bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of the irradiance and yield calculation of bifacial PV systems in the USA and Germany by combining ray tracing and view factor model
Authors: Grommes Eva-Maria , Schemann Felix , Klag Frederik , Nows Sebastian , Blieske Ulf
Published: February 2023

Compared to conventional photovoltaic (PV), there are more influencing factors in bifacial photovoltaics to be considered to calculate incoming irradiance and energy yield. Accurate models to investigate the influences of the elevation, the albedo of the ground, the shading conditions between the PV rows and many other rear-side related factors are required. This paper combines the ray tracing (RT) and view factor (VF) models to calculate the irradiance with a subsequent electrical yield calculation using the one-diode model. To verify the results of the developed open-source simulation program BifacialSimu, accurate data from a plant in Golden, USA (single-axis tracked) and a commercially operated plant in Germany (fixed-tilt) are used. Through comparisons to the actual data, it can be concluded that a combination of RT and VF models seems to be valid for longer simulation periods with several months since the relative errors balance out. The RT-only simulation accurately reproduces the precise hourly radiation and electrical yield pattern. Still, a continuous positive deviation was found, which does not even out over long periods and is thus less accurate than the VF/RT combination. A simulation for a single month with RT can take several hours. Thus, the best simulation mode results according to user requirements.
Updated mortality estimation formulae for salmonids passing through Francis turbines at hydropower plants
Authors: Tomanova Sylvie , Courret Dominique , Tymen Blaise , Richard Sylvain , Dumond Lionel , Sagnes Pierre
Published: February 2023

Downstream migrating fish can be strongly affected by hydroelectric facilities. To set up adapted mitigation measures, it is important to identify these impacts (e.g. induced mortality rates). For Francis turbines, two mortality prediction formulas, developed in 1989 and updated in 2000, are currently used in France for salmonids according to turbine characteristics and fish size (Larinier and Dartiguelongue, 1989, updated by Bosc and Larinier, 2000). However, their use is limited when some parameters are unknown, such as turbine speed. Moreover, the updated version of can be criticized because of its unpublished development procedure and its unknown predictive power. The main purpose of this study is to update the existing formulae to meet the following objectives: (1) a transparent development procedure, (2) formulae simplification, (3) the use of simple (usually the best-known) turbine parameters, and (4) a maximization of the predictive power and an assessment of prediction errors. Based on data from 73 in situ mortality tests available in peer-reviewed and ‘grey’ literature, we developed two new formulae to estimate salmonid mortality rate in Francis turbines. The first one uses turbine peripheral speed, diameter and fish size (correlation between predicted and observed mortality rates r = 0.89, and root mean square error RMSE = 0.11). The second one is based on usually known parameters: turbine discharge, water head and fish size, to allow a broader applicability (r = 0.89, RMSE = 0.10). This study comforts the validity of previous formulae and provides two new ones allowing a satisfactory precision in the estimations.
Effet bénéfique d’une combinaison de feedback, d’observation et d’imagerie motrice sur la performance du départ plongé en natation
Authors: Robin Nicolas , Carien Robbin , Dominique Laurent , Hatchi Vanessa , Hue Olivier
Published: February 2023

Pour favoriser la performance, certains entraîneurs ont souvent recours au feedback (FB) verbal, à l’Observation d’un Modèle (OM) ou à l’imagerie motrice (IM) consistant à simuler mentalement réaliser une action. Cette étude avait pour but de tester les effets d’une combinaison de FB, d’OM et d’IM sur la performance du 25 m départ plongé en natation chez des non-experts. Cent-six étudiants volontaires (Mage = 19,3), aléatoirement divisés en 3 groupes : FB, FB+OM et FB+OM+IM, ont réalisé 3 phases réparties sur 6 séances. Séance 1 (pré-test), ils ont réalisé 5 × 25 m départs plongés (filmés et chronométrés). Les 4 séances suivantes (8 × 25 m départ plongé), ils recevaient un FB verbal (chaque 2 essais), ceux du groupe FB+OM bénéficiaient en plus de la vidéo et ceux du groupe FB+OM+IM s’imaginaient réaliser un plongeon après la vidéo. Séance 6 (post-test) : similaire à la séance 1. Les résultats montrent que tous les participants ont amélioré leur vitesse de coulée, mais seul le groupe FB+OM+IM a amélioré la distance de coulée et le temps sur 25 m. L’intérêt de combiner les modalités de pratique, pour améliorer le 25 m départ plongé, est discuté au regard de la littérature.
Neue Daten zur Vorsorgekoloskopie: NordICC-Studie
Authors: Duchmann Rainer
Published: February 2023

Die Vorsorgekoloskopie wurde in Deutschland im Jahr 2002 in den Leistungskatalog der
gesetzlichen Krankenkassen eingeführt. Deutschland übernahm damals
weltweit eine Vorreiterrolle. Anders als in Ländern ohne Vorsorgekoloskopie
ging die Neuerkrankungsrate am kolorektalen Karzinom (CRC) parallel hierzu um ca.
ein Viertel zurück, die Sterblichkeitsrate bei Männern und Frauen
sank um ca. 35% bzw. 40%. Um die Teilnahme der Bevölkerung
an der Darmkrebsvorsorge zu erhöhen, startete am 1. Juli 2019 ein
Einladungsverfahren zur Darmkrebsfrüherkennung.
Prävention des Pankreaskarzinoms
Authors: Scherübl Hans
Published: February 2023

Das Pankreaskarzinom nimmt in Deutschland stetig an Häufigkeit zu und stellt aktuell die dritthäufigste tumorbedingte Todesursache dar. Voraussichtlich rückt es bis 2030 auf den 2. Platz und bis 2050 auf den 1. Platz der krebsbedingten Todesfälle vor. Das Pankreasadenokarzinom wird in der überwiegenden Mehrzahl der Fälle spät diagnostiziert und die 5-Jahre-Überlebensrate liegt nach wie vor bei nur 10 %. Zu den beeinflussbaren Risikofaktoren zählen das Tabakrauchen, ein übermäßiges Körpergewicht, der Alkoholkonsum, der Typ-2-Diabetes und das metabolische Syndrom. Der Rauchstopp und die gewollte Gewichtsabnahme (bei Adipositas) können das Pankreaskrebsrisiko um etwa 50 % reduzieren. Zudem ist die Früherkennung des sporadischen Pankreaskarzinoms im Stadium IA – nun mit einem 5-Jahre-Überleben von 80 % – bei Menschen über 50 mit neu diagnostiziertem Diabetes eine realistische Perspektive geworden. Aktuelle Entwicklungen hierzu werden kurz beschrieben.
Managing the Root in Acute Type A Aortic Dissections: Are We Ready for a Standardized Approach?
Authors: Lopez-Marco Ana , Yates Martin T. , Adams Benjamin , Lall Kulvinder , Yap John , Di Salvo Carmelo , Uppal Rakesh , Oo Aung
Published: February 2023

Objectives Surgical repair of Type A aortic dissection (TAAD) requires exclusion of the primary entry tear and reestablishment of flow into the distal true lumen. Provided that the majority of tears occur within the ascending aorta (AA), replacing only that segment seems a safe option; however, this strategy leaves the root susceptible to dilatation and need for reintervention. We aimed to review the outcomes of the two strategies: aortic root replacement (ARR) and isolated ascending aortic replacement.

Methods Retrospective analysis of prospectively collected data for all consecutive patients who underwent repair of acute TAAD at our institution from 2015 to 2020 was conducted. Patients were divided into two groups: (1) ARR and (2) isolated AA replacement as index operation for TAAD repair. Primary outcomes were mortality and need for reintervention during the follow-up.

Results A total of 194 patients were included in the study; 68 (35%) in the ARR group and 126 (65%) in the AA group. There were no significant differences in postoperative complications or in-hospital mortality (23%; p = 0.51) between groups. Seven patients (4.7%) died during follow-up and eight patients underwent aortic reinterventions, including proximal aortic segments (two patients) and distal procedures (six patients).

Conclusion Both aortic root and AA replacement are acceptable and safe techniques. The growth of an untouched root is slow, and reintervention in this aortic segment is infrequent compared with distal aortic segments, hence preserving the root could be an option for older patients provided that there is no primary tear within the root.
Stanford Type A Aortic Dissection in A Patient with Primary Antiphospholipid Syndrome and Coronavirus Disease 2019
Authors: Ahmad Sarah A. , Khalid Nauman , Chhabra Lovely , Kayani Waleed T. , Helmy Tarek
Published: February 2023

Acute aortic dissection is one of the most lethal diseases, affecting the lining of the aortic wall. We describe a case of Stanford Type A aortic dissection in a patient with underlying primary antiphospholipid syndrome (APS) complicated by coronavirus disease 2019 (COVID-19). APS is characterized by recurrent venous and/or arterial thrombosis, thrombocytopenia, and rarely vascular aneurysms. The hypercoagulable milieu attributable to APS and the prothrombotic state from COVID-19 posed a challenge in achieving optimal postoperative anticoagulation in our patient.
Scaling and lateral maneuverability of pitching foil in periodic freestream
Authors: Isoda Y. , Tanaka Y. , Tanaka H. , Kawano M.
Published: February 2023

We formulate the thrust and lift coefficients using scaling laws to develop a guideline for the lateral maneuverability of a pitching foil in a periodic freestream. The scaling laws for thrust and lift coefficients of two-dimensional pitching foil in a periodic freestream are derived by considering added mass and circulatory forces. We examined the validity of scaling laws by conducting water tunnel experiments at a Reynolds number of 4.2 × 103. The key parameters are the pitch amplitude and phase difference between the periodic freestream and pitching foil. The pitch amplitude was changed from 4° to 24° with 4° increments, and the phase difference was changed from 0 to 2π with 0.25π increments. It was discovered that our scaling laws were consistent with experimental data for small pitch amplitude. By using scaling laws, we proposed guidelines to control the thrust and lift coefficients for lateral maneuver. Our guideline demonstrates that pitch amplitude can be employed to control the thrust coefficient to cancel out drag, and the phase difference is useful to control the lift coefficient without changing the adjusted thrust coefficient.
Patterns of intensive care unit emergencies
Authors: Yartsev Alex , Yang Feibi
Published: February 2023

Objective Little is known about the epidemiology of medical emergencies occurring in the intensive care unit (ICU). The aim of this study is to draw attention to the importance of auditing emergency events in the ICU. We hypothesised that emergency events occurring in the ICU would be clustered during periods of decreased medical and nursing attention and would occur in patients who had a higher illness severity and a greater risk of death. Methods A retrospective observational cohort study was carried out in a 36-bed tertiary intensive care unit. The data capture all intensive care patients admitted to the ICU from 1 January to 1 December 2020. The number of emergency events occurring during each clock hour was correlated with ICU shift staffing patterns. In-hospital mortality and illness severity scores for patients experiencing emergency events were compared with those for all other ICU patients. Results Serious medical emergencies were most frequent during the day, specifically during the morning ICU round (30% of all such events occurred between 08:00 and 12:00 hours), and there were peaks of incidence in the hour following each nursing and medical shift handover (following shift change times at 08:00, 15:00 and 21:00 hours). Agitation-related emergency events were least frequent during the periods of nursing day shift and afternoon shift overlap (07:00–08:00 hours and 13:00–15:00 hours). Patients who experienced serious medical emergency events in the ICU had a higher in-hospital mortality rate (28.3%) compared with the overall ICU mortality of 10.5% (OR = 4.89, 95% CI: 3.04–7.86). Conclusions Patients who deteriorate suddenly in the ICU have greater illness severity and a significantly increased risk of death. The incidence of serious emergency events correlates with patterns of ICU staffing and work routines. This has implications for rostering, clinical workflow and education program design.
Future application of an attention bias test to assess affective states in sheep
Authors: Monk Jessica E. , Campbell Dana L. M. , Lee Caroline
Published: February 2023

The affective states of animals comprise a key aspect of welfare that can be difficult to assess. An attention-bias test was developed for sheep, which assessed allocation of attention between a predator threat and a food reward, as a potential measure of affective state. The method was pharmacologically validated as a measure of anxiety-like states, finding that ‘anxious’ sheep were more vigilant, less likely to feed and spent more time looking towards the previous location of a dog than did ‘calm’ sheep. Across six further validation studies, the method was modified and explored as a measure of other types of affective states. This perspective article aims to provide guidance on what the method can tell us about affective state and make recommendations for further research by using this approach. Evidence was strongest across the studies for the test as a measure of anxiety-like states, but it is clear that there are other factors affecting animal behaviour during testing that need to be further investigated. One study showed potential for a modified method to assess depression-like states in sheep, while the impact of chronic stress on affect and attention bias remains unclear. It is likely that the test cannot be used to measure positive affect in sheep without further modification, due to the fear-eliciting nature of the test. Versions of the method using food as a positive stimulus allow for a clearer interpretation of attention than do versions using a conspecific photograph, and are recommended for use in future studies where appetite is not expected to be a confounding factor. In this context, vigilance behaviour may indicate trait anxiety or fearfulness, while other measures of attention may be more sensitive to transient changes in affect. Modifications to the method are suggested to allow for a clearer characterisation of attention in livestock species and to improve the practical application of the test. Overall, the attention-bias test shows promise as a measure of negative affective states, but the method is still very new and further research is needed to better determine its potential use as a welfare-assessment tool.
Self-efficacy mediates the effect of providing HIV self-testing kits on HIV testing frequency among Chinese men who have sex with men: results from a randomised controlled trial
Authors: Zhang Ci , Huang Daoping , Goldsamt Lloyd A. , Wang Honghong , Wiley James , Shen Yan , Chi Yuanyuan , Li Xianhong
Published: February 2023

Background HIV self-testing (HIVST) could promote HIV tests; however, knowledge about the mechanisms by which providing HIVST kits impacts the uptake of HIV testing is limited. This study aimed to examine how self-efficacy mediates the association between providing HIVST kits and HIV testing frequency. Methods In this randomised controlled trial, HIV-negative men who have sex with men (MSM) were recruited in China and randomly assigned 1:1 into intervention and control groups. MSM in the control group could access site-based HIV testing services (SBHT). MSM in the intervention group could access SBHTs plus free HIVST kits. HIV testing self-efficacy, number of SBHTs, number of HIVSTs, and the total number of HIV tests were assessed every 3 months for 1 year. Results Data from 216 MSM (intervention group: 110; control group: 106) were included in analysis. Results from Pearson’s correlations and point-biserial correlations showed that participants with higher self-efficacy scores underwent a higher number of HIV tests (r = 0.241, P < 0.001), more HIVSTs (r = 0.162, P < 0.001), and more SBHTs (r = 0.138, P < 0.001). Bootstrap tests using PROCESS indicated self-efficacy partially mediated the effect of providing HIVST on the number of HIVSTs (indirect effect: 0.018, 95% bias-corrected confidence interval [BC CI]: 0.003–0.035; direct effect: 0.440, 95% BC CI: 0.366–0.513) and on total HIV tests (indirect effect 0.053 (0.030–0.787); direct effect 0.452 (0.365–0.539)), and completely mediated the effect of providing HIVST on the number of SBHTs (indirect effect 0.035 (0.019–0.056); direct effect 0.012 (−0.059 to 0.083)). Conclusions Our findings indicated self-efficacy mediated the effect of HIVST provision on HIV testing frequency, suggesting improving self-efficacy might be an effective way to promote HIV testing among Chinese MSM.
A gender perspective on the global migration of scholars
Authors: Zhao Xinyi , Akbaritabar Aliakbar , Kashyap Ridhi , Zagheni Emilio
Published: February 2023

Although considerable progress toward gender equality in science has been made in recent decades, female researchers continue to face significant barriers in the academic labor market. International mobility has been increasingly recognized as a strategy for scientists to expand their professional networks, and that could help narrow the gender gap in academic careers. Using bibliometric data on over 33 million Scopus publications, we provide a global and dynamic view of gendered patterns of transnational scholarly mobility, as measured by volume, distance, diversity, and distribution, from 1998 to 2017. We find that, while female researchers continued to be underrepresented among internationally mobile researchers and migrate over shorter distances, this gender gap was narrowing at a faster rate than the gender gap in the population of general active researchers. Globally, the origin and destination countries of both female and male mobile researchers became increasingly diversified, which suggests that scholarly migration has become less skewed and more globalized. However, the range of origin and destination countries continued to be narrower for women than for men. While the United States remained the leading academic destination worldwide, the shares of both female and male scholarly inflows to that country declined from around 25% to 20% over the study period, partially due to the growing relevance of China. This study offers a cross-national measurement of gender inequality in global scholarly migration that is essential for promoting gender-equitable science policies and for monitoring the impact of such interventions.
How to avoid a local epidemic becoming a global pandemic
Authors: Stenseth Nils Chr. , Schlatte Rudolf , Liu Xiaoli , Pielke Roger , Li Ruiyun , Chen Bin , Bjørnstad Ottar N. , Kusnezov Dimitri , Gao George F. , Fraser Christophe , Whittington Jason D. , Bai Yuqi , Deng Ke , Gong Peng , Guan Dabo , Xiao Yixiong , Xu Bing , Johnsen Einar Broch
Published: February 2023

Here, we combine international air travel passenger data with a standard epidemiological model of the initial 3 mo of the COVID-19 pandemic (January through March 2020; toward the end of which the entire world locked down). Using the information available during this initial phase of the pandemic, our model accurately describes the main features of the actual global development of the pandemic demonstrated by the high degree of coherence between the model and global data. The validated model allows for an exploration of alternative policy efficacies (reducing air travel and/or introducing different degrees of compulsory immigration quarantine upon arrival to a country) in delaying the global spread of SARS-CoV-2 and thus is suggestive of similar efficacy in anticipating the spread of future global disease outbreaks. We show that a lesson from the recent pandemic is that reducing air travel globally is more effective in reducing the global spread than adopting immigration quarantine. Reducing air travel out of a source country has the most important effect regarding the spreading of the disease to the rest of the world. Based upon our results, we propose a digital twin as a further developed tool to inform future pandemic decision-making to inform measures intended to control the spread of disease agents of potential future pandemics. We discuss the design criteria for such a digital twin model as well as the feasibility of obtaining access to the necessary online data on international air travel.
Extramural English for early language learning
Authors: Hannibal Jensen Signe , Lauridsen Jørgen T.
Published: February 2023

Due to the online global presence of English, many EFL learners encounter English outside the classroom from an early age. This study examined teachers’ perceptions of the language learning affordances, challenges, and benefits in the early English classroom (ages 7–11) of English learnt outside school (extramural English (EE), Sundqvist & Sylvén, 2016). A mixed-methods approach, including a survey, interviews, and data from Facebook interest groups on teaching English, was used to gauge teacher perceptions. Results showed that generally teachers had positive attitudes towards the learning potentials of EE (especially related to fostering vocabulary learning) and for creating motivation for learning English. Teachers found less benefits of playing digital games than from watching YouTube videos. Teachers also reported demotivation in students stemming from being bored in class or from feeling behind compared to others, i.e., personal expectations of English skills were high. The study points to a need for focus in teacher education on the benefits of extramural activities for their students’ learning (especially gaming). This means fostering awareness in prospective teachers of the importance of incidental learning processes as these are key in the global English context. Moreover, sharing ideas for integrating EE into teaching practices is needed.
D-wave excited

tetraquark states with

and

*
Authors: Yang Zi-Yan , Chen Wei
Published: February 2023

We study the mass spectra of D-wave excited

tetraquark states with

and

in both symmetric

and antisymmetric

color configurations using the QCD sum rule method. We construct the D-wave diquark-antidiquark type of

tetraquark interpolating currents in various excitation structures with

. Our results support the interpretation of the recently observed

resonance as a D-wave

tetraquark state with

in the

or

excitation mode, although some other possible excitation structures cannot be excluded exhaustively within theoretical errors. Moreover, our results provide the mass relations

and

for the positive and negative

-parity D-wave

tetraquarks, respectively. We suggest searching for these possible D-wave

tetraquarks in both the hidden-charm channels

and

, as well as open-charm channels such as

and

.
Optimization and utilization of waste fly ash and silica fume based eco-friendly geopolymer mortar using response surface methodology
Authors: Sadiq A N , Ariffin M A M , Anwar M K , Lee H S , Singh J K
Published: February 2023

Cement is the primary ingredient in concrete, which is one of the crucial building materials. The evolution of greenhouse gases, particularly carbon dioxide, which is produced during the hydration stage, has increased because of excessive use of concrete. Geopolymer, an alumina-silicate based bonding substance is made up of waste materials such as Fly ash (FA) or Silica Fume (SF) in the presence of alkaline solutions has been developed to reduce the effect of carbon emissions on the environment. This paper studied the optimization and utilization of FA and SF replacement as pozzolanic materials for the development of sustainable geopolymer mortar and to achieve optimal mechanical strength using response surface methodology (RSM). According to the study, with the addition of 90% FA and 10% SF content to the geopolymer design mix significantly improves their mechanical properties. When SF and sodium hydroxide are combined to create geopolymer mortar, they work as an alkaline catalyst, dramatically reducing carbon emission of the waste materials and providing it an edge over cement-based mortar. The construction of self-sustaining infrastructures ensuring human safety and eco-friendly practices will be encouraged by the multi-objective approach of RSM.
Isolation and characterization of biological soil crust forming algae from Malaysia
Authors: Jusoh N , Rahim M Q F A , Othman F S , Mohamad S E , Abdullah N
Published: February 2023

Soil erosion permanently reduces the quality of physicochemical and biological properties, soil fertility, and land productivity, all of which have a significant impact on cultivated areas. Communities that live on the top few centimetres of soil surfaces, are known as “biological soil crust” (BSC). This microorganism is essential for soil stabilisation, water retention, and soil fertility. A case study of a Japanese company that uses these organisms to combat soil erosion has inspired this study. Ground covers, slope drains, silt fences, blankets, and plastic covers are currently used to reduce soil erosion which are expensive and less environmentally friendly. An artificially induced BSC can be created on the specific targeted area. The first step in implementing this strategy in Malaysia is to collect, isolate, and identify the BSC-forming algae species. Our findings show that the isolated algae (C3 strain), based on its morphology, has been identified as the Tribonema species and has a yellow-green filament under a microscope. The C3 strain therefore, has been chosen as the potential native BSC forming algae. This research aims to provide information on isolated strains of Malaysian algae for application as BSC in tropical settings.
A feasibility study on the green synthesis of iron oxide nanoparticles using Chlorella vulgaris extract for photocatalytic degradation of crystal violet
Authors: Mohamad Rodzi U S , Kiew P L , Lam M K , Tan L S
Published: February 2023

Iron oxide nanoparticles have recently been proposed as an efficient and environmentally friendly material for wastewater treatment. In comparison to chemical and physical approaches, green nanoparticles synthesis method that employs microalgae or plant extract is regarded as more cost-effective and environmentally friendly. In this study, iron oxide nanoparticles were synthesised using Chlorella vulgaris extract, and their feasibility in removing crystal violet dye from wastewater via photocatalytic degradation was investigated. Iron oxide nanoparticles was synthesized by adding C. vulgaris extract to 0.1 M iron (III) chloride solution. The X-ray diffraction (XRD) peaks revealed that the iron oxide nanoparticles were crystalline in nature. The nanoparticles were also analysed using Field Emission Scanning Electron Microscope (FESEM), revealing a sphere with cylindrical shape of about 109 nm in size, with the Energy Dispersive X-ray (EDX) elemental analysis showing the highest proportion of O followed by Fe. The ability of iron oxide nanoparticles to remove crystal violet dye in the dark and in the presence of ultraviolet (UV) light was investigated. The percentage removal was consistently higher under the presence of UV lamp at all durations tested (30 – 90 minutes), indicating the feasibility of iron oxide nanoparticles to photodegrade crystal violet dye.
Preliminary study on the occurrence of microplastics in a local sewage treatment plant
Authors: Liew W L , Hee Y Y , Mohd Nazri N A , Muda K , Zaidi N S
Published: February 2023

Recent studies have found that sewage treatment plants are potential source of microplastics pollution to its receiving freshwaters, which potentially affect freshwater ecosystems. This study aimed to investigate the occurrence of microplastics in sewage treatment plant, i.e., outlet of a primary clarifier and within an activated sludge system. A digestion method (oxidation digestion using Fenton’s reagent coupled with wet peroxide oxidation technique) followed by microplastics extraction were attempted. Microplastics were detected, through instrumental characterizations, in all sewage samples in this study with microplastics found in the primary clarifier included polyamide, polytetrafluoroethylene and polyethylene terephthalate, while microplastics in the activated sludge system were polyamide, polystyrene and polyvinyl chloride. Results indicated that the sewage treatment plant successfully reduced microplastics from the primary clarifier to the activated sludge system by retaining bigger sizes of microplastics during early treatment stages of the system.
Evaluation of the vulnerability and resilience towards urban flash floods in Kuala Lumpur, Malaysia
Authors: Rosedi N , Ishak M Y
Published: February 2023

The effects of extreme events such as flooding vary across different urban settings, causing vulnerability to differ spatially. The frequency and intensity flood pose debilitating challenges to economies, infrastructure, communities, households, and individuals across various regions, drawing considerable research attention into the vulnerability and resilience towards the deleterious impacts. This research investigates vulnerability and resiliency of urban villagers in response to the increasing threats from floods. Using structured questionnaire distributed among household from urban villagers in Malaysia, this research examines their dimensions of resiliency in facing flood. A hundred and ten respondents identified as the head of the affected households took part in the study where their resource allocation due to floods over a year was determined and their resilience towards floods was also analyzed. The findings reveal the households demonstrating an intricate relationship where despite being urban poor, they do not consider the recurring event as the most major daily threat. Instead, they prioritize safety, health, and sufficient food supply as most of them have made a resource allocation for these items. Social adaptation, particularly comfortable neighbourhood, the duration of stay in the area, and network among the community became the key factors of staying within the same area despite the recurring flash floods. This research recommends that it is equally important to consider the resiliency in disaster planning and policies. By critically consider this complex relationship between household vulnerability and resiliency, would help in formulating effective flood management and town planning for sustainable development.
2023 roadmap for potassium-ion batteries
Authors: Xu Yang , Titirici Magda , Chen Jingwei , Cora Furio , Cullen Patrick L , Edge Jacqueline Sophie , Fan Kun , Fan Ling , Feng Jingyu , Hosaka Tomooki , Hu Junyang , Huang Weiwei , Hyde Timothy I , Imtiaz Sumair , Kang Feiyu , Kennedy Tadhg , Kim Eun Jeong , Komaba Shinichi , Lander Laura , Le Pham Phuong Nam , Liu Pengcheng , Lu Bingan , Meng Fanlu , Mitlin David , Monconduit Laure , Palgrave Robert G , Qin Lei , Ryan Kevin M , Sankar Gopinathan , Scanlon David O , Shi Tianyi , Stievano Lorenzo , Tinker Henry R , Wang Chengliang , Wang Hang , Wang Huanlei , Wu Yiying , Zhai Dengyun , Zhang Qichun , Zhou Min , Zou Jincheng
Published: February 2023

The heavy reliance of lithium-ion batteries (LIBs) has caused rising concerns on the sustainability of lithium and transition metal and the ethic issue around mining practice. Developing alternative energy storage technologies beyond lithium has become a prominent slice of global energy research portfolio. The alternative technologies play a vital role in shaping the future landscape of energy storage, from electrified mobility to the efficient utilization of renewable energies and further to large-scale stationary energy storage. Potassium-ion batteries (PIBs) are a promising alternative given its chemical and economic benefits, making a strong competitor to LIBs and sodium-ion batteries for different applications. However, many are unknown regarding potassium storage processes in materials and how it differs from lithium and sodium and understanding of solid–liquid interfacial chemistry is massively insufficient in PIBs. Therefore, there remain outstanding issues to advance the commercial prospects of the PIB technology. This Roadmap highlights the up-to-date scientific and technological advances and the insights into solving challenging issues to accelerate the development of PIBs. We hope this Roadmap aids the wider PIB research community and provides a cross-referencing to other beyond lithium energy storage technologies in the fast-pacing research landscape.
Carbon nanotube branch-grown nickel nanoparticles/graphene composites for a high-capacitance electrode
Authors: Jung Mingyu , Sivakumar Periyasamy , Park Ho Seok
Published: February 2023

Despite the high capacitance and low cost, transition metal oxides have the limitation of low electrical conductivities and structural instability. In order to resolve these problems, herein, we propose a one-pot facile synthesis approach to construct a hierarchically structured nanohybrid material, where carbon nanotube (CNT) branches encapsulate NiO nanoparticles inside the tubes and interconnect them with steam-activated reduced graphene oxide. This unique hierarchical structure is attributed to large accessible surface areas, rapid electronic conduction, fast ion diffusion, and buffering effects. Moreover, the mixed Ni and NiO particles acts as catalysts to grow CNT branches and high capacitance redox active materials. In particular, the resulting composite electrode deliver a high specific capacitance of up to 1605.81 F g−1 at a current density of 1 A g−1 as well as, an excellent cycle stability with 71.56% capacitance retention after more than 10 000 cycles. Consequently, this research provides a rational material design chemistry to construct hierarchical architectures and multiple compositions of CNT/graphene/metal oxide nanoparticle hybrids for high-capacitance electrodes of composite capacitors.
Assessing the role of reinforcement size and weight percentage on the mechanical and wear characteristics of Al7050‐TiO2‐hBN hybrid composites
Authors: Srivallirani K , Rao M Venkateswara
Published: February 2023

In the present study, hybrid composites of Al7050 reinforced with TiO2 (1, 3 and 5%) and hexagonal boron nitride (hBN, 2, 4 and 6%) have been developed by using two different sized reinforcing particles (∼ 40 μm and ∼ 20 μm) through stir casting route with an aim to investigate the role of particles size within the micrometer level on mechanical and wear characteristics. From the microhardness measurements, higher hardness was measured for the composites with the increased content of the reinforcement. Similar trend was observed for the composites with both the reinforcement sizes. From the impact strength measurements, more values were observed for the composites having 20 μm sized reinforcements. With the increased fraction of hBN (6%), no significant improvement in the impact strength was noticed for the composites with 40 μm sized reinforcements. On the other hand, significant increase in the impact strength was measured for the composites with 20 μm sized reinforcements. Increased tensile strength (from 95 ± 4.6 up to 156.8 ± 6.1 MPa) with the higher fraction of reinforcements was measured at the cost of losing ductility as reflected in the decreased % of elongation (from 15.2 to 11.65). With the decreased size of reinforcement from 40 to 20 μm, the composites exhibited more strength and lower ductility. From the wear studies, it was clearly observed a decreased trend in the wear rate and increased coefficient of friction with the increased reinforcement content. Compared with 40 μm reinforcements, adding 20 μm sized reinforcements has shown higher level of impact on reducing the wear rate. The results demonstrate that the size difference of reinforcing particles in the level of a few micrometers also significantly affects the performance of the composites.
A comparative study of scour around various shaped bridge pier
Authors: Baranwal Anubhav , Shankar Das Bhabani , Setia Baldev
Published: February 2023

The study of scouring around bridge piers is very significant and plays a very important role in the safe and economical design of bridge piers. The term scouring is a process by which bed particles around the periphery of the pier get eroded and removed over a certain depth resulting in the formation of a scour hole around the bridge piers. This paper presents a detailed investigation of local scouring around six different shapes namely rectangular, circular, chamfered, joukowsky, oblong, and sharp-nosed of bridge pier models for selecting the best and most economical bridge pier shapes based on local scouring. For the experimental studies, local scour depth is measured around all six different shapes of bridge piers with varying discharges and velocities of 0.0169 m3 s−1 to 0.0355 m3 s−1 and 0.17 m s−1 to 0.30 m s−1 respectively. It is found that scour depth around the rectangular shape of bridge pier is larger due to development of strong intensity of horseshoe vortex caused by flat exposed frontal area and scour depth around the sharp nose shape of the pier is smaller because of flow is bifurcated due to smooth curvature caused less intensity of development of horseshoe vortex. In the comparison of obtained results, it is reported that scour depth around a pier is exactly proportional to velocity of approach flow and exposed frontal area of the bridge pier. The result of this study can be likely used to help in selecting the best shape of the bridge piers as sharp nose shape of bridge piers is better among the other six bridge pier shapes for design purposes.
Temperature tunable Bragg transmission multichannel filters made of two quarter-wave stacks separated by defect layers
Authors: Netheti V S Bhagavan , Kumar B Santosh , Kumar M M Sandeep , Chandrasekhar A , Raju P Kanaka , Podagatlapalli G Krishna
Published: February 2023

We report on simulated temperature-tunable single-channel/multichannel transmission filters with 0.37 nm/K shift in the peak wavelength is observed in the infrared region (1300 nanometers −1650 nanometers) using a one-dimensional photonic crystal structure. A single channel can be selected in the photonic bandgap region based on the thickness of the quarter wave stacks and temperature. The transmission coefficient of the transmitted defect modes is approximately the same as that required for telecommunication. For 20000 defect layers, 4000 channels were created with full width at half maximum of 0.7 picometers at the center wavelength of ∼1550 nm and channel separation of ∼0.18 nanometer between 1500 nanometers-1600 nanometers.
Porous liner coated inlet duct: a novel approach to attenuate automotive turbocharger inlet flow-induced sound propagation
Authors: Ravanbod Mohammad , Ebrahimi-Nejad Salman , Mollajafari Morteza , SalehiRad Bardia
Published: February 2023

Automotive turbochargers generate high-frequency noise, especially at their inlet air duct, which has become a long-standing problem for both passengers and pedestrians and hence is required to be mitigated by provisions such as the use of absorptive materials and novel inlet duct designs. This paper proposes utilizing a thin porous material coating liner on the inlet duct of the turbocharger compressor in order to absorb the incident excitation and hence, broadband reduction of the flow-induced sound wave propagation. To this end, first, a sound-absorbing inlet duct model is designed based on efficient structural parameters. Then, three different types of absorptive materials are used as coating liners to analyze the impact of varying material properties on the acoustic absorption performance of the system. Meanwhile, a sensitivity analysis is carried out to evaluate the influence of coating layer thickness on the system’s flow-induced sound insulation performance. The research involves applying a finite element approach to conducting acoustic pressure and poroacoustics studies over the desired frequency range of human hearing (1–20 kHz). In this regard, sound transmission loss (TL) and sound pressure level (SPL) are investigated for the models with and without liners. The results indicate that sound-absorbing materials can be employed to significantly diminish flow-induced sound levels in the turbocharger inlet duct. According to the results, absorptive liners would considerably increase the maximum TL and lessen the sharp drop in TL that appeared in the model without liners at around 4321 Hz. In addition, the average TL has increased due to the replacement of valleys with peaks. The sensitivity analyses demonstrated that denser absorptive materials and larger liner thicknesses are associated with higher TL levels and better sound attenuation response. By adding 15 mm of rock wool liner to the designed inlet duct, the average TL and root mean square of TL were increased up to

98

and

32

d
B
,

respectively. The proposed design procedure of this study unlocks a fundamental approach that can be practically applied to many promising fields, such as aerospace and automotive engineering.
On Euler characteristic and Hitchin-Thorpe inequality for four-dimensional compact Ricci solitons
Authors: Cheng Xu , Ribeiro Ernani , Zhou Detang
Published: February 2023

In this article, we investigate the geometry of

4
4

-dimensional compact gradient Ricci solitons. We prove that, under an upper bound condition on the range of the potential function, a

4
4

-dimensional compact gradient Ricci soliton must satisfy the classical Hitchin-Thorpe inequality. In addition, some volume estimates are also obtained.
Alternative proofs of Mandrekar’s theorem
Authors: Bergqvist Linus
Published: February 2023

We present two alternative proofs of Mandrekar’s theorem, which states that an invariant subspace of the Hardy space on the bidisc is of Beurling type precisely when the shifts satisfy a doubly commuting condition [Proc. Amer. Math. Soc. 103 (1988), pp. 145–148]. The first proof uses properties of Toeplitz operators to derive a formula for the reproducing kernel of certain shift invariant subspaces, which can then be used to characterize them. The second proof relies on the reproducing property in order to show that the reproducing kernel at the origin must generate the entire shift invariant subspace.
Atypical cardiac amyloidosis phenotypes identified at transplant: a case series
Authors: Rushakoff Joshua A , Kransdorf Evan P , Kittleson Michelle M , Neyer Jonathan R , Luthringer Daniel , Patel Jignesh K
Published: February 2023

Background

Transthyretin amyloidosis (TTR) is increasingly implicated as an aetiology of advanced cardiomyopathy. Typically, both genetic variant (TTRv) and wild-type (TTRwt) amyloidosis present with a restrictive phenotype. We present a series of three patients who were found to have cardiac amyloidosis on explant following heart transplant (HT) who had atypical, non-restrictive phenotypes.

Case Summary

All three patients were men, three were Black, and only one had an alternative pre-HT explanation for their advanced, dilated cardiomyopathy. Pre-HT transthoracic echocardiograms were notable for left ventricular (LV) dilation (>95th percentile for height and gender), low EF, and normal LV wall thickness. Explants showed varying amounts of amyloid deposition, ranging from diffuse biventricular patterns to perivascular involvement. Mass spectrometry confirmed the presence of TTRv (two cases) and TTRwt (one case).

Discussion

Patients with dilated cardiomyopathy may harbour cardiac amyloidosis. Uncertainty remains regarding the contribution of amyloidosis to the development of a dilated phenotype. The pathogenic Val142Ile variant seen in two of these patients, a variant common in Black patients, suggests a need for further investigation into the potential relationship between TTRv amyloidosis and dilated cardiomyopathy.
Difference in apical resorption activity during rat molar root formation in response to mechanical force
Authors: Lou Yixin , Matsumoto Yoshiro , Iseki Sachiko , Ono Takashi
Published: February 2023

Objective

To investigate whether there is a difference in apical resorption activity during the development of roots in response to mechanical force in vivo.

Methods

Maxillary first molars (M1) from postnatal day (PN) 21 and PN35 male rats were selected as representatives of the root-developing and root-completing groups, respectively. A mechanical force of 3 cN was applied to M1 on PN21 and PN35, and the maxilla was collected on PN28 and PN42. Odontoclastogenesis and root morphology were investigated using micro-focus X-ray computed tomography, followed by immunohistochemistry and quantitative real-time polymerase chain reaction to clarify root resorption activity.

Results

Development of the mesiobuccal root (MBR) preceded the mesial root (MR). In the PN28 force application (FA) group, the dentine was bent, but the histology, including Hertwig’s epithelial root sheath (HERS), was intact. No odontoclasts and resorption lacunae were found in the apical area of the MRs, and only lateral root resorption was observed. External apical root resorption (EARR) was observed in the MR of PN42 (FA) and in the MBR of both PN28 (FA) and PN42 (FA). The expression of osteopontin changed accordingly. No significant change occurred in osteoprotegerin or receptor activator of nuclear factor-κB ligand expression in the MRs of the PN28 (FA) group.

Limitations

Our animal model did not adequately simulate the clinical process of tooth movement in humans.

Conclusions

Force application delayed HERS dissociation on the compression side of the developing roots, leading to inhibitory effects on cementogenesis, which resulted in decreased odontoclast differentiation and prevention of EARR.
Firm names and profitability in German food processing
Authors: Hirsch Stefan , Khalilov Murad , Dalhaus Tobias , Mishra Ashok K
Published: February 2023

We analyse the signalling effect of a strategy known as eponymy whereby owners integrate their name into the company name. Using microdata from German food processors, we find that eponymous companies generate 2.8 per cent-points higher return on assets, which implies additional yearly profits of €253,000 for a median-sized company. The eponymy effect increases with ownership concentration, indicating that the more control an owner holds over the company, the stronger the signalling. Long names ranking low in the alphabetical order mitigate the effect. This study applies a novel approach to investigate the causal effect of firm naming and thus has implications for food processors.