bluuebunny/crossref_metadata_2025 huggingface dataset:
Solid Freeform Fabrication by GMA Welding: Geometry Modeling, Adaptation and Control
Authors: Kwak Yong-Min , Doumanidis Charalabos
Published: December 2021

This paper introduces the Gas Metal Arc Welding process with deposition shape control to solid freeform fabrication for large sculpted metal objects and rapid tooling of molds and dies. Besides full density and toughness properties, GMAW deposition must ensure near-net-shape surface geometry. To this end, an analytical model of deposited morphology is derived, based on linearized superposition of ellipsoidal unit deposition globules. The time-varying parameters of these primitives are identified in-process using laser scanning measurements of the bead width. An experimental description of width on the GMAW inputs is also established. On this basis, bead width control through the wire feed is implemented in real time, using Smith prediction to cope with sensor delays, and feedforward to compensate for the predeposited terrain. This controller was validated in the laboratory, in stainless steel deposition in single and overlaid beads.
Modeling the Temperature/Force Phenomena of an Extra-Low Carbon Steel in Two-Phase Hot Rolling
Authors: Hwu Yhu-Jen , Wu Chang-Huei
Published: December 2021

Extra-low carbon steel had been rolled in conventional hot rolling mill. For improving its mechanical and metallurgical properties, its high phase transformation temperature typically encountered in the finishing mill section that results in abrupt change of flow stress and consequently the rolling force. A simple temperature/force model is proposed to predict the strip temperature and mill loading force to achieve better understanding of complicated phenomena encountered in the field and also for future initial rolling condition setup. Preliminary results based on the model are satisfactorily close to the on-line rolling data from the seven-stand mill of China Steel Corporation.
Industrial Design to Rapid Mold Making for Accelerated Time-to-Market of Consumer Electronic Products
Authors: Wang Fu-Chung , Plancarte Juan , Wright Paul K. , Fabbrizio Vito , Kramer Alan
Published: December 2021

The demand for quick time-to-market and the short product life cycle of consumer electronics are now pushing the development time for these products even shorter. The success of a rapid product development requires careful considerations of product markets, production needs, and available design and fabrication resources at the early development stage, and a seamlessly integrated design to fabrication environment for rapid product realization. In this paper, through a case study on the prototyping production of a finger-print recognition device, we illustrate a rapid product development through an integrated CAD/CAM environment. Rapid production of an accurate aluminum mold for 200 prototypes is highlighted. The result was a product prototype delivered within a short period of development time according to the proposed schedule. Time analysis of the entire development process was provided, and some potential improvements based on the analysis were also identified for future development of similar products.
Influence of Kinematic Characteristics on Grinding Ultra-Precision Substrates
Authors: Tso Pei-Lum , Teng Chieng-Chung
Published: December 2021

This study concerns with the kinematic characteristics of grinding ultra-precision substrate with the rotary-table vertical-spindle surface grinder. The relative position, velocity, acceleration of single grain on cup-wheel traveling along the substrate have been calculated and studied. Factors affecting the flatness of the ground substrate may be considered as: the non-uniformity of relative velocity, the non-uniformity of relative acceleration, the passing ratio of center to periphery of the substrate, the mean thickness of undeformed chip. These are influenced considerably by the value of the rotational speed ratio of cup-wheel and worktable as well as the wheel infeed rate. The experimental study indicated that the passing ratio is the main factor and the inclination of grinding wheel axis must be appropriately performed to improve the flatness of ground substrate.
Grit Interaction Model for Rotary Disc Truing of CBN Grinding Wheels
Authors: Prusak Zbigniew , Webster John A.
Published: December 2021

Performance of a grinding operation depends mainly on material removal ability of the grinding wheel used, which is closely related to its cutting sharpness. In the case of CBN wheels, the cutting sharpness can be traced to the interaction between CBN and diamond grits during truing process. This paper presents a mathematical model for predicting the number of collisions that a CBN grit is subjected to in truing process when various designs of truing disc are used. The model takes into account geometric and kinematic characteristics of wheel-truer engagement, and interaction between colliding grits. Various characteristics of truer, wheel and truing process are also included. Grit retention parameter z, which was introduced in this research, accounts for the capability of retaining grits in truer and wheel. Modelling results are compared to results from truing and grinding tests.
Precision Sensing of Arc Length in GTAW Based on Arc Light Spectrum
Authors: Li P. J. , Zhang Y. M.
Published: December 2021

This work aims at improving the measurement accuracy of arc length using the spectrum of arc light at a particular wavelength during gas tungsten arc welding with argon shield. To this end, effects of welding parameters on spectral distributions were studied. To verify the effects of base metal and arc length, the arc column was also sampled horizontally as layers for spectral analysis. Results showed that spectral lines of argon atoms are determined by arc length and independent of welding parameters other than the arc length. Based on these findings, a compact arc light sensor has been designed to measure the arc length with an adequate accuracy. A closed-loop arc length control system has been developed with the proposed sensor.
Research on Digital Control of Meter-In and Meter-Out Independent Regulating for High Inertia Load
Authors: Wang Qingfeng , Gu Linyi , Lu Yongxiang
Published: December 2021

The smoothness of acceleration and deceleration process is a serious problem in valve control system with high inertia load, especially in the hydraulic systems in construction machines.

In this paper, a meter-in and meter-out independent regulating method, in which the two sides of actuator are controlled by a meter-in valve and a meter-out valve respectively, is put forward, in one hand, the meter-out valve could control the actuator’s outlet pressure to avoid the ultra-high outlet pressure when actuator decelerates or brakes suddenly. On the other hand, the dynamic damping ratio of valve control system could be raised through calculated flow feedback control algorithm.

Secondly, a grading control algorithm in dynamic process of high inertia load is adopted. When the actuator’s velocity is far from its command value, the actuator’s inlet and outlet pressure are controlled. After the velocity error decrease to a threshold, a state feedback control algorithm based on parameters on line estimating is employed to realize both its velocity accuracy and the smoothness of dynamic process.

Experiments show that the actuator’s velocity could increase or decrease to its command value accurately, smoothly and rapidly after the above method and algorithm are applied.
A Novel Thin Film Solid Oxide Fuel Cell for Microscale Energy Conversion
Authors: Morse Jeffrey D. , Jankowski Alan F. , Hayes Jeffrey P. , Graff Robert T.
Published: December 2021

A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, manifold, and fuel cell stack components for applications in miniature and microscale energy conversion. Scaling towards miniaturization is accomplished by utilizing thin film deposition combined with novel micromachining approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which are not directly scalable. Results demonstrating the generation of electrical current in the temperature range of 200–400°C for a thin film solid oxide fuel cell stack fabricated on a silicon wafer will be presented.
Three-Dimensional Graphic Analysis of Absorption Cycles
Authors: Shelton Sam V. , Vodenicker John P. , Schaefer Laura A.
Published: December 2021

Due to new computer software tools and high speed personal computers, it is now possible to quickly analyze and optimize complex absorption heat pump cycles. These cycles utilize fluid mixtures and can have a large number of components. Absorption cycles are typically displayed on two-dimensional graphs, but these diagrams can cause confusion in understanding new cycle configurations and their potentials and limitations. This study uses three-dimensional graphs to create accurate representations of four cycles. In the advanced cycles, the many opportunities for internal heat recovery can be clearly seen. Additionally, the three-dimensional representations can justify the inclusion or removal of cycle components. They are an excellent tool for those new to the field to more quickly understand the cycles, and for those experienced with absorption to be innovative in developing new cycles.
A Role for Exergy Analysis and Optimization in Aircraft Energy-System Design
Authors: Bejan Adrian
Published: December 2021

This paper outlines a newly emerging body of work that relies on exergy analysis and thermodynamic optimization in the design of energy systems for modern aircraft. Exergy analysis establishes the theoretical performance limit. The minimization of exergy destruction brings the design as closely as permissible to the theoretical limit The system architecture springs out of this constrained optimization principle. A key problem is the extraction of maximum exergy from a hot gaseous stream that is gradually cooled and eventually discharged into the ambient. The optimal configuration consists of a heat transfer surface with a temperature that decays exponentially in the flow direction. This configuration can be achieved in a counterflow heat exchanger with an optimal imbalance of flow capacity rates. The same optimal configuration emerges when the surface is minimized subject to specified exergy extraction rate. Similar opportunities for optimally matching components and streams exist in considerably more complex systems for power and refrigeration. They deserve to be pursued, and can be approached first at the conceptual level, based on exergy analysis and thermodynamic optimization. The application of such principles in aircraft energy system design also sheds light on the design principle that generated all the systems that use powered flight, engineered and natural.
Constitutive Modeling for Impact Simulation of Random Fiber Composite Structures
Authors: Lee Haeng-Ki , Simunovic Srdan
Published: December 2021

A constitutive model for progressive crushing is presented to predict impact behavior and damage evolution in random carbon fiber polymer matrix composites (RCFPMCs). Based on the ensemble-volume averaging process and first-order effects of eigenstrains due to the existence of prolate fibers, an effective yield criterion is derived to estimate the overall elastoplastic damage responses. First, an effective elastoplastic constitutive damage model for aligned fiber-reinforced composites is proposed. A micromechanical damage constitutive model for RCFPMCs is then developed. The governing field equations and overall yield function for aligned fiber-orientations are averaged over all orientations to obtain the constitutive relations and effective yield function of RCFPMCs. Finally, the complete progressive damage constitutive model is implemented into finite element code DYNA3D to solve large scale problems such as automobile components and systems. An advantage of the progressive damage analysis is that the information from the progressive damage model can be implemented into finite element code as material input properties and thus the calculations required in the constitutive model can be greatly reduced.
Integrated Transient Thermal and Mechanical Analysis of Molded PBGA Packages During Thermal Shock
Authors: Mercado Lei L. , Lee Tien-Yu Tom , Cook Jeff
Published: December 2021

During thermal shock, large thermal gradients exist within a molded plastic ball grid array (PBGA) package. The conventional assumption of uniform temperature distribution becomes invalid. In this paper, an integrated thermal-mechanical analysis was performed to evaluate the transient effect of thermal shock. For comparison, an isothermal analysis was also conducted. The computational fluid dynamics (CFD) method was used to obtain the thermal boundary conditions surrounding the package. The heat transfer coefficient obtained through CFD was compared to two analytical solutions. It was found that the analytical values were not acceptable in the time period of interest. Therefore, to obtain the actual maximum die stress, CFD solution has to be used instead of analytical solutions to derive the thermal boundary condition. This boundary condition was then applied to the package and a sequentially coupled heat transfer and thermal stress analysis was performed. The transient analysis has shown that high stresses occur in the die due to thermal shock, which can not be seen under the traditional isothermal assumption. The impact of PBGA package parameters on transient die stress was also studied, including mold thickness and substrate thickness. The results in this paper could be applied to either wire bond or flip-chip PBGA packages.
Static and Dynamic Crush Testing and Analysis of a Rail Vehicle Corner Structural Element
Authors: Mayville Ronald A. , Hammond Randolph P. , Johnson Kent N.
Published: December 2021

This paper presents the results of an experimental study to establish the strength and energy absorption capability of cab car rail vehicle corner structures built to current strength requirements and for structures modified to carry higher loads and absorb more energy. We reviewed current structures and designed an end beam test element — the most common way of meeting current requirements — whose strength in the baseline state was at least 150,000 lbf. This design was then modified to provide a strength of over 400,000 lbf. The designs, which included consideration of the deformation and fracture response under impact loading, were carried out using conventional structural engineering methods and explicit finite element analysis.
Filler Dispersion Measurements Within Thermal Management Materials for Electronic Applications
Authors: Mathis Nancy E.
Published: December 2021

An interfacial technique to measure thermal conductivity within filled samples has been investigated in order to meet the requirements of developers of electronics packaging and interconnect materials. By summarizing several homogeneity studies conducted on filled materials, this work illustrates the need to better characterize fiber dispersion during development and production of filled materials intended for thermal management.
Heat and Mass Transfer in Advanced Batteries
Authors: Wang C. Y. , Gu W. B. , Cullion R. , Thomas B.
Published: December 2021

This paper presents an overview of heat and mass transfer issues in advanced rechargeable batteries such as nickel-metal hydride (Ni-MH) and lithium-ion (Li-ion) batteries. These batteries are important power sources for ultra-clean, fuel-efficient vehicles and modern portable electronics. Recent demands for environmentally responsible vehicles and strong portable power have prompted fundamental studies of heat and mass transport processes in battery systems in conjunction with electrochemistry and materials science. In this paper, discussions are presented on what are the critical heat and mass transfer issues present in advanced batteries and how these issues affect the battery performance, safety, life cycle, and cost. A theoretical framework describing the transport phenomena with electrochemical reactions is provided. Selected results are presented to illustrate the importance of coupled electrochemical and thermal modeling for advanced batteries. The recent progress is also reviewed in developing and validating battery models at Penn State GATE Center for Advanced Energy Storage.
Augmented Performance of Flow Boiling Heat Transfer in a Tube With Axial Micro-Grooves and its Augmentation Mechanisms
Authors: Cheng Lixin , Chen Tingkuan
Published: December 2021

Experiments of upward flow boiling heat transfer with water in a vertical smooth tube and a tube with axial micro-grooves were respectively conducted. Both of the tested tubes have a length of 2.5 m, an inner diameter of 15 mm and an outlet diameter of 19 mm. The tube with axial micro grooves has many micro rectangle grooves in its inner wall along the axial direction. The grooves have a depth of 0.5 mm and a width of 0.3 mm. The tests were performed at an absolute pressure of 6 bar. The heat flux ranged from 0 to 550 kW/m2 and the mass flux was selected at 410, 610 and 810 kg/m2s, respectively. By comparison, flow boiling heat transfer coefficients in the enhanced tube are 1.6 ∼ 2.7 fold that in the smooth tube while the frictional pressure drop in the enhanced tube is slightly greater than that in the smooth tube. The augmentation of flow boiling heat transfer in the tube with axial micro-grooves is apparent. Based on the experimental data, a correlation of flow boiling heat transfer is proposed for the enhanced tube. Finally, the mechanisms of heat transfer enhancement are analyzed.
Analysis of Conjugate Heat Transfer in a Three-Dimensional Microchannel Heat Sink for Cooling of Electronic Components
Authors: Fedorov Andrei G. , Viskanta Raymond
Published: December 2021

A three-dimensional model is developed to investigate flow and conjugate heat transfer in the microchannel-based heat sink for electronic packaging applications. The incompressible laminar flow Navier-Stokes equations of motion as well as the energy conservation equations for the fluid and solid are employed as the governing model equations which are numerically solved using the generalized single-equation framework for solving conjugate problems.

First, the theoretical model developed is validated by comparing the model predictions of the thermal resistance and the friction coefficient with available experimental data for a wide range of Reynolds numbers. Then, the parametric calculations are performed to investigate the effects of different working fluids, solid substrate materials and channel geometry on conjugate heat transfer in the microchannel heat sink.

The bulk and wall temperature and heat flux distributions as well as the average heat transfer characteristics are reported and discussed. Important practical design recommendations are also provided regarding the cooling efficiency of the microchannel heat sink.
A Critical Review of Drying Models for Coated Paper
Authors: Noboa Homero L. , Seyed-Yagoobi Jamal
Published: December 2021

Drying of coated paper is a complex process that includes the three mechanisms of heat transfer (conduction, convection, and radiation) coupled with water (liquid, vapor and bound), air, and binder mass transfer. Limited work has been conducted so far to mathematically simulate this drying process. This paper critically reviews the major relevant theoretical models and discusses each model’s strengths and shortcomings. The critical review reveals that there is a need for a better and more complete model to capture all the physics of the process of drying of coated paper. Furthermore, the theoretical results (e.g. drying rates, heat and mass transfer fluxes, temperature and species’ concentration profiles) should be directly verified against laboratory and machine data under various operating conditions.
Determination of Surface Heat Flux in Quenching
Authors: Alam M. K. , Pasic H. , Anagurthi K. , Zhong R.
Published: December 2021

Quench probes have been used to collect temperature data in controlled quenching experiments; the data is then used to deduce the heat transfer coefficients in the quenching medium. The process of determination of the heat transfer coefficient at the surface is the inverse heat conduction problem, which is extremely sensitive to measurement errors. This paper reports on an experimental and theoretical study of quenching carried out to determine the surface heat flux history during a quenching process by an inverse algorithm based on an analytical solution. The algorithm is applied to experimental data from a quenching experiment. The surface heat flux is then calculated, and the theoretical curve obtained from the analytical solution is compared with experimental results. The inverse calculation appears to produce fast, stable, but approximate results. These results can be used as the initial guess to improve the efficiency of iterative numerical solutions which are sensitive to the initial guess.
A Tomographic Reconstruction Method for Three-Dimensional Liquid Crystal Thermography
Authors: Mishra D. , Lutjen P. M. , Prasad V.
Published: December 2021

Liquid crystal thermography generates two-dimensional temperature information in a fluid layer. Three-dimensional temperature field can be reconstructed using the two-dimensional temperature fields obtained at various locations with the help of synchronized transverse movements of the light sheet and camera (Lutjen et al., 1999). However, it is not feasible to generate a large number of liquid crystal thermographs that are needed for the reconstruction of a high resolution three-dimensional temperature field. A tomographic reconstruction method is suggested here that can be appropriately used to produce a high resolution three-dimensional reconstruction from a limited number of two-dimensional images of the full temperature field. The two-dimensional temperature fields generated from the experiments can be used to obtain an integrated information of the three-dimensional field from various directions known as projections of the actual three-dimensional field and can be used to reconstruct a high resolution volumetric temperature field.
A Technique for Direct Measurement of Local Convective Heat Flux Using Interferometry
Authors: Naylor D. , Duarte N.
Published: December 2021

An interferometric procedure is described for measuring the local surface temperature gradient directly from a wedge (finite) fringe field. For a two-dimensional temperature field, it is shown that the local convective heat transfer coefficient can be obtained by measuring the angle of intersection of a fringe with an isothermal surface. Using an uncertainty analysis it is shown that this method gives the most accurate results for the measurement of relatively low gradients. A correction term for refraction effects and an expression for the optimum wedge fringe spacing are also derived. Measurements of the natural convection from a vertical flat plate are compared to the boundary layer solution.
A Thermal Law of the Wall for Separating and Recirculating Flows
Authors: Cruz Daniel O. A. , Silva Freire Atila P.
Published: December 2021

The characteristics of the turbulent boundary layer near a separation point are studied here. The emphasis is on providing analytical expressions for the velocity and temperature near wall solutions which are also valid in the region of reverse flow. These expressions can then be used as boundary conditions in numerical schemes that use two-equation differential models. The paper proposes a new expression for the description of the near wall characteristic length which is shown to hold also in the reverse flow region. The specified velocity profiles are based on a previous formulation of the problem by Cruz and Silva Freire (IJHMT, 41, 2097 2111, 1998) but, as written here, they are presented for the first time. The temperature profiles near the wall are also described by a newly proposed expression that reduces to the logarithmic profile in the attached region, and assumes a minus half power law profile at the separation point. In the separated region, the logarithmic profile is recovered. All results are validated through the data of Vogel and Eaton (Trans. ASME JHT, 107, 922 929, 1985).
High Integrity Protection Systems and Pressure Relief Systems
Authors: Raney Glenn A. , Summers Angela E.
Published: December 2021

Many Users are applying high integrity protection systems (HIPS) for overpressure protection of vessels and pipelines. HIPS can be an excellent alternative to standard, passive protection systems, if they are designed correctly. Various standards are applicable when HIPS are used in lieu of pressure relief valves. This paper will address the design issues, as well as the applicable industry standards.
Magneto-Rheological Fluids in Squeeze-Flow: Validation of Quasi-Steady Mathematical Models
Authors: Stanway Roger , Sims Neil D. , Johnson Andrew R.
Published: December 2021

It is now well established that magneto-rheological (MR) fluids can provide the basis for constructing controllable vibration damping devices. Moreover, the characteristics of MR fluids are generally compatible with industrial requirements and there is enormous scope for commercial exploitation. In this paper the authors describe the design and construction of a vibration isolator which incorporates an MR damper. The damper is unusual in that it operates in the squeeze-flow mode. A quasi-steady model of the MR damper is summarised and then extended to include the vibration isolator dynamics. Model predictions are compared with experimental results. It is shown that by employing the MR damper a wide range of control can be exercised over the transmissibility of the vibration isolator. Also the quasi-steady model is able to account for observed behaviour.
An Application of Distributed Computing to the Finite Element Investigation of Lift Force on a Freely-Rotating Sphere in Simple Shear Flow
Authors: Buscaglia Gustavo C. , Ferrari Hugo E. , Carrica Pablo M. , Dari Enzo A.
Published: December 2021

An application of “cluster computing” in finite element CFD is reported, demonstrating the feasibility of solving relevant 3D problems on low-cost architectures (PC’s connected by fast Ethernet network). The main ingredients of our implementation are described.

The results concern the lift force on a solid particle in simple shear flow. It is shown that, if the particle is allowed to rotate freely about its center, the self-established rotation significantly alters the lift coefficient. in particular, the lift force points away from a wall for any Re (≤ 100), while if the particle does not rotate the lift changes sign.

Suitable estimates for the typical time involved in the angular acceleration of solid spherical particles are derived.
Draft Genome Sequences of Four Streptomycin-Sensitive Erwinia amylovora Strains Isolated from Commercial Apple Orchards in Ohio
Authors: Jimenez Madrid A. M. , Klass T. , Roman-Reyna V. , Jacobs J. , Lewis Ivey M. L.
Published: December 2021

Erwinia amylovora
is the causative agent of fire blight, a devastating disease of apples and pears worldwide. Here, we report draft genome sequences of four streptomycin-sensitive strains of
E. amylovora
that were isolated from diseased apple trees in Ohio.
Draft Genome Sequence of Aestuariibacter halophilus Type Strain JC2043
Authors: Emsley Sarah A. , Pfannmuller Kaysa M. , Ushijima Blake , Saw Jimmy H. , Gaylor Michael O. , Videau Patrick
Published: December 2021

Aestuariibacter halophilus
strain JC2043, a Gram-negative gammaproteobacterium, is often used as a reference organism for assigning taxonomy within the family
Alteromonadaceae
. Isolates of this species have also been investigated for compound degradation (e.g., phthalates and oil) and biofilm association. Presented here is the draft genome sequence of
A. halophilus
strain JC2043.
Supplemental Material: Enhanced precipitation in the Gulf of Mexico during the Eocene–Oligocene transition driven by interhemispherical temperature asymmetry
Authors: Hou Mingqiu , Zhuang Guangsheng , al. et
Published: December 2021

Table S1: Leaf wax isotopic records in the Gulf of Mexico; Table S2: Reconstructions of mean annual precipitation based on leaf wax carbon isotopic records; Table S3: Sea surface temperature reconstructions; Table S4: Leaf wax isotopic records of modern trees.
Supplemental Material: Linkages between nitrogen cycling, nitrogen isotopes, and environmental properties in paleo-lake basins
Authors: Cao Jian , al. et
Published: December 2021

Raw data.
Swell wave progression in the English Channel: implications for coastal monitoring
Authors: Dhoop Thomas , Thompson Charlie
Published: December 2021

Energetic swell waves, particularly when they coincide with high water levels, can present significant coastal hazards. To better understand and predict these risks, analysis of the sea levels and waves that generate these events and the resulting coastal impacts is essential. Two energetic swell events, neither of which were predicted by modelled flood forecasts, occurred in quick succession in the English Channel. The first event, on 30 January 2021, produced moderate significant wave heights at or just below the 0.25 year return period along the southwest English coast, but combined with significant swell caused overtopping at East Beach in West Bay and at Chesil Beach. The second event, on 1 February 2021, generated the highest wave energy periods measured at many locations along the southern English coastline and, at high water, caused waves to run up over the promenades at Poole Bay and Christchurch Bay and caused overtopping at Hayling Island. Both events are described in detail, and their spatial footprints are mapped through a joint return period analysis using a copula function. It is found that typical joint return period analysis of water level and significant wave height underestimates potential impacts, while a joint consideration of water level and wave power (P) describes the 31 January event better and a joint consideration of water level and energy period (T
e) best describes the 1 February event. Therefore, it is recommended that T
e and P are adopted for coastal monitoring purposes, and that future studies further explore the use of both parameters for swell monitoring.
AAC Castle red spring wheat
Authors: Randhawa H.S. , Brown P.D. , Fetch J. Mitchell , Fetch T. , McCallum B. , Henriquez M.A. , Menzies J.
Published: December 2021

AAC Castle, an awned hard red spring wheat (Triticum aestivum L.), cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stem, stripe rust, common bunt and loose smut. It also expressed tolerance to the orange wheat blossom midge. Based on 39 station years of data in the registration trials from 2014 to 2016, the grain yield of AAC Castle was about 17% higher than 5700PR but similar to the other checks. AAC Castle was significantly shorter than AAC Foray and CDC Terrain, but had similar lodging resistance and maturity. AAC Castle had higher test weight, protein concentration, falling number and flour yield than AAC Foray and CDC Terrain. AAC Castle is eligible for grade of the Canada Prairie Spring Red wheat market class.
Quaternionic Dirac free particle
Authors: Giardino Sergio
Published: December 2021

In this paper, we solve the quaternionic Dirac equation [Formula: see text] in the real Hilbert space, and we ascertain that their free particle solutions set comprises eight elements in the case of a massive particle, and a four elements solutions set in the case of a massless particle, a richer situation when compared to the four elements solutions set of the usual complex Dirac equation [Formula: see text]. These free particle solutions were unknown in the previous solutions of anti-Hermitian quaternionic quantum mechanics, and constitute an essential element in order to build a quaternionic quantum field theory [Formula: see text].
A highly sensitive D-type photonic crystal fiber infrared sensor with indium tin oxide based on surface plasmon resonance
Authors: Liu Wei , Hu Chunjie , Zhou Lei , Yi Zao , Shi Ying , Liu Chao , Lv Jingwei , Yang Lin , Chu Paul K.
Published: December 2021

A highly sensitive surface plasmon resonance (SPR) sensor composed of a photonic crystal fiber (PCF) with the D-type structure is designed and analyzed by the full-vector finite element method (FEM). Indium tin oxide (ITO) is adopted as the plasmonic substance on account of the low cost and controllable infrared range (1500–2600 nm). By optimizing the structural parameters, the sensor shows a maximum wavelength sensitivity of 46,000 nm/RIU and average sensitivity of 13,166.67 nm/RIU for analyte refractive indexes between 1.355 and 1.385. This PCF combining a circular layout and D-type structure offers excellent sensitivity while the deposition and manufacturing complexity can be reduced. This sensor will possess an extremely expansive development space in the field of chemical analysis and environmental safety.
Quantitative measure of the isospin splitting of the effective nucleon mass
Authors: Haddad S.
Published: December 2021

The effective nucleon mass splits into two components, one for the proton and another for the neutron, in the case of adding the isovector coupling channel of the nuclear interaction, while being the same in the case of considering only the isoscalar coupling. A quantitative measure of the splitting is defined by the root mean square (RMS) value of the effective nucleon mass splitting and applied to the effective nucleon mass splitting in lead and tin isotopes. The isospin splitting of the effective nucleon mass is found to increase almost linearly with the asymmetry parameter.
Predictive Group Learning Behavior Approach and Inquiry Learning For Higher Education
Authors: He Mingyong
Published: December 2021

Group work can inspire students, encourage constructive learning, and improve essential critical thinking, communication, and decision-making in the present competitive world. The risk factors in group learning include students who prefer working alone and strongly despise dealing with things created by gathering in teams. Online learners often have problems locating lasting peace times for group therapy sessions are considered an essential factor. A predictive Group Learning Behavior Approach (PGLBA) has been proposed. Students who commute to college agree to group conferences and workgroup learning and Inquiry learning for higher education. The grounded Inquiry Learning Approach is invented to strengthen students’ enjoyment of active group learning, and the students find times for group meetings that are often mutually advantageous. The simulation analysis is performed based on performance, accuracy, and efficiency proves the proposed framework’s reliability. The experimental results show that the proposed PGLBA-IL model enhances the accuracy ratio of 81.2%, an efficiency ratio of the number of students 86.4%, and the overall performance analysis ratio of 85.1% compared to others existing approaches.
The Weyl–Mellin quantization map
Authors: Carotenuto Alessandro , Lizzi Fedele , Mercati Flavio , Manfredonia Mattia
Published: December 2021

In this paper, we present a quantization of the functions of spacetime, i.e. a map, analog to Weyl map, which reproduces the [Formula: see text]-Minkowski commutation relations, and it has the desirable properties of mapping square integrable functions into Hilbert–Schmidt operators, as well as real functions into symmetric operators. The map is based on Mellin transform on radial and time coordinates. The map also defines a deformed ∗ product which we discuss with examples.
UNIVERSAL RISK BUDGETING
Authors: GARIVALTIS ALEX
Published: December 2021

I juxtapose Cover’s vaunted universal portfolio selection algorithm ([Cover, TM (1991). Universal portfolios. Mathematical Finance, 1, 1–29]) with the modern representation of a portfolio as a certain allocation of risk among the available assets, rather than a mere allocation of capital. Thus, I define a Universal Risk Budgeting scheme that weights each risk budget, instead of each capital budget, by its historical performance record, á la Cover. I prove that my scheme is mathematically equivalent to a novel type of [Cover, TM and E Ordentlich (1996). Universal portfolios with side information. IEEE Transactions on Information Theory, 42, 348–363] universal portfolio that uses a new family of prior densities that have hitherto not appeared in the literature on universal portfolio theory. I argue that my universal risk budget, so-defined, is a potentially more perspicuous and flexible type of universal portfolio; it allows the algorithmic trader to incorporate, with advantage, his prior knowledge or beliefs about the particular covariance structure of instantaneous asset returns. Say, if there is some dispersion in the volatilities of the available assets, then the uniform or Dirichlet priors that are standard in the literature will generate a dangerously lopsided prior distribution over the possible risk budgets. In the author’s opinion, the proposed “Garivaltis prior” makes for a nice improvement on Cover’s timeless expert system, that is properly agnostic and open to different risk budgets from the very get-go. Inspired by [Jamshidian, F (1992). Asymptotically optimal portfolios. Mathematical Finance, 2, 131–150], the universal risk budget is formulated as a new kind of exotic option in the continuous time Black–Scholes market, with all the pleasure, elegance, and convenience that entails.
Fifty years of P vs. NP and the possibility of the impossible
Authors: Fortnow Lance
Published: December 2021

Advances in algorithms, machine learning, and hardware can help tackle many NP-hard problems once thought impossible.
Declarative machine learning systems
Authors: Molino Piero , Ré Christopher
Published: December 2021

The future of machine learning will depend on it being in the hands of the rest of us.
Dynamic Load Cycle Effects on PEMFC Stack CO Tolerance under Fuel Recirculation and Periodic Purge
Authors: Koski Pauli , Viitakangas Jaana , Ihonen Jari
Published: December 2021

This work presents first experimental evidence on the effects of dynamic load cycle on PEM fuel cell system CO tolerance, a topic which to date has not been comprehensively investigated. The experiments were performed with a 1 kW fuel cell system employing components, design, and operation conditions corresponding to automotive applications. To distinguish between the load cycle and other factors affecting the CO tolerance, the experiments were repeated with static and dynamic load cycles, as well as with pure and CO contaminated fuel. The measurement data showed that dynamic load cycle improves the CO tolerance in comparison to static load with the same average current density. Moreover, the cell voltage deviation data indicated that the difference could be explained by higher electrochemical CO oxidation rate under the dynamic load cycle. These results allow us to estimate the effect of the load cycle on CO tolerance and understand its origins, thus giving valuable input for fuel quality standardization and fuel cell system development work.
VIKOR Method for Evaluating the Management Quality of Teacher Education with Probabilistic Hesitant Fuzzy Information
Authors: Zhiqi Li
Published: December 2021

In the era of enhancing the quality of education, teacher quality, as the core factor affecting the quality of education, has received unprecedented attention in the field of education. The monitoring on teacher quality is the basis of fully understanding and effectively improving the quality of teachers in compulsory education within the county. Comprehensive and systematic study on teacher quality control in compulsory education within the county is the key to improve the teacher quality of it as well as improve and complement research in related fields. And in stark contrast to the importance of the problem, there is no in-depth and systematic result on the monitoring on teacher quality within the county which becomes a matter of concern in current research in the field of education issues. And the management quality evaluation of teacher education is frequently viewed as the multiple attribute decision-making (MADM) issue. An extended VIKOR model is established to provide a new approach to solve the management quality evaluation of teacher education. The VIKOR method with probabilistic hesitant fuzzy information is applied to rank the optional solutions. Lastly, a numerical example about management quality evaluation of teacher education is illustrated to test the newly proposed method’s practicability.
A Carrier Parameter Decoupling Algorithm for High Order APSK Modulation
Authors: Gao Xiangchuan , Zhang Xupeng , Duan Linlin , Gong Kexian , Sun Peng , Wang Wei , Jiang Hua , Wang Zhongyong
Published: December 2021

In satellite communication, carrier parameter estimation usually uses a serial structure, and the accuracy of frequency offset estimation (FOE) will greatly affect the accuracy of phase offset estimation (POE). A new carrier synchronization mode (NCSM) can realize the decoupling of carrier FOE and POE to a certain extent, but this mode is based on multibase phase shift keying (MPSK) modulation analysis, the decoupling performance is poor when uses in amplitude phase shift keying (APSK) modulation, and the decoupling performance of NCSM has a low tolerance of frequency offset. An improved carrier parameter estimation decoupling technique is proposed to solve these problems. The simulation results show that, compared with the original method, under the premise of ensuring the accuracy of carrier parameter estimation, the proposed method is more robust to the modulation mode, the POE has stronger antioffset ability, and the normalized FOE range has been significantly enhanced.
Numerical Simulation Algorithm Design of Influence on Existing Tunnel by Underpass Construction of New Tunnel
Authors: Wu Huajun
Published: December 2021

Simulation is a powerful tool that can be used for systematic planning, analysis, and decision-making. Proper designing is preliminary required to construct a new tunnel over an existing tunnel to ensure safety and durability. Once an underpass tunnel completes, the interaction between the tunnel structure and the nearby soil gains a stable state and the stress of the tunnel is balanced. However, the stability of an existing tunnel is affected if the construction in the nearby area is not properly analyzed. This article proposes a numerical simulation model to empirically analyze lining force and surface settlement in order to ensure safety in engineering practice. The existing tunnel structure working condition is simulated under the new tunnel. The artificial honeybee colony algorithm is used to extract the parameter fusion characteristic value of tunnel influence and the model of estimating the bending moment of group piles. The structural mechanics of existing tunnels under new tunnels are analyzed using the triple bend model to improve the bearing capacity of existing tunnels under new tunnels. Based on the above analysis, numerical simulation experiments are designed. The proposed method has high accuracy and strong fitting ability and can effectively reduce the displacement of existing tunnels. Moreover, the method can improve the bearing capacity of tunnels. For tunneling operation, the results of the simulation may be used as a recommendation.
Intelligent Automatic 3D Printing Machine Based on Wireless Network Communication
Authors: Zhang Wei , Deng Xiangwen , Cai Jie
Published: December 2021

With the advent of the era of big data, people have higher requirements for material and spiritual gains and happiness, and their demands for various services in the communications field are diversified. The most significant change is the 3D printing technology. With its unique advantages, 3D printing is gradually sweeping the world. In order to explore whether the technology or digital model based on wireless network communication can realize the automation and intelligence of 3D printing, this article applies a variety of scientific methods such as simulation experiment method, data collection method, and sample analysis method; collects samples; and simplifies the algorithm, using basic experimental methods, orthogonal experiments, and single‐factor experiments to study the various influencing factors in the automatic printing process to obtain the optimal parameter combination. Experimental results show that with the support of wireless communication network hardware and data, the timeliness and quality of 3D printing can be significantly improved. These are the basis for realizing 3D printing automation and intelligence. Further experiments show that the wireless communication network intelligent automatic 3D printing machinery adjusts 3D printing parameters through wireless communication technology, combined with intelligent real‐time monitoring and sensing equipment; we can find that the printing efficiency of the 3D printing machinery is increased by about 15%, and the economic cost is saved by about 20%. It basically shows the practicality of the experimental research results.
Bonding Performance for Repairs Using Bulk Fill and Conventional Methacrylate Composites
Authors: Benzi Janaina Galvão , Pucci César Rogério , Freitas Maiara Rodrigues , Suzy Liporoni Priscila Christiane , Zanatta Rayssa Ferreira
Published: December 2021

This study compared the bond strength of a composite repair made with a bulk fill composite and a conventional one using different surface treatments. Specimens were prepared as truncated cones (bases: 4 mm × 2 mm, height: 4 mm) using a bulk fill (OBFa: Filtek One) or a conventional resin (FTKa: Filtek Z250) (n = 66). They were artificially aged (10,000 cycles, 5°C–55°C, 30 sec) and subdivided according to surface treatments: NT—no treatment (control), Abr—abrasion with a diamond tip, and sand—sandblasting with aluminum oxide (50 μm). Treatments were performed over the smaller diameter surface, followed by adhesive (Scothbond Universal) application. A new specimen with similar dimensions was constructed over it using either the OBF or the FTK, totaling 12 groups (n = 11). Bond strength was assessed by tensile test. The data were submitted to two-way ANOVA separately for OBFa and FTKa, followed by Tukey’s test (

p
<
0.05

). For the aged OBFa groups, there was significant differences for composite type and surface treatment, with higher values of bond strength when repaired with the same material (OBFa/OBF > OBFa/FTK), and sandblasting and bur abrasion presented higher values compared to the control group (NT). For the aged FTKa groups, there were no differences for the composite or surface treatment. Therefore, the bulk fill resin composite tested present better repair performance when the same composite was used, while the conventional resin composite was less influenced by the material and the surface treatment performed.