bluuebunny/crossref_metadata_2025_split huggingface dataset:
Presentation of combinatorial concepts in mathematics textbooks and its compliance with a concept development theory
Authors: Zenkl David 
Published: August 2021

Článek analyzuje přístupy k vybraným kombinatorickým konceptům v pěti českých středoškolských učebnicích matematiky s cílem zjistit, do jaké míry tyto učebnice poskytují podporu učitelům pro výuku založenou na teorii poznávacího procesu v matematice. Analýza učebnic byla vedena na pozadí teorie generických modelů, přičemž důraz byl položen na přítomnost a kvalitu a) izolovaných modelů a nemodelů budoucího poznatku, b) výzev k zobecňování jako nutnému předpokladu tvorby generického modelu, c) grafických reprezentací jako nezbytné podpory rozvoje kombinatorického uvažování. Bylo zjištěno, že učebnice jsou si v mnoha směrech dosti podobné, ale v jistých ohledech se odlišují. V učebnicích jsme identifikovali mj. nedostatečnou motivaci pro kombinatoriku, nízký počet izolovaných modelů budoucího poznatku, absenci explicitních výzev k zobecňování a z toho plynoucí absenci významného konceptu izomorfismus. Navzdory výzkumně prokázanému pozitivnímu vlivu přítomnosti a vlastní tvorby grafických reprezentací na rozvoj žákovského kombinatorického myšlení se v učebnicích vyskytují reprezentace zřídka, a navíc s malou rozmanitostí. Autoři učebnic až na výjimky nevyzývají čtenáře k tvorbě vlastních grafických reprezentací. Od analyzovaných učebnic se odlišuje jedna, která obsahuje časté výzvy k tvorbě vlastních reprezentací, pracuje záměrně s izomorfními úlohami a vyzývá čtenáře k zobecňování konkrétních postupů.
Numerical simulation of hydrodynamic oscillation of side-by-side double-floating-system with a narrow gap in waves
Authors: Zhang Zhiyang , Liu Weixing , Zheng Xiongbo , Liu Hengxu , Li Ningyu 
Published: August 2021

Abstract
In offshore oil and gas exploration and transportation, it is often encountered that the multi-floating structures work side by side. In some sea conditions, there is a strong coupling between the multi-floating structures that seriously affects the safety of offshore operations. Therefore, the prediction of the relative motion and force between the multi-floating structures and the wave elevation around the multi-floating-system has become a hot issue. At present, the problem of double-floating-system is mostly based on linear potential flow theory. However, when the gap width between two floating bodies is small, the viscous and nonlinear effects are not negligible, so the potential flow theory has great limitations. Based on the viscous flow theory, using the finite difference solution program of FLOW3D and using volume of fluid technology to capture the free surface, a three-dimensional numerical wave basin is established, and the numerical results of the wave are compared with the theoretical solution. On this basis, the hydrodynamic model of side-by-side double-floating-system with a narrow gap is established, and the flow field in the narrow gap of the fixed double-floating-system under the regular wave is analyzed in detail. The law of the gap-resonance is studied, which provides valuable reference for the future research on the multi-floating-system.
Position-dependent finite symmetric mass harmonic like oscillator: Classical and quantum mechanical study
Authors: Rath Biswanath , Mallick Pravanjan , Mohapatra Prachiprava , Asad Jihad , Shanak Hussein , Jarrar Rabab 
Published: August 2021

Abstract
We formulated the oscillators with position-dependent finite symmetric decreasing and increasing mass. The classical phase portraits of the systems were studied by analytical approach (He’s frequency formalism). We also study the quantum mechanical behaviour of the system and plot the quantum mechanical phase space for necessary comparison with the same obtained classically. The phase portrait in all the cases exhibited closed loop reflecting the stable system but the quantum phase portrait exhibited the inherent signature (cusp or kink) near origin associated with the mass. Although the systems possess periodic motion, the discrete eigenvalues do not possess any similarity with that of the simple harmonic oscillator having m = 1.
Study of dynamic pressure on the packer for deep-water perforation
Authors: Huang Hao , Deng Qiao , Zhang Hui 
Published: August 2021

Abstract
The packer is one of the most important tools in deep-water perforation combined well testing, and its safety directly determines the success of perforation test operations. The study of dynamic perforating pressure on the packer is one of the key technical problems in the production of deep-water wells. However, there are few studies on the safety of packers with shock loads. In this article, the three-dimensional finite element models of downhole perforation have been established, and a series of numerical simulations are carried out by using orthogonal design. The relationship between the perforating peak pressure on the packer with the factors such as perforating charge quantity, wellbore pressure, perforating explosion volume, formation pressure, and elastic modulus is established. Meanwhile, the database is established based on the results of numerical simulation, and the calculation model of peak pressure on the packer during perforating is obtained by considering the reflection and transmission of shock waves on the packer. The results of this study have been applied in the field case of deep-water well, and the safety optimization program for deep-water downhole perforation safety has been put forward. This study provides important theoretical guidance for the safety of the packer during deep-water perforating.
Crystallization law of karst water in tunnel drainage system based on DBL theory
Authors: Wang YongDong , Liu Yang , Qi ChuFan , Zhou TianYue , Ye Ming , Wang Tao 
Published: August 2021

Abstract
When a tunnel is constructed in a karst area, crystallization of the drainage pipe caused by karst water often threatens the normal operation of the tunnel. This work contributes to this field of research by proposing a functional model based on the diffusion boundary layer (DBL) theory proposed by Dreybrodt in the 1990s. The model is formed by determining the flow rate distribution of the drainage pipe in a laminar flow state and turbulent state, and then by applying Fick’s diffusion law and Skelland’s approximate formula. Then, to further verify the applicability of the functional model, a model test was carried out in the laboratory and the test results are compared to the theoretical results. The results show that the crystallization rate of karst water is mainly affected by the roughness of the pipe wall, followed by the slope of pipes. The slope can affect flow state by controlling the flow rate, which in turn affects the crystallization rate of karst water. When the slope of the drainage pipe is 3, 4, and 5%, the error between the experimental results and the theoretical calculation results is 24.7, 8.07, and 27.9%, respectively, and when the liquid level in the pipe is 7.2, 10.2, and 13.3 mm, the error is 27.9, 9.82, and 2.07%, respectively. Considering that the flow will take away the crystalline deposits on the pipe wall in the experiment, although some results have certain errors, they do not affect the overall regularity.
Diesel engine waste heat recovery system comprehensive optimization based on system and heat exchanger simulation
Authors: Li Da , Sun Qiang , Sun Ke , Zhang Guodong , Bai Shuzhan , Li Guoxiang 
Published: August 2021

Abstract
To further improve the thermal efficiency of diesel engines, a waste heat recovery system model utilizing organic Rankine cycle (ORC) is constructed and verified through system bench test and heat exchanger bench test. To recover waste heat from diesel engine exhaust, ethanol, cyclopentane, cyclohexane, R1233zd (E), and R245fa were selected for comparison. The quality of heat source, the quality of evaporator, the system output, and the system complicity were taken as variables for comparison. Analysis shows that for ORC systems without recuperator, ethanol system has the best system output of the five in a wide operation temper range, with the highest exergy efficiency of 24.1%, yet the exergy efficiency increase after the application of recuperator, 9.0%, is limited. For low temperature exhaust, cyclopentane system has the best performance with or without recuperator, and the cyclopentane system with recuperator has the best performance in terms of exergy efficiency, 27.6%, though complex heat exchangers are also required for high power output. The system output of the R1233zd system is better than the R245fa system, yet the advantage of low evaporate temperature can be better utilized for low quality waste heat recovery.
Smartphone assisted oral health data recording – an android based software application development
Authors: Nagarajappa Sandesh , Vyas Shaleen 
Published: August 2021

Background. Smartphone compared to the traditional pen-paper method could enhance oral health data recording procedure by reducing the cost of data collection, risk of data loss, early detection of errors and reducing data entry time. The present research developed a mobile/tablet-based software application to capture oral health data and test its adaptability and operations in oral health surveys.
Methods. A comparative cross-sectional study was conducted among the general population of Sanwer town, Indore district. The initial testing of the application was done on 120 individuals. A random sampling (lottery method) followed by a systematic sampling strategy was employed to select 120 households. A “one per household” design was implemented for the survey. The initial oral health data collection was done using mobile-assisted software application followed by a second examination scheduled after 15 days on the same participants using the conventional Pen-paper method to collect oral health data.
Results. Six Investigator Recorder (IR) teams conducted the oral health data collection. Data collection through Smartphone-based application displayed less meantime (3.57 minutes) in comparison to pen-paper method (4.87 minutes) (p≤0.001). Survey team response showed the majority of investigators having strong agreement on user satisfaction and speed of data entry using software application.
Conclusion. The initial testing of mobile-assisted recording system (MARS) efficiently captured oral health data among the general population with wide variations in oral disease level. The application facilitated minimal or no wastage of paper and had a high level of user-satisfaction, accuracy, speed of entry and low potential for any data loss.
Coronavirus (COVID-19) infection - impact on cardiovascular system
Authors: Ahmed Mariam , Ball Patrick Anthony , Morrissey Hana 
Published: August 2021

Aim. This review aimed to explain novel coronavirus (COVID-19) infection impact on cardiovascular system and patients management in community and primary care settings.
Method. Literature search and review limited to 2020 of published papers identified dealing with Coronavirus and cardiovascular disease.
Results. Coronavirus is a large family of positive-sense, enveloped, single-stranded RNA viruses that belong to the Nidovirales order. Covid-19 refers to infection with the SARS-CoV-2 variant. Myocardial injury has a considerable association with mortality outcomes for COVID-19 infection. The prognosis of patients with underlying cardiovascular diseases, who had not sustained myocardial injury was relatively favourable. Inflammation may also be a potential mechanism for myocardial injury. So far, current evidence suggests statistically significant associations between cardiac injury and mortality in patients with COVID-19. Whether this is mediated by destruction of angiotensin converting enzyme 2 in heart cells or by other mechanisms, is being investigated.
Conclusion. In patients with underlying cardiovascular diseases, aggressive treatment for COVID-19 should be considered and clinicians should be aware of the significantly increased risk of serious infection and worse prognosis in this patient group. New evidence and studies are continually emerging and will confirm or refute our current understanding about COVID-19 impact. Primary care practitioners are urged to continue to monitor the evolving evidence to appropriately manage their patients who are at risk of, or currently diagnosed with cardiovascular conditions.
MYCOLOGICAL ANALYSIS OF DRIED FISHES COLLECTED FROM OPEN MARKETS WITH SPECIAL FOCUS ON MYCOTOXIN PRODUCTION
Authors: Thiyagarajan Santhanamari , Jamal Alruwaili 
Published: August 2021

Dried fishes are salted and sun dried fish products consumed by large population owing to their nutrient richness, flavor and long shelf life properties. Contamination of dried fishes by mycotoxin producing fungi pose serious threat to food safety and public health. A total of 27 samples belonging to three varieties of dried fishes collected in Chennai city, India were screened for the isolation of mycotoxin producing fungal contaminants. Mycological examination of samples revealed the prevalence of six types of fungi viz., A. parasiticus (27.27%), A. niger (22.72%), A. fumigatus (18.18%), Penicillium sp. (18.18%), Cladosporium sp. (9.09%) and Euratium sp. (4.54%). Detection using thin layer chromatography indicated that 18.18% of isolates belonging to A. parasiticus, A. fumigatus, Penicillium sp. were positive, while A. niger, Cladosporium sp., and Euratium sp. were negative for mycotoxin production. Further to the bioassay with Artemia larvae, substantial lethality was observed with the mycotoxin of A. parasiticus (100%), followed that of by A. fumigatus and Penicillium sp. (each 50%). The HPLC studies indicated that the mycotoxin produced by A. parasiticus was Aflatoxin G2. Need for proper hygienic practices during processing and handling of dried fishes in order to avoid fungal contamination and likelihood mycotoxicosis in consumers has been suggested.
CHARACTERIZATION OF WHITE SESAME SEED OIL AND ITS BIOACTIVE COMPONENTS
Authors: Aslam Farhan , Iqbal Sanaullah , Imran Muhammad , Anjum Aftab Ahmad , Gilani Syed Amir , Farooq Zubair , Tariq Hafiza Bushra , Terentev Sergei , Terekhova Anna , Shariati Mohammad Ali 
Published: August 2021

The purpose of this study was to evaluate the physicochemical properties of white sesame seed oil (WSSO) (PB-Till 90) along with their bioactive components. Among physicochemical properties; free fatty acids (0.95 ± 0.05 %), peroxide value (0.88 ± 0.03 meq/kg), thiobarbituric acid value (0.045 ± 0.0 mg malonaldehyde/kg-oil), free radical scavenging activity (DPPH) (85.07 ± 0.01 %), and iodine value (113.4 ± 1.46 g/100gm) were observed. Fatty acid (%) profile, determined by gas chromatography, mostly comprised of unsaturated fatty acids. Bioactive components were determined using HPLC and include tocopherol mg/kg (α 8.12 ± 0.0, δ 23.98 ± 0.02, γ 3.125 ± 0.01), polyphenol mg/kg (Gallic acid 0.985 ± 0.001, protocatechuic acid 0.018 ± 0.001, syringic acid 0.024 ± 0.002, ferulic acid 0.134 ± 0.001), stigmasterol 6689.34 ± 0.02 and lignans mg/kg (sesamin 18340 ± 8.5, sesamolin 28340 ± 13.7 and sesamol 224 ± 2.0) were quantified. The results show that WSSO from variety PB-Till 90 has good physicochemical properties and contain appreciable quantities of bioactive components to make its usage as a functional food ingredient.
SIGHTS TO AUTHENTICATION AND ADULTERATION OF THE COFFEE IN GLOBAL ASPECT
Authors: Čurlej Jozef , Bobková Alica , Zajác Peter , Čapla Jozef , Hleba Lukas 
Published: August 2021

Coffee presents a valuable food product for several reasons, covering areas like a source of health benefits substances for the human body, brain energizing/stimulating product and its social aspect raising from coffee consumption. This study aims to summarise the most common practices used in coffee adulteration and the methods focused to confirm the authenticity of the coffee, the quality, and price determinants according to a place of origin and/or selection between Robusta versus Arabica coffee beans. Nowadays, several scientific approaches are used for this purpose, based on chemical or molecular analysis. Literature and the data presented in this article were collected from studies published in scientific journals. On the other hand, the article introduces how to protect customer\s rights in the global coffee trade.
Patient Risk Factors for Violent Restraint Use in a Children’s Hospital Medical Unit
Authors: Noah Akaninyene , Andrade Gabriela , DeBrocco Dawn , Dunn Michelle , Herz Katherine , Worsley Diana , Camacho Pete , Doupnik Stephanie K. 
Published: August 2021

BACKGROUND AND OBJECTIVES
To inform efforts to reduce violent restraint use, we examined risk factors for restraint use among hospitalized children with known behavior concerns.

METHODS
We conducted a retrospective cross-sectional study of restraint events in all hospitalizations from 2017 to 2019 on a 10-bed medical-surgical unit with dedicated mental health clinician support. We examined characteristics of restraint events, used adjusted logistic regression models to identify independent risk factors for restraint use, and used an adjusted Poisson regression model to determine the adjusted rate of restraint events per hospital day.

RESULTS
The sample included 1507 hospitalizations representing 1235 patients. Among included hospitalizations, 48% were for a psychiatric indication awaiting transfer to an inpatient psychiatric unit, and 52% were for a primary medical or surgical problem. Sixteen percent had a restraint event. Patient demographic characteristics were not associated with risk of a restraint event. Having a psychiatric indication for hospitalization was an independent risk factor for restraint use (odds ratio: 2.85; 95% confidence interval: 2.06–3.94). Rate of restraint use per day decreased as length of stay increased; hospitalizations lasting 9 days or longer had a 58% lower rate of restraint use per day than 1- to 2-day hospitalizations (P &lt; .001).

CONCLUSIONS
Interventions to reduce restraint use may benefit from incorporating information about a patient’s psychiatric risk factors, including type and number of diagnoses and reason for hospitalization. Future efforts could investigate whether providing enhanced behavior supports during the first several days of a patient’s hospitalization reduces violent restraint use.
Influenza-Related Knowledge, Beliefs, and Experiences Among Caregivers of Hospitalized Children
Authors: Hofstetter Annika M. , Opel Douglas J. , Stockwell Melissa S. , Hsu Clarissa , deHart M. Patricia , Zhou Chuan , Mangione-Smith Rita M. , Englund Janet A. 
Published: August 2021

OBJECTIVECaregivers frequently decline influenza vaccine for their hospitalized child. In this study, we aimed to examine factors impacting their influenza vaccine decision-making.METHODSWe conducted a cross-sectional survey study of English- and Spanish-speaking caregivers of children hospitalized at a tertiary care pediatric hospital between November 2017 and April 2018. The survey assessed influenza-related knowledge, beliefs, experiences, and vaccine hesitancy. Multivariable logistic regression examined associations between survey responses and child influenza vaccination status at admission (already vaccinated versus not yet vaccinated this season) and, among caregivers with vaccine-eligible children, influenza vaccine acceptance (versus declination) for their child during hospitalization.RESULTSCaregivers (N =522; 88.9% response rate) were mostly non-Hispanic white (66.9%) and English-speaking (97.7%). At admission, 63.2% of children were already vaccinated this season. The caregiver view that influenza vaccination is important for their child’s health was the strongest positive predictor of having an already vaccinated child (adjusted odds ratio [aOR]: 3.16; 95% confidence interval [CI]: 2.46–4.05); vaccine hesitancy was the strongest negative predictor (aOR: 0.61; 95% CI: 0.50–0.75). Among caregivers with vaccine-eligible children, 30.3% accepted influenza vaccine for their hospitalized child. Their belief regarding the child health benefits of influenza vaccination was associated with vaccine acceptance during hospitalization (aOR: 6.87; 95% CI: 3.38–13.96). Caregiver vaccine hesitancy and agreement that children with mild illness should delay vaccination negatively impacted vaccine acceptance (aOR: 0.39; 95% CI: 0.25–0.62; aOR: 0.33; 95% CI: 0.20–0.56, respectively).CONCLUSIONSWe identified key factors impacting influenza vaccine decision-making among caregivers of hospitalized children, a critical step to improving uptake in this population.
Within-Hospital Concordance of Opioid Exposure Diagnosis Coding in Mothers and Newborns
Authors: Clark Rebecca R.S. , French Rachel , Lorch Scott , O’Rourke Kathleen , Rosenbaum Kathleen E. Fitzpatrick , Lake Eileen T. 
Published: August 2021

BACKGROUND AND OBJECTIVES
We measured within-hospital concordance of mothers with opioid use disorder (OUD) and newborns with neonatal abstinence syndrome (NAS) or opioid exposure (OE). Secondarily, we described the demographics of mothers and newborns with and without opioid-related diagnoses.

METHODS
We used hospital discharge abstracts from California, Florida, New Jersey, and Pennsylvania in 2016. Descriptive statistics were used to compare newborns and mothers with and without opioid-related diagnoses. Within-hospital frequencies of mothers with OUD and newborns with NAS and OE were compared. Pearson’s correlation coefficients were calculated.

RESULTS
In 474 hospitals, we found 896 702 mothers (0.6% with OUD) and 910 867 newborns (0.47% with NAS, 0.85% with OE, and 0.07% with both). Although the frequency of mothers and newborns with opioid-related diagnoses in a hospital was strongly correlated (r = 0.81), more infants were identified than mothers in most hospitals (68.3%). Mothers with OUD were more likely to be white (79% vs 40.9%), on Medicaid (75.4% vs 44.0%), and receive care in rural hospitals (20.6% vs 17.6%), compared with mothers without OUD. Newborns with NAS had demographics similar to women with OUD. Newborns with OE were disproportionately Black (22% vs 7%) or Hispanic (22% vs 9%).

CONCLUSIONS
More newborns are diagnosed with opioid-related disorders than mothers are. Although infants diagnosed with NAS had demographics similar to mothers with OUD, infants with OE were more likely to be Black or Hispanic. The lack of diagnostic coding of maternal OUD and the racial differences in diagnoses warrant attention.