bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the effects of a load shedding at a lignite power plant
Authors: Prause Jens H. , Koltermann Jan , Meinke Sebastian , Holtz Dorian , Hassel Egon 
Published: March 2021

AbstractThe load‐shedding scenario describes an unscheduled load reduction in a power plant so that it produces only the electricity that is needed by the plant itself. The reason for such a scenario is a collapse of power supply in the transmission network. In the subsequent restoration of the electrical supply, different options are distinguished. An essential part of each option is island operating or black start capable thermal power plants. The load‐shedding scenario is complex and multilayered. If process steam is also decoupled during the load shedding, high exhaust steam temperatures in the turbine stages can lead to plant shutdown. In addition, component damage can be expected in thick‐walled components due to high temperature and pressure amplitudes. Thus, it can be shown in this paper that the lifetime losses are highest at the high‐pressure preheater 6 and at the deheater and that the process heat coupling cannot be operated with constant mass flow under all circumstances. In order to investigate these issues, a detailed model of a lignite power plant has been created, which was developed in Modelica for simulating and comparing scenarios for a variety of applications. The model comprises the entire water‐steam cycle including turbines, preheaters and pumps, as well as a very detailed boiler model including the air supply, coal mills, heating surfaces, and piping. Furthermore, the power plants' control system has been implemented in a very precise way. In addition, the study involves a calculation of lifetime consumption for specific components to evaluate the effects. In summary, it can be stated that this study examines the thermodynamic aspects during a load‐shedding scenario for the first time. It focuses on processes within the power plant and thus differs significantly from other studies on this topic, which approach the issue from the electrical grid side.
Imposing C0 and C1 continuity constraints during CAD‐based adjoint optimization
Authors: Damigos Marios G. , De Villiers Eugene 
Published: March 2021

AbstractThis article presents a method for performing adjoint‐based aerodynamic shape optimization by manipulating the standard CAD geometry of the shape to be optimized. A standard CAD file gives access to the boundary representation (BRep) of the shape and consequently its boundary surfaces which are usually trimmed patches. This is a sensible choice as the open format of such files is a requirement for the computation of the shape derivatives. The method addresses the continuity issues that emerge during the update of the shape by imposing up to C1 constraints between different CAD patches. A parameterization scheme based on NURBS surfaces is then defined, in which the aforementioned constraints are inherently satisfied. The proposed method is firstly demonstrated in a simple geometric case and then in the full‐scale optimization of industrial‐like cases such as the S‐section of a cooling duct and the tail surface of a passenger car.
Simulated gastric hydrolysis and developmental toxicity of dibutyltin bis(2‐ethylhexyl thioglycolate) in rats
Authors: Costlow Richard D. , Nasshan Hans , Frenkel Peter , Salsbury Joseph 
Published: March 2021

AbstractPreviously, dibutyltin dichloride (DBTC) was the putative toxophore for dibutyltin bis‐alkyl and bis‐thio esters. Recent chemical and toxicological data on dioctyltin bis(2‐ethylhexyl thioglycolate) suggest the thioglycolate esters of alkyltins do not generate the dichloride toxophore. Our results, using 119Sn‐nuclear magnetic resonance (NMR) spectroscopy, demonstrated that dibutyltin bis(2‐ethylhexyl thioglycolate) (DBTE) is hydrolyzed to dibutyltin chloro‐(2‐ethylhexyl thioglycolate) (DBTEC) under simulated gastric conditions. No DBTC was detected. DBTE was administered orally to presumed‐pregnant Sprague–Dawley rats in a corn oil vehicle at 2.5, 8.5, and 25.0 mg/kg/day (Gestation Day 5 [GD5] through GD19). There were no maternal deaths, no treatment‐related statistically significant reductions in feed consumption, maternal body weight or weight gain, or adverse gestational outcomes. Maternal thymus weight was significantly reduced in rats at 25 mg/kg. There were no effects on fetal growth, no dose‐dependent pattern of external, visceral, or skeletal malformations, and no increase in anatomical variations. Based on the obtained experimental data, it is concluded here that DBTE forms DBTEC, not DBTC, in the stomach, and DBTE was not teratogenic nor fetotoxic in rats, a species sensitive to DBTC. The maternal no‐observed‐adverse‐effect level (NOAEL) was 8.5 mg/kg/day, and the developmental NOAEL was 25 mg/kg/day, the high dose. The maternal LOAEL was 25 mg/kg/day based on reduced maternal thymus weight.
Connected search for a lazy robber
Authors: Adler Isolde , Paul Christophe , Thilikos Dimitrios M. 
Published: March 2021

AbstractThe node‐search game against a lazy (or, respectively, agile) invisible robber has been introduced as a search‐game analogue of the treewidth parameter (and, respectively, pathwidth). In the connected variants of the above games, we additionally demand that, at each moment of the search, the clean territories are connected. The connected search game against an agile and invisible robber has been extensively examined. The monotone variant (where we demand that the clean territories are progressively increasing) of this game corresponds to the graph parameter of connected pathwidth. It is known that the price of connectivity to search for an agile robber is bounded by 2, that is, the connected pathwidth of a graph is at most twice (plus some constant) its pathwidth. We investigate the study of the connected search game against a lazy robber. A lazy robber moves only when the cops' strategy threatens the vertex that he currently occupies. We introduce two alternative graph‐theoretical formulations of this game, one in terms of connected tree‐decompositions and one in terms of (connected) layouts, leading to the graph parameter of connected treewidth. We observe that the connected treewidth parameter is closed under contractions and prove that for every , the set of contraction obstructions of the class of graphs with connected treewidth at most is infinite. Our main result is a complete characterization of the obstruction set for . We also show that, in contrast to the agile robber game, the price of connectivity is unbounded.
A limit theorem for small cliques in inhomogeneous random graphs
Authors: Hladký Jan , Pelekis Christos , Šileikis Matas 
Published: March 2021

AbstractThe theory of graphons comes with a natural sampling procedure, which results in an inhomogeneous variant of the Erdős–Rényi random graph, called ‐random graphs. We prove, via the method of moments, a limit theorem for the number of ‐cliques in such random graphs. We show that, whereas in the case of dense Erdős–Rényi random graphs the fluctuations are normal of order , the fluctuations in the setting of ‐random graphs may be of order , or . Furthermore, when the fluctuations are of order they are normal, while when the fluctuations are of order they exhibit either normal or a particular type of chi‐square behavior whose parameters relate to spectral properties of . These results can also be deduced from a general setting, based on the projection method. In addition to providing alternative proofs, our approach makes direct links to the theory of graphons.
The lateral line system and its innervation in the Japanese eel Anguilla japonica (Teleostei: Elopomorpha: Anguillidae)
Authors: Nakae Masanori , Kuroki Mari , Sato Mao , Sasaki Kunio 
Published: March 2021

AbstractThe lateral line system and its innervation were examined in the Japanese eel Anguilla japonica. Although the species has seven lateral line canals and 13 superficial neuromast groups, the components are generally similar to those in many other teleosts. The lateral line system of A. japonica is distinctive in having a rostral commissure connecting the left and right supraorbital canals, pouches in the cephalic lateral line canals and superficial neuromasts along the lower lip, and lacking a postotic canal. Four tube‐like elements, two along the supratemporal canal and the other two along the temporal portion of the trunk canal, respectively, are also reported. The functional significance of cephalic lateral line pouches, homologies of the four tube‐like elements, and other distinctive characters are discussed.
Identification of radiative and advective populations in Canadian temperature time series using the Linear Pattern Discrimination algorithm
Authors: Žaknić‐Ćatović Ana , Gough William A. 
Published: March 2021

AbstractLong‐term high‐frequency air temperature time series, typically considered the most authoritative observed records for the detection of climate changes, appear physically heterogeneous by nature. We examine multiple Canadian air temperature records for the presence of physical heterogeneities, using the analysis of their diurnal temperature patterns as the main criterion for the separation of temperature series into ‘homogeneous’ populations. Based on the key differences observed in their diurnal air temperature patterns, two distinct populations of the air temperature sample are identified and assumed to be the result of different heat exchange mechanisms. The Linear Pattern Discrimination (LPD) algorithm, implemented in the R‐code, is introduced in this work and applied to 66‐year long hourly temperature records of 25 Canadian stations for the separation of the radiative temperature population from the advective temperature population and examination of incidences of specific, advective cases in air temperature data. The LPD analysis reveals a predominance of a remarkably warmer, radiatively driven air temperature regime. In contrast, the significantly colder and geographically controlled advective temperature regime plays a counterbalancing role on the overall magnitude of the midlatitude air temperature signal. Our findings suggest that a substantial temperature increase in annual averages of advective minima amplifies the effect of a positively shifted radiative temperature range, intensifying the overall heating observed in the Canadian North and northwestern regions.
Root dynamics along a restoration chronosequence of revegetated grasslands in degraded alpine meadows of the Qinghai‐Tibetan Plateau, China
Authors: Hu Lei , Zi Hongbiao , Luo Xueping , Lerdau Manuel , Wang Changting 
Published: March 2021

AbstractRevegetation using perennial grass, such as Elymus nutans is an effective approach in abating grassland degradation on the Qinghai‐Tibetan Plateau. However, knowledge of root dynamics along restoration chronosequences of revegetated grasslands are limited. To gain better insight into root dynamics, we used minirhizotrons to examine changes in root traits, including root standing crop, production, mortality, and turnover along a restoration chronosequence of three revegetated grasslands (cultivated in 2002, 2006, and 2010 corresponding to late, middle, and early recovery stage) in four consecutive growing seasons (2014, 2015, 2016, and 2017). We found that the aboveground plant biomass was higher in the middle recovery stage than that in the early and late recovery stages, while plant species richness showed an increasing trend from the early to late recovery stage. Similar with the plant biomass response, the belowground root standing crop and production were significantly higher in the middle recovery stage than in the early and late recovery stages. Root mortality was decreased and root turnover tend to be stable from the early to late recovery stage. Root turnover was positively correlated with soil NO3−‐N content and negatively correlated with aboveground plant biomass. Moreover, root standing crop and mortality increased from May to September across all growing seasons; however, root production decreased within this period. Our study highlighted significant links between aboveground and belowground plant parts that may help effectively manage revegetated grassland on the Qinghai‐Tibetan Plateau.
A regression‐based approach to compute the pixels sensitivity map of linear accelerator portal imaging devices
Authors: Ahmad Mahmoud , Nourzadeh Hamidreza , Siebers Jeffrey 
Published: March 2021

PurposeTo determine the pixel sensitivity map (PSM) for amorphous silicon electronic portal imaging devices (EPIDs) using a single flood field signal.Method and materialsA raw EPID signal results from the incident particle energy fluence, the inherent pixels response, and the background signal. In large open fields, particle energy fluence is a slow‐varying signal that is locally considered spatially constant. Pixels response is a fast and abrupt varying behavior. The background signal is due to the EPID panel electronics, which is determined during radiation absence. To determine the PSM, after correcting for the background signal, we apply a model that captures the underlying smooth particle energy fluence‐induced signal. This fluence signal‐fitted model is then used to determine the PSM. Here, we use a polynomial‐based regression surface model in both x and y dimensions. To validate the generated PSM, we measure beams and compute PSMs for multiple beam energies with and without flattening filters and for multiple source‐to‐imager distances. Since the PSM is a detector characteristic, it should be independent of those variables. We also intercompare measurements of fixed slit fields with the EPID being shifted between measurements.ResultsThe fluence signal of the flattening filter‐free (FFF) beams was optimally modeled as a 12th degree polynomial surfaces, which had 0.1% residuals near the central axis. The 6 and 10 MV FFF PSMs were within ˜0.1%, and independent of the EPID SID, suggesting that the PSM is energy independent. The 6, 10, and 15 MV flattened‐beam PSMs were well modeled as 12th degree polynomial surfaces, which were equivalent within ˜0.24% but differed from the FFF PSM by up to 0.5% near the beam central axis. Applying the FFF PSMs to the flattened‐beam measurements reduced the central‐axis deviation between the raw and corrected signal to 0.1%, confirming the PSM energy independence hypothesis. When the FFF PSM is utilized, output verification with shifted slit deliveries agreed within ˜0.5% for all beam energies, which is within the radiation delivery uncertainty of ˜0.57%.ConclusionPSM for MV EPIDs can be determined by separating out the slowly varying, well‐behaved fluence signal from the pixel‐to‐pixel sensitivity variations. The quality of the PSM is found to be dependent on the quality of the surface fit, which is best for the 6 MV FFF beam measured at SID equal to 180 cm. Within fitting errors, the PSM is independent of beam energy for 6, 10, and 15 MV beams with and without flattening filters. The PSM generation does not require shifting the EPID panel nor multiple EPID panel irradiations and should be usable for linacs with fixed geometry EPIDs.
Effect of diagnostic ultrasound and microbubble‐enhanced chemotherapy on metastasis of rabbit VX2 tumor
Authors: Zhang Yi , Tang Najiao , Huang Leidan , Qiao Wei , Zhu Qiong , Liu Zheng 
Published: March 2021

PurposeUltrasound‐targeted microbubble destruction (UTMD) has been widely applied to enhance chemotherapy of tumors, yet few studies have focused on the metastatic potential induced by UTMD. This study aimed to explore the metastasis of VX2 tumors after treatment with UTMD and chemotherapy.MethodsForty‐four New Zealand rabbits bearing subcutaneous VX2 tumors were enrolled for the treatment of UTMD with chemotherapy. For UTMD, the tumors were insonated using two pulsing protocols of diagnostic ultrasound (DUS, VINNO and ECARE) with a mechanical index (MI) of 0.29–0.33, tone burst of 8.0 cycles, and frequencies of 3–4 MHz. A total dose of 2 ml SonoVue® was injected intermittently during 10‐min UTMD exposure. The combination therapy was treated using doxorubicin (DOX, 2 mg/kg) and DUS, while the tumors treated using DOX only served as the control. Tumor size was measured using the tumor volume formula. Survival time was observed until animal death or the end of the study (120 days). Specific organs (lung, liver, kidney, and brain) were removed for metastatic evaluation.ResultsThere were no statistical differences in overall metastasis classification and individual organ metastases among all groups (P > 0.05). The tumor growth rate only showed inhibition on the 5th day (P < 0.01). The survival time did not demonstrate any significant difference between UTMD and chemotherapy only (P > 0.05).ConclusionsUTMD using long‐pulse DUS with commercial microbubbles did not pose a risk of metastasis enhancement in DOX chemotherapy.
Researcher practitioner engagement in health research: The development of a new concept
Authors: Daniels Nicola , Gillen Patricia , Casson Karen 
Published: March 2021

AbstractThe engagement of frontline practitioners in the production of research‐derived knowledge is often advocated. Doing so can address perceived gaps between what is known from research and what happens in clinical practice. Engagement practices span a continuum, from co‐production approaches underpinned by principles of equality and power sharing to those which can minimalize practitioners' contributions to the knowledge production process. We observed a conceptual gap in published healthcare literature that labels or defines practitioners' meaningful contribution to the research process. We, therefore, aimed to develop the concept of “Researcher Practitioner Engagement” in the context of academically initiated healthcare research in the professions of nursing, midwifery, occupational therapy, physiotherapy, and speech and language therapy. Guided by Schwartz‐Barcott et al.'s hybrid model of concept development, published examples were analyzed to establish the attributes, antecedents, and consequences of this type of engagement. Academic researchers (n = 17) and frontline practitioners (n = 8) with relevant experience took part in online focus groups to confirm, eliminate, or elaborate on these proposed concept components. Combined analysis of theoretical and focus group data showed that the essence of this form of engagement is that practitioners' clinical knowledge is valued from a study's formative stages. The practitioner's clinical perspectives inform problem‐solving and decision‐making in study activities and enhance the professional and practice relevance of a study. The conceptual model produced from the study findings forms a basis to guide engagement practices, future concept testing, and empirical evaluation of engagement practices.
Protecting individuals living with overweight and obesity: Attitudes and concerns toward COVID‐19 vaccination in Canada
Authors: Vallis Michael , Glazer Stephen 
Published: March 2021

AbstractObjectiveThe aim of this study was to assess attitudes toward coronavirus disease 2019 (COVID‐19) vaccination and the degree of fear of COVID‐19 among those living with obesity.MethodsTwo samples were recruited for an online survey: one sample was a representative sample of Canadians living with overweight and obesity (n = 1,089), and the second was a convenience sample of individuals recruited from obesity clinical services or patient organizations (n = 980). Respondents completed ratings of their comfort receiving a COVID‐19 vaccination along with the Vaccine Hesitancy Scale and the Fear of COVID‐19 Scale.ResultsApproximately one‐third of respondents, regardless of sample or weight category, were not comfortable receiving a vaccination, and one‐half expressed moderate or greater perceived risks of vaccination. Confidence in vaccinations was extremely low, especially for those in the clinical sample. Fear of COVID‐19 was substantial and predicted attitudes toward vaccination. Females were less comfortable receiving the vaccine and perceived more risks than males.ConclusionsThese results suggest those living with obesity are highly ambivalent about COVID‐19 vaccination. Despite their being at high risk, their confidence in vaccines is very low. Results suggest the need for patient‐centered counseling, with a focus on shared decision‐making to strengthen confidence and reduce perceived risk.
Form‐based security in mobile health data collection systems
Authors: Katarahweire Marriette , Bainomugisha Engineer , Mughal Khalid A. , Ngubiri John 
Published: March 2021

AbstractMobile Health Data Collection Systems (MHDCS) use electronic forms for data collection in place of paper surveys. Data is entered into the electronic forms by community health workers with smartphones. These systems are used in clinical trials and continuous monitoring of participants. Data collected in MHDCS is diverse with varying sensitivity levels. This therefore calls for the application of different security mechanisms to protect the data. In this paper, a data sensitivity classification model is proposed. It determines the sensitivity levels of form attributes depending on the context and sensitive parameters. The electronic form is the starting point of the data collection process. We augment the form with sensitivity levels and a mapping of security mechanisms to the sensitivity levels is made. Through threat modeling, we identify potential threats and possible mitigations. We demonstrate the feasibility of our approach by prototyping the proposed model into the Open Data Kit tool suite. Tests show that the security mitigations specified during form design are executed once the secure form is loaded on the mobile device during data collection. Our ultimate aim is to facilitate the addition of security requirements into the data collection processes right from the start of the design process.
Physicochemical Properties of Cassava Starch‐Konjac Glucomannan Composites
Authors: Liu Yawei , Xu Bing , An Fei , Liu Jie 
Published: March 2021

AbstractCross‐linked cassava starch‐konjac glucomannan composite (CCS‐KGM), native cassava starch‐sodium trimetaphosphate‐konjac glucomannan composite (NCS‐STMP‐KGM), and cross‐linked cassava starch‐sodium trimetaphosphate‐konjac glucomannan composite (CCS‐STMP‐KGM) are prepared to study the effect of STMP and KGM on the native cassava starch and cross‐linked cassava starch. A small amount of KGM adheres to the surface of cassava starch granules in the three composites. The results of Fourier transform infrared spectroscopy indicate that cross‐links form in the cross‐linked cassava starch and three composites. The X‐ray diffraction analysis reveals that the crystallization type of native cassava starch modified by STMP and KGM remains unchanged (A‐type). The mean particle size of cross‐linked cassava starch and the three composites are larger than that of native cassava starch. STMP and KGM decrease the swelling power and water loss rate of native cassava starch. Dynamic rheological results suggest that STMP and KGM increase storage modulus and loss modulus of native cassava starch gel. It provides the possibility for both STMP and KGM to improve the gel properties of native cassava starch rather than cross‐linked reaction, and also expands the application field of KGM with low cost.