bluuebunny/crossref_metadata_2025 huggingface dataset:
Force Relationships in the Machining of Low-Carbon Steels of Different Sulphur Contents
Authors: Boulger F. W. , Hartner H. E. , Lankford W. T. , Garvey T. M.
Published: February 2022

The force relationships obtained in the machining of a series of low-carbon open-hearth steels containing various amounts of sulphur from 0.025 to 0.250 per cent were investigated in a constant-pressure lathe and in a conventional lathe. A wire-resistance, strain-gage dynamometer was used to measure the forces acting on a high-speed tool for various cutting conditions. In the constant-pressure test, sulphur additions increased the feed obtained with a given thrust load. The addition of sulphur reduced the forces acting on the tool for equivalent feeds in both test lathes. Theoretical calculations disclosed that the effectiveness of increased sulphur contents results from decreased friction between the chip and the tool and from an accompanying reduction in strain during chip formation. The decrease in friction and strain reduced the work required for removal of a unit volume of metal during machining. Shear stress was not a direct function of sulphur content, but generally decreased with feed. Results of conventional lathe tests generally corroborated those obtained in the constant-pressure lathe.
Leaded Steel and the Real Area of Contact in Metal Cutting
Authors: Shaw M. C. , Smith P. A. , Cook N. H. , Loewen E. G.
Published: February 2022

The action of lead in free-machining steel is discussed and the thickness of the layer of lead responsible for the improved lubrication between chip and tool is found to be extremely thin. Measurements made on the same steel with and without lead present enable the real area of contact between chip and tool to be estimated and this is found to be between 1 and 2 per cent of the apparent area of contact. The cutting characteristics of steel containing lead are compared with those for steel without lead as well as those for pure lead. It is found that the presence of lead makes effective fluids such as carbon tetrachloride less sensitive to an increase in cutting speed.
Cutting-Fluid Evaluation
Authors: Husa H. W.
Published: February 2022

Transfer of radioactive material from a cutting tool to the chips produced in facing the end of a steel tube is used as a means of measuring tool-wear rate. The lathe is operated at commercial feeds and speeds. This technique permits accurate tool-wear evaluation with very short machining time and a consequent small consumption of stock. Protection of personnel against radiation requires simple precautions. Evaluation of a cutting oil may require consideration of the roughness of the cut surface or the cutting temperature in addition to the tool-wear rate. The properties of the material cut influence the type of tool wear experienced and may affect the choice of variables which must be considered in addition to tool-wear rate. Results for typical compound and mineral oils in the machining of both 1015 and 1045 steels are reported.
An Effort to Use a Laboratory Test as an Index of Combustion Performance
Authors: Ceely F. J. , Wheater R. I.
Published: February 2022

This paper discusses results of a study in progress to determine if the CRL reactivity test can be applied as an index of combustion performance in pulverized fuel-fired steam generators. Before undertaking an extensive program of correlating laboratory data against actual combustion experience, it was necessary to conduct the study on a limited basis to establish whether or not the results would justify an extensive effort. The authors present some significant data accumulated during this study phase and conclude that further investigation is warranted on a larger scale.
Determination of Thermal Conductivities of Metals by Measuring Transient Temperatures in Semi-Infinite Solids
Authors: Hsu S. T.
Published: February 2022

The temperature on the flat side of a semi-infinite solid is suddenly raised to a certain value. Then at two stations inside the solid, the temperature variations with time are recorded by means of thermocouples, a string galvanometer, and synchronized photographic equipment. Both the thermal conductivity and specific heat can be determined in the same experiment. The time for measurement is only 30 sec. The result is estimated to be accurate to within 2 per cent for certain metals.
Properties of Misaligned Journal Bearings
Authors: DuBois G. B. , Ocvirk F. W. , Wehe R. L.
Published: February 2022

Properties of misaligned journal bearings under hydrodynamic conditions of lubrication are presented as observed from experimental data. Curves in dimensionless form give journal-bearing attitude as a function of the usual bearing variables and the couples which produce misalignment. Examples are given showing the application of the dimensionless curves to typical problems of misaligned bearings.
The Fluid Dynamic Theory of Gas-Lubricated Bearings
Authors: Ausman J. S.
Published: February 2022

A differential equation for the pressure distribution in gas-lubricated slider bearings is derived from the basic equations of fluid mechanics. The equation is an extension of Harrison’s gas-bearing equation in that the infinite width and isothermal restrictions have been removed. A perturbation solution is proposed and is carried out for the special case of an infinitely wide, self-lubricating journal bearing. Comparisons with numerical solutions to Harrison’s equation indicate that the first three terms in the series solution are sufficient to determine the pressure distribution and bearing load with reasonable accuracy.
On the Theory of Grease-Lubricated Thrust Bearings
Authors: Slibar A. , Paslay P. R.
Published: February 2022

Experimental results have shown that grease can be considered to be a Bingham material. By introducing the yield criteria due to Hencky-von Mises-Huber, the stress-deformation rate relations for the lubricating material are derived. Making use of the characteristic parameters of a rotating thrust bearing, a perturbation procedure is used to obtain a solution governing the steady state. When the critical shear stress of the grease equals zero, this solution becomes the viscous one. Curves are given for design purposes which can be used by the lubrication engineer directly to obtain the prediction of the properties of a thrust bearing.
Cavitation Characteristics of Gate Valves and Globe Valves Used as Flow Regulators Under Heads Up to About 125 Feet
Authors: Ball J. W.
Published: February 2022

The series of tests discussed in this paper was made for the purpose of determining whether or not gate valves or globe valves could be used satisfactorily for regulating releases from irrigation-distribution systems under heads up to about 125 ft. Both types of valves proved unsuitable for making free-flow releases because of the wide dispersion of the jets under throttled conditions. Confinement of the jets to pipelines downstream induced cavitation in and downstream of the valves and a study was made of the pressures in the pipelines upstream and downstream of 6, 8, 10, and 12-in. gate valves, and a 6-in. globe valve to evolve a means of eliminating or minimizing the cavitation. A pressure relationship or “cavitation index” was found to be a useful means of determining the limits of differential head and back pressure to either control the location of, minimize, or eliminate cavitation damage. The design of the water passage immediately downstream from the valves and the pressure within this passage were the two main factors influencing the cavitation characteristics of an installation. One of the most effective means of eliminating cavitation damage below gate valves was the placing of sudden enlargements in the pipe sections immediately downstream. No damage could be detected in the concrete lining of the sudden enlargement under heads up to 150 ft with back pressures of approximately 15 ft, although noise similar to that which accompanies cavitation was present at heads in excess of about 90 ft.

A limited number of tests were made to study the resistance of rubber-like products to cavitation-erosion and their use in protecting the downstream pipe wall against this erosion. The conclusion was reached that such protection should not be used except in cases where cavitation will be mild.

Some consideration was given to venting the area in the top of the pipe just downstream of the valve, but this was considered objectionable because of the influence of entrained air on flow conditions and measuring devices, particularly propeller meters, placed downstream. Moreover, it was doubtful that air admitted to this region would reach all critical zones of local cavitation.

The information obtained from the valve investigation is very useful as design criteria for irrigation-distribution systems where valves are used for regulating the releases.
Eight Years of Experience With Austenitic Steel Piping Materials at Elevated Steam Conditions
Authors: Fairchild F. P.
Published: February 2022

In order to give perspective to the present status of the development of the art, the author presents a factual record of experience with austenitic, heavy-wall, steel piping materials, some of which have been in service since 1948, at elevated steam conditions, in the electric generating stations of Public Service Electric and Gas Company in New Jersey. He describes some of the welding techniques which have been developed over this period and points out some of the areas in which there is need of further development.
Austenitic Steels in High-Temperature Steam Piping
Authors: Curran R. M. , Rankin A. W.
Published: February 2022

A review is presented of the operating experience and service difficulties with austenitic steel turbine piping at the 1050 F and 1100 F temperature levels. Reasons are advanced for the difficulties encountered and recommendations are made to prevent recurrence of these difficulties in future installations.
Application of Digital Computers to Bearing Design
Authors: Sternlicht B. , Maginniss F. J.
Published: February 2022

This paper describes the application of modern digital computing equipment to a study of the operating characteristics of journal and thrust bearings. Results of such a study are used in the design of these bearings. As originally programmed for the Card Programmed Calculator, approximations to the pressure distribution, side leakage, and total load in journal bearings were made under the assumptions of rigid bearings and constant temperature. Present development of the type 650 Magnetic Drum Calculator permits a more rigorous solution accounting for variations in viscosity and density of the lubricant, as well as any prescribed shape of the oil film. Faster and more precise solutions are possible both for thrust and journal bearings. In addition to the calculation of pressure, temperature profile, flow, and load, results for the thrust bearing include a determination of the moments acting on the bearing sector, and a consequent locating of the center of pressure. A numerical example and a computer flow chart are included as guides to the design engineer. Operating techniques, time, and cost factors also are discussed to throw light on the application of a computer from both the engineering and economic standpoints. A derivation of the governing equations in dimensionless form is contained in the Appendix.
New Finite-Difference Technique for Solution of the Heat-Conduction Equation, Especially Near Surfaces With Convective Heat Transfer
Authors: Elrod H. G.
Published: February 2022

Finite-difference methods have come into wide use for solving special problems including transient-heat conduction. Dusinberre has ably presented the possibilities of finite-difference methods. The success of most such methods depends on the existence of a certain degree of uniformity of behavior of the temperature over the finite intervals of both space and time selected for the computation process. In some cases, however, this required uniformity constitutes a handicap since temperatures are changing so rapidly that inconveniently short time intervals have to be chosen. This paper represents an effort to develop a finite-difference method free from the foregoing defect.
Heat Transfer to Laminar Boundary Layers With Variable Free-Stream Velocity
Authors: Seban R. A.
Published: February 2022

Heat-transfer coefficients have been determined for the laminar boundary layer of a two-dimensional subsonic flow of air over a flat plate. By the agency of blisters attached to the wind-tunnel wall the boundary layer, formed under almost constant free-stream velocity, was subjected to a strong acceleration which produced a three to four-fold increase in the free-stream velocity, followed by a moderate deceleration. Maximum velocities ranged from 260 to 900 fps. The heat-transfer results are correlated on the basis expected for laminar flow and it is further demonstrated that a prediction method based on constant fluid properties gives satisfactory correspondence with experiment.
Rate of Temperature Change of Simple Shapes
Authors: Paschkis Victor , Hlinka J. W.
Published: February 2022

Charts have been prepared showing rates of temperature change in simple shapes plotted against temperature. Additional curves show time values, so that one graph yields any of the three relationships: Rate-temperature, rate-time, temperature-time. Samples of the charts are shown, examples of use are given, and limits of the graphs are tabulated. Methods used in establishing the charts are given.
Skewed Boundary-Layer Flow Near the End Walls of a Compressor Cascade
Authors: Moore R. W. , Richardson D. L.
Published: February 2022

Turbulent end-wall boundary layers with considerable skewness are caused by the relative motion of adjacent blade rows in an axial compressor. Flow conditions similar to those near the hub of an axial-compressor rotor were produced in a stationary cascade of blades, and the results of extensive measurements of boundary-layer flow between the blades are presented. An estimate based on the data of the values of terms in the momentum integral equation in the free-stream direction shows the importance of the crossflow in determining boundary-layer growth. A qualitative description of end-wall flow is given.
An Experimental Study of Centrifugal-Pump Impellers
Authors: Acosta A. J. , Bowerman R. D.
Published: February 2022

Experimental investigations were made on four two-dimensional impellers and on a well-designed commercial three-dimensional Francis impeller. The over-all performance of each of these impellers was measured and internal-energy loss and pressure-distribution data were also obtained for several impellers. The exit angle of the two-dimensional impellers was fixed and the inlet angle was systematically varied. However, the hydraulic characteristics of these impellers were all found to differ, the source of the variation being in the various loss distributions and hence internal flow patterns in the impellers. The two-dimensional and three-dimensional impeller-loss distributions were also different. The Francis-impeller performance agreed better with potential theory than that of the two-dimensional impellers, and it is concluded that the different loss distributions of the two types are responsible.
Computer Representations of Engineering Systems Involving Fluid Transients
Authors: Ezekiel F. D. , Paynter H. M.
Published: February 2022

This paper deals with the applications of modern analog and digital computing machines to engineering solutions of fluid-transient problems. It is not concerned with the structural or operating details of the computers themselves. Rather, described here are methods for computer representations of various physical elements commonly used in hydraulic and pneumatic systems such as conduits, valves, pumps, and so forth. These are presented in such forms that they can be incorporated readily as component parts into a simulated engineering installation. Such methods permit rapid determination of critical dimensions as well as ready exploration of alternatives for balances between cost and performance.
Creep Characteristics of Type 347 Stainless Steel at 1050 and 1100 F in Tension and Compression
Authors: Manjoine M. J.
Published: February 2022

Cold-drawn and stress-relieved Type 347 heavy-wall tubing flows plastically at service temperatures (1050-1100 F) when subjected to a stress below the 10,000-hr rupture strength. Precipitation induced by the strain and temperature conditions causes an extended period of abnormally high creep resistance. The duration of this period increases with decreasing stress and is longer for compression than for tension. The creep and rupture strengths for service duration over 10,000 hr are poorer than those reported for Type 347 annealed bar stock.
Electrical Effects Accompanying the Stick-Slip Phenomenon of Sliding of Metals on Plastics and Lubricated Surfaces
Authors: Sohl G. W. , Gaynor J. , Skinner S. M.
Published: February 2022

The electrical transients which accompany the stick-slip phenomenon in boundary lubrication have been investigated by an apparatus which permits simultaneous oscillographic measurement of any two of the following: The instantaneous load, the instantaneous frictional drag, the electrical transient potentials during the stick-slip motion. The phenomenon has been investigated with unlubricated metal-metal contact using four metals in various combinations, lubricated metal-metal contact using various combinations of metals and five lubricants, and metal-plastic contact; in all cases, the contact was a sliding contact at low speed, since this accentuates the stick-slip phenomenon. Definite time correlation between the mechanical stick-slip and the electrical transients has been found. The characteristics of the electrical discharge appear to favor a charge-discharge mechanism rather than a thermoelectric potential or a dielectric breakdown mechanism, although further experiments are necessary to provide unambiguous proof of such a conclusion. Certain related frictional experiments were performed which, however, also favor such a mechanism.
Power–Force–Velocity Profiling as a Function of Used Loads and Task Experience
Authors: Fessl Isabella , Wiesinger Hans-Peter , Kröll Josef
Published: February 2022

Purpose: To evaluate cohort-specific reliability and concurrent validity of 3 different vertical power–force–velocity (P–F–v) profiles to determine force, velocity, maximal power, and the slope of the force–velocity relationship using squat jumps. Methods: Fifteen male sport students and 15 elite ski jumping athletes (male = 11; female = 4) conducted 2 block-randomized test–retest sessions with 5-point-method or 2-point-method loading conditions. A third P–F–v profile was established by excluding the data point most declining the coefficient of determination (r2) of the 5-point method. Results: Acceptable absolute and relative reliability were found across methods in ski jumping athletes (intraclass correlation coefficient [ICC] ≥ .79, coefficient of variation [CV] ≤ 6.2%). However, force values were significantly lower in the retest (≤2.1%, d ≤ 0.75). In contrast, no systematic differences (P ≥ .461), but unacceptable absolute and relative reliability, were found in sport students (ICC ≥ .63, CV ≤ 14.8%). The P–F–v parameters of the different collecting and evaluating approaches yielded high to excellent correlations (ski jumping athletes: r ≥ .64; sport students: r ≥ .61), but maximal power (≤4.6%) and velocity (<6.2%,) values of sport students revealed significant differences. Conclusion: The similarity of P–F–v testing and basic ski jumping training daily exercises seems to be more significant to obtain reliable force–velocity parameters than the methodological approach. Accordingly, P–F–v profiles seem to be reliable with the proposed methods only in highly task-experienced athletes but not in less task-experienced cohorts like sport students.
Pickleball, Personality, and Eudaimonic Well-Being in Middle-Aged and Older Adults
Authors: Ryu Jungsu , Heo Jinmoo , Lee Sunwoo
Published: February 2022

This study explored how personality and serious leisure activities, such as playing pickleball, contribute to eudaimonic well-being in middle-aged and older adults. Data were collected at pickleball events at the 2017 Huntsman World Senior Games from a convenience sample of 250 players aged between 50 and 91 years (M = 65.11, SD = 7.49). Of the five personality dispositions examined, conscientiousness (β = 0.32, p < .001), neuroticism (β = −0.22, p < .01), and openness to experience (β = 0.18, p < .01) were discovered to be significant predictors of eudaimonic well-being. Serious leisure also contributed to eudaimonic well-being (β = 0.28, p < .01). The findings of this study enhance the understanding of the behaviors exhibited by older adults and elucidate the positive impact exerted on eudaimonic well-being by personality and serious leisure.
A Two-Step Horizon Optimum Switching Vector-Model Predictive Control with a Novel Shunt Active Filter Reference Current Extraction
Authors: Cheepati Kumar Reddy , Rivera Marco , Wheeler Patrick , Subburaj Vivekanandan , Krishnan Suresh , Daram Suresh Babu , Amaresh Karnam
Published: February 2022

Shunt active filters (SAFs) can be used for harmonic mitigation, reactive power compensation and power factor control in electrical distribution networks. Model predictive controller (MPC) can be used to give optimum performance for SAF’s due to its inherent cost function optimization. The SAF’s reference current extraction technique in finite control set-MPC (FCS-MPC) plays a vital role in the effectiveness of the SAF’s operation. The advantage of FCS-MPC is that it closely tracks the reference and injects the required compensating currents by optimizing the SAF’s switching vector and it does not require an external modulator for pulse generation. FCS-MPC can be implemented as either an optimal switching vector MPC (OSV-MPC) or an optimal switching sequence MPC (OSS-MPC) technique. The OSV-MPC technique is simple and efficient for SAF applications. In this paper, a novel reference current extraction technique, the inverse matrix average pq-synchronous reference frame (SRF) (IMApq-SRF) technique, is proposed along with the OSV-MPC technique. Practically a two-step delay compensation is essential in the implementation of the technique for the control of an SAF. Hence in this paper a two-step horizon OSV-MPC technique is proposed along with an IMApq-SRF reference current extraction technique to improve the power quality in distribution networks. The presented results show that the proposed methodology gives optimum SAF performance under a large range of supply and load conditions.
∗-Lie-type maps on alternative ∗-algebras
Authors: De Oliveira Andrade Aline Jaqueline , Barreiro Elisabete , Ferreira Bruno Leonardo Macedo
Published: February 2022

Let [Formula: see text] and [Formula: see text] be two alternative ∗-algebras with identities [Formula: see text] and [Formula: see text], respectively, and [Formula: see text] and [Formula: see text] nontrivial symmetric idempotents in [Formula: see text]. In this paper, we study the characterization of multiplicative ∗-Lie-type maps. As application, we get a result on alternative [Formula: see text]-algebras.
The design of an open-source carbonate reservoir model
Authors: Costa Gomes Jorge , Geiger Sebastian , Arnold Daniel
Published: February 2022

This work presents a new open-source carbonate reservoir case study, the COSTA model, that uniquely considers significant uncertainties inherent to carbonate reservoirs, providing a far more challenging and realistic benchmarking test for a range of geo-energy applications. The COSTA field is large, with many wells and large associated volumes. The dataset embeds many interacting geological and petrophysical uncertainties in an ensemble of model concepts with realistic geological and model complexity levels and varying production profiles. The resulting number of different models and long run times creates a more demanding computational challenge than current benchmarking models.

The COSTA model takes inspiration from the shelf-to-basin geological setting of the Upper Kharaib Member (Early Cretaceous), one of the most prolific aggradational parasequence carbonate formations sets in the world. The dataset is based on 43 wells and the corresponding fully anonymised data from the northeastern part of the Rub Al Khali basin, a sub-basin of the wider Arabian Basin. Our model encapsulates the large-scale geological setting and reservoir heterogeneities found across the shelf-to-basin profile, into one single model, for geological modelling and reservoir simulation studies.

The result of this research is a semi-synthetic but geologically realistic suite of carbonate reservoir models that capture a wide range of geological, petrophysical, and geomodelling uncertainties and that can be history-matched against an undisclosed, synthetic ‘truth case’. The models and dataset are made available as open-source to analyse several issues related to testing new numerical algorithms for geological modelling, uncertainty quantification, reservoir simulation, history matching, optimization and machine learning.

Supplementary material:
supplementary data associated with this article can be found in the data repository for the COSTA model available at
https://doi.org/10.17861/6e36e28d-50d9-4e31-9790-18db4bce6e5d
and supplementary material is available at
https://doi.org/10.6084/m9.figshare.c.5823571
Detecting Feedback Vertex Sets of Size
k
in
O
⋆
(2.7
k
) Time
Authors: Li Jason , Nederlof Jesper
Published: February 2022

In the Feedback Vertex Set (FVS) problem, one is given an undirected graph
G
and an integer
k
, and one needs to determine whether there exists a set of
k
vertices that intersects all cycles of
G
(a so-called feedback vertex set). Feedback Vertex Set is one of the most central problems in parameterized complexity: It served as an excellent testbed for many important algorithmic techniques in the field such as Iterative Compression [Guo et al. (JCSS’06)], Randomized Branching [Becker et al. (J. Artif. Intell. Res’00)] and Cut&Count [Cygan et al. (FOCS’11)]. In particular, there has been a long race for the smallest dependence
f(k)
in run times of the type

O
⋆
(f(k))

, where the

O
⋆

notation omits factors polynomial in
n
. This race seemed to have reached a conclusion in 2011, when a randomized
O
⋆
(3

k

) time algorithm based on Cut&Count was introduced.

In this work, we show the contrary and give a

O
⋆
(2.7
k
)

time randomized algorithm. Our algorithm combines all mentioned techniques with substantial new ideas: First, we show that, given a feedback vertex set of size
k
of bounded average degree, a tree decomposition of width
(1-Ω (1))k
can be found in polynomial time. Second, we give a randomized branching strategy inspired by the one from [Becker et al. (J. Artif. Intell. Res’00)] to reduce to the aforementioned bounded average degree setting. Third, we obtain significant run time improvements by employing fast matrix multiplication.
Ion Exchange Resin Modified Carbon Paste Electrode Applied to Simultaneous Determination of Cd (II) and Pb (II)
Authors: de Almeida Leandro Silva , Maciel Juliana Villela , Sant’Anna Cadaval Tito Roberto , Dias Daiane
Published: February 2022

A new, simple, sensitive and fast analytical method was developed to simultaneous quantification of Cd(II) and Pb(II) in cooling water by anodic square wave redissolution voltammetry (SWASV) using a modified carbon paste electrode composite with carbon black, resin functionalized with sulphonic group and paraffin. The experimental conditions such as supporting electrolyte (composition, pH and ionic strength) and SWASV parameters were optimized. The best conditions of Cd(II) and Pb(II) (higher peak current) were obtained in 0.1 mol l−1 BR buffer (pH 4.6) from −1.1 to 0.3 V, amplitude of 60 mV, frequency of 40 Hz, potential step of 5 mV, potential and deposition time of −1.1 V and 240 s, respectively. The analytical curve of Cd(II) and Pb were linear from 10 to 50 μg l−1 (R2 = 0.999) with quantification limit of 0.06 and 0.12 μg l−1, respectively. The method was successfully applied in cooling water from thermoelectric industry and the concentrations of Cd(II) and Pb(II) were 3.27 ± 0.30 and 2.80 ± 0.18 mg l−1, respectively. The method accuracy was evaluated through the comparison with the comparative method (SWV with Hanging Mercury Drop Electrode) and the relative error obtained was smaller than 9.8%.
Molecular Insights into How the Dimetal Center in Dihydropyrimidinase Can Bind the Thymine Antagonist 5‐Aminouracil: A Different Binding Mode from the Anticancer Drug 5‐Fluorouracil
Authors: Lin En-Shyh , Luo Ren-Hong , Yang Ya-Ching , Huang Cheng-Yang
Published: February 2022

Dihydropyrimidinase (DHPase) is a key enzyme for pyrimidine degradation. DHPase contains a binuclear metal center in which two Zn ions are bridged by a posttranslationally carbamylated lysine. DHPase catalyzes the hydrolysis of dihydrouracil to N‐carbamoyl‐β‐alanine. Whether 5‐aminouracil (5‐AU), a thymine antagonist and an anticancer drug that can block DNA synthesis and induce replication stress, can interact with DHPase remains to be investigated. In this study, we determined the crystal structure of Pseudomonas aeruginosa DHPase (PaDHPase) complexed with 5‐AU at 2.1 Å resolution (PDB entry 7E3U). This complexed structure revealed that 5‐AU interacts with Znα (3.2 Å), Znβ (3.0 Å), the main chains of residues Ser289 (2.8 Å) and Asn337 (3.3 Å), and the side chain of residue Tyr155 (2.8 Å). These residues are also known as the substrate‐binding sites of DHPase. Dynamic loop I (amino acid residues Pro65‐Val70) in PaDHPase is not involved in the binding of 5‐AU. The fluorescence quenching analysis and site‐directed mutagenesis were used to confirm the binding mode revealed by the complexed crystal structure. The 5‐AU binding mode of PaDHPase is, however, different from that of 5‐fluorouracil, the best‐known fluoropyrimidine used for anticancer therapy. These results provide molecular insights that may facilitate the development of new inhibitors targeting DHPase and constitute the 5‐AU interactome.
Enhanced Anomaly-Based Fault Detection System in Electrical Power Grids
Authors: Elmasry Wisam , Wadi Mohammed
Published: February 2022

Early and accurate fault detection in electrical power grids is a very essential research area because of its positive influence on network stability and customer satisfaction. Although many electrical fault detection techniques have been introduced during the past decade, the existence of an effective and robust fault detection system is still rare in real-world applications. Moreover, one of the main challenges that delays the progress in this direction is the severe lack of reliable data for system validation. Therefore, this paper proposes a novel anomaly-based electrical fault detection system which is consistent with the concept of faults in the electrical power grids. It benefits from two phases prior to training phase, namely, data preprocessing and pretraining. While the data preprocessing phase executes all elementary operations on the raw data, the pretraining phase selects the optimal hyperparameters of the model using a particle swarm optimization (PSO)-based algorithm. Furthermore, the one-class support vector machines (OC-SVMs) and the principal component analysis (PCA) anomaly-based detection models are exploited to validate the proposed system on the VSB dataset which is a modern and realistic electrical fault detection dataset. Finally, the results are thoroughly discussed using several quantitative and statistical analyses. The experimental results confirm the effectiveness of the proposed system in improving the detection of electrical faults.
Effect Evaluation of Biomedical Experiment Teaching Based on Intelligent Sensor
Authors: Ma Zhicong
Published: February 2022

With the continuous development and progress of nanotechnology, its biosensors have been widely used in biomedical experimental teaching, and good experimental results have been achieved. Graphene, as a new nanomaterial with large surface area, good thermal conductivity, and unique electrical conductivity, has unique advantages in the field of biosensor preparation. Based on this, this paper will prepare the electrochemical sensor applied to biomedical experimental teaching based on graphene, optimize the detection sensitivity and detection range of graphene electrochemical sensor based on the corresponding experimental conditions, and improve its corresponding stability and reusability. At the level of electrochemical activity of biosensors, this paper innovatively uses the electric AC impedance method to detect the electrochemical activity, so as to accurately evaluate the key characteristics of biosensors. Based on the preparation of biosensors and the results of biological experiments, this paper will design a network-based biomedical experiment teaching effect evaluation system, and realize the basic functions of teacher-student interaction, teaching effect evaluation, sensor performance evaluation and so on. Based on the above, the electrochemical sensor based on graphene and a conductive polymer solution is actually prepared in this paper. At the same time, the electrocatalysis experiment is carried out based on the sensor, and the experimental teaching effect is systematically evaluated. The experimental results show that the sensitivity of the biosensor proposed in this paper is increased by about 10% compared with the traditional biosensor, the corresponding preparation complexity is reduced by nearly 1/3, and the corresponding reusability is increased by 30%. Therefore, the biomedical experiment teaching effect evaluation system proposed in this paper has good evaluation effect. It can provide accurate reference for the evaluation of biological experiment teaching effect, so it has important value and significance.
Evolutionary Game Analysis of E‐Commerce Intellectual Property Social Cogovernance with Collective Organizations
Authors: Li Ji , Xu Chunming
Published: February 2022

China’s E‐commerce market is very active. Despite the impact of COVID‐19, the market has ushered in major development opportunities. Alongside, the level of intellectual property protection in China is constantly improving. However, there are relatively few studies on intellectual property protection in the field of E‐commerce. This study introduces the theory of social cogovernance and explores the construction of China’s E‐commerce intellectual property protection system with the participation of collective organizations. Evolutionary game method is applied to model construction. Through numerical simulation, the study analyzes the evolution of E‐commerce platform and collective organization strategic choice. The results depict that improving the open space provided by E‐commerce platforms for collective organizations and strengthening their public service capabilities can promote the construction of social cogovernance systems. The establishment of reasonable reward and punishment mechanisms can increase cooperation enthusiasm. We also discuss the theoretical and practical implications for governments, E‐commerce platforms, and collective organizations, to improve the level of intellectual property protection in E‐commerce. This study can provide suggestions for China’s E‐commerce intellectual property protection, improve the overall level of intellectual property protection in China, and provide a reference for global E‐commerce intellectual property protection.
Magnetization for Burgers’ Fluid Subject to Convective Heating and Heterogeneous-Homogeneous Reactions
Authors: Gangadhar Kotha , Kumari Manda Aruna , Subba Rao M. Venkata , Alnefaie Khaled , Khan Ilyas , Andualem Mulugeta
Published: February 2022

The flow of Burgers’ fluid in the magnetic field new mathematical modeling is introduced in this article which is heated convectively and maintained. The thermal energy transport aspects are examined by employing the space- and temperature-related heat source. In the present investigation, the homogeneous-heterogeneous reactions will present the features of scrutiny of the fluid concentration. For the purpose of dimensionless similarity transformations, ordinary differential equations (ODEs) are utilized practically. Developed ODEs are solved by introducing the concepts of Runge–Kutta–Fehlberg’s fourth-fifth method. The graphs show the pertinent outcome. The relaxation time parameter is exhibited by diminishing the thermal distribution of Burgers’ fluid property, and this will depend on the relaxation time factor. Biot number and retardation time factor behaviors are analyzed by opposing the behavior of the material factor of Burgers’ fluid. The response of homogeneous strength is deteriorated by the concentration rate of the fluid, and this will augment the data using the heterogeneous response with greater magnitude. By using already published studies, it is investigated that the present investigation is validated.
A Review on Factors Influencing the Mismatch Losses in Solar Photovoltaic System
Authors: Dhass A. D. , Beemkumar N. , Harikrishnan S. , Ali Hafiz Muhammad
Published: February 2022

In the last two decades, it is persistently emphasized to develop energy generation systems free from greenhouse gas emissions since these gases cause global warming, and it leads to unpredictable monsoons. Consequently, it might not be a conducive environment for human beings and animals to dwell. To ascertain the green environment for the next generations and reduce the use of fossil fuels, renewable energy sources are highly suggested to generate electrical energy. Solar photovoltaic is reckoned to be one of the promising methods to generate electricity; however, it has a lower conversion value due to various losses resulting from external and internal parameters. Among various losses that occurred in the solar photovoltaic system, mismatch loss is imperative, which causes the system to perform poorly. Solar photovoltaic systems have made topical advances in the use of highly effective solar cell materials to achieve high efficiency. In this analysis, performance parameters are influenced by the internal and external conditions of the solar photovoltaic systems and they lead to an increase in the loss of the system. The present review is focused to fetch fruitful information on the several studies that analyzed the effects on the solar photovoltaic systems of parasitic resistances, dust generated by tresses, clouds, solar radiation, temperature, relative humidity, different connection topologies, circuit implementation for partial shading, and remedies suggested by the potential authors.
Pediatric Sickle Cell Disease in Sudan: Complications and Management
Authors: Talha Meysaa , Osman Bashier , Abdalla Safa , Mirghani Hind , Abdoon Iman
Published: February 2022

Background. Sickle cell disease (SCD) is a life-threatening genetic disorder due to the formation of sickle hemoglobin molecule (HbS) that polymerizes in hypoxic conditions leading to SCD-related complications. Different approaches have been used in the management of SCD including symptomatic management, supportive management, and preventive management. Objectives. To assess the management of SCD in pediatric patients in Gaafar Ibnauf Referral Hospital in Khartoum locality, Sudan. Method. A descriptive, retrospective, hospital-based study was conducted in Gaafar Ibnauf Hospital using a data collection sheet. The study included all medical files of pediatric patients with SCD attending the hospital during the period from the first of April 2018 to the first of July 2018. The data were analyzed using descriptive statistics and the chi-square test.

P
<
0.05

was considered statistically significant. Results. Out of 207 pediatric patients, 53.1% were females (mean age of 7.5 ± 3.1 years), with a 1.1 : 1 female:male ratio and low socioeconomic status. Only 4.3% of participants had health insurance. The Messeryia tribe in western Sudan had the highest prevalence of the disease among the Sudanese tribes (11.1%). Vaso-occlusive crisis (33.3%), infections (13.5%), and neurological complications (10.6%) were the most frequent complications reported during routine visits. After initiation of management, only 3.4% of pediatric patients had hemolytic crises, and 1.4% of the anemic patients had splenomegaly. 100% of patients received folic acid, 73.9% used hydroxyurea, and 69.6% underwent blood transfusion for the management of SCD. Prophylactic penicillin was prescribed for 15% of patients, and 41.1% were immunized with pneumococcal vaccine (PPSV23). Most patients had been scheduled for planned follow-up visits every 3–6 months (93.2%). Hydroxyurea and blood transfusion significantly reduced fever and vaso-occlusive crisis. Conclusion. The SCD treatment protocol in Gaafar Ibnauf Children’s Hospital, involving preventive and symptomatic therapy, is consistent with the internationally implemented protocols for SCD management. However, immunization and prophylactic penicillin approaches are deficient.
Admissibility Analysis of a Sampled‐Data Singular System Based on the Input Delay Approach
Authors: Chen Guoquan , Zheng Minjie , Yang Shenhua , Li Lina
Published: February 2022

This study investigates the sampled‐data admissibility problem for a singular system. The objective of this paper is to design a sampled‐data controller to ensure the admissibility of a singular system and to construct an appropriate Lyapunov–Krasovskii functional (LKF) to get less conservative results for the sampled‐data singular system. To accomplish these objectives, the system is converted into a time‐delay system by the input delay approach firstly, and both lower and upper bounds of the delay are considered. Secondly, by introducing a suitable LKF, the admissibility criteria are obtained. Then, when estimating the derivative of the LKF, a relaxation variable is introduced by the method of reciprocally convex inequality, and it is proved that the conservatism is reduced. Finally, two numerical examples are given to prove that the designed sampled‐data controller can ensure the states of the systems under the influence of external interference.
Prediction of Chinese Semantic Word-Building Patterns Based on Complex Network Features
Authors: Wang Minfeng
Published: February 2022

The research on prediction of Chinese semantic word-formation patterns based on complex network features has certain practical and theoretical significance in the field of natural language understanding. In this paper, complex networks are introduced into the prediction of Chinese semantic word-formation patterns, and a new prediction method of Chinese semantic word-formation patterns based on complex networks is proposed. And a solution that combines the semantic word-building rules of Chinese language with pattern recognition algorithm is put forward. Aiming at this scheme, a variety of pattern recognition algorithms are compared and analyzed, and the most suitable binary logistic regression model and naive Bayes model are found to predict Chinese semantic word-building patterns. The semantic loss is reduced, and the text classification model and corresponding classification algorithm are constructed, by introducing the maximum common subgraph theory to calculate text similarity under the complex network representation. The results of the experiments show that using complex networks to predict Chinese semantic word-formation patterns is both effective and feasible. The computer can judge the semantic word-formation pattern more accurately using the semantic word-formation pattern prediction model based on this theory.
Mechanisms of Vitamin C Regulating Immune and Inflammation Associated with Neonatal Hypoxic-Ischemic Encephalopathy Based on Network Pharmacology and Molecular Simulation Technology
Authors: Li Shangbin , Li Shuangshuang , Zhao Qian , Huang Jiayu , Meng Jinfeng , Yan Weichen , Wang Jie , Ren Changjun , Hao Ling
Published: February 2022

Background. There are still controversies about the curative effect of vitamin C in treating HIE, and its mechanism of action is not entirely clear. This study is designed to explore the potential molecular mechanism of vitamin C in treating neonatal hypoxic ischemic encephalopathy (HIE). Methods. The effect targets of vitamin C and the pathogenic targets of neonatal HIE were obtained via retrieval of public databases to screen out the molecular targets of vitamin C acting on neonatal HIE. Gene Ontology (GO) functional annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed on the main targets. Vitamin C and the optimum target structural components are subjected to molecular docking and molecular dynamics simulation analysis via computer software so as to verify their binding activity and stability. Result. Based on 16 overlapping targets of vitamin C and HIE, seven main targets were identified in this study. According to GO and KEGG analysis, molecular functions (top 25 items) and signal pathways (21 items) related to inflammatory reaction, immune response, and cell transcriptional control may be potential pathways for vitamin C to treat neonatal HIE. Molecular docking and molecular dynamics simulation were adopted to definitively determine the 4 optimum core target spots. Conclusion. The efficacy of vitamin C on HIE is involved in the immunoregulation and inflammation-related functional processes and signal pathways. These molecular mechanisms, including core targets, will contribute to the clinical practice of neonatal HIE in the future.
Analysis of the Curative Effect of Continuous Nursing Based on Data Mining on Patients with Liver Tumors
Authors: Peng ChunFen , Bao LiHong , Wang JingQiong
Published: February 2022

Studies have shown that the physical, psychological, and social problems of liver cancer patients are more serious than those of other cancer patients and their quality of life is significantly reduced. This may be related to the poor treatment effect of patients with advanced liver cancer. Patients often have adverse symptoms such as cancer pain, pleural effusion, and ascites, etc., which have a great impact on patients’ psychology and recovery from illness. With the change of the medical model, it has become history to rely solely on drugs to care for patients with advanced liver cancer and comprehensive nursing intervention has become very important. Continuous nursing intervention focuses on individualized and full-hearted care, effectively alleviating patients’ anxiety and fear and improving patients’ environmental adaptability and psychological defense mechanisms. However, in the field of liver cancer, there is no detailed comparison between the efficacy of continuous nursing and traditional conventional nursing. This article applies the hidden Markov model, starts with medical data mining, and describes the process achieved by the application of this article and the analysis of the results obtained by the two nursing methods, which reflect the difference in curative effect evaluation, and it proves that continuous nursing has more advantages in the curative effect of patients with liver tumors.