bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, characterization, and thermal and computational investigations of the l-histidine bis(fluoride) crystal
Authors: Reis Ian Felipe Sousa , Viana Jailton Romão , de Oliveira Neto João Gomes , Stoyanov Stanislav R. , de M. Carneiro José Walkimar , Lage Mateus Ribeiro , dos Santos Adenilson Oliveira
Published: July 2022

Nonlinear optical materials have been investigated recently due to their potential technological applications in information storage and communications. In this context, semi-organic crystals can effectively combine the desired nonlinear optical properties of amino acids with the promising mechanical and thermal properties of inorganic materials. In this work, we have synthesized and characterized a semi-organic crystal of the amino acid l-histidine and hydrofluoric acid and investigated the chemical interactions between the organic and inorganic moieties. The crystal of l-histidine bis(fluoride) has been produced by slow solvent evaporation and characterized by X-ray diffraction (XRD) crystallography and thermogravimetric and differential thermal analyses. The XRD conducted using the Rietveld method shows that the unit cell is orthorhombic with the P21212 space group and contains four l-histidine bis(fluoride) units. Both differential thermal analysis and temperature-dependent XRD show that the crystals are thermally stable up to 191°C and do not undergo phase transition. The computational Hirshfeld surface analysis of the crystal structure reveals the main intermolecular interactions. Density functional theory has been employed to calculate the ionic interaction energy and electrostatic potential maps and confirm the spontaneity of ionic association at 191°C. The combined experimental and computational results show that the thermal stability of the semi-organic l-histidine bis(fluoride) crystal makes it suitable for nonlinear optical applications in optical sensing and communication systems.

Graphical abstract
In situ investigation of the influence of varying load conditions on tooth deformation and wear of polymer gears
Authors: Herzog Christoph , Wolf Michael , Schubert Dominik , Drummer Dietmar
Published: July 2022

A new method for in situ deformation and wear measurement of polymer gears has been developed at the LKT and validated for polyamide-66 (PA66) gears at constant loading torque and rotational speed. This contribution contains a more comprehensive validation of the newly developed test method by examining polybutylenterephtalate (PBT) gears under varying loading conditions. The deformation test method is based on measuring and analysing the timing differences between the index pulse signals of rotary encoders on the input and output shaft of the test rig. Since the total tooth deformation is a combination of different effects, such as elastic and plastic deformation, thermal expansion and wear, different testing modes with a low and a high torque level are implemented to separate the effects of elastic deformation on the one hand and plastic deformation and wear on the other hand. As a consequence, the new test rig design allows a deeper understanding of the wear and deformation behaviour of polymer steel gear sets over time. This potential is used to analyse the interactions of different loading conditions on the time-dependent deformation of plastic gears. The influence of both, different transmitting torques and rotational speeds is examined.

The test method shows good correlation with well-established ex situ measurements for different combinations of rotational speeds and loading torques and thus could be validated. Long-term gear tests under varying rotational speeds and loading torques show increasing wear and deformation at higher speeds and torques confirming the state of the art described in the literature. In addition, the time dependent deformation behaviour at different load conditions due to superposition of wear and plastic deformation could be analysed in detail.
An exponential lower bound for Zadeh’s pivot rule
Authors: Disser Yann , Friedmann Oliver , Hopp Alexander V.
Published: July 2022

The question whether the Simplex Algorithm admits an efficient pivot rule remains one of the most important open questions in discrete optimization. While many natural, deterministic pivot rules are known to yield exponential running times, the random-facet rule was shown to have a subexponential running time. For a long time, Zadeh’s rule remained the most prominent candidate for the first deterministic pivot rule with subexponential running time. We present a lower bound construction that shows that Zadeh’s rule is in fact exponential in the worst case. Our construction is based on a close relation to the Strategy Improvement Algorithm for Parity Games and the Policy Iteration Algorithm for Markov Decision Processes, and we also obtain exponential lower bounds for Zadeh’s rule in these contexts.
Monte Carlo Tree Search: a review of recent modifications and applications
Authors: Świechowski Maciej , Godlewski Konrad , Sawicki Bartosz , Mańdziuk Jacek
Published: July 2022

Monte Carlo Tree Search (MCTS) is a powerful approach to designing game-playing bots or solving sequential decision problems. The method relies on intelligent tree search that balances exploration and exploitation. MCTS performs random sampling in the form of simulations and stores statistics of actions to make more educated choices in each subsequent iteration. The method has become a state-of-the-art technique for combinatorial games. However, in more complex games (e.g. those with a high branching factor or real-time ones) as well as in various practical domains (e.g. transportation, scheduling or security) an efficient MCTS application often requires its problem-dependent modification or integration with other techniques. Such domain-specific modifications and hybrid approaches are the main focus of this survey. The last major MCTS survey was published in 2012. Contributions that appeared since its release are of particular interest for this review.
Multi-objective optimal design and seismic assessment of an inerter-based hybrid control system for storage tanks
Authors: Zahedin Labaf Daniele , De Angelis Maurizio , Basili Michela
Published: July 2022

In this paper, a hybrid control system (HCS) endowing a base isolation system (BIS) with a Tuned Mass Damper Inerter (TMDI) is proposed for the protection of steel storage tanks from severe structural damages induced by seismic events. Among all the components of industrial plants, cylindrical steel storage tanks are widely spread and play a primary role when subjected to seismic hazard, since they suffer of many critical issues related to their dynamic response such as high convective wave height and base shear force. The adopted base isolation system is realized with spring and damper elements, whereas the TMDI is realized with a tuned mass damper connected to the ground by the inerter. The developed mechanical model consists of a MDOF system, which considers the impulsive and convective modes as well as the TMDI dynamics. An optimal design problem is tackled, making use of a multi-objective approach, with the scope to mitigate simultaneously the convective and impulsive response of the storage tank. A zero mean white noise excitation is assumed as input in the optimal design procedure. Once the HCS is optimally designed, a systematic investigation of its seismic effectiveness is reached through parametric analysis. Modal parameters and frequency response functions are discussed. A literature case study comparing the effectiveness of the proposed optimally designed HCS with traditional base isolation is illustrated and performances are assessed through stochastic excitation and natural earthquakes.
Moss cover and browsing scores as sustainability indicators of mountain ungulate populations in Mediterranean environments
Authors: Refoyo P. , Peláez M. , García-Rodríguez M. , López-Sánchez A. , Perea R.
Published: July 2022

Here, we aimed to define ecological indicators of environmental change for monitoring the effect of a reintroduced species, the Iberian ibex (Capra pyrenaica), over the vegetation of a natural protected area with contrasting habitats. This species was reintroduced 30 years ago in the Sierra de Guadarrama National Park, Spain, and its population has since grown exponentially, reaching high densities in some areas. We tested the suitability of two complementary indicators: browsing damage on woody species and the percentage of moss cover loss on rocky outcrops. For this purpose, we used a mathematical approach to zone the natural protected area according to the historical presence of the species and established five different Iberian ibex pressure classes (Classes I–V). Our results showed a direct link between Iberian ibex pressure and vegetation status. Model predictions suggested 10% moss loss in the areas with low pressure (Class I) but 64% loss in the areas with high pressure (Class III), mostly due to ungulate trampling on rocks. Similarly, browsing damage increased with increasing pressure classes for different woody species. Low palatable plant species such as Pinus spp. showed little change in browsing damage for increasing ungulate pressure whereas more palatable plants (e.g., Erica arborea) showed significantly greater browsing damage variation across pressure classes (i.e., high sensitive to herbivory pressure). Both, moss cover on rocks and widely distributed palatable woody plants proved useful ecological indicators for monitoring ungulate populations in mountainous areas with a diverse array of habitats (e.g., rocky vs. woody). This methodology may help select the most suitable indicators for each type of ecosystem or dominant habitat in ungulate-dominated ecosystems.
The diverse life-course cohort (DLCC): protocol of a large-scale prospective study in China
Authors: He Huijing , Pan Li , Hu Yaoda , Tu Ji , Zhang Ling , Zhang Minying , Liu Gongshu , Yuan Juxiang , Ou Qiong , Sun Zhiwei , Nai Jing , Cui Ze , Zhang Jingbo , Wang Jing , Wu Jianhui , Han Xiaoyan , Niu Yujie , Li Xiaoming , Hou Dongqing , Yu Chengdong , Jiang Chenchen , Liu Qihang , Lin Binbin , Shan Guangliang
Published: July 2022

The Diverse Life-Course Cohort (DLCC) is a large-scale prospective study including around 130,000 participants in mainland China. The primary aims of DLCC include contributing to knowledge on noncommunicable chronic disease determinants, particularly cardiometabolic diseases, and exploring the long-term effect of ambient air pollutants or other environmental risk factors on health among all-age populations. The cohort consists of several sub-populations that cover the whole life-course and diverse resources: from premarital to adolescents, adults from workplace and communities ranged from 18 to 93 years old. Baseline assessment (2017–2021) included face-to-face standardized questionnaire interview and measurements to assess social and biological factors of health. Blood samples were collected from each participant (except for children younger than 6) to establish the biobank. DLCC consists of two visits. Visit 1 was conducted from 2017, and 114850 individuals from one of the world-class urban agglomerations: Beijing, Tianjin, and Hebei area were recruited. By the end of 2021, at least one follow-up was carried out, with an overall follow-up rate of 92.33%. In 2021, we initiated Visit 2, newly recruited 9,866 adults from Guangdong province (South China) and Hebei province (Central China), with research focuses on the comparations on ambient pollution hazards and other unique dietary or environmental risks for health. The baseline survey of Visit 2 was finished in July 2021. DLCC is still ongoing with a long-term follow-up design, and not limited by the current funding period. With reliable data and the well-established biobank which consists of over 120,000 individuals’ blood samples, DLCC will provide invaluable resources for scientific research.
Iron/multiwalled carbon nanotube (Fe/MWCNT) hybrid materials characterization: thermogravimetric analysis as a powerful characterization technique
Authors: Alzate Manuela , Gamba Oscar , Daza Carlos , Santamaria Alexander , Gallego Jaime
Published: July 2022

Nanomaterials and nanocomposites have gained relevance in science and technology due to their excellent properties. Therefore, the characterization of these materials is important. Thermogravimetric analysis is a powerful technique for the characterization of iron-carbon nanotubes (Fe/MWCNT) as hybrid nanomaterials, which may be prepared by impregnation step (alkaline or microwave-assisted precipitation). High-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD and in situ XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) were the instrumental techniques used to characterize these hybrid materials. Through TGA, it was possible to determine the quantity of effective impregnated iron on the MWCNT. Further, in a TGA, nitrogen atmosphere reveals a thermal event reflecting the iron reduction by C from MWCNT and the shape of the signal reflects the dispersion and size of the iron particles on the surface. This thermal event is related to the particle sizes and chemical nature of iron oxides present. Thermal events from TGA may be correlated with the results obtained from XRD, XPS, and HR-TEM. The presence of smaller and well-distributed iron nanoparticles impacts the shape of the reducing event in the TGA. The reduction temperature as observed in TGA curves is related to the nature of metal compounds present, such as nitrates or oxides. These results suggest that TGA can be used as a rapid and economical technique for the evaluation of different Fe/MWCNT hybrid material properties. These results may facilitate the estimation of the structural and chemical nature of the Fe/MWCNT nanohybrid materials and permit the projections of potential applications.
Static FET PET radiomics for the differentiation of treatment-related changes from glioma progression
Authors: Müller Marguerite , Winz Oliver , Gutsche Robin , Leijenaar Ralph T. H. , Kocher Martin , Lerche Christoph , Filss Christian P. , Stoffels Gabriele , Steidl Eike , Hattingen Elke , Steinbach Joachim P. , Maurer Gabriele D. , Heinzel Alexander , Galldiks Norbert , Mottaghy Felix M. , Langen Karl-Josef , Lohmann Philipp
Published: July 2022

Purpose

To investigate the potential of radiomics applied to static clinical PET data using the tracer O-(2-[18F]fluoroethyl)-l-tyrosine (FET) to differentiate treatment-related changes (TRC) from tumor progression (TP) in patients with gliomas.

Patients and Methods

One hundred fifty-one (151) patients with histologically confirmed gliomas and post-therapeutic progressive MRI findings according to the response assessment in neuro-oncology criteria underwent a dynamic amino acid PET scan using the tracer O-(2-[18F]fluoroethyl)-l-tyrosine (FET). Thereof, 124 patients were investigated on a stand-alone PET scanner (data used for model development and validation), and 27 patients on a hybrid PET/MRI scanner (data used for model testing). Mean and maximum tumor to brain ratios (TBRmean, TBRmax) were calculated using the PET data from 20 to 40 min after tracer injection. Logistic regression models were evaluated for the FET PET parameters TBRmean, TBRmax, and for radiomics features of the tumor areas as well as combinations thereof to differentiate between TP and TRC. The best performing models in the validation dataset were finally applied to the test dataset. The diagnostic performance was assessed by receiver operating characteristic analysis.

Results

Thirty-seven patients (25%) were diagnosed with TRC, and 114 (75%) with TP. The logistic regression model comprising the conventional FET PET parameters TBRmean and TBRmax resulted in an AUC of 0.78 in both the validation (sensitivity, 64%; specificity, 80%) and the test dataset (sensitivity, 64%; specificity, 80%). The model combining the conventional FET PET parameters and two radiomics features yielded the best diagnostic performance in the validation dataset (AUC, 0.92; sensitivity, 91%; specificity, 80%) and demonstrated its generalizability in the independent test dataset (AUC, 0.85; sensitivity, 81%; specificity, 70%).

Conclusion

The developed radiomics classifier allows the differentiation between TRC and TP in pretreated gliomas based on routinely acquired static FET PET scans with a high diagnostic accuracy.
The role of culture and evolving attitudes in travel behaviour assimilation among south asian immigrants in Melbourne, Australia
Authors: Shafi Rahman , Delbosc Alexa , Rose Geoffrey
Published: July 2022

A range of studies have found that immigrants generally start out using different travel modes but over time they ‘assimilate’ toward adopting similar travel modes to the general population. These studies tend to focus on ‘when’ and ‘if’ travel assimilation occurs, with some studies using socioeconomic factors to explain ‘why’ this occurs. But few studies have explored the role of culture, attitudes and other ‘soft’ factors in shaping the process of travel assimilation among immigrants. In Australia, South Asians have been the largest and fastest growing immigrant group, and as skilled migrants they face few ‘hard’ barriers to car use. The aim of this paper is to explore the interaction between cultural influences, attitudes and initial travel experiences upon arrival in Australia on long-term travel assimilation amongst South Asian immigrants. Qualitative interviews with 20 South Asian immigrants were used to identify a range of cultural and psychosocial factors, such as perceptions towards travel modes and gender-based cultural norms. Attitudes and behaviours evolve during their early years in Australia, beginning with a ‘honeymoon period’ – a phase where all travel modes are seen as positive – before car use begins to dominate. The findings have implications for how we understand the interactions between attitudes, cultural practice and travel behaviour and how they evolve over time. They also imply that policymakers have only a narrow window of time to encourage sustainable transport among South Asian immigrants before the travel ‘honeymoon period’ wears off.
Synthesis and catalytic olefin metathesis activity of amberlyst-15 supported cyclic and bicyclic alkyl amino carbene ruthenium complexes
Authors: Deme János , Nagyházi Márton , May Zoltán , Hancsók Jenő , Valyon József , Kéki Sándor , Tuba Róbert , Turczel Gábor
Published: July 2022

Amberlyst-15 supported cyclic alkyl amino carbene and bicyclic alkyl amino carbene ruthenium olefin metathesis catalysts for sustainable catalytic applications have been synthesized by the well-known wet impregnation method utilizing ionic complex/support interaction. Surface coverages are as high as 4 and 7 wt% were achieved in the case of the significantly higher pore volume Amberlyst-15, compared to Amberlyst-36. These phase separable catalysts show high activity in cross metathesis, ring closing metathesis and ethenolysis reactions compared to the reported heterogenized olefin metathesis catalysts. Leeching tests revealed no more than 1.5 ppm ruthenium content for the investigated metathesis reactions, which is well below the accepted 10 ppm limit in case of consumer products.
Modeling Eye Movements During Decision Making: A Review
Authors: Wedel Michel , Pieters Rik , van der Lans Ralf
Published: July 2022

This article reviews recent advances in the psychometric and econometric modeling of eye-movements during decision making. Eye movements offer a unique window on unobserved perceptual, cognitive, and evaluative processes of people who are engaged in decision making tasks. They provide new insights into these processes, which are not easily available otherwise, allow for explanations of fundamental search and choice phenomena, and enable predictions of future decisions. We propose a theoretical framework of the search and choice tasks that people commonly engage in and of the underlying cognitive processes involved in those tasks. We discuss how these processes drive specific eye-movement patterns. Our framework emphasizes the central role of task and strategy switching for complex goal attainment. We place the extant literature within that framework, highlight recent advances in modeling eye-movement behaviors during search and choice, discuss limitations, challenges, and open problems. An agenda for further psychometric modeling of eye movements during decision making concludes the review.
How do environmental protection expenditure and green technology innovation affect synergistically the financial performance of heavy polluting enterprises? Evidence from China
Authors: Tang Yongjun , Yue Saifan , Ma Wenchao , Zhang Lulu
Published: July 2022

In recent years, economic growth has caused an increasing number of environmental problems in China. In order to achieve the goal of carbon peak on schedule, enterprises need to accelerate green transformation and upgrading. Environmental protection expenditure and green technology innovation are important means of corporate environmental governance strategy, but it is unknown whether they can promote the sustainable development of enterprises. Therefore, this article will analyze the effect of enterprise environmental protection expenditure and green technology innovation on financial performance. Based on relevant theories, this study builds a theoretical model to demonstrate how enterprise environmental protection expenditure and green technology innovation can affect the financial performance of heavy polluting enterprises. Empirical tests are carried out using 293 heavy polluting enterprises in China as the sample. The results reveal that: (i) Enterprise environmental protection expenditure has significant negative effects on current enterprise financial performance, while green technology innovation can significantly promote enterprise financial performance. (ii) When the lag period is two periods, the enterprise environmental protection expenditure and green technology innovation have positive effects on enterprise financial performance respectively, and the effects are the most significant. (iii) Enterprise environmental protection expenditure and green technology innovation synergistically promote enterprise financial performance in the current period, and the impact has a lag effect. (iv) In state-owned enterprises and enterprises with higher corporate governance level, the synergetic promotion effect of environmental protection expenditure and green technology innovation on enterprise financial performance is more significant. Finally, this study provides suggestions for promoting the transformation and upgrading of heavy polluting enterprises and achieving sustainable development from the perspectives of the government, enterprises and the public.
Ethics of Buying DNA
Authors: Koplin Julian J. , Skeggs Jack , Gyngell Christopher
Published: July 2022

DNA databases have significant commercial value. Direct-to-consumer genetic testing companies have built databanks using samples and information voluntarily provided by customers. As the price of genetic analysis falls, there is growing interest in building such databases by paying individuals for their DNA and personal data. This paper maps the ethical issues associated with private companies paying for DNA. We outline the benefits of building better genomic databases and describe possible concerns about crowding out, undue inducement, exploitation, and commodification. While certain objections deserve more empirical and philosophical investigation, we argue that none currently provide decisive reasons against using financial incentives to secure DNA samples.
Gassing During Tapping of Silicon
Authors: Vachaparambil Kurian J. , Panjwani Balram , Olsen Jan Erik
Published: July 2022

During tapping of metal from silicon furnaces, a significant amount of gas is often released through the tap-hole. The gas is combustible, and a flame jet is created which poses a safety threat to operators. Due to the high temperatures involved, thermal NOx is also produced. This is a threat to the environment and the health of the operators. These phenomena, known as gassing, have been studied here by a mathematical model for reactive turbulent flows. The results show that the flame jet can extend several meters out from the tap-hole, and that the strength of the flame jet increases with the amount of gassing. The simulations also show that the NOx production increases with the amount of gas exiting the tap-hole, and that the thermal NOx formation does not substantially impact the length of the gas jet.
The Impact of COVID-19 on Primary Educational Publishers in Australia
Authors: Reid Grace , Mrva-Montoya Agata
Published: July 2022

Based on interviews with 10 professionals from primary educational publishers and educational technology companies based in Australia, this article examines the challenges and impact of COVID-19 on publishing operations and outputs, and the future of the sector. The publishers had to deliver digital materials quickly, effectively and often for free to assist educators with the transition to remote learning, while working remotely themselves. They also had to transfers sales, support and professional learning online. Overall, while operationally challenging, the pandemic has accelerated the demand for digital products and facilitated growth of the sector.
The effect of edge serration on the performance of stone-tip projectiles: an experimental case study of the Maros Point from Holocene South Sulawesi
Authors: Ferdianto Anton , Suryatman  , Fakhri  , Hakim Budianto , Sutikna Thomas , Lin Sam C.
Published: July 2022

Serrated stone points have been documented in a variety of archaeological settings worldwide. In Indonesia, serrated points known as Maros point began to appear during the mid-Holocene as part of the Toalean techno-complex in southern South Sulawesi. Researchers have speculated functional and cultural reason behind the emergence of these distinctive artefact as projectile points, an assumption that has yet to be verified by archaeological data. In particular, the edge serration has been suggested to allow for deeper penetration and/or act as barbs to prevent the easy withdrawal of the points from the target. In this study, we experimentally test these functional hypotheses regarding the effect of edge serration on stone arrowheads resembling Maros points when fired using different bow draw weights. We also investigate variation in breakage and impact fracture pattern between serrated and non-serrated points. Our result show that, compared to the non-serrated points, the serrated arrows not only deliver deeper penetrations, but also require less force to withdraw from the ballistic gel target. However, these relationships are complicated by the inclusion of skin and bone in the ballistic target. The findings demonstrate that the effect of serrated stone points on projectile performance depends on factors such as the projectile delivery system and prey type. Moreover, under identical firing settings, the serrated points develop more variable macrofracture patterns than the non-serrated points, likely owing the irregular edge morphologies. Taking these results together, we discuss the implications of our experimental study on the appearance of Maros points and the Toalean techno-complex in South Sulawesi during the mid-Holocene.
Understanding metaphorical understanding (literally)
Authors: Stuart Michael T. , Wilkenfeld Daniel
Published: July 2022

Metaphors are found all throughout science: in published papers, working hypotheses, policy documents, lecture slides, grant proposals, and press releases. They serve different functions, but perhaps most striking is the way they enable understanding, of a theory, phenomenon, or idea. In this paper, we leverage recent advances on the nature of metaphor and the nature of understanding to explore how they accomplish this feat. We attempt to shift the focus away from the epistemic value of the content of metaphors, to the epistemic value of the metaphor’s consequences. Many famous scientific metaphors are epistemically good, not primarily because of what they say about the world, but because of how they cause us to think. Specifically, metaphors increase understanding either by improving our sets of representations (by making them more minimal or more accurate), or by making it easier for us to encode and process data about complex subjects by changing how we are disposed to conceptualize those subjects. This view hints towards new positions concerning testimonial understanding, factivity, abilities, discovery via metaphor, and the relation between metaphors and models.
The impact of overbalance pressure on the alteration of sandstone geomechanical properties
Authors: Gamal Hany , Elkatatny Salaheldin
Published: July 2022

The overbalance pressure drilling technique is well common and practiced during the drilling operations in the petroleum field. This parameter is very critical and affects the drilled formation characteristics, and therefore, the main objective of the current study is to evaluate the impact of overbalance pressure that is applied during the drilling operation on the rock elastic and strength characteristics by employing integrated lab experimental work. Berea Buff sandstone rock type was utilized to interact with water-based drilling fluid (barite-weighted) under an extended range of overbalance pressure [300 to 1000 psi]. The current research presents extensive lab analyses that cover filtration tests for rock-mud interaction, scratch testing for determining the rock strength profile, sonic data acquisition, elastic properties determination, and spectrometry of scanning electron microscope and nuclear magnetic resonance spectrometry to study the internal pore structure changes. The analysis was performed before the mud interaction for the saturated samples (base case) and after applying different overbalance pressure (pre-mud interaction) to evaluate the rock properties alterations. The obtained results showed the high degree of impact of the overbalance pressure on the sonic wave propagation as the compressional and shear wave velocities increased by 17 and 6%, respectively with increasing the overbalance pressure. Poisson’s ratio showed a stable trend, while Young’s modulus showed an increasing trend by 23% increase with the extended range of the overbalance pressure. The rock strength showed deterioration behavior with increasing the overbalance pressure. The unconfined compression strength decreased by 10% and the tensile strength showed a 9% reduction. The internal pore spectrometry showed the rock structure alterations due to mud solids precipitations and filtrate fluid impact on the rock integrity during the rock-mud interaction. In addition, statistical analysis illustrated the high degree of relationship between the recorded rock characteristics with the overbalance pressure as a controlling factor on the rock and mud interaction.
XFEM modeling of the effect of in-situ stresses on hydraulic fracture characteristics and comparison with KGD and PKN models
Authors: Esfandiari Morteza , Pak Ali
Published: July 2022

Increasing the permeability of hydrocarbon reservoirs by creating artificial cracks that are induced by injection of fluids under high pressure is called hydraulic fracturing (HF). This method is widely used in petroleum reservoir engineering. For design of Hydraulic Fracture operations, several analytical models have been developed. KGD and PKN are the first and most used analytical models in this area. Although number of advanced softwares are developed in recent years, KGD and PKN models are still popular and have even been used in a number of softwares. In both models the characteristics of the fracture namely: fracture length (L), fracture width (w), and fluid pressure at the crack mouth (p) are determined based on closed form relations using the reservoir rock shear stiffness, Poisson’s ratio, fluid injection rate, and injection time. Despite their ease of use, KGD and PKN models do not consider some important geo-mechanical and hydro-mechanical parameters and this shortcoming makes their results to be approximate. The aim of this study is evaluating the effects of in-situ stress on the fracture length, width, and fluid pressure employing XFEM method. In this study, tensile fracture mode and cohesive zone model are used for creation and propagation of cracks. In this paper, by conducting a series of numerical simulations using XFEM and after verification of the results, the accuracy of the analytical formulas of KGD and PKN models are examined. The results show that due to some simplifying assumptions used in KGD and PKN analytical models and neglecting some hydraulic and geomechanical parameters such as in-situ stresses, the length, width, and fluid pressure of the crack obtained from analytical formulas differ from the results of the numerical simulations. In this paper, the effects of in-situ stresses on hydraulic fracture characteristics (width, length, and crack mouth fluid pressure) are investigated and presented in the form of a number of correction (modification) factors that can be used for improvement of the results of KGD and PKN models. The findings of this study can help for more accurate design of hydraulic fracture process in oil industry for increasing the production of hydrocarbon reservoirs.
Ultralight and hyperelastic SiC nanofiber aerogel spring for personal thermal energy regulation
Authors: Song Limeng , Fan Bingbing , Chen Yongqiang , Gao Qiancheng , Li Zhe , Wang Hailong , Zhang Xinyue , Guan Li , Li Hongxia , Zhang Rui
Published: July 2022

Multifunctionalization is the development direction of personal thermal energy regulation equipment in the future. However, it is still a huge challenge to effectively integrate multiple functionalities into one material. In this study, a simple thermochemical process was used to prepare a multifunctional SiC nanofiber aerogel spring (SiC NFAS), which exhibited ultralow density (9 mg/cm3), ultralow thermal conductivity (0.029 W/(m·K) at 20 °C), excellent ablation and oxidation resistance, and a stable three-dimensional (3D) structure that composed of a large number of interlacing 3C-SiC nanofibers with diameters of 300–500 nm and lengths in tens to hundreds of microns. Furthermore, the as-prepared SiC NFAS displayed excellent mechanical properties, with a permanent deformation of only 1.3% at 20 °C after 1000 cycles. Remarkably, the SiC NFAS exhibited robust hyperelasticity and cyclic fatigue resistance at both low (∼−196 °C) and high (∼700 °C) temperatures. Due to its exceptional thermal insulation performance, the SiC NFAS can be used for personal thermal energy regulation. The results of the study conclusively show that the SiC NFAS is a multifunctional material and has potential insulation applications in both low- and high-temperature environments.
Zur Rolle von Unterhaltungsmagazinen in der Pandemie. Zwischen entdifferenzierten Sammelsurien und differenzierten Wissensvermittlern
Authors: Lickhardt Maren
Published: July 2022

Dieser Artikel untersucht, wie illustrierte Unterhaltungsmagazine Covid-19 in zwei Zeiträumen thematisieren: von Februar bis Juli 2020 und von Oktober bis Dezember 2021. Die Zeitschriften stellen nicht nur eine Kontaktszene zwischen Wissenschaft und Öffentlichkeit dar, sondern vermitteln auch zwischen verschiedenen professionellen Diskursen, die die Pandemie bearbeiten, und müssen selektieren, welchen Bearbeitungsmodus sie präferieren. Während sich die Zeitschriften, weil sie sich ohnehin im permanenten Krisenmodus befinden, zunächst insofern kaum von der Pandemie irritieren lassen, als sie diese im boulevardesken Modus bearbeiten, indem sie etwa die Reaktion von Prominenten zeigen, die ihrerseits Laien sind, stellen sie in der zweiten Untersuchungsphase auf seriöse Vermittlung von Wissenschaft um und tragen zur Popularisierung von medizinischem und epidemiologischem Wissen bei.
Antioxidant Machinery and Glyoxalase System Regulation Confers Salt Stress Tolerance to Wheat (Triticum aestivum L.) Plants Treated with Melatonin and Salicylic Acid
Authors: Talaat Neveen B. , Todorova Dessislava
Published: July 2022

Plant growth regulators melatonin (MT) and salicylic acid (SA) have potent roles in plant salt tolerance. However, only a few reports have studied the influence of their combined treatment on plant salt tolerance. The current study, as a first investigation, was aimed to evaluate the effect of MT and SA combined treatment on the antioxidant and glyoxalase defense machineries of salt-stressed wheat plants. In the present study, the potential role of 70 μM MT and/or 75 mg l−1 SA on mitigating salt injury (6.0 and 12.0 dS m−1 salinity levels) was investigated in wheat (Triticum aestivum L. cv. Sids 14). Exogenously applied MT and/or SA improved the activity of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase, glutathione peroxidase, and glutathione S-transferase, which effectively scavenged reactive oxygen species (ROS) in stressed plants. Excessive accumulation of the toxic methylglyoxal was reversed via the up-regulation of the glyoxalase system (glyoxalase I and glyoxalase II) and the ascorbate–glutathione cycle. Foliar applications also reduced membrane damage by lowering lipid peroxidation and protein oxidation due to effective ROS detoxification by antioxidants such as ascorbate, glutathione, phenols, and flavonoids. Moreover, exogenous MT and/or SA applications increased endogenous MT and SA levels under both non-saline and saline conditions. The combined treatment of MT and SA yielded the best results. Overall, this combined treatment regulated the antioxidant machinery and glyoxalase system, suggesting a role for it in salt stress mitigation. Therefore, it can be considered as an effective method for reducing salt toxicity in sustainable agricultural systems.
Chaotic Wind Driven Optimization with Fitness Distance Balance Strategy
Authors: Tang Zhentao , Tao Sichen , Wang Kaiyu , Lu Bo , Todo Yuki , Gao Shangce
Published: July 2022

Wind driven optimization (WDO) is a meta-heuristic algorithm based on swarm intelligence. The original selection method makes it easy to converge prematurely and trap in local optima. Maintaining population diversity can solve this problem well. Therefore, we introduce a new fitness-distance balance-based selection strategy to replace the original selection method, and add chaotic local search with selecting chaotic map based on memory to further improve the search performance of the algorithm. A chaotic wind driven optimization with fitness-distance balance strategy is proposed, called CFDBWDO. In the experimental section, we find the optimal parameter settings for the proposed algorithm. To verify the effect of the algorithm, we conduct comparative experiments on the CEC 2017 benchmark functions. The experimental results denote that the proposed algorithm has superior performance. Compared with WDO, CFDBWDO can gradually converge in function optimization. We further verify the practicality of the proposed algorithm with six real-world optimization problems, and the obtained results are all better than other algorithms.
Level of Fear in Front-Line Nurses During the COVID-19 Pandemic, a Cross-Sectional Study in Iran
Authors: Moradi Maryam , Sharififar Simintaj
Published: July 2022

Introduction:

The front-line nurses are at risk of physical and psychological damage during an epidemic. This study aimed to investigate the level of nurses’ fear in coronavirus disease 2019 (COVID-19) central hospitals in Iran.

Methods:

The study is cross-sectional. The questionnaire was designed in 2 parts (demographic and the level of fear). The sampling method was quota and random. The questionnaires were completed by the same nurses after 4 weeks.

Results:

A total of 345 questionnaires were distributed (the response rate was 89.27%). A total of 121 nurses (39.3%) were female. Most participants were in the 26-30 y group. paired t-test showed the mean fear of COVID-19 in the first and the fourth weeks was significant (P < 0.001). There was a statistical relationship between demographic variables of gender, age, marriage, number of working shifts, having children, and work experience of nurses with the level of fear.

Conclusions:

Health-care providers have shown resilience and a spirit of professional sacrifice to overcome problems. The nurses experienced a level of disease-related fear in close contact with COVID-19 patients. It is essential to apply strategies to optimize safe working conditions and minimize psychological harm and provide regular and intensive training to all health-care providers to improve preparedness.
“Numberless Little Risks”: ‘Tropical Exposure’ in Globalizing Actuarial Discourse, 1852–1947
Authors: Aitken Rob
Published: July 2022

I argue that life insurance and imperial meaning making are deeply implicated in each other. As life insurance expanded internationally in the nineteenth century, and as insurers became advocates of White settlement, they grappled with what actuarial science meant in the context of their orientalist conceptions of colonial populations. In particular, actuaries were concerned with tropical markets and the racialized/exceptionalized differences they perceived in those markets. To address these tensions, insurers attempted two strategies: (1) incorporating tropical rates as additional premiums designed to cover the “extra mortality” of tropical markets; and (2) advocating for social practices of “sanitary progress” related to public health and sanitation. These practices, framed in orientalist terms, were not adopted in any smooth manner but in fumbling and meandering ways as insurers tried to understand what kinds of lives tropical settlers might be and how those lives might be priced. They eventually liberalized life insurance rates for White settlers in tropical settings, but insurers then confronted questions on how newly socialized “native” lives might be rendered calculable. This story of tropical exposure in globalizing actuarial discourse reinforces the ways in which race and racialized/exceptionalized differences were at the core of life insurance and the calculative devices it assembled between 1852 and 1947.
Notes on a Perilous Journey to the United States: Irregular Migration, Trafficking in Persons, and Organized Crime
Authors: Correa-Cabrera Guadalupe , Schaefer Kathleen Blair
Published: July 2022

This article examines the interplay between transnational criminal actors (essentially human smugglers), local crime groups, and drug cartels in the phenomenon of trafficking in persons coming from Central America along Mexico’s eastern migration routes. The analysis focuses on sex trafficking, compelled labor for criminal activities, and other forms of labor trafficking. Through qualitative research that involved 336 semistructured interviews with migrants, activists, and other persons familiar with the subject, this work describes and maps trafficking trends throughout Mexico’s eastern migration routes. It also sheds light on the role of drug cartels and other crime groups (local and transnational) in these activities.
Interactions, relationships and belonging: comparing social connectedness and perceived isolation among older women living alone in private homes and in assisted living
Authors: Berlin Melissa , Perone Angela K.
Published: July 2022

Age-related changes shape social connectedness, isolation and loneliness among older adults. Ageing often accompanies decisions about ageing in place or moving (i.e. senior living facility). Scant research compares these two living arrangements and even sparser research focuses on older women. This study, thus, poses the following questions: How do older women (aged 75+ years) experience social connectedness and perceived isolation? How does this experience vary between older women living alone in private homes and those living in assisted living facilities? Data include semi-structured interviews with women aged 75+ years who live alone in a private home or in an assisted living facility (N = 16). Findings revealed differences in three aspects of social connectedness: interactions, relationships and belonging. Private home participants' interactions underscored intentionality, with minimal investment in forging new or deeper relationships and an emphasis on belonging to the world through awareness, contribution and cognitive ability. The experiences of participants living in assisted living were characterised by availability of interactions and casual relationships. They emphasised belonging to the facility community, while positioning themselves between the status of resident and staff. Surprisingly, most participants in both groups did not express feelings of perceived isolation. Both had adapted their social connectedness expectations to reflect their current situation.
Temporary Leaders and Stable Institutions: How Local Bureaucratic Entrepreneurs Institutionalize China's Low-Carbon Policy Experiments
Authors: Gong Weila
Published: July 2022

Traditional analysis of China's policy experimentation has focused on the role of central–local relations and rotating leaders in shaping the local agenda-setting process. Less is known about the role of less mobile mid-level local bureaucrats who serve as bridges in the implementation process. This paper examines why some cities have performed better than others at implementing and maintaining low-carbon policy experiments. Drawing on a comparison of four case cities and over 100 expert interviews, I argue that the availability of bureaucratic entrepreneurs and their resource mobilization capacity determine the level of local engagement in climate policy experimentation. This study shows that the institutionalization of local policy experiments is not only driven by the central government or rotating top local leaders but also by bureaucratic entrepreneurs who help policy experiments survive periodic changes in the bureaucracy. The findings have important implications for the fulfilment of China's 2060 carbon neutrality pledge.
Die Bedeutung peripartaler mütterlicher Angst- und depressiver Störungen für die frühkindliche Entwicklung
Authors: Sommer Maria , Knappe Susanne , Garthus-Niegel Susan , Weidner Kerstin , Martini Julia
Published: July 2022

Zusammenfassung. Theoretischer Hintergrund: Aktuelle Studien zeigen spezifische Zusammenhänge von peripartalen psychischen Störungen und kindlichen Entwicklungsauffälligkeiten. Fragestellung: Haben Kinder von Müttern mit einer peripartalen Angst- oder depressiven Störung ein erhöhtes Risiko für (visuo–)‌motorische, sprachliche und kognitive Entwicklungsauffälligkeiten? Methode: In der prospektiven MARI-Studie ( N = 306) wurden peripartale psychische Störungen mit dem CIDI-V in jedem Schwangerschaftstrimester sowie 2, 4 und 16 Monate nach der Geburt erhoben. Die kindliche Entwicklung wurde mit dem Neuropsychologischen Entwicklungs-Screening im Alter von 4 ( N = 263) und 16 Monaten ( N = 241) erfasst. Ergebnisse: Maternale depressive Störungen vor der Schwangerschaft waren negativ mit der visuellen Entwicklung (4 Monate; OR = 3.3) und der Haltungs- und Bewegungssteuerung (16 Monate; OR = 4.4) des Kindes assoziiert. Diskussion: Entwicklungsauffälligkeiten könnten u. a. durch ein verändertes Interaktionsverhalten (z. B. weniger Blickkontakt/Ermutigung) betroffener Mütter begründet sein.