of Khazir River A Geomorphological Study Along the Area from Nedoush Valley to the Upper Zap
Authors: Al،Mohsen Asbahia Younis , Hasan Haneen Muhanned
Published: January 2023

The study tackled the phenomenon of river islands in the Al-Kazir river, along the Nedoush valley to the Upper Zab river, which is part of the administrative borders of Mosul and Erbil governorates in northern Iraq. It addresses the main natural and human factors that facilitate the formation of the river islands, including the impact of geological factors and climate, the slope of the stream, and meanders, in addition to delineating the direct fundamental role of the river load on the islands’ formation. It also shows the impact of human factors such as agriculture, grazing, and most importantly, quarries. Then shows the difference in the islands’ numbers and sizes along the study area.
Velocity Patterns inside the Proposed Makhool Dam Reservoir with Different Operation Plans
Authors: Altawash M M , Al Thamiry H A
Published: January 2023

The Makhoul Dam project proposed to be established is considered one of the strategic projects in Iraq as it works to insurance large quantity of water spare in flood seasons, increase the storage capacity of the dams in Iraq, as well as increase food security. The Makhool Dam is located on Tigris River in Salah al-Din Governorate, and 8 km south of the meeting point of the Tigris River with the Lower Zab River. The lake area is about 256 km2. In this research, a mathematical model was prepared by using HEC-RAS Two Dimension Software to analyze the velocity patterns and water depths inside makhool dam reservoir at the highest operational water elevation, based on the designs prepared by the Iraqi Ministry of Water Resources which is 150.25 m.a.s.l. The present study was conducted to investigate velocity patterns with the difference outlet discharges and changing the operation of the spillway gates within Makhool reservoir. The velocities were predicted and evaluated by utilizing modeling efficiency was 99.7%. This shows that the velocity distribution can be described the pattern with a good accuracy. The obtained velocities were ranged from -0.5 m/s to 5.1 m/s, the maximum velocities were near the dam axis.
Detection of Groundwater Table by Using Ground Penetrating Radar in Two Selected Sites/Northern Iraq
Authors: Salih Sabbar Abdalah , Dhahir Mahmood Nayef , Ahmed Muhana Mutaab
Published: January 2023

A non-damaging geophysical measurement technique test method ground penetrating radar (GPR) was carried out successfully in two sites in the middle and north of Iraq in order to investigate the feasibility of detecting the shallow underground water level in both selected sites. The results show that the groundwater depths in Baiji site were between 0.95m, and 1.2m, while in Hammam AL-Aleel site were between 1.0m to 1.1m near the river. It was also noticed in Hammam AL-Aleel site that the GPR image showed the appearances of dramatically and clear dissolving features that sometimes coincide with the level of groundwater which was approximately about 4m depth to the west of Northern Thermal Power Plant (NTPP), due to the existence of Fatha formation; while in the east of (NTPP) there was no solubility features due to the absence of Fatha formation and the presence of quaternary coarse sediments. This technique has been proved to be an effective detection method for underground water level and can serve as a reference for future application using the dependent physical property of permittivity and conductivity in engineering site investigation, hydrogeological investigations, and the detection of subsurface cavities.
Mosul dam issues: analysis of the problem based on several studies
Authors: Obead Imad Habeeb , Fattah Mohammed Y.
Published: January 2023

Mosul Dam is the Middle East’s second-largest dam in terms of reservoir capacity. Since its inception in 1986, this dam has been plagued by seepage difficulties in its base caused by the breakdown of gypsum. Underneath the foundation, there are strata of anhydrite. This occurrence has sparked worry the dam’s stability. This paper presents a survey of studies conducted by several researchers on concerns related to the stability and safety of the Mosul Dam in Iraq. Additionally, the implications of the dam breach scenarios are to be presented and discussed. In another word, the Mosul Dam issues are assessed with different references to geologic challenges of the abutments and foundation, dissolution of gypsum and formation of sinkholes, dissolution of gypsum and seepage, and the probable scenarios for concerns of dam failure. After the ISIS conflict, maintenance has been disrupted and signs at the dam have triggered renewed concerns. Consequently, the Iraqi government have contracted the Italian engineering company Trevi to start remedial work on the dam. This work was in 2016. Therefore, the present state of Mosul Dam was declared as safe and stable.
Physicochemical Parameters of River Water and their Relation to Zooplankton: A Review
Authors: Majeed Osama S. , Nashaat Muhanned R. , Al-Azawi Ahmed J. M.
Published: January 2023

Rivers are dynamic systems that respond to various physicochemical characteristics. In this review, we focused on the most important physicochemical parameters that influenced zooplankton composition and diversity in the rivers, including water temperature, dissolved oxygen, biochemical oxygen demand, hydrogen ion concentration, electrical conductivity, salinity, total dissolved solids, total suspended solids, turbidity, total hardness, calcium, magnesium, total alkalinity, bicarbonate, phosphate, nitrate, sulphate, and water velocity. As well as, we define these environmental factors and determined the minimum and maximum values for each factor. In general, we can be concluded that physicochemical factors that exceed standard values affected negatively on the zooplankton composition and diversity.
Hydrochemical and Biological study of surface water in Al-Kut city
Authors: Aldafiay Hayder Abbas , Hussain Tariq Abed , Alhashimi Mohammed Ali , Muslam Ruaa Issa
Published: January 2023

In this study, physicochemical and biological examinations of water samples were performed. These analyses included measuring the pH, EC, TDS, TSS, DO, BOD, and COD. Turbidity was also measured. Along with the primary cations and anions, heavy metals such as Fe, Mn, Zn, Cd, Cu, Co, Pb, Ni, Cr, As, Mo, Hg, Al, Li, Be, Se, V, U, and Sr are included. The study of hydrochemistry incorporates both the geochemistry of the surface water in Al-Kut city as well as the water from the Tigris River that is discharged into the main river. There are a total of sixteen surface water samples that have been collected. These samples have been dispersed as sixteen from the Tigris River portion of the study region separately, which discharged onto the main river. In order to evaluate the quality of the water for a variety of applications, physicochemical parameters of water samples are tested, and the results of those analyses are compared to both Iraqi and international standards. The findings support the hypothesis that the pH of the Tigris River ranges from neutral to slightly alkaline. It is characterized by having slightly brackish water and an abundance of Ca2+ and SO4 =, which are the predominant ions in the water. In the Tigris River, the cations are arranged in the following order: Ca2+ Na+> Mg2+>K+, and the anions are organized as follows: SO4 = > Cl- > HCO3 -. The Tigris River in the city of Al-Kut was contaminated with PO4 3- and NO3. The concentrations of the trace elements Al, As, Sr, Mn, Fe, Li, Cd, Cr, Cu, Ni, Co, Pb, Zn, Mo, V, and Ba in the Tigris River are all within the acceptable limits, with the exception of Sr and b, which both exceed these limits. Trace elements appear to be concentrated in the Tigris River. According to BOD, the situation with the Tigris River is critical. The BOD and COD readings were visibly affected by the various forms of excreta that were not treated in the waste water. Because the water in the Tigris River is high in salinity (both TDS and EC) and nutrients, it cannot be used for drinking. However, the water may be used for irrigation, and its quality ranges from acceptable to outstanding.
The effective of time etching and different acids on the morphological porous silicon
Authors: Al-Jubouri Furqan Saleh , Salman Hamida. I. , Al-Kadumi Ahmed. K.
Published: January 2023

This paper study the characteristics of nano crystalline silicon prepared with the use of electrochemical etching with etching time (15,20) min for salt and Nitric acid (HNO3) and etching time (15,20) min for Ethanol and Hydrofluoric acid, and study the effect of this solutions on the characteristics of porous silicon (ps) will be produced by electrochemical etching by using electrochemical etching from p-type bulk silicon with resistivity (1-10 Ω.cm) with different time. after that, make a comparison for the morphological properties for porous silicon. Research employing X-ray diffraction and scanning electron microscopy instruments were also performed on the samples that were produced as a result. Micromachining etching uses electrochemical etching of silicon in HF solution. New wafer-etched structures are reported. Wall arrays, hole arrays, meander-shaped structures, spiral-like walls, microtubes, and more are produced. The electrochemical etch process and KOH etching time of the original pattern on final geometries are modelled.
Optimal digital filter selection for remote photoplethysmography (rPPG) signal conditioning
Authors: Guler Saygun , Golparvar Ata , Ozturk Ozberk , Dogan Huseyin , Kaya Yapici Murat
Published: January 2023

Remote photoplethysmography (rPPG) using camera-based imaging has shown excellent potential recently in vital signs monitoring due to its contactless nature. However, the optimum filter selection for pre-processing rPPG data in signal conditioning is still not straightforward. The best algorithm selection improves the signal-to-noise ratio (SNR) and therefore improves the accuracy of the recognition and classification of vital signs. We recorded more than 300 temporal rPPG signals where the noise was not motion-induced. Then, we investigated the best digital filter in pre-processing temporal rPPG data and compared the performances of 10 filters with 10 orders each (i.e., a total of 100 filters). The performances are assessed using a signal quality metric on three levels. The quality of the raw signals was classified under three categories; Q1 being the best and Q3 being the worst. The results are presented in SNR scores, which show that the Chebyshev II orders of 2nd, 4th, and 6th perform the best for denoising rPPG signals.
A computationally efficient and high-fidelity 1D steady-state performance model for PEM fuel cells
Authors: Zhao Jian , Li Xianguo , Shum Chris , McPhee John
Published: January 2023

The performance of a proton exchange membrane (PEM) fuel cell is determined by many factors, including operating conditions, component specifications, and system design, making it challenging to predict its performance over a wide range of operating conditions. Existing fuel cell models can be complex and computationally demanding or may be over-simplified by neglecting many transport phenomena. Therefore, a high-fidelity and computationally efficient model is urgently needed for the model-based control of fuel cells. In this study, semi-implicit multi-physics numerical models have been established, taking the mass, momentum, reactants, liquid water, membrane water, electrons, ions, and energy in all fuel cell components into account. The developed 1D model is of high fidelity by incorporating the two-phase flow, non-isothermal effect, and convection, and is still computationally efficient. These models are validated against data from an auto manufacturer with good agreements, and the computing efficiency is evaluated on a modest laptop computer. The modeling results suggest that the two-phase flow model exhibits better prediction accuracy than the single-phase flow model when reactants are fully humidified, while under low humidity conditions, the two models present equivalent performance as liquid water does not exist in the fuel cell components. The results also suggest that the maximum convective/diffusive ratio of H2, O2, and vapor mass fluxes can be 12%, 5.3%, and 35%, respectively, which are ignored in most diffusion-dominant models. The developed models are computationally efficient, requiring only 0.56 s and 0.26 s to simulate a steady-state operation of fuel cells for the two- and single-phase flow models, respectively. This implies that the developed models are suitable for the control of PEM fuel cells.
Affine Hecke algebras and quantum symmetric pairs
Authors: Fan Zhaobing , Lai Chun-Ju , Li Yiqiang , Luo Li , Wang Weiqiang
Published: January 2023

We introduce an affine Schur algebra via the affine Hecke algebra associated to Weyl group of affine type C. We establish multiplication formulas on the affine Hecke algebra and affine Schur algebra. Then we construct monomial bases and canonical bases for the affine Schur algebra. The multiplication formula allows us to establish a stabilization property of the family of affine Schur algebras that leads to the modified version of an algebra

K

n

c

{\mathbf K}^{\mathfrak c}_n

. We show that

K

n

c

{\mathbf K}^{\mathfrak c}_n

is a coideal subalgebra of quantum affine algebra

U

(

g
l

^

n

)

{\mathbf {U}}(\widehat {\mathfrak {gl}}_n)

, and

(

U

(

g
l

^

n

)
,

K

n

c

)

\big ({\mathbf {U}}(\widehat { \mathfrak {gl}}_n), {\mathbf K}^{\mathfrak c}_n)

forms a quantum symmetric pair. The modified coideal subalgebra is shown to admit monomial and stably canonical bases. We also formulate several variants of the affine Schur algebra and the (modified) coideal subalgebra above, as well as their monomial and canonical bases. This work provides a new and algebraic approach which complements and sheds new light on our previous geometric approach on the subject. In the appendix by four of the authors, new length formulas for the Weyl groups of affine classical types are obtained in a symmetrized fashion.