bluuebunny/crossref_metadata_2025 huggingface dataset:
Unsteady Interaction Between Purge Flow and Secondary Flow in High-Lift Low-Pressure Turbine
Authors: Qu Xiao , Wu Meng , Zhang Yanfeng , Lu Xingen , Li Liunan , Jiang Yuyan , Zhu Junqiang
Published: May 2024

The coupling effect between the complex vortex system and the rim purge flow in the endwall region of a high-lift low-pressure turbine (LPT) will significantly influence the evolution of secondary flow and the corresponding losses. This article focused on the unsteady interaction mechanism between the rim purge flow and the secondary flow inside the high-lift LPT under the periodic wake passing. The large eddy simulation (LES) method was used to reveal the influence mechanism of rim purge flow, rotor–stator cavity interaction, and unsteady wakes on the secondary flow. Detailed experimental measurement was carried out for the flow field of high-lift LPT under the influences of static purge flow. The results showed that the rim purge flow significantly increased the overturning and underturning downstream of the endwall region, resulting in aggravating secondary loss. The rotating-rim increased the difference of the circumferential velocity between the mainstream and the purge flow, aggravating the Kelvin–Helmholtz (K–H) instability, inducing the K–H vortex structure with stronger energy amplitude, and further increasing the endwall flow loss. The incoming wakes weakened the energy amplitude of the K–H vortex at the rim purge outlet, and thinned the thickness of the low-energy fluid at the blade leading edge. In addition, the interaction between the wakes and the secondary vortices further suppressed the development of the secondary flow. Nevertheless, the incoming wakes caused additional mixing losses and made a negative impact on the overall aerodynamic performance of the high-lift LPT.
Analysis of the Bifurcating Duct of an Inlet Particle Separator in Transonic Flow Conditions
Authors: Castaldi Marco , Mayo Ignacio , Demolis Jacques , Eulitz Frank
Published: May 2024

To increase the reliability of turboprop and turboshaft engines in extreme operating conditions, filtering protections such as inlet particle separators (IPSs) can be installed at the intake. The flow inside an IPS is highly 3D and unsteady, with fluctuations especially pronounced when transonic conditions are reached. Locally, shocks can occur, increasing the pressure losses. In this paper, we aim at providing the transonic analysis of an industrial IPS designed for aerodynamic lab testing. As a first step, we define the threshold beyond which sonic conditions are reached in the boundary cross sections of the IPS, in terms of inlet total pressure and Reynolds number, by means of a 1D semi-empirical model. Second, we select a critical configuration, very close to these conditions, and we perform CFD simulations to analyze the locations and evolution of the transonic flow inside the IPS. Different models are presented, i.e., steady and unsteady Reynolds-averaged Navier–Stokes, detached eddy simulation, and large eddy simulation, characterized by three levels of resolution (based on the grid size). The results show the evolution of some transonic shocks: the steady-state model is only providing information on averaged quantities, while the time-resolved simulations offer a more precise overview in the time domain (velocity and Mach number fluctuations). The analysis in the frequency domain reveals the frequencies of the transonic fluctuations, which can negatively affect the IPS. Finally, we discuss three alternative designs to effectively improve the operating range and mitigate the risks related to the transonic instabilities, comparing the differences in separation efficiency with respect to the baseline case. The results prove that the optimal design choice is given by the trade-off between operating range, pressure losses, and separation efficiency.
Condensation of RNase L promotes its rapid activation in response to viral infection in mammalian cells
Authors: Cusic Renee , Burke James M.
Published: May 2024

Oligoadenylate synthetase 3 (OAS3) and ribonuclease L (RNase L) are components of a pathway that combats viral infection in mammals. Upon detection of viral double-stranded RNA (dsRNA), OAS3 synthesizes 2′-5′-oligo(A), which activates the RNase domain of RNase L by promoting the homodimerization and oligomerization of RNase L monomers. Activated RNase L rapidly degrades all cellular mRNAs, shutting off several cellular processes. We sought to understand the molecular mechanisms underlying the rapid activation of RNase L in response to viral infection. Through superresolution microscopy and live-cell imaging, we showed that OAS3 and RNase L concentrated into higher-order cytoplasmic complexes known as dsRNA-induced foci (dRIF) in response to dsRNA or infection with dengue virus, Zika virus, or West Nile virus. The concentration of OAS3 and RNase L at dRIF corresponded with the activation of RNase L–mediated RNA decay. We showed that dimerized/oligomerized RNase L concentrated in a liquid-like shell surrounding a core OAS3-dRIF structure and dynamically exchanged with the cytosol. These data establish that the condensation of dsRNA, OAS3, and RNase L into dRIF is a molecular switch that promotes the rapid activation of RNase L upon detection of dsRNA in mammalian cells.
Unraveling the gut microbiota of Mexican pinnipeds: the dominance of life histories over phylogeny
Authors: Pacheco-Sandoval A. , Schramm Y. , Heckel G. , Giffard-Mena I. , Lago-Lestón A.
Published: May 2024

Studying how phylogeny influences the composition and functions of microbiotas within animal hosts is essential for gaining insights into the connection between genetics, ecology, and health in the animal kingdom. However, due to limited comprehensive studies, this influence remains unclear for many wild mammals, including Mexican pinnipeds. We employed 16S rRNA gene deep-sequencing to investigate the impact of phylogeny on the gut microbiota of four pinniped species inhabiting Mexican shores: the Pacific harbor seal (
Phoca vitulina richardii
), the northern elephant seal (
Mirounga angustirostris
), the California sea lion (
Zalophus californianus
), and the Guadalupe fur seal (
Arctocephalus philippii townsendi
). Our results indicated that factors such as diets and shared life histories exerted more influence on microbiota composition than phylogeny alone. Notably, otariid species sharing similar life histories displayed greater microbiota similarity than phocids, which have distinct life histories and fewer microbiota similarities. Furthermore, harbor seals have more microbial similarities with the two otariid species than with elephant seals. Of particular concern, we observed a higher abundance of potentially pathogenic bacteria (e.g.,
Photobacterium damselae
and
Clostridium perfringens
) in harbor seals and Guadalupe fur seals compared to other pinnipeds. This finding could pose health threats to these species and nearby human populations.

IMPORTANCE

Pinnipeds in Mexico host microbial communities that remain understudied. While several factors can influence microbiota composition, the role of phylogenetic relationships among these pinnipeds remains unclear due to limited knowledge of the microbiota in certain species. This study aimed to fill this gap by characterizing the composition and function of the gut microbiota in the four pinniped species that occur in Mexico. Our analysis reveals that shared diets and life histories contribute to similarities in the composition of gut microbial communities. This study also highlights the potential differences in the metabolic capabilities and adaptations within the gut microbiota of pinnipeds. Understanding how phylogeny impacts microbial communities enhances our insights into the evolutionary dynamics of marine mammals.
+Ciencia
: a training program to increase evidence-based science communication and literacy for Hispanic high school and undergraduate students
Authors: Colón Carrión Nicole , Fuentes Nathalie , Gerena González Valeria A. , Hsiao-Sánchez Nicole , Colón-Cruz Luis , de Jesús Morales Kevin , De Jesús Morales Kenneth J. , González Morales Maria , Lazcano Etchebarne Cayetana , Ramos Benítez Marcos J.
Published: May 2024

Science misinformation represents a significant challenge for the scientific community. Hispanic communities are particularly vulnerable due to language barriers and the lack of accessible information in Spanish. We identified that a key step toward enhancing the accessibility of information for non-native English-speaking communities involves imparting science communication education and training to Hispanic youth. Our goal was to provide them with the skills to become science ambassadors who can effectively engage with their communities and bridge communication gaps. To address this, we developed the first science communication training program in Spanish for Hispanic high school and undergraduate students in Puerto Rico. The program called
+Ciencia
aims to provide training and education on science communication for Hispanic minorities through experiential and collaborative learning. In the short term, our multifaceted approach works to counter misinformation and promote science literacy within the broader community. Over the long term, our grassroots efforts with students will evolve into a generation of professionals equipped with strong engagement skills and comprehensive training in science communication with a specific focus on Hispanic audiences. Herein, we describe the components of this educational program and provide open access to educational materials and articles developed by three cohorts.
Bacteriophage cocktail shows no toxicity and improves the survival of
Galleria mellonella
infected with
Klebsiella
spp.
Authors: Kelly Lucy , Jameson Eleanor
Published: May 2024

Klebsiella
spp. are causative agents of healthcare-associated infections in patients who are immunocompromised and use medical devices. The antibiotic resistance crisis has led to an increase in infections caused by these bacteria, which can develop into potentially life-threatening illnesses if not treated swiftly and effectively. Thus, new treatment options for
Klebsiella
are urgently required. Phage therapy can offer an alternative to ineffective antibiotic treatments for antibiotic-resistant bacteria infections. The aim of the present study was to produce a safe and effective phage cocktail treatment against
Klebsiella pneumoniae
and
Klebsiella oxytoca
, both in liquid
in vitro
culture and an
in vivo Galleria mellonella
infection model. The phage cocktail was significantly more effective at killing
K. pneumoniae
and
K. oxytoca
strains compared with monophage treatments. Preliminary phage cocktail safety was demonstrated through application in the
in vivo G. mellonella
model: where the phage cocktail induced no toxic side effects in
G. mellonella
. In addition, the phage cocktail significantly improved the survival of
G. mellonella
when administered as a prophylactic treatment, compared with controls. In conclusion, our phage cocktail was demonstrated to be safe and effective against
Klebsiella
spp. in the
G. mellonella
infection model. This provides a strong case for future treatment for
Klebsiella
infections, either as an alternative or adjunct to antibiotics.

IMPORTANCE

Klebsiella
infections are a concern in individuals who are immunocompromised and are becoming increasingly difficult to treat with antibiotics due to their drug-resistant properties. Bacteriophage is one potential alternative therapy that could be used to tackle these infections. The present study describes the design of a non-toxic phage cocktail that improved the survival of
Galleria mellonella
infected with
Klebsiella
. This phage cocktail demonstrates potential for the safe and effective treatment of
Klebsiella
infections, as an adjunct or alternative to antibiotics.
Immunological and microbial shifts in the aging rhesus macaque lung during nontuberculous mycobacterial infection
Authors: Cinco Isaac R. , Napier Ethan G. , Rhoades Nicholas S. , Davies Michael H. , Allison Derek B. , Kohama Steven G. , Bermudez Luiz , Winthrop Kevin , Fuss Cristina , Spindel Eliot R. , Messaoudi Ilhem
Published: May 2024

Nontuberculous mycobacteria (NTM) are environmentally ubiquitous organisms that predominately cause NTM pulmonary disease (NTMPD) in individuals over the age of 65. The incidence of NTMPD has increased in the U.S., exceeding that of
Mycobacterium tuberculosis
. However, the mechanisms leading to higher susceptibility and severity of NTMPD with aging are poorly defined in part due to the lack of animal models that accurately recapitulate human disease. Here, we compared bacterial load, microbial communities, and host responses longitudinally between three young (two female and one male) and two aged (two female) rhesus macaques inoculated with
Mycobacterium avium
subsp.
hominissuis
(MAH) in the right caudal lobe. Unilateral infection resulted in a low bacterial load in both young and aged animals confined to the infected side. Although a robust inflammatory response was only observed in the inoculated lung, immune cell infiltration and antigen-specific T cells were detected in both lungs. Computed tomography, gross pathology, and histopathology revealed increased disease severity and persistence of bacterial DNA in aged animals. Additional analyses showed the translocation of gut and oral-pharyngeal bacterial DNA into the lower respiratory microbiome. Finally, single-cell RNA sequencing revealed a heightened inflammatory response to MAH infection by alveolar macrophages in aged animals. These data are consistent with the model that increased disease severity in the aged is mediated by a dysregulated macrophage response that may be sustained through persistent antigen presence.

IMPORTANCE

Nontuberculous mycobacteria (NTM) are emerging as pathogens of high consequence, as cases of NTM pulmonary disease (NTMPD) have exceeded those of
Mycobacterium tuberculosis
. NTMPD can be debilitating, particularly in patients over 65 years of age, as it causes chronic cough and fatigue requiring prolonged treatments with antibiotics. The underlying mechanisms of this increased disease severity with age are poorly understood, hampering the development of therapeutics and vaccines. Here, we use a rhesus macaque model to investigate the impact of age on host-NTM interactions. This work shows that aging is associated with increased disease severity and bacterial persistence in aged rhesus macaques, thus providing a preclinical model to develop and test novel therapeutics and interventions.
Evaluation of the Tasso+ blood self-collection device for quantitation of plasma cytomegalovirus (CMV) DNAemia in adult solid organ transplant recipients (SOTr)
Authors: Phan Tran , Kumar Lakshin , Woo Marissa , Sadowska-Klasa Alicja , Castor Jared , Pepper Greg , Fisher Cynthia E. , Limaye Ajit P.
Published: May 2024

Quantitative monitoring of cytomegalovirus (CMV) DNAemia in venous blood is standard in solid organ transplant recipients (SOTr) but is limited by the need for phlebotomy facilities and personnel. The aim of the study was to evaluate the Tasso+ capillary blood (CB) self-collection device for quantitation of plasma CMV DNAemia. Thirty adult SOTr with suspected CMV DNAemia were enrolled to have a supervised Tasso+ CB sample collection within 24 h of a venous sample. CMV DNA was quantitated in paired samples by using the Abbott M2000 Real-Time qPCR instrument. The participants were provided with a study-specific survey that measured patient acceptability of the Tasso+ device compared with venipuncture. A Tasso + CB sample was successfully collected in 28/30 (93%) patients, and 44 paired samples were analyzed. Concordance for detection of CMV DNAemia above the limit of detection (LOD) was 91% (42/44), and the Tasso + CB sample was estimated to be 95% sensitive at a viral load (VL) of 308 IU/mL. Among samples with a quantifiable DNAemia result with both methods (
N
= 31), there was excellent correlation between methods (Spearman R
2
= 0.99). The difference in CMV VL between venous and Tasso+ CB samples was not dependent on time (
P
> 0.1). Of 12 who completed the survey, 11 (92%) expressed a preference for Tasso+ CB collection over venipuncture. Collection of CB with the Tasso+ device is feasible, patient-acceptable, and yields generally comparable CMV DNAemia load to standard venous samples, but with lower sensitivity. Future studies to optimize and evaluate this methodology for patient self-collected samples are warranted.

IMPORTANCE

We evaluate an FDA-cleared blood self-collection device (Tasso+) and demonstrate that it is patient-acceptable and yields a liquid blood sample with quantitative CMV DNAemia results comparable to those of standard venipuncture samples. This opens up possibilities for self-blood collection to monitor for CMV and potentially other viruses in transplant and other at-risk populations.
Identifying globally relevant learnings from Africa’s challenges and solutions to climate change and air pollution-related health impacts: a data science scoping review protocol
Authors: Wright Caradee Yael , Jaca Anelisa , Kapwata Thandi , Naidoo Natasha , Awokola Babatunde , Bainomugisha Engineer , Berhane Kiros T , Blesic Suzana , Kehbila Anderson , Naidoo Rajen , Nemukula Bono , Nyarko Benjamin Kofi , Okekunle Akinkunmi Paul , Oni Tolu , Quansah Reginald , Thiam Sokhna , Zakari Ibrahim Sidi , Beyene Negussie
Published: May 2024

Introduction

Leveraging data science could significantly advance the understanding of the health impacts of climate change and air pollution to meet health systems’ needs and improve public health in Africa. This scoping review will aim to identify and synthesise evidence on the use of data science as an intervention to address climate change and air pollution-related health challenges in Africa.

Methods and analysis

The search strategy will be developed, and the search will be conducted in the Web of Science, Scopus, CAB Abstracts, MEDLINE and EMBASE electronic databases. We will also search the reference lists of eligible articles for additional records. We will screen titles, technical reports, abstracts and full texts and select studies reporting the use of data science in relation to the health effects and interventions associated with climate change and air pollution in Africa.

Ethics and dissemination

There are no formal ethics requirements as we are not collecting primary data. Results, once published, will be disseminated via conferences and shared with policy-makers and public health, air pollution and climate change key stakeholders in Africa.
Profiles of health literacy and digital health literacy in clusters of hospitalised patients: a single-centre, cross-sectional study
Authors: Andersen Marit Helen , Hermansen Åsmund , Dahl Kari Gire , Lønning Kjersti , Meyer Käthe Birgitte , Vidnes Tone Karine , Wahl Astrid Klopstad
Published: May 2024

Objective

To investigate health literacy (HL) and digital health literacy (eHL) among patients hospitalised in surgical and medical wards using a cluster analysis approach.

Design

Cross‐sectional study using Ward’s hierarchical clustering method to measure cluster adequacy by evaluating distances between cluster centroids (a measure of cohesion). Different distances produced different cluster solutions.

Setting and participants

The study was conducted at a Norwegian university hospital. A total of 260 hospitalised patients were enrolled between 24 May and 6 June 2021.

Data collection

All data were collected by self-reported questionnaires. Data on HL and eHL were collected by the Health Literacy Questionnaire (HLQ) and the eHealth Literacy Questionnaire (eHLQ). We also collected data on background characteristics, health status and patient diagnosis.

Results

We found six HLQ clusters to be the best solution of the sample, identifying substantial diversity in HL strengths and challenges. Two clusters, representing 21% of the total sample, reported the lowest HLQ scores in eight of nine HLQ domains. Compared with the other clusters, these two contained the highest number of women, as well as the patients with the highest mean age, a low level of education and the lowest proportion of being employed. One of these clusters also represented patients with the lowest health status score. We identified six eHL clusters, two of which represented 31% of the total sample with the lowest eHLQ scores in five of seven eHLQ domains, with background characteristics comparable to patients in the low-scoring HLQ clusters.

Conclusions

This study provides new, nuanced knowledge about HL and eHL profiles in different clusters of patients hospitalised in surgical and medical wards. With such data, healthcare professionals can take into account vulnerable patients’ HL needs and tailor information and communication accordingly.
Advantages of bystander-performed conventional cardiopulmonary resuscitation in out-of-hospital cardiac arrest presumably caused by drowning in Japan: a propensity score-matching analysis using an extended nationwide database
Authors: Kaneto Yoshifumi , Owada Hitoshi , Kamikura Takahisa , Nakashima Kento , Ushimoto Tomoyuki , Inaba Hideo
Published: May 2024

Objectives

This study aimed to determine whether the association between conventional bystander cardiopulmonary resuscitation (BCPR) and better outcomes in drowning-associated out-of-hospital cardiac arrest (OHCA) differs between young and older people or between non-medical and medical drowning in Japan.

Design

Observational study.

Setting

This study used data from the Japanese Fire and Disaster Management Agency databases.

Participant

Of the 504 561 OHCA cases recorded in the nationwide database between 2016 and 2019, 16 376 (3.2%) were presumably caused by drowning.

Main outcome measure

The main outcomes were a 1-month neurological prognosis defined as cerebral performance category 1 or 2 and 1-month survival as measures.

Result

The incidence of drowning as a presumed cause of OHCA was high in the winter and the middle-aged and older generations in Japan. However, OHCA caused by drowning in the younger generation frequently occurs in the summer. Furthermore, younger patients had higher incidences of bystander-witnessed cardiac arrest (22.0%), BCPR provision (59.3%) and arrest in outdoor settings (54.0%) than middle-aged and older generations (5.9%, 46.1% and 18.7% respectively). If the patient was younger or the arrest was accidental, the conventional BCPR group had better neurological outcomes than the compression-only BCPR group (95% CI of adjusted OR, 1.22 to 12.2 and 1.80 to 5.57, respectively). However, in the case of middle-aged and older generations and medical categories, there was no significant difference in outcomes between the two types of BCPR. This conventional group’s advantage was maintained even after matching.

Conclusion

Conventional bystander CPR yielded a higher neurologically favourable survival rate than compression-only BCPR for OHCA caused by drowning if the patient was younger or the arrest was non-medical. Conventional CPR education for citizens who have the chance to witness drownings should be maintained.
Patient satisfaction among Saudi academic hospitals: a systematic review
Authors: Alasiri Ahmed Ali , Alotaibi Saad A , Schussler Eric
Published: May 2024

Purpose

To systematically review the patient’s satisfaction (PS) levels within academic hospitals in Saudi Arabia from January 2012 to the end of October 2022.

Data sources

Articles were gathered from PubMed, ProQuest, Google Scholar and Web of Science.

Study selection/data extraction

This review identified studies that assessed PS in Saudi Arabian university hospitals. Articles published before January 2012, as well as commentary letters, conference papers, theses and dissertations, were excluded. The study employed the five domains of PS as outlined by Boquirenet al. Two independent reviewers independently identified qualifying studies, used the Joanna Briggs Institute tools to evaluate the quality of each study and extracted essential data from each article.

Results

Out of the 327 studies identified during the search phase, 11 met the project’s objectives and criteria. Six studies reported overall PS rates ranging from 78% to 95.2%, with only one study indicating lower PS levels in emergency departments. Most studies demonstrated that technical skill is the primary domain influencing PS in academic hospitals.

Conclusion

There is a need for further investigation to explore the factors influencing PS using standardised survey instruments suitable for Saudi culture. Contradictory results regarding PS are clearly evident in the literature; therefore, it is advisable to standardise the assessment process to reduce discrepancies within the academic hospital setting in Saudi Arabia.
Markers of enterocyte damage, microbial translocation, and systemic inflammation following 9 h of heat exposure in young and older adults
Authors: Lee Ben J. , Russell Sophie L. , Meade Robert D. , McCormick James J. , King Kelli E. , Kenny Glen P.
Published: May 2024

Heat stress induced damage to the gastrointestinal barrier can induce local and systemic inflammatory reactions implicated in heat-stroke. Gastrointestinal barrier damage has been shown to be greater in older relative to young adults following hyperthermia. However, comparisons between young and older adults have been limited to brief exposures (3 h), which may not reflect the duration of heat stress experienced during heat waves. We therefore evaluated markers of intestinal epithelial damage (log transformed intestinal fatty acid binding protein, IFABPLOG), microbial translocation (soluble cluster of differentiation 14, sCD14LOG), and systemic inflammation (tumour necrosis factor alpha, TNF-αLOG; interleukin 6, IL-6LOG; C-reactive protein, CRP) in 19 young (interquartile range: 21–27 years; 10 females) and 37 older (68–73 years; 10 females) adults before and after 9 h of rest in 40 °C (9% relative humidity). The magnitude of the increase in IFABPLOG was 0.38 log pg/mL (95% CI, 0.10, 0.65 log pg/mL) greater in the older relative to young cohort ( P = 0.049) after 9 h heat exposure. At baseline both IL-6LOG and CRP concentrations were higher in the older (IL-6: 2.67 (1.5) log pg/mL, CRP: 0.28 (1.5) mg/mL) relative to the young (IL-6: 1.59 log pg/mL, SD 1.2; CRP: 0.11 mg/mL, SD 1.7) group (both P ≤ 0.001). The change in IL-6 and CRP was similar between groups following 9 h heat exposure (IL-6: P = 0.053; CRP: P = 0.241). Neither sCD14LOG and TNF-αLOG were different between groups at baseline nor altered after 9 h heat exposure. Our data indicate that age may modify intestinal epithelial injury following 9 h of passive heat exposure.
Geochemistry, geochronology, and radiogenic isotopes of the Balmer and Confederation assemblages of the Laird Lake Area, Red Lake greenstone belt, Canada: implications for Archean tectonic evolution
Authors: Gélinas Brigitte R. , Hollings Pete , Friedman Richard
Published: May 2024

The Laird Lake property, southwest Red Lake greenstone belt, straddles the contact between the Balmer (2.99–2.96 Ga) and the Confederation (2.74–2.73 Ga) assemblages. The property is 10 km along strike from the Madsen and Starrat–Olsen Au mines that are hosted near the contact. The Balmer assemblage consists of fine-grained, aphyric, locally pillowed mafic volcanic rocks, ultramafic intrusive and volcanic rocks with flow breccia textures hosting local spinifex-bearing clasts, and banded-iron formations. In contrast, the Confederation assemblage comprises porphyritic mafic volcanic rocks intercalated with intermediate to felsic volcanic rocks that include crystal lapilli tuffs, crystal tuffs, and tuffs. The Balmer assemblage is composed of tholeiitic mafic volcanic rocks with minor Al-undepleted komatiites, whereas the Confederation assemblage is calc–alkalic. Neodymium isotopes, in conjunction with trace element geochemistry, suggests that parts of the Balmer assemblage were weakly contaminated by an older intermediate basement. Both arc and back-arc volcanism occurs in the Confederation assemblage, with the arc rocks showing a stronger crustal component than the back-arc rocks. A maximum U–Pb age of 2741 ± 19 Ma for a crystal tuff and an age of 2737.68 ± 0.79 Ma for a diorite are consistent with a Confederation assemblage affinity for the intermediate calc–alkaline rocks south of the Au-bearing horizon. The Balmer assemblage represents an oceanic plateau formed by plume magmatism on the margins of the North Caribou Terrane, whereas the Confederation assemblage at Laird Lake formed in an oceanic arc setting where both arc and back-arc volcanism occurred simultaneously.
Dual-junction gallium nitride solar cells with hybrid tunnel junction layers
Authors: Hou Jei-Li , Lin Wei-Heng , Chen Wei-Shou , Chang Sheng-Po , Chang Shoou-Jinn
Published: May 2024

The authors reported the fabrication of a dual-junction (2J) GaN solar cell (SC) with hybrid tunnel junction (TJ) layers. Compared with the single-junction (1J) SCs, it was found from the XRD spectra that the crystal quality of the SC with TJ was almost identical. However, the efficiencies of bottom 1J SC, top 1J SC, and 2J SC increase from 1.18 to 1.07, 1.12 to 1.20, and 1.59 to 1.73, respectively, when the concentrated suns increased from 1 to 100 suns. It was found that the use of hybrid TJ layers could result in a higher conversion efficiency in 2J SC and was essential in SCs for serially connecting multiple active junctions.
Viscous dissipation and Joule heating in case of variable electrical conductivity Carreau–Yasuda nanofluid flow in a complex wavy asymmetric channel through porous media
Authors: Ahmed Sameh E. , Arafa Anas A. M. , Hussein Sameh A.
Published: May 2024

This paper focuses on flow structures and thermal fields of the Carreau–Yasuda (CY) nanofluid model through a two-dimensional, wavy, complicated vertical asymmetrical conduit filled with porous elements. Formulations of the viscous dissipation in the case of CY nanofluids are derived and nonlinear radiation flux as well as joule heating are examined. Buongiorno’s nanofluid approach, which involves Brownian motion and thermophoresis aspects is considered. The electrical conductivity of the suspension is considered as a variable where it depends upon the ambient temperature and concentration distributions and the Joule heating impacts are not neglected. The approach of solving the problem is contingent upon converting the system to dimensionless form then the lubrication approach with low magnetic Reynold numbers is applied. Numerical solutions are found for the resultant system, and wide ranges are considered for Weissenberg number We, non-Newtonian parameter n and Darcy number [Formula: see text], namely, [Formula: see text], [Formula: see text] and [Formula: see text], respectively. The major results indicated that gradients of the pressure are higher in case of shear thickening [Formula: see text] comparing to in the instance of shear thinning [Formula: see text]. Also, the velocity is enhanced, close to the channel’s lowest portion, as the Weissenberg number is growing. The variable electrical conductivity gives a higher mass transfer rate compared to the constant property.
Preparation, structure and spectral characteristics of Zinc tellurite glasses system doped with different concentrations of Tm3+
Authors: Fang Yan , He Chongjun , Chen Fangzhou , He Yiyang , Lu Yuangang , Liu Lijuan , Xia Mingjun , Deng Chenguang , Li Qian , Chen Huiting
Published: May 2024

Gallium-tellurite glass is a new optical material with good transmittance in the infrared region up to 6.5[Formula: see text]. Three different tellurate glasses were prepared: TeO2–ZnO–Ga2O3(TZG), TeO2–ZnO–La2O3(TZL) and TeO2–ZnO–B2O3(TZB). X-ray diffraction indicates that no crystal precipitates in the three glass systems, which maintain a stable glass state. Raman scattering experiments and fluorescence emission spectroscopy measurements were carried out on the tellulate glasses doped with the same concentration of [Formula: see text]. It was found that the phonon energy of TZG(TeO2–ZnO–Ga2O3)-doped thulium glass is the lowest, and the emission light at 1380[Formula: see text]nm is the strongest with [Formula: see text]nm fluorescence FWHM. These results show that Tm-doped TZG glass is a good luminescent material. Refractive indices were measured by the minimum deviation method. Sellmeier dispersion equation is obtained, which can be used to calculate the refractive index within visible and near-infrared spectral range. Furthermore, different [Formula: see text] concentrations (0.4%, 0.8%, 1.2% and 2%) TZG glasses were prepared, the emission spectra and fluorescence lifetime were measured, and the emitted light was strongest when the thulium ion doping concentration is 1.2%. All the results suggest that these newly developed ternary tellurite glass systems are promising candidates for near/mid-infrared laser glass fibers, fiber amplifiers, or lasers.
Optimizing Elliptical Cylindrical Antenna Array for Improved Wireless Communication Using Novel PSO Algorithm
Authors: Rao Thadikamalla Nageswar , Rao Amara Prakasa
Published: May 2024

This paper presents a novel approach to optimize the thinning of an elliptical cylindrical array (ECA) composed of uniformly stimulated, isotropic antennas with the objective of achieving a directed beam characterized by a significantly reduced relative Sidelobe Level (SLL). The optimization process employs the Novel Particle Swarm Optimization (NPSO) method, which offers a fresh perspective on addressing electromagnetic optimization challenges by its ability to effectively explore solution spaces. By employing the NPSO algorithm, which emulates the collective behavior of swarming particles to search for optimal solutions, this study addresses complex optimization challenges inherent in antenna array design. This study focuses on identifying the optimal combination of ON–OFF components (use the minimum number of ON antenna elements) within the antenna array to produce a radiation pattern exhibiting the greatest decrease in SLL. Additionally, the First Null Beam Width (FNBW) is targeted for optimization without predefined values. The optimization approach also considers the effect of thinned array element spacing on the overall performance metrics. Out of total 36 elements, only 15 elements are switched ON and the remaining of the elements are OFF, so the total reduction or thinning of ECAA is 41.66%. Simulation results demonstrate that the proposed methodology enables a simultaneous reduction of more than half of the antenna array elements while achieving superior SLL minimization. This significant reduction in antenna elements not only contributes to simplifying the array design, but also enhances the array’s beamforming capabilities.
Investigation of Dynamic Coupling Effect on Bridge Frequency Measurement
Authors: Yang Judy P. , Jiang Han-Cyuan , Yau J. D. , Urushadze Shota
Published: May 2024

In this study, a multidisciplinary approach combining a numerical analysis in three dimensions and a laboratory test is developed to investigate the dynamic coupling effect as induced by vehicle–bridge interaction in the indirect measurement. To unveil such dynamic coupling and its influence on the frequency measurement, a single degree-of-freedom test vehicle is exclusively designed with adjustable frequency, which is a low-cost, easy-to-use, and reliable tool for measuring beam frequencies in the laboratory while providing valuable data for validating numerical models, calibrating sensors, and evaluating bridge performance. From the multidisciplinary analysis, the shifts of frequencies for both vehicle and bridge are consistently demonstrated as a result of vehicle–bridge interaction effect. Moreover, for the identification of higher-order bridge frequencies, the contact-point response works better than the vehicle’s response, even with shifted frequencies being observed in the three-dimensional numerical results. As an extension, a parametric study is conducted numerically to include various practical conditions, including different types and boundary conditions of a bridge as well as pavement irregularity.
The geometrization of quantum mechanics, frozen stars, the Bohm–Poisson and nonlinear Klein–Gordon equations
Authors: Perelman Carlos Castro
Published: May 2024

We revisit the nonlinear Klein–Gordon-like equation that was proposed by us which captures how quantum mechanical probability densities curve spacetime, and find an exact solution that may appear to be “trivial” but with important physical implications related to the physics of frozen stars and with Mach’s principle. The nonlinear Klein–Gordon-like equation is essentially the static spherically symmetric relativistic analog of the Newton–Schrödinger equation. We finalize by studying the higher-dimensional generalizations of the nonlinear Klein–Gordon-like equation and examine the relativistic Bohm–Poisson equation as yet another equation capturing the interplay between quantum mechanical probability densities and gravity.
Kählerian Norden spacetime admitting conformal η-Ricci–Yamabe metric
Authors: Yadav S. K. , Suthar D. L.
Published: May 2024

In this paper, we investigate conformal [Formula: see text]-Ricci–Yamabe soliton on semiconformally flat Kählerian Norden spacetime in conjunction with the Kählerian Norden torse-forming vector field. Furthermore, we examine various physical aspects of such soliton on special fluid spacetime, such as dust fluid, dark fluid, radiation era, viscous fluid, and heat flux. In addition, we light up the harmonic features of conformal [Formula: see text]-Ricci-Yamabe soliton on semiconformally flat Kählerian Norden spacetime. Finally, we also deduce the necessary and sufficient conditions for a [Formula: see text]-form [Formula: see text], which is the [Formula: see text]-dual of the vector field [Formula: see text] on such a spacetime, to be a solution of the Schrödinger-Ricci equation.
Bouncing behavior of anisotropic cosmological model
Authors: Sobhanbabu Y. , Santhi M. Vijaya , Rao A. Srinivasa , Prasuna P. Jnana
Published: May 2024

We study locally rotationally symmetric (LRS) Bianchi type-I cosmological model in the presence of general theory of relativity. The source for energy–momentum tensor is assumed a perfect fluid. The field equations have been solved by using special form of the average scale factor [Formula: see text], where [Formula: see text] is initial cosmic time and [Formula: see text] is constant, proposed by Cai et al. [J. High Energy Phys. 710, 071 (2007)]. The physical properties and bouncing behavior of the model are discussed through graphical representation. The violation of strong energy condition (SEC) further supports the behavior of accelerated expansion of the Universe. The stability analysis of the model is discussed through geometrical representation.
Applications of zinc stable isotope analysis in environmental and biological systems: a review
Authors: Junqueira Tassiane P. , Vriens Bas , Leybourne Matthew I. , Harrison Anna L. , Sullivan Kaj V. , Jeong Hyeryeong , Araújo Daniel F.
Published: May 2024

Zinc (Zn) is an essential trace element that is involved in both biotic and abiotic processes in Earth's surface environments. Over the last 20 years, advances in mass spectrometry instrumentation have enabled unprecedented high-precision Zn isotope abundance ratio determinations in natural and anthropogenic samples. Supported by a solid theoretical background inherited from the traditional non-metal stable isotopes (C, N, H, O, S), the understanding of the controlling factors of Zn isotope fractionation has rapidly evolved. In this article, we review the main applications and findings of Zn isotopes in a variety of scientific domains, including metal contamination, magmatic differentiation, plant uptake, weathering, global climate change, dietary and trophic chains, and biomedicine. The analytical aspects of Zn isotope determination in solid and water samples and the principles and mechanisms of Zn isotope fractionation are also reviewed. This work aims to provide a general yet in-depth panorama of Zn isotope chemistry and to demonstrate the versatility and potential of this isotope system for studying the biological, geological and chemical cycling of Zn.
Physico-mechanical properties of halite and gypsum–mudstone crushed rock backfills of the Mercia Mudstone Group
Authors: Umeaghadi Chibuike C. , Lucock Thomas , Hartley Richard , Berry Jessica , Bailey Matthew T.
Published: May 2024

Permanent disposal of radioactive waste in deep geological repositories (DGRs) relies on engineered barriers, such as crushed rock backfills, to ensure that wastes are isolated and contained. The performance of crushed rock backfill, during construction, operation and closure, relies on optimizing its mechanical properties. This paper explores how density and composition influence the strength of (i) crushed halite and (ii) crushed gypsum–mudstone mixtures of the Triassic Mercia Mudstone Group, which is a potential DGR host rock in the UK. Unconfined compressive strength (UCS) testing of compacted halite demonstrated that strength correlated with compaction density, with UCS increasing from 220 kPa at a density of 1.72 g cm
−3
up to 6600 kPa at the maximum achieved density of 1.83 g cm
−3
. Direct shear testing revealed an angle of internal friction for crushed halite samples of 39°–40° at a density of 1.5 g cm
−3
. Direct shear testing of gypsum–mudstone composites from 100% gypsum to 100% mudstone revealed that higher gypsum percentages provide greater frictional shearing resistance, whilst higher mudstone percentages promote more cohesive strength. Data are also presented on bulk materials characterization by X-ray fluorescence (XRF), scanning electron microscopy with energy-dispersive spectrometry (SEM-EDS) and optical microscopy. This research provides insights into how the strength properties of compacted crushed halite and gypsiferous mudstone backfills can be engineered through control of density and composition.
Generic modelling to develop thermal yield nomograms for coaxial deep borehole heat exchangers (DBHEs)
Authors: Banks David , Brown Christopher S. , Kolo Isa , Falcone Gioia
Published: May 2024

Numerical modelling of coaxial deep borehole heat exchangers (DBHEs) can be resource-intensive. Simpler, transparent analytical models and nomograms would be valuable to developers and geologists for evaluating thermal output. In this paper, Beier’s published analytical computational model was used to produce nomograms of geothermal heat yield by systematically varying the DBHE depth and rock thermal conductivity, while assuming two generic simplified DBHE designs, a geothermal gradient of 25°C km
−1
and a fluid circulation rate of 5 l s
−1
. Continuous 25 year heat yields from a 1000 m DBHE range from 27.3 to 54.8 kW for thermal conductivities of 1.6–3.6 W m
−1
 K
−1
. For a 3000 m DBHE, they range from 165 to 281 kW. Effective borehole thermal resistance (
R
b,eff
) increases strongly as DBHE depth increases due to internal heat transfer between the upflow and downflow elements. Simulations correspond well with results from industry-standard Earth Energy Designer software for a shallow 200 m coaxial BHE. They modestly underestimate the OpenGeoSys numerical modelled thermal yields by 2–4% for DBHE in the depth range 1000–3000 m. Modelled temperature evolution closely approximates an analytical ‘line heat source’ approach, implying that simpler analytical approaches are plausible for DBHE simulation. Future research should focus on methods for forward quantification of
R
b,eff
.
The First Computer Program
Authors: Rojas Raúl
Published: May 2024

Mathematician and inventor Charles Babbage's code sketches are the first attempt to specify how to mechanize complex algorithms with a computer.
A Quantum Leap in Factoring
Authors: Monroe Don
Published: May 2024

The cryptography-threatening Shor algorithm for quantum computing sees its greatest theoretical advance in more than 25 years.
FASA-DRAM: Reducing DRAM Latency with Destructive Activation and Delayed Restoration
Authors: Du Haitao , Qin Yuhan , Chen Song , Kang Yi
Published: May 2024

DRAM memory is a performance bottleneck for many applications, due to its high access latency. Previous work has mainly focused on data locality, introducing small but fast regions to cache frequently accessed data, thereby reducing the average latency. However, these locality-based designs have three challenges in modern multi-core systems: (1) inter-application interference leads to random memory access traffic, (2) fairness issues prevent the memory controller from over-prioritizing data locality, and (3) write-intensive applications have much lower locality and evict substantial dirty entries. With frequent data movement between the fast in-DRAM cache and slow regular arrays, the overhead induced by moving data may even offset the performance and energy benefits of in-DRAM caching.

In this article, we decouple the data movement process into two distinct phases. The first phase is Load-Reduced Destructive Activation (LRDA), which destructively promotes data into the in-DRAM cache. The second phase is Delayed Cycle-Stealing Restoration (DCSR), which restores the original data when the DRAM bank is idle. LRDA decouples the most time-consuming restoration phase from activation, and DCSR hides the restoration latency through prevalent bank-level parallelism. We propose FASA-DRAM, incorporating destructive activation and delayed restoration techniques to enable both in-DRAM caching and proactive latency-hiding mechanisms. Our evaluation shows that FASA-DRAM improves the average performance by 19.9% and reduces average DRAM energy consumption by 18.1% over DDR4 DRAM for four-core workloads, with less than 3.4% extra area overhead. Furthermore, FASA-DRAM outperforms state-of-the-art designs in both performance and energy efficiency.
Software Drift
Authors: Neville-Neil George V.
Published: May 2024

Open source forking.
A Life of Complexity
Authors: Savage Neil
Published: May 2024

Following his parents' advice on going to university led Avi Wigderson to the ACM A.M. Turing Award.
Multiple Image Distortion DNN Modeling Individual Subject Quality Assessment
Authors: Fotio Tiotsop Lohic , Servetti Antonio , Pocta Peter , Van Wallendael Glenn , Barkowsky Marcus , Masala Enrico
Published: May 2024

A recent research direction is focused on training Deep Neural Networks (DNNs) to replicate individual subject assessments of media quality. These DNNs are referred to as Artificial Intelligence-based Observers (AIOs). An AIO is designed to simulate, in real-time, the quality ratings of a specific individual, enabling an automatic quality assessment that accounts for subjects characteristics and preferences. Training AIOs is a promising but challenging research area due to the greater noise in individual raw opinion scores compared to the Mean Opinion Score. Effective learning from noisy labels necessitates the training of complex models on large-scale datasets. Unfortunately, this is challenging for AIOs as the media quality assessment community lacks extensive datasets that include individual opinion scores. To address the complexity of the task, we first created a dataset comprising two million samples, with synthetic labels derived from human annotation. We then trained a customized network for image quality assessment, named Multi-Distortion ResNet50 (MDResNet50), on this dataset. The weights of the MDResNet50 were subsequently utilized to initialize the learning process of each AIO, thereby avoiding the need to train a complex model from scratch on a small-scale dataset with raw individual opinion scores. Computational experiments show that our approach significantly advances the state-of-the-art in the AIO research. In particular: (i) we demonstrate through a simulation the ability of AIOs to mimic two well-known behavioral characteristics of a subject, i.e., bias and inconsistency, when scoring the media quality; (ii) we train and release DNN-based AIOs that, compared to the state-of-the-art, exhibit a higher performance with a statistical significance in assessing multiple image distortions; (iii) we train AIOs that more accurately mimic the sensitivity of real subjects to noise and color saturation and also better predict the opinion score distribution compared to the state-of-the-art AIOs.