bluuebunny/crossref_metadata_2025 huggingface dataset:
Typical Analysis of Water Hammer in a Pumping Plant of the Colorado River Aqueduct
Authors: Peabody R. M.
Published: February 2023

This paper presents a method of analysis of surge conditions in a pumping system by arithmetical integration and is an extension of the work done by Professor Knapp at the California Institute of Technology. The analysis utilizes the step-by-step method, includes the complete characteristics of the pumping equipment, and determines their effect upon surge conditions. The valve characteristics are also included, and this is the first presentation of such a method of analysis.
Further Experiments in the Planing of Hardwoods
Authors: Davis E. M.
Published: February 2023

This paper is supplementary to a previous one, and gives results of further experiments in the planing of hardwoods.

Results are given in tabular and graph form showing the percentage of defective pieces obtained in planing samples of twenty-two woods with six different cutting angles; seven woods with unjointed knives and with four different amounts of jointing; and sixteen woods with four different depths of cut.
Obsolescence in Woodworking Machinery
Authors: Norton Paul T.
Published: February 2023

The author discusses the economic aspects of obsolescence of production machinery in general and its relation to cost accounting.

With respect to the woodworking industry, index figures for recent years are given of machinery purchases for comparison with figures for orders for metal-working machinery.

The author then points out the danger to an industry as a whole of the use of obsolete equipment and continues with a discussion of the problem in its relation to profits and governmental depreciation regulations. Finally there is considered the subject of unamortized values in studies of machine replacements.
Development of the Focke Helicopter
Authors: Focke Heinrich
Published: February 2023

The paper gives a description of the methods used in the development of the Focke helicopter. After a short review of the analytical and experimental information regarding the helicopter in existence prior to 1932, the author states the fundamental requirements to be met and indicates the procedure adopted to satisfy them. The analytical discussion is based on the Glauert-Lock theory of the autogiro rotor, and the author shows in outline the various steps in extending the theory to cover the helicopter rotor.

Finally, the construction and testing of the first machine are described, together with its successful flights.
Industrial Power
Authors: Clarke Charles W. E.
Published: February 2023

This paper covers briefly the progress that has been made in the generation of power in industrial plants. The author points out that industries and utilities are cooperating in the generation and interchange of electric energy in order to reduce waste in many manufacturing processes.

Higher steam pressures and temperatures are widely used, along with superposition of new turbines on old equipment. Only a few installations have pressures and temperatures which exceed 900 lb per sq in. and 850 F, respectively. A number of prominent industrial plants are described to indicate the application of all types of steam turbines to the three steam cycles most commonly employed. Steam-pressure-reducing and desuperheating equipment, as developed for topping units in central stations, is finding new applications in industry. Where large quantities of process steam are needed, many interesting arrangements of modern equipment can be used to reduce the cost of power generation.

The trend in design of boilers is toward larger units, higher steaming rates, and more complicated automatic controls to permit utilization of several different kinds of fuel in the same furnace. This presupposes the proper treatment of boiler feedwater, the importance of which is emphasized. Operating data from two outstanding installations are included. Among smaller plants there is a tendency toward the use of a self-contained boiler; also, there has been a revival of semi-outdoor constructions.

Progress is being made toward better utilization of unusual fuels, such as pulverized anthracite culm, lignite, acid sludges, and black liquor, the latter of which is obtained in the process of manufacturing kraft paper.

Improvements in electrical equipment for industrial plants include metal-clad switchgear, which may be located in any available space; also, air circuit breakers for voltages up to 5000 may soon be available in order to eliminate the fire hazard from using oil. Modern insulation on wire and cable offers greater resistance to high temperatures and the effects of moisture and other harmful substances.
Thin Oil Films
Authors: Claypoole Walter
Published: February 2023

A method is described for depositing very thin lubricating-oil films of any specified thickness of the order of 10−7 in. on polished metal in connection with experiments on boundary friction. The oil to be deposited is converted into a highly dispersed fog consisting largely of positively charged particles. The oil is readily deposited on a negatively charged metal surface at a rate depending on the nature of the oil, the potential gradient at the metal surface, and the concentration of the oil particles in the fog. The rate of deposition is best determined by observation of the progressive change in the interference color produced over a thickness range between 5 × 10−6 cm and 30 × 10−6 cm. Comparison of color with a standard stepped film of barium stearate laid down by the Langmuir and Blodgett technique gives a high degree of accuracy to the determination of film thickness.

Experiments have been made on the wearability of very thin oil films, and on the determination of the coefficient of static friction. An instrument is described which has been found especially suitable for this work. The author points out that a low value of the coefficient of static friction is a measure of the oiliness value of an oil-metal combination.
High-Temperature-Steam Experience at Detroit
Authors: Van Duzer R. M. , McCutchan Arthur
Published: February 2023

This paper is a continuation of the one presented in December, 1933, in which the 10,000-kw, 1000-F turbine installed by The Detroit Edison Company, was described in detail together with the results obtained with various materials used in the construction of a small 1100-F superheater and piping system. The turbine installation was dismantled in 1937 after 26,453 hours of service and the 1100 F equipment has been continued in service for the further testing of materials.

The turbine operation has demonstrated the practicability of 1000-F operation. An examination of all principal materials used in the construction of the turbine, piping, and superheater showed that with several exceptions the alloys were in good condition. Measurements made to determine creep disclosed only small amounts.

The results of 1100-F steam-corrosion tests on 18 steels indicate that the scale formations offer material protection against subsequent steam attack and that the corrosion process is different in steam from that in air. A comparison of creep determinations made on four machined pipe sections—two in service at 380 lb per sq in. and 1100 F, and two in service at 380 lb per sq in. and 925 F—and laboratory specimens at the same temperature and stress tend to disprove the theory that total diametral elongation of a pipe subject to internal pressure is materially less than that indicated by tensile-creep tests.
The Vectorscope
Authors: Dashefsky George J.
Published: February 2023

This paper describes a new instrument capable of rapidly summing up a number of vectors. The machine consists of a disk, mounted in gimbals in the manner of a nautical compass, on which are placed weights representing the vectors to be added. A spot of light on the screen indicates directly the resultant vector and its direction, as well as its horizontal and vertical components.

The mathematical principle is developed and the instrument is shown to be suitable for studying crankshaft arrangements with respect to unbalanced moments and torsional vibration. The suitability of any firing order for any crankshaft configuration may be ascertained simply and quickly.

It is shown that the instrument is inherently adapted to making harmonic analyses of periodic functions and the theory of this application is discussed. Results by this method of analysis compare favorably with other methods.
Five Years’ Progress of Oil and Gas Power
Authors: Degler Howard E.
Published: February 2023

The last “Five Years’ Progress of Oil and Gas Power” has been primarily that of constantly lowering the engine weight, decreasing the bulk, increasing the flexibility, and lowering the installed cost per horsepower. With these worth-while improvements also came better performance, lower fuel consumption, and a more quietly operating engine. These gradual changes and improvements have broadened the field of application to such an extent that, from the first development, running into hundreds of pounds per horsepower and turning over at from 100 to 150 rpm, engines have been reduced in weight and increased in speed to an extent that now offers possibilities for universal application. Undoubtedly, the Diesel engine is recognized today as one of the most economical and reliable prime movers known, and is fast taking its place in applications for which it seemed unsuited a few years ago.
The Analogy Between Fluid Friction and Heat Transfer
Authors: Von Kármán Th.
Published: February 2023

The results of the modern turbulence research on velocity distribution near solid walls are applied to extend Reynolds’ analogy between fluid friction and heat transfer to liquids. Discrepancies between the experimental results and the theory of Taylor and Prandtl are explained. A new theoretical formula which fits the experimental results more satisfactorily is suggested and compared with the empirical equations of Dittus and Boelter.
Fundamental Relationships in the Design of Cooling Towers
Authors: Nance G. Russell
Published: February 2023

This paper presents a few theoretical considerations encountered when an attempt is made to correlate actual tower performance with that which may be predicted from thermodynamic considerations alone. The results of observed tests are correlated by means of empirical equations and sufficient material has been presented to enable the reader to check the performance of different types of towers with a fair degree of accuracy. A discussion follows in which information relative to the merits of various types of cooling systems is presented and suggestions are made as to the most economical type of tower to install.
Toward Economic Air-Line Equipment
Authors: Bonnalie A. F.
Published: February 2023

The paper is a discussion of some of the apparent factors determining the worth of the transport airplane. The author treats size, speed, range, and utilization as being among the major considerations for economic operation. Items of interest both in cost of operation and in sales of service are included.

The author finds no immediate limit to the size of airplanes, but does raise the question of crowding when larger numbers of passengers are involved. He also points out that, due to continual improvement, equipment in the future will be more economic.
Whip Stress in a Locomotive Main Rod at 100 Miles per Hour
Authors: Davidson M. W.
Published: February 2023

Older railway motive-power units are being operated at, and new equipment is being designed for, higher speed than has prevailed in the recent past. The paper presents a precise method for the determination of inertia flexural, or whip, stress in locomotive main rods.

One hundred miles per hour is the speed that is chosen for illustrating the method, and for exhibiting the stresses which are developed; since at the present time that seems to be the general operating goal for fast rail traffic. Also, speeds of this order are frequently attained by the main rod and the mechanism in general when locomotives are slipping.

Accurate equations for the inertia forces and couples are obtained for use in determining the inertia reactions and loads. These equations are of universal applicability to all the parts and fractional parts of the mechanism.

The rod bending moments and accompanying stresses were determined through the use of the external wrist-pin reactions in combination with the distributed rod-inertia loading. The moments and stresses were found for six or seven sections along the body of the rod for each of twelve crank positions spaced at 15-deg intervals. Finally the total tensile unit stress is found for each section and crank position, by combining that which is due to whip, with that which results from rod axial-inertia forces and the force of the steam.
Calculation of the Elastic Curve of a Helical Compression Spring
Authors: Keysor H. C.
Published: February 2023

Equations for the elastic curve of a helical compression spring are developed, without making the usual assumption of axial loading. The load is found to be eccentric, in general, being axial only under certain conditions. Elastic curves are given for both axial and eccentric loading. These curves are sinusoidal, showing that deflection along the bar is not linear, as is customarily assumed. A reversed deflection is found to occur in the closed end, back of the tip contact point, which increases the deflection of the spring as a whole, and shows that it is not correct to consider the entire closed end as inactive. An axial load is theoretically possible under certain conditions, but practically axial loading is difficult to obtain and cannot be counted on with any certainty. The effect of load eccentricity on stress is considered, and an approximate formula for estimating this effect is given. Reference is made to laboratory tests by another investigator which are in good agreement with the theory here presented.
Thermostatic Bimetals
Authors: Eskin S. G. , Fritze J. R.
Published: February 2023

The use of thermostatic bimetals has increased rapidly during the last fifteen years. In this period, considerable study has been given the subject. The present paper reviews the available information dealing with the theory and practice in the application of bimetals. A lack of essential data concerning various pertinent properties of the material is indicated. Basic principles are thoroughly considered, as in the analysis of the mechanics by Professor Timoshenko and in the properties of nickel-iron alloys. However, a considerable fund of useful data is also presented in the form of curves and tables which give the properties of representative bimetals.
Automatic Integrating Pressure-Traverse Recorder for Study of Flow Phenomena in Steam-Turbine Nozzles and Buckets
Authors: Kraft H. , Berry T. M.
Published: February 2023

The high efficiency of modern steam turbines can be safely predicted only when the flow phenomena in all passages of the turbine are well understood. The General Electric Company maintains an air-test laboratory where these passages are studied over a wide range of conditions. The principal test is a series of impact-pressure traverses in an air stream simulating flowing steam. The test is a “contour-map survey” of emerging energy, formerly requiring thousands of observations. Recently an instrument has been built which automatically traverses the passage, calculates the corresponding flow and energy quantities, integrates them against the traversed path, and records the integrals in an easily readable manner. The high speed of the instrument increases greatly the range of possible tests. Its inherent accuracy of 0.1 per cent surpasses the best previous performance. The instrument, using mechanical devices for measuring, calculating, and integrating, has all moving parts controlled by electric and photoelectric means.
Permanence of the Physical Properties of Plastics
Authors: Delmonte J.
Published: February 2023

Plastic materials are subject to certain changes in physical properties during their various applications. Particularly significant are the creep and cold-flow phenomena. In the paper a general equation is developed expressing plastic-deformation rate as a function of a coefficient of viscous resistance and of a coefficient of internal resistance. Data for laminated phenolics, polyvinyl chloride acetate, methyl methacrylate, polystyrene, and cellulose acetate are compared. Experimental evidence is presented to show that after a sufficient length of time plastic deformation assumes a constant rate, continuing indefinitely. The dual nature of the molecular structure of plastics is emphasized, in which true elastic deformation may occur, as well as a time-dependent plastic deformation, even at very low stresses. Further data are presented on the shrinkage of various plastics after exposure to elevated temperatures, and the swelling of these materials after exposure to high humidity or water immersion. Loss in impact strength upon exposure to high temperatures is also disclosed for laminated phenolics.
Superheat Control and Steam Purity in High-Pressure Boilers
Authors: Frisch Martin
Published: February 2023

The author discusses the problem of designing a high-pressure boiler to deliver steam at high temperatures. The problem becomes more difficult as the capacity increases since proper selection and maintenance of boiler materials, design of the separate boiler and furnace units, and maintenance of the latter becomes increasingly more difficult if superheat control and steam purity are to be maintained. The author analyzes these design features and points out the compromises necessary to meet varying operating conditions. He discusses superheater design, maintenance of heat-absorbing surfaces, boiler circulation, relation of furnace-exit temperatures to slagging and boiler performance, and safe metal temperatures in water-walls and superheaters.
Field Checks of the Salt-Velocity Method
Authors: Dodkin Oswald H.
Published: February 2023

This paper gives the results of some tests made in Brazil on which verification of the reliability of the salt-velocity method of measuring discharge was obtained by cross checks with the method itself, by check tests with the Gibson pressure-time method, and by volumetric tests. These show a highly satisfactory agreement even in setups where the testing layout was far from ideal.
A Novel Incipient Fault Detection Technique for Roller Bearing Using Deep Independent Component Analysis and Variational Modal Decomposition
Authors: Salunkhe Vishal G. , Desavale R. G. , Khot S. M. , Yelve Nitesh P.
Published: February 2023

Roller bearing failure can result in downtime or the entire outage of rotating machinery. As a result, a timely incipient bearing defect must be diagnosed to ensure optimal process operation. Modern condition monitoring necessitates the use of deep independent component analysis (DICA) to diagnose incipient bearing failure. This paper presents a deep independent component analysis method based on variational modal decomposition (VMD-ICA) to diagnose incipient bearing defect. On a newly established test setup for rotor bearings, fast Fourier techniques are used to extract the vibration responses of bearings that have been artificially damaged using electro-chemical machining. VMD techniques diminish the noise of the measurement data, to decompose data processed into multiple sub-datasets for extracting incipient defect characteristics. The simplicity of the VMD-ICA model enriched the precision of diagnosis correlated to the experimental results with weak fault characteristic signal and noise interference. Moreover, deep VMD-ICA has additionally demonstrated strong performance in comparison to experimental results and is useful for monitoring the condition of industrial machinery.
Spatial and temporal variation of three-dimensional ship noise coherence in a submarine canyon
Authors: DeCourcy Brendan J. , Lin Ying-Tsong
Published: February 2023

Ship noise recorded by a vertical hydrophone array in the Mississippi Canyon region of the Gulf of Mexico is shown to contain the acoustic influence of bathymetric features, seabed properties, and water column sound speeds. Noise coherence is demonstrated to be an effective metric not just for identifying ship traffic in recorded data but also for “fingerprinting” the environment. A three-dimensional acoustics model adopting automatic identification system ship track information and realistic oceanographic conditions is used to compute noise coherence distributions across the canyon area and enables numerical study of the water column sound speed effects that can lead to temporal changes in noise coherence. The study shows the importance of including in situ sound speed measurements or constraints in passive ship noise localization from coherence measurements. Seasonal variability is also examined with models suggesting a strong influence of seasonal changes.
Critical workforce skills for bachelor-level geoscientists: An analysis of geoscience job advertisements
Authors: Shafer G.W. , Viskupic K. , Egger A.E.
Published: February 2023

Understanding the skills bachelor-level geoscientists need to enter the workforce is critical to their success. The goal of this study was to identify the workforce skills that are most requested from a broad range of geoscience employers. We collected 3668 job advertisements for bachelor-level geoscientists and used a case-insensitive, code-matching function in Matlab to determine the skills geoscience employers seek. Written communication (67%), field skills (63%), planning (53%), and driving (51%) were most frequently requested. Field skills and data collection were frequently found together in the ads. Written communication skills were common regardless of occupation. Quantitative skills were requested less frequently (23%) but were usually mentioned several times in the ads that did request them, signaling their importance for certain jobs. Some geoscience-specific skills were rarely found, such as temporal understanding (5%) and systems thinking (0%). We also subdivided field skills into individual tasks and ranked them by employer demand. Site assessments and evaluations, unspecified field tasks, and monitoring were the most frequently requested field skills. This study presents the geoscience community with a picture of the skills sought by employers of bachelor-level geoscientists and provides departments and programs with data they can use to assess their curricula for workforce preparation.
Two new species of miniature tetras of the fish genus Priocharax from the Rio Juruá drainage, Acre, Brazil (Teleostei: Characiformes: Characidae)
Authors: Mattox George M.T. , Britz Ralf , Souza Camila S. , Casas André L.S. , Lima Flávio C.T. , Oliveira Claudio
Published: February 2023

Two new miniature tetra species of the Neotropical characid genus Priocharax Weitzman and Vari, 1987 are described, raising the known species diversity to seven. Both species occur in the Rio Juruá system, Cruzeiro do Sul municipality, Acre State, Brazil. Priocharax toledopizae sp. nov. occurs in streams flowing to the lower Rio Moa, a tributary of Rio Juruá, and is distinguished from congeners by a combination of presence of claustrum and infraorbitals 1 and 2, absence of infraorbital 3, and presence of five branched pelvic-fin rays. Priocharax marupiara sp. nov. is known from Igarapé Canela Fina, tributary of Rio Juruá, and is diagnosed by a combination of fewer maxillary teeth (21–27 vs. 27–58 in remaining species), fewer branched anal-fin rays (18–23 vs. 22–27 in two species) and colour pattern. Both species differ from each other in the general body shape: Priocharax toledopizae is more robust with deep body and Priocharax marupiara more elongate. DNA barcode data support the specific distinctness of the two new species and that of the other five species in the genus. We describe a remarkable sexual dimorphism of the pelvic girdle of Priocharax toledopizae in which the pelvic musculature is enlarged forming a pedicel for the fin in mature males. Most localities where these species were found suffer from significant degradation mainly due to litter accumulation and suppression of the riparian forest, raising concerns about their conservation status.
Dynamics of interacting scalar field model in the realm of chiral cosmology
Authors: Patil Trupti , Panda Sukanta , Sharma Manabendra , Ruchika
Published: February 2023

The strange behaviour of the universe’s dark sector offers us the flexibility to address cosmological problems with different approaches. Using this flexibility, we consider a possible exchange of energy among the dark sector components as a viable candidate model. In the present work, we investigate the interaction between two scalar fields within the generalization of a two-component chiral cosmology. We also show that there exists a unique equivalence between fields and fluids description of interacting dark sector model. Later, a detailed analysis of the dynamics of the dark energy-dark matter model with coupling in both kinetic and potential parts has been performed using a method of qualitative analysis of dynamical systems. Moreover, the cosmological viability of this model is analyzed for the potential of an exponential form via the phase-space study of autonomous system for various cosmological parameters.
Exploring dark $$Z_d$$-boson in future large hadron-electron collider
Authors: Goyal Ashok , Kumar Mukesh , Kumar Satendra , Rahaman Rafiqul
Published: February 2023

The interaction between the dark $$U(1)_d$$

U

(
1
)

d

sector with the visible Standard Model (SM) sector takes place through the kinetic mixing between the dark photon $$U(1)_d$$

U

(
1
)

d

field $$Z_d^\mu $$

Z
d
μ

and the SM $$U(1)_Y$$

U

(
1
)

Y

gauge field $$B_\mu $$

B
μ

. After the electroweak and $$U(1)_d$$

U

(
1
)

d

symmetry breaking, the dark photon $$Z_d^\mu $$

Z
d
μ

acquires a mass and mixes with the SM neutral vector boson $$Z_\mu $$

Z
μ

. This mixing leads to parity-violating coupling between the $$Z_d^\mu $$

Z
d
μ

and SM. The coupling between the dark photon and SM can be explored in low energy phenomenology as well as in collider experiments. The Lorentz structure of dark photon interaction with SM fermions is explored in the proposed high energy future Large Hadron-electron collider, which would provide efficient energy and a clean environment using cross-section and asymmetries associated with polarisation observable of the dark photon in leptons decay. A $$\chi ^2$$

χ
2

-analysis is performed to compare the strength of various variables for both the charge- and neutral-current processes. Based on this analysis, $$90\%$$

90
%

confidence level (C.L.) contours in the $$\varepsilon $$
ε
-$$m_{Z_d}$$

m

Z
d

and $$\varepsilon $$
ε
-$$g_V$$

g
V

plane are obtained to put limits on the $$Z_d^\mu $$

Z
d
μ

mass up to 100 GeV, coupling strength $$\varepsilon $$
ε
and on the Lorentz structure of dark photon coupling with the SM fermions ($$g_V$$

g
V

) at $$\sqrt{s} \approx 1.3$$

s

≈
1.3

 TeV.
Cosmological analogies for geophysical flows, Lagrangians, and new analogue gravity systems
Authors: Faraoni Valerio , Jose Sonia
Published: February 2023

Formal analogies between the ordinary differential equations describing geophysical flows and Friedmann cosmology are developed. As a result, one obtains Lagrangian and Hamiltonian formulations of these equations, while laboratory experiments aimed at testing geophysical flows are shown to constitute analogue gravity systems for cosmology.
Aspects of supergroup gauge theory
Authors: Kimura Taro
Published: February 2023

In this paper, provide a survey of recent studies of supergroup gauge theory. We first discuss the supermatrix model as a zero-dimensional toy model of supergroup gauge theory and its geometric and algebraic characterization. We then focus on four-dimensional Yang–Mills theory with supergroup gauge symmetry and explore its nonperturbative properties, including instanton calculus, Seiberg–Witten geometry, Bethe/gauge correspondence, and its realization with intersecting defects.
Double stratification impact on radiative MHD flow of nanofluid toward a stretchable cylinder under thermophoresis and brownian motion with multiple slip
Authors: Majeed Aaqib , Zeeshan Ahmad , Jawad Muhammad
Published: February 2023

In this paper, numerical investigations have been performed on intricate double stratification impact with a radiative mixed convective nanofluid over a cylinder. Double stratifications comprise heat transfer used in many practical applications like power station engineering, ground-water reservoirs, thermal stratification of reservoirs, and rivers, density stratification of atmosphere, oceans, different heterogeneous mixtures, and manufacturing processing. Characteristics of heat and mass transfer have also been considered. The developing mathematical expression for momentum, energy transportation, and nano-concentration involving Brownian motion and thermophoresis inspiration are considered. The modeled equations are formulated into ordinary differential equations by applying a suitable similarity approach, which is then tackled numerically via MATLAB. Graphical illustrations of dimensionless velocity, energy, and volumetric concentration distribution are drawn against a few values of appropriate parameters. Results elucidate that enhancement occurs in the concentration profile, whereas decrement is noted for the temperature field for different values of thermophoresis and thermal stratification parameters. Our results elucidate good agreement as compared with the previously published one. The higher value of Hartmann number indicates a higher coefficient of friction.
QBGA–SVM for Face Recognition of Livable Cities
Authors: Li Qizhen , Ouyang Aijia , Peng Xuyu , Hu Xijun
Published: February 2023

With the continuous expansion of urbanization, the problem of human settlements has become increasingly prominent. Green, economical, intelligent and livable cities have become the urgent needs of future urban planning. The evaluation of urban livability is not only one of the judgment criteria of urban competitiveness, but also an important factor affecting the speed of urban development. Among them, the safety factor of the city is the important guarantee of other aspects, so this paper intends to design a high-precision face recognition algorithm to make efforts for the safety construction of livable cities. Aiming at the shortcomings of the standard support vector machine (SVM), combined with the quantum-behaved mechanism, a quantum-behaved genetic algorithm–SVM (QBGA–SVM) is proposed in the paper. The experimental results for the human face databases show that QBGA–SVM is superior to the comparison algorithms in both accuracy and stability. Finally, QBGA–SVM is applied to face images of the real world, and the results are better than the other algorithms.
A Shifted Logistic Map
Authors: Buscarino Arturo , Fortuna Luigi
Published: February 2023

In this paper, the peculiarities of a quadratic map are investigated, unveiling the hidden relationship with the classical logistic map. Moreover, the improvements in generating odd-periodic oscillations and the related intermittent behavior using the shifted logistic formulation are shown from an experimental point of view.
Chaotic Dynamics Arising from Sliding Heteroclinic Cycles in 3D Filippov Systems
Authors: Yang Qigui , Huang Yousu
Published: February 2023

Filippov systems are a representative class of piecewise smooth dynamical systems with sliding motion. It is known that such systems can exhibit complex dynamics, but how they generate chaos remains to be further studied. This paper establishes three Shilnikov-type heteroclinic theorems for 3-dimensional (3D) Filippov systems divided by a smooth surface, which admit heteroclinic cycles sliding on the switching surface. These theorems correspond to two typical scenarios of sliding heteroclinic cycles: (i) connecting two saddle-foci; (ii) connecting one saddle and one saddle-focus. In the presence of a sliding heteroclinic cycle, the corresponding Filippov system can be analytically proved to have a chaotic invariant set nearby the singular cycle under some assumed conditions. These results provide a reasonable explanation for the chaotic behaviors of 3D Filippov systems. Two numerical examples are presented to validate the theorems.
Stability and Bifurcation Analysis of a Beddington–DeAngelis Prey–Predator Model with Fear Effect, Prey Refuge and Harvesting
Authors: Wang Jiao-Guo , Meng Xin-You , Lv Long , Li Jie
Published: February 2023

In this paper, a Beddington–DeAngelis prey–predator model with fear effect, refuge and harvesting is investigated. First, the positivity of solutions and boundedness of system are given. Then, the existence and local stability of equilibria of such system are obtained. Next, not only different codimension-one bifurcations, such as saddle-node bifurcation, transcritical bifurcation and Hopf bifurcation take place, but also Bogdanov–Takens bifurcation of codimension-two occurs as predicted by the center manifold theorem and bifurcation theory. Finally, some numerical simulations are carried out to confirm our theoretical results.
Aligning Software Architecture Training with Software Industry Requirements
Authors: Yepez Wilson Libardo Pantoja , Alegria Julio Ariel Hurtado , Kiweleker Arvind
Published: February 2023

The activities of software design, documenting, and evaluating the structure of software systems, referred to as Software Architecture, have been increasingly getting significant attention in industries. This situation is because of the explicit and prominent role assigned to quality attributes while developing software systems. By considering the high relevance of Software Architecture to industry, many academic institutes have introduced a course on Software Architecture as a part of undergraduate programs in Software Engineering. However, teachers offering this course face numerous challenges. Some of these challenges stem from how software architecture is practised in industries and others from teaching them in an academic setting. This paper describes an experience of designing a software architecture course that aligns the competencies expected from professional software architects with teaching practices imparting those competencies. Such an alignment is necessary to improve the employability of graduate students, make their progression from academic institutes to industries an effortless one, and for better learning outcomes. In the absence of such alignment, fresh graduates need to re-train, leading to training costs and delayed recruitment of fresh graduates by their prospective employers. The experience reports recurring challenges observed by earlier researchers, strategies to address them and our experience in implementing those strategies. The teaching strategies suggested are potentially helpful and practical, especially to less-experienced instructors teaching a course on Software Architecture.
Cable knots obtained by positively twisting torus knots
Authors: Lee Sangyop
Published: February 2023

The twisted torus knot [Formula: see text] is a knot obtained from the torus knot [Formula: see text] by twisting [Formula: see text] adjacent stands fully [Formula: see text] times. If [Formula: see text] or [Formula: see text] is a multiple of [Formula: see text], then [Formula: see text] is known to be a cable of a nontrivial knot or a torus knot. Assuming that [Formula: see text] and [Formula: see text] is not a multiple of [Formula: see text], we determine the parameters [Formula: see text] for which the positively twisted torus knot [Formula: see text] is a cable knot.
On de Sitter spacetime and string theory
Authors: Berglund Per , Hübsch Tristan , Minic Djordje
Published: February 2023

We review various aspects of de Sitter spacetime in string theory: its status as an Effective Field Theory spacetime solution, its relation to the vacuum energy problem in string theory, its (global) holographic definition in terms of two entangled and noncanonical conformal field theories as well as a realization of a realistic de Sitter universe endowed with the observed visible matter and the necessary dark sector in order to reproduce the realistic cosmological structure. In particular, based on the new insight regarding the cosmological constant problem in string theory, we argue that in a doubled, [Formula: see text]-duality-symmetric, phase-space-like and noncommutative generalized-geometric formulation, string theory can naturally lead to a small and positive cosmological constant that is radiatively stable and technically natural. Such a formulation is fundamentally based on a quantum spacetime, but in an effective spacetime description of this general formulation of string theory, the curvature of the dual spacetime is the cosmological constant of the observed spacetime, while the size of the dual spacetime is the gravitational constant of the same observed spacetime. Also, the three scales associated with intrinsic noncommutativity of string theory, the cosmological constant scale, the Planck scale as well as the Higgs scale, can be arranged to satisfy various seesaw-like formulae. Along the way, we show that these new features of string theory can be implemented in a particular deformation of cosmic-string-like models.
Hindman’s theorem in the hierarchy of choice principles
Authors: Fernández-Bretón David
Published: February 2023

In the context of [Formula: see text], we analyze a version of Hindman’s finite unions theorem on infinite sets, which normally requires the Axiom of Choice to be proved. We establish the implication relations between this statement and various classical weak choice principles, thus precisely locating the strength of the statement as a weak form of the [Formula: see text].
Review of "Vibrant Matter: A Political Ecology of Things by Jane Bennett," Bennett, J. (2010).
Vibrant Matter: A Political Ecology of Things.
Duke University Press.
Authors: Mathis Wesley
Published: February 2023

In
Vibrant Matter: A Political Ecology of Things
(2010), Jane Bennett encourages her readers to slow down the internal thoughts of human superiority over "intrinsically inanimate matter" --- thoughts that prevent them from "detecting...a fuller range of the nonhuman powers circulating around and within human bodies" and their political systems (p. ix). Some readers of CDQ may wonder why a book from 2010 is worth our attention in 2022. The COVID-19 pandemic, the U.S. Supreme Court's ruling on women's reproductive autonomy, and the restrictions placed on the EPA's control over carbon emissions all suggest a clear resurgence of what Bennett calls the oft-repeated "vitalism-materialism debate" (p. 90)---the debate over how far affect, agency, animacy, and vitality extend. Bennett resolves the tensions of that debate by fusing traditional ideas of mechanistic materialism with the notions of an unknowable agency in all matter (not just humans), an agency that lacks representation in current political thought. If technical communicators and designers dedicated to crisis/risk communication as well as those studying and producing political technologies (Cheek, 2021, 2022) didn't see the application of Bennett's "vital materialism" at the end of the Bush era's heated debates over stem cell research and the war in Iraq as well as the North American power blackout of 2003, then perhaps, given the current political climate, I can persuade them to find merit in revisiting Bennett's arguments.
Reactivity of renal and mesenteric resistance vessels to angiotensin II is mediated by NOXA1/NOX1 and superoxide signaling
Authors: Stevenson Mark D. , Vendrov Aleksandr E. , Yang Xi , Chen Yuenmu , Navarro Hernán A. , Moss Nicholas , Runge Marschall S. , Arendshorst William J. , Madamanchi Nageswara R.
Published: February 2023

Renal reactivity to angiotensin II (ANG II) is mediated by superoxide signaling produced by NADPH oxidase (NOX)A1/NOX1. Acute vasoconstriction of renal arteries by ANG was blunted in Noxa1−/− compared with wild-type mice. NOXA1/NOX1/O2•− signaling was also observed in ANG II stimulation of vascular smooth muscle cells and isolated mesenteric resistance arteries, indicating that it contributes to ANG II-induced hypertension. A NOXA1/NOX1 assembly inhibitor (C25) has been characterized that inhibits superoxide production and ameliorates the effects of ANG II.
Medicinal Plants for Viral Respiratory Diseases: A Systematic Review on Persian Medicine
Authors: Hajimonfarednejad Mahdie , Ostovar Mohadeseh , Hasheminasab Fatemeh Sadat , Shariati Mohammad Ali , Thiruvengadam Muthu , Raee Mohammad Javad , Hashempur Mohammad Hashem
Published: February 2023

Introduction. Many medicinal plants have been introduced in Persian medicine references for various respiratory disorders. Considering the growing interest in herbal medicines, this review aimed to introduce medicinal herbs recommended by Persian Medicine (PM) references for respiratory diseases and to discuss their activity against respiratory viruses. Methods. The medicinal plants recommended for respiratory disorders were extracted from the main PM textbooks. Subsequently, their activity against respiratory viruses was systematically investigated via queries of scientific databases. Results. Searching PM references for medicinal plants used in the management of respiratory disorders yielded 45 results. Of them, 18 possess antiviral activity against respiratory viruses. There were 29 in vitro studies (including studies on human cell lines) and 5 in vivo studies. Conclusion. This research demonstrated that many of the medicinal plants mentioned for the respiratory diseases in PM have considerable activity against respiratory viruses. However, human studies regarding the reported medicinal plants are scarce.
Point Cloud Registration Methods for Long-Span Bridge Spatial Deformation Monitoring Using Terrestrial Laser Scanning
Authors: Zhang Hongwei , Zhu Yanjie , Xiong Wen , Cai C. S.
Published: February 2023

In recent years, efforts have been devoted to utilizing terrestrial laser scanning for bridge spatial performance inspection, but they are still restricted to small or medium-span bridges, like some historical heritages. Due to the large-scale dimensional features of long-span bridges, applications of 3D point cloud techniques still remain challenging, such as the extra-long scan range and extreme-small incidence angle when scanning a bridge with a span over 1000 m. Moreover, rare attempts can be found for the performance evaluation of point cloud registration methods for long-span bridges as well, which is a critical basis for further spatial deformation recognition on the point cloud data. Hence, in this study, a cross-evaluation of three iterative closest point (ICP) registration methods is conducted for long-span suspension bridges, namely, traditional ICP, kd-tree-based ICP, and feature point-based ICP algorithms. We conducted field laser scanning on the Ma’anshan Yangtze Bridge, an 1880 m long suspension bridge located in China. The results show that the feature point-based ICP algorithm outperforms the other two in terms of convergence rate and execution time for a single iteration due to the smaller number of registration points compared to the other two algorithms. Moreover, it also gives more precise values in terms of bridge tower spatial deformation identification. Meanwhile, due to efficient data organization, the kd-tree-based ICP algorithm takes less time for a single iteration than the traditional ICP algorithm. Finally, two suggestions for algorithm improvement in terms of efficiency optimization and accuracy improvement of long-span bridge deformation analysis are proposed based on the assessment results.
Experimental Estimation of Energy Absorbed and Impact Strength of Kevlar/Basalt-Epoxy Interwoven Composite Laminate Added with Al2O3 Nanoparticles after High-Velocity Bullet Impact
Authors: Jensin Joshua J. , Singh Dalbir , Venkatanarayanan P. S. , Snehit Ch. Sai , Bipin Sai Eswar A. , Desta Melaku
Published: February 2023

The use of composites has increased exponentially in most industries, especially in the aerospace industry; the usage of composites has increased by almost 40% in the last 15 years. Aerospace components are often subject to high-impact loads, so it is important to use impact-resistant materials. Kevlar is known for its high-impact resistance and is commonly used as a fiber with various resins to achieve the desired properties. This paper mainly focuses on weaving Kevlar with basalt fiber in plain weave type by the traditional handloom weaving method. The epoxy resin, along with the harder, is then mixed with the aluminum oxide nanoparticles (Al2O3) in different percentages [1%-KB1, 3%-KB2, and 5%-KB3] to form the matrix. The laminate fabricated is then subjected to the high-velocity bullet impact of around 250 m/s. A steel hemispherical head projectile was used in the testing, and it was found to be penetrated through all the specimens making holes. The impact strength for all the different specimens was then estimated by calculating the bullet damage area and energy absorbed. The plate added with 3% Al2O3 nanoparticle was found to have improved impact strength when compared with the other two specimens. This plate can be used for bulletproof and other high-velocity impact applications.
Magnetic Resonance Diffusion-Weighted Imaging to Evaluate the Clinical Efficacy of CalliSpheres Drug-Loaded Microspheres in the Treatment of Advanced Bladder Cancer
Authors: Yang Xi , Chen Wei
Published: February 2023

The MR diffusion-weighted imaging technique was used to evaluate the efficacy and safety of CalliSpheres drug-loaded microspheres for transarterial chemoembolization in the treatment of advanced bladder cancer. 35 patients with advanced bladder cancer were treated with CalliSpheres DLMS for transarterial chemoembolization. Imaging techniques such as magnetic resonance (MR) diffusion-weighted imaging were used to evaluate the therapeutic effect. The changes in serum tumor markers, immune function indexes, and oxidative stress indexes in patients before and after treatment were compared, and the quality of life of patients and the incidence of adverse reactions during follow-up were also evaluated. The results showed that the overall response rate (ORR) was 74.29% and that the disease control rate (DCR) was 97.14%. Compared with that before treatment, the ADC value of the tumor in patients with advanced bladder cancer detected by MR diffusion-weighted imaging technology was significantly increased after treatment and the maximum tumor diameter was significantly decreased

P
<
0.05

. Compared with those before treatment, the levels of serum tumor markers (CA199, CA724, and CA125) in advanced bladder cancer patients after treatment decreased

P
<
0.05

. The levels of T-lymphocyte subsets (CD3+ and CD4+) decreased, and CD8+ levels increased

P
<
0.05

. The levels of superoxide dismutase decreased

P
>
0.05

. At the same time, the subscale evaluation of function, symptoms, quality of life, adverse reactions, and economics of patients with advanced bladder cancer on the QLQ-C30 scale improved after treatment, and the incidence rate and recurrence rate during the follow-up period were 8.57% and 11.43%, respectively. It showed that CalliSpheres DLMS had a good clinical effect and high safety in the treatment of advanced bladder cancer and was a safe and feasible treatment method. The use of MR diffusion-weighted imaging technology could achieve quantitative evaluation of clinical efficacy of advanced bladder cancer.