bluuebunny/crossref_metadata_2025 huggingface dataset:
Nozzle Coefficients for Free and Submerged Discharge
Authors: Folsom R. G.
Published: February 2023

This paper presents in brief form a summary of investigations made at the hydraulic laboratory of the University of California, in cooperation with the A.S.M.E. Special Research Committee on Fluid Meters, to determine nozzle coefficients for free and submerged discharge. A description of test facilities and procedure is included. The results given concern a series of A.S.M.E. long-radius nozzles for 3-in., 4-in., and 8-in. pipes tested with pipes of different wall roughness, various upstream piping arrangements, and different pressure-tap locations. Some data on I.S.A. nozzles which have been manufactured at the University shops are added.
Organization—Design for Modern Business
Authors: Raymond Fairfield E.
Published: February 2023

Questions of organization for large-scale enterprise are of increasing importance, since existing concepts applicable to single-unit organizations are becoming noticeably inadequate. More dynamic concepts appear to be necessary to comprehend those particular activities essential to a business and to provide adequate channels of coordination in an effort to humanize management. For each degree of specialization, in ascending from the smallest to the largest size of business, the direct channels of coordination following the lines of authority need to be supplemented by appropriate channels to make mutuality of interest effective. Decentralization, in contrast to centralized authority, may not only facilitate leadership, but also provide a means by broadening the organization structure to draw administrator and worker closer together, materially enhancing their unity of purpose. Recent developments point not only to an increasing functionalization of administration, but also to the reversal of the long-accepted pyramidal structure of management where the work group becomes the unit of management and the superstructure of organization must be justified on the service it renders these units. With increasing frequency the lack of constructive research in the field of organization has been remarked upon. In these times when the effectiveness of large-scale business is being challenged, is it not appropriate to seek for more comprehensive and possibly dynamic concepts of organization?
Pulsating Air Velocity Measurement
Authors: Bailey Neil P.
Published: February 2023

This paper includes an analysis of the weaknesses of three methods of air velocity measurement, that is, (1) the hot-wire anemometer, (2) the Thomas or Callandar meter, and (3) nozzles, orifices, or pitot tubes used with liquid manometers, and the author points out that these methods give unreliable results when the air flow is pulsating. After analyzing the influence of plenum chambers he then describes a modified proportional flowmeter in which the pressure change of a nozzle, orifice, or pitot tube produces an air velocity through a small orifice which is always proportional to the instantaneous velocity of the main air flow; therefore, by measuring volumetrically the air that passes through the small orifice, the average velocity of the main air flow can be determined. Included in the paper are test results obtained with this meter on a 3¼ × 4½-in. single-cylinder C.F.R. internal-combustion engine.
Changes in a High-Pressure Drum to Eliminate Recurrence of Cracks Due to Corrosion Fatigue
Authors: White Albert E.
Published: February 2023

This paper gives the results of an investigation which was undertaken for the purpose of determining the cause of the cracks found in the No. 5 boiler at the Edgar Station of the Boston Edison Company. It also discusses the cause of the cracks found in the water columns and in certain of the superheater fittings and headers of this same boiler. The boiler in question is one of the first high-pressure units installed in this country and, therefore, it was quite essential that the cause of the cracks be determined and suitable steps be taken to prevent their recurrence. The study sets forth the changes which were made.

As a result of the investigation it was not felt that any of the difficulty could be attributed to faulty metal. The material was of the proper chemical composition and had suitable physical properties.

The primary cause of the cracks was believed due to corrosion fatigue resulting from stresses set up by changes in temperature on the surface of the metal in combination of a relatively low pH value of the water which was at times in contact with the metal that developed cracks.

As a result of the removal of the cracked metal and the changes in design which would prevent fluctuating temperatures on the surface of the drum at the boiler feedwater inlet, as well as other design changes which would raise the pH value, particularly in the water columns, it is not anticipated that further cracking will take place.
The Resistance to Relaxation of Materials at High Temperature
Authors: Robinson Ernest L.
Published: February 2023

Relaxation tests at high temperature give direct information on the permanent tightness of bolted joints and shrinkage assemblies. They also give direct measurements of the effectiveness of strain-relief anneals. Indirectly they give, in relatively short time and small furnace space, reliable information on long-time constant-stress behavior although direct computation of either type of performance from the other is uncertain. In relaxation tests, total strain is definitely limited, whereas, creep rates based on constant-stress tests may, but do not necessarily, correspond to excessive amounts of strain, thus giving too optimistic indications of strength. Although advantageous, relaxation tests do not take the place of constant-stress tests. A simple formulation for relaxation is given which holds good for considerable periods although rather sudden changes of trend suggest the possibility of physical changes in the material which are not easily predictable in advance. Test results are given on six materials at various temperatures.
Modern Boiler Furnaces
Authors: Bailey E. G.
Published: February 2023

The paper considers the fusing temperatures of various kinds of coal ash and slag, and their significance with respect to furnace temperatures, operation, and design.

A method of comparing furnace operating results is suggested consisting of (1) taking accurate gas temperatures throughout a furnace, (2) then calculating from them the rates of heat absorption in different zones, (3) calculating an “equivalent heat-receiving-surface temperature” for each zone, (4) taking samples of ash and slag from different portions of the furnace and determining the fusing-temperature range from such samples, (5) plotting these data as a “gas-ash temperature graph” against heat-absorbing surface, (6) comparing the data as shown on such graph with observed behavior of ash and slag in the furnace, and (7) comparing different furnaces, different coals, and methods of operation through the use of such graphs. Examples of the use of the method are given.

There is also included a comparison of methods for measuring furnace temperatures. Colored motion pictures illustrating some phenomena relating to slag in furnaces were shown at the time of presentation of the paper.
Studies in Boundary Lubrication: Variables Influencing the Coefficient of Static Friction Between Clean and Lubricated Metal Surfaces
Authors: Campbell W. E.
Published: February 2023

A thorough survey has been made of the literature on static-friction measurement. It is shown that there are large discrepancies among the results of different investigators and it is concluded that the differences are largely due to lack of control of experimental technique. A complete bibliography is presented.

An experimental study of several of the more important variables influencing static friction is described. The variables studied are the effect of load, vibration, and cleanliness of the surfaces. An inclined-plane and a horizontal-plate apparatus are used. It is concluded that the method of cleaning the surfaces is the factor which has the greatest influence upon the results and it is shown that invisible films which may be deposited upon the surfaces during the cleaning process can exert large effects upon static-friction measurements.

A method of cleaning is described which involves polishing the surfaces with moist abrasive. This method yields high and reproducible values for static friction between unlubricated surfaces. It is shown that sulphide and oxide films on steel, copper, and brass produce a lowering in static friction and that the amount of lowering depends upon the thickness of the film.

A comparison is made between the static and the kinetic values obtained on several bearing metals lubricated with typical oils. It is shown that the static values are in general considerably higher than the kinetic values, and it is concluded that the differences which are observed are due in large part to viscosity effects in the kinetic measurements.

An analysis of static-friction measurements on typical lubricating oils leads to the conclusion that moisture and corrosion effects are responsible for many of the phenomena observed. It is concluded that static-friction measurements do not lend themselves to routine testing of oils, but that they can be used to considerable advantage for studying single variables influencing boundary lubrication.
By-Product Fuels in the Steel Industry
Authors: Fox E. G. , Clemmitt W. B.
Published: February 2023

A normal annual supply of by-product gases, having a heat content equivalent to about 32,000,000 tons of coal, results from the production of metallurgical coke and from the smelting of pig iron. This paper deals comprehensively with the uses within the steel industry of coke-oven gas, blast-furnace gas, and mixtures of the two gases, which constitute the by-product fuels. After outlining the characteristics and combustion properties of each, the authors give in some detail their applications to the various heating requirements of steel production. The process of mixing the two gases to obtain the maximum heat value is explained thoroughly. The fact is stressed that by-product fuels be utilized in processes where the greatest economic value will result. The method of arriving at the potential values of these gases in relation to that of tar, fuel oil, and coal is fully expounded, several examples of cost analyses being cited to illustrate the procedure.
Power and Steam Plants for Oil-Refinery Service
Authors: Steinbeck C. E.
Published: February 2023

This paper describes the general layout of the oil-company power plants, the various major items which will be used in their design, and the economy of the arrangement for both the Pacific Gas and Electric Company and the oil refineries.
The Flow of Water in Channels Under Steep Gradients
Authors: Durand W. F.
Published: February 2023

In the case of water flowing down a steep slope with the upper surface exposed to the air, the usual conditions and equations for hydraulic flow under moderate velocities no longer apply. The changed conditions involve greatly increased velocities, insufflation by air, a surface in contact with the air, uneven, foamy and rolling, with consequent air resistance as an important factor in the problem.

The questions of interest involve the history of the water from its start at a zero or moderate velocity at the top of the slope until it reaches the bottom, or until a limit velocity is reached where the resistance to flow equals the acceleration, and measurably steady conditions continue. Specifically, the questions of chief interest are: With given conditions at the top of the slope, what velocity will be acquired after a given length of run or after a given period of time? The present paper gives a mathematical stepwise solution of these problems, depending on a knowledge of the initial conditions and a known or assumed value of a coefficient β, relating the resistance to flow at a given point in the run or at a given instant of time, to the square of the velocity. Values of the coefficient β await the results of observation on actual cases of such flow. With representative sets of such values, an attempt at generalization could be made. A further important question relates to the details of the way in which the air enters a stream of rapidly flowing water, thus producing the insufflation which is so important a factor in the problem.
An Improved System in the Application of Noncondensing or Extraction Turbines
Authors: Cross H. W. , Wells E. S.
Published: February 2023

The purpose of this paper is to demonstrate methods by which the electrical output of noncondensing or extraction turbines may be increased. The electrical output is definitely established by the energy drop between initial and exhaust conditions and by the quantity of steam flow. By increasing the total steam temperature at the throttle for a given pressure, the available energy is increased and consequently the electrical output. The application of a combined desuperheater and feedwater heater at the exhaust is shown to be advantageous in realizing gains from the use of higher-temperature steam. Examples demonstrating the possibilities inherent in such systems are illustrated and explained.
Some Problems in the Design and Operation of Merchant Vessels
Authors: Lee Robert C.
Published: February 2023

This paper presents certain technical aspects of ship design and operation as viewed from the standpoint of the executive administration of the merchant marine. The author evaluates the recent developments in hull and machinery design and construction in terms of economics. From the records of the Scantic Line and the American Republics Line, operating-cost figures are cited to demonstrate the relation of the various factors involved in ship operation. A review of shipbuilding costs and sales values of ships is included. Among other important matters discussed in the paper are safety provisions, crew training and personnel relations, and finally mention is made of the need for better and more efficient methods of cargo handling. The problems are proposed without solutions being available for many of them, in the hope that subsequent discussion may develop answers.
Where Does Interpretation Begin?—Analysis of the Oil-Engine Power Cost Report
Authors: Schweitzer P. H.
Published: February 2023

This paper is an analysis of fuel-oil and lubricating-oil economy based on the 1937 A.S.M.E. Oil-Engine Power Cost Report. Both analyses are divided into two sections, the factual and the interpretative parts. The nature of the factual analysis does not permit drawing any conclusion beyond the one that, in making more judicious use of graphical representations, the usefulness of the Cost Report can be greatly increased. Conclusions from the interpretative analysis are as follows:

1 Engine load has a great effect on both fuel- and lubricating-oil economy.

2 Engine type has a great effect on lubricating-oil economy and a small effect on fuel-oil economy.

3 Year of manufacture has a great effect on both fuel- and lubricating-oil economy.

4 In both cases the improvement is wholly due to advance in design and construction.

5 Engine size has practically no effect on either fuel- or lubricating-oil economy.

6 Engine speed has practically no effect on either fuel- or lubricating-oil economy.

7 Fuel gravity has practically no effect on fuel economy.

8 Other factors may have some small effect on fuel- and lubricating-oil economy but they have not been sufficiently investigated.
Generator Characteristics as Affecting System Operation
Authors: Wright Sherwin H.
Published: February 2023

In an interconnected power system the frequency regulation and tie-line power swings are influenced by the electrical characteristics of all electric equipment connected to the system, including generators, lines, and miscellaneous motors, as well as by the mechanical characteristics of all rotating apparatus. In this paper the interrelated action of these factors is visualized by means of the mechanical analogy developed in connection with power-system stability, and this is augmented by a discussion of angular displacement with load and kinetic-energy values for typical machines, generator reactance, and short-circuit ratio.
Steam-Turbine Governors
Authors: Caughey Reed J.
Published: February 2023

This paper has been prepared as a contribution to a symposium on the subject of steam-turbine governors. The importance of the subject at present arises more from the increasing complexity of interconnection requirements than from any definite deficiency in existing apparatus. Attempts have recently been made to draft specifications for governing equipment that might be applicable both to steam and hydraulic prime movers. The purpose of this paper is to state briefly the essential characteristics, functions, and behavior of governing apparatus both for condensing and superposed turbines. Definitions are suggested for terms and phrases frequently used without definite significance. In conclusion the essential points of a brief specification are outlined for the purpose of discussion.
The Field of System Governing
Authors: Davis Albion
Published: February 2023

The field of system governing lies between the problems of pulsating loads and electrical stability on the one hand and frequency or time control on the other. It is concerned with the short period swings or hunting action for which poor governors are usually responsible. With proper instruments, poor governor units may be detected readily and corrections made. Sensitive governors may be substituted for them. The paper discusses some of the elements of governing from the standpoint of the system operator and suggests certain essential requirements which new governors should meet.
Regulation of System Load and Frequency
Authors: Estrada Herbert , Dryar H. A.
Published: February 2023

This paper discusses the practices of the Philadelphia Electric Company system in the regulation of system load and frequency, including the scheduling and actual operation of generating capacity with regard to reliability and economy. A summary of the principles of economical load allocations on both steam and hydrogenerating stations is presented. The effect of changes in system load or generation on frequency, the self-regulation characteristic of the system, and the combined system governor action are discussed from the standpoint of the individual and the interconnected group of systems. The practices of the interconnection, of which the Philadelphia Electric Company is a member, in manually regulating the frequency and the incident problems thereto are considered. A discussion of governor instantaneous and average speed regulation, sensitivity, and response is given, with particular reference to their effect on frequency regulation.
The Influence of Crystal Size on the Wear Properties of a High-Lead Bearing Metal
Authors: Connelly John R.
Published: February 2023

This paper, describes work done to correlate metallurgical aspects of a bearing metal with mechanical testing under conditions existing in a bearing. Previous work by Karelitz and Kenyon (1), and by the author (2) and (3) have concerned effects of different composition of bearing metal and different loading and size of specimen. The present investigation was made to determine the effect on removal of the bearing-metal surface and the pressure at which the oil film breaks down as a result of variations in the crystalline structure of the bearing metal. In this work both the chemical composition of the bearing metal and the size of the specimen were constant. The crystalline structure was varied and the resulting change in properties determined.
Cavitation of Hydraulic-Turbine Runners
Authors: Sharp R. E. B.
Published: February 2023

This paper contains a brief analytical discussion of runner cavitation. The I. P. Morris cavitation equipment is described, and results with this apparatus are compared with those of the Holtwood laboratory. A calibration gage in the development stage is also described. Stroboscopic apparatus for photographing runners during operation under cavitating conditions is illustrated, and various photographs above and below the sigma break are reproduced and discussed. A comparison of the index test of a prototype with a model at the same value of sigma is submitted.
The Engineering Method in Management
Authors: Peterson Andrew I.
Published: February 2023

Professional management in modern industry demands competence and vital direction of a high order, approached only with scientific objectivity. Engineering and economics are the basic tools of the profession. The author reduces the problems inherent in applied economics to four types: The selection, replacement, and apportionment of elements of production; the analysis of optimum enterprise economy; the rationalization of the dynamics of specific industries; and the interpretation and guidance of the trends and adjustments in the parent social environment. The paper indicates the necessity for more critical research and broader training in industrial management.
Ages of the granitic basement of Long Valley Caldera, California, USA, and siting of the Quaternary granite-rhyolite pluton
Authors: Hildreth Wes , Fierstein Judy , Vazquez Jorge
Published: February 2023

The leucogranitic crystal-mush pluton beneath the iconic Long Valley Caldera, California, USA, released >820 km3 of crystal-poor Pleistocene rhyolite, which was hosted by numerous Mesozoic granitic plutons, only a few of which had been dated until now. Reported here are U-Pb zircon ages, determined by sensitive high-resolution ion microprobe−reverse geometry (SHRIMP-RG), for 11 circumcaldera granitoids, all of them either Triassic or Cretaceous. Growth of the 35-km-wide Quaternary rhyolite-leucogranite plutonic reservoir was fostered by collocation of (1) a dense swath of late Pliocene basaltic vents, (2) a left-stepping extensional reentrant in the rangefront fault zone of the Sierra Nevada batholith, and (3) a sharp offset of the Proterozoic continental margin as represented by the Sr-isotope 0.706 line. We further consider whether the basement architecture of as many as 26 separate Triassic and Cretaceous plutons and intervening septa and pendants of Paleozoic metasedimentary rocks influenced siting of the Quaternary pluton and whether the ragged margin of Proterozoic lithosphere helped to focus asthenospheric edge upwelling that intensified crustal melting and intrusion in both the Triassic and the Quaternary.
Supplemental Material: Tracking isotopic sources of immiscible melts at the enigmatic magnetite-(apatite) deposit at El Laco, Chile, using Pb isotopes
Authors: Pietruszka Dorota K. , al. et
Published: February 2023

Supplemental Text: The Pb-Pb age calculation using the two-stage model. Table S1: Sample location (WGS-84). Table S2: Mean values of NBS 981 measurements used for mass fractionation of Pb isotopic ratios obtained using TIMS. Table S3: Uncorrected Pb isotopic ratios of the primary standard GOR-132-G. Table S4: Corrected Pb isotopic ratios of the secondary standard BCR-2G. Table S5: Common Pb calculations of the whole-rock magnetite, El Laco. Table S6: Weighted mean values and uncertainties of plagioclase, melt inclusions, and clinopyroxene analyses analyzed by SIMS. Table S7: Pb isotope composition from Neogene-Quaternary volcanoes from the Central Volcanic Zone in the Andes—literature review. Table S8: Pb isotopic composition from Ordovician–Devonian sedimentary rocks—literature review. Table S9: The slope of isochrons m and the corresponding model ages for the two-stage model. Figure S1: The cathodoluminescence (CL) and crossed-polar (CPL) photomicrographs of plagioclase phenocryst from EL Laco andesite. Figure S2: MLA analyses of LAC-AND sample. Figure S3: MLA analyses of LCO-1 sample. Figure S4: Clinopyroxene weighted mean error ellipses plotted on Figs. 5 and 6 from the main manuscript. Figure S5: Cross plots of SIMS analyses—LAC-AND sample. Figure S6: Cross plots of SIMS analyses—LCO-1 sample. Figure S7: Cross plots of SIMS analyses—LCO-9 sample.
Exploring what is important during burn recovery: a qualitative study investigating priorities of patients and healthcare professionals over time
Authors: Hoffmann Christin , Davies Philippa , Elliott Daisy , Young Amber
Published: February 2023

Objectives

This qualitative study aimed to investigate: (1) priorities of patients and healthcare professionals during recovery from a burn injury, (2) how priorities change over time and (3) how priorities map to outcomes currently reported in burns research.

Design

Semi-structured interviews were conducted. Interviews were audio recorded, transcribed and analysed thematically.

Setting, participants

A total of 53 patients and healthcare professionals were recruited from four National Health Service (NHS) burn services across England and Wales across England and Wales. Patient participants (n=32) included adults, adolescents and parents of paediatric patients, with a variety of burn injuries in terms of severity and cause of burn injury. Healthcare professionals (n=21) were NHS staff members involved in burn care and included professionals with a range of clinical experience and roles (eg, nurses, surgeons, occupational therapists, physiotherapist, administration).

Results

Ten themes relating to priorities (outcomes) during recovery from a burn injury were identified for patients and professionals. Of those, six were identified for patients and professionals (‘pain and discomfort’, ‘psychological well-being’, ‘healing’, ‘scarring’, ‘function’, ‘infection’), three were unique to professionals (‘patient knowledge, understanding and support’, ‘sense of control’, ’survival’) and one was unique to patients (‘uncertainty’). Results highlighted that importance of these priorities changes over time (eg, ‘survival’ was only a concern in the short term). Likewise, priorities differed between patients and professionals (eg, ‘pain’ was important to patients throughout their recovery, but not for professionals). Seven out of 10 themes overlapped with outcomes commonly assessed in burn research.

Conclusion

Professionals’ and patients’ priorities (important outcomes) change over time after burn injury and differ between those groups. Burn care research should consider measuring outcomes at different time points during the recovery from a burn injury to accurately reflect complexity of burn recovery.
Maternal use of methamphetamine alters cardiovascular function in the adult offspring
Authors: Belcher Adam M. , Rorabaugh Boyd R.
Published: February 2023

Methamphetamine is one of the most commonly used illicit drugs during pregnancy. Most studies investigating the impact of maternal use of methamphetamine on children have focused on neurological outcomes. In contrast, cardiovascular outcomes in these children have not been characterized. Recent studies in rodents provide evidence that prenatal exposure to methamphetamine induces changes in cardiac gene expression, changes in the heart's susceptibility to ischemic injury, and changes in vascular function that may increase the risk of developing cardiovascular disorders later in life. Importantly, these changes are sex-dependent. This review summarizes our current understanding of how methamphetamine use during pregnancy impacts the cardiovascular function of adult offspring and highlights gaps in our knowledge of the potential cardiovascular risks associated with prenatal exposure to methamphetamine.
On a nonlocal contracting flow for closed convex plane curves
Authors: Hao Ruixia , Zhang Run
Published: February 2023

The aim of this paper is to present a convex curve evolution problem which is determined by both local (curvature [Formula: see text]) and global (area [Formula: see text]) geometric quantities of the evolving curve. This flow will decrease the perimeter and the area of the evolving curve and make the curve more and more circular during the evolution process. And finally, as [Formula: see text] goes to infinity, the limiting curve will be a finite circle in the [Formula: see text] metric.
Volume comparison theorems in Finsler spacetimes
Authors: Lu Yufeng
Published: February 2023

In a [Formula: see text]-dimensional Lorentz–Finsler manifold with [Formula: see text]-Bakry–Émery Ricci curvature bounded from below, where [Formula: see text], using the Riccati equation techniques, we establish the Bishop–Gromov volume comparison theorem for the so-called standard sets for comparisons in Lorentzian volumes (SCLVs). We also establish the Günther volume comparison theorem for SCLVs when the flag curvature is bounded above.
Oscillatory Dynamics Induced by Time Delays in the Quorum Sensing System of Pseudomonas Aeruginosa
Authors: Gao Chunyan , Chen Fangqi
Published: February 2023

In this work, a sufficiently simple quorum sensing model allows one to perform detailed analytic studies to gain insights into the dynamical mechanisms in Pseudomonas aeruginosa. It is shown that an optimal rate of model parameters is essential to induce oscillations without considering time delays. Theoretical analysis and numerical simulation reveal that the delays can induce subcritical Hopf bifurcation and oscillation hysteresis. By using the center manifold and normal form theory, the explicit formulas for determining the stability and direction of periodic solutions bifurcating from Hopf bifurcations are derived. Numerical results show that the global periodic solutions bifurcating from the equilibrium exist when the delay is faraway from the first critical value. Moreover, the length of the delay can determine the amplitudes and the periods of the oscillations. A two-parameter diagram of delays is given to illustrate their crucial roles in coordinating and regulating oscillatory dynamics of the system. These results may help to further understand the dynamics of quorum sensing system in Pseudomonas aeruginosa and provide beneficial guidelines in the process of bacterial delivery of drugs.
APPROXIMATING OPTION PRICES UNDER LARGE CHANGES OF UNDERLYING ASSET PRICES
Authors: JUN JAE-YUN , RAKOTONDRATSIMBA YVES
Published: February 2023

When one invests in portfolios of derivatives (such as options), the delta-gamma approximation (DGA) is often used as a risk management strategy to reduce the risk associated with the underlying asset price. However, this approximation is locally accepted only for small changes of the underlying asset price. When these changes become large, the option prices estimated by the DGA may significantly differ from those of the market (or those that are estimated using, for instance, the Black–Scholes model), depending mainly on the time-to-maturity, implied volatility, and moneyness. Hence, in practice, before the change of the underlying asset price becomes large, rebalancing operations are demanded to minimize the losses occurred due to the error introduced by the DGA. The frequency of rebalancing may be high when the rate at which the underlying asset price significantly changes. Nonetheless, frequent rebalancing may be unattainable, as there are associated transaction costs. Hence, there is a trade-off between the losses resulting from the inaccurate performance of the DGA and the transaction costs incurring from frequent hedging operations. In the present work, we show two approaches that can outperform the DGA, in this way to increase the accuracy of estimating the option prices with the ultimate goal of reducing the losses due to the estimation error. The first method is similar to the DGA but we change the reference value that the DGA uses (that is, the initial price of the underlying asset) to the underlying asset price forecasted for the time horizon. We coin this method as the extended delta-gamma approximation (EDGA). The second method that we consider in this work is the locally weighted regression (LWR) that locally regresses the option prices from the changes of the underlying asset prices, with the same reference value that is employed in the EDGA method. Finally, we compare the performance of the two methods presented in this work to that of some existing methods.
The i-extended zero-divisor graphs of idealizations
Authors: Bennis Driss , Alaoui Brahim El , L’hamri Raja
Published: February 2023

Let R be a commutative ring with zero-divisors [Formula: see text] and [Formula: see text] be a positive integer. The [Formula: see text]-extended zero-divisor graph of [Formula: see text], denoted by [Formula: see text], is the (simple) graph with vertex set [Formula: see text], the set of nonzero zero-divisors of [Formula: see text], and two distinct nonzero zero-divisors [Formula: see text] and [Formula: see text] are adjacent whenever there exist two positive integers [Formula: see text] such that [Formula: see text] with [Formula: see text] and [Formula: see text]. The [Formula: see text]-extended zero-divisor graph of [Formula: see text] is well studied in 10. In this paper, we characterize the [Formula: see text]-extended zero-divisor graphs of idealizations [Formula: see text] (where [Formula: see text] is an [Formula: see text]-module). Namely, we study in detail the behavior of the filtration [Formula: see text] as well as the relations between its terms. We also characterize the girth and the diameter of [Formula: see text] and we give answers to several interesting and natural questions that arise in this context.
Thermal and Dynamic Radiation in the THz Range Under Spin Current Injection in Magnetic Junctions
Authors: Chigarev S. G. , Fomin L. A. , Rai D. P. , Vilkov E. A. , Byshevsky-Konopko O. A. , Zagorsky D. L. , Doludenko I. M. , Panas A. I.
Published: February 2023

An experimental approach to the problem of the energy distribution of radiation in the THz range created by an electron flow passing through a magnetic junction between thermal and dynamic is considered. The experimental results obtained during the operation of a spin-injection emitter based on an array of heterogeneous magnetic nanowires (NWs) confirmed the assumption about the “competition” of thermal and dynamic radiation processes.
A Graph-Based Blocking Approach for Entity Matching Using Contrastively Learned Embeddings
Authors: Mugeni John Bosco , Amagasa Toshiyuki
Published: February 2023

Data integration is considered a crucial task in the entity matching process. In this process, redundant and cunning entries must be identified and eliminated to improve the data quality. To archive this, a comparison between all entities is performed. However, this has quadratic computational complexity. To avoid this, `blocking' limits comparisons to probable matches. This paper presents a k-nearest neighbor graph-based blocking approach utilizing state-of-the-art context-aware sentence embeddings from pre-trained transformers. Our approach maps each database tuple to a node and generates a graph where nodes are connected by edges if they are related. We then invoke unsupervised community detection techniques over this graph and treat blocking as a graph clustering problem. Our work is motivated by the scarcity of training data for entity matching in real-world scenarios and the limited scalability of blocking schemes in the presence of proliferating data. Additionally, we investigate the impact of contrastively trained embeddings on the above system and test its capabilities on four data sets exhibiting more than 6 million comparisons. We show that our block processing times on the target benchmarks vary owing to the efficient data structure of the k-nearest neighbor graph. Our results also show that our method achieves better performance in terms of F1 score when compared to current deep learning-based blocking solutions.
Design of New Nonisolated High Gain Converter for Higher Power Density
Authors: Rajesh Ramachandran , Prabaharan Natarajan
Published: February 2023

A high gain nonisolated DC-DC converter using a single power semiconductor switch is proposed in this article. The operation of the proposed converter is explained under continuous conduction mode (CCM), discontinuous conduction mode (DCM), and boundary conduction mode (BCM). The mathematical expressions for steady-state voltage gain, voltage stress, and current stress of diodes and switch are provided. Also, the design of inductors and capacitors in the CCM mode is explained with appropriate mathematical equations. The proposed topology is tested with a 200 W prototype at 50 kHz and a 60% duty cycle. The dynamic behavior of the proposed converter is examined by changing the duty cycle value and also load values. The proposed converter is verified with experimental results to prove the effectiveness of its operation. The proposed converter provides higher steady-state voltage gain as compared with recently developed topologies. The efficiency and power density of the proposed converter is 90% and 1.16 kW/L, respectively.
PIV and CFD Study on Crossflow Characteristics in a 7-Pin Wire-Wrapped Bundle Channel
Authors: Li Rongjie , Fan Dajun , He Minghan , Qiu Ruoxiang , Tang Yanze , Tian Wangsheng , Gu Long
Published: February 2023

China initiative Accelerator Driven System (CiADS) combines a linac, spallation target and a Lead-cooled Fast Reactor (LFR) together, which is designed to transmute nuclear waste and accelerate the progress of China’s energy technology research towards the goal of carbon neutrality. A LFR uses helical wire-wrap spacers as positioning components to enhance crossflow mixing in the reactor core. To study the velocity distribution and crossflow characteristics in wire-wrapped rod bundle channels, a 2 : 1 magnified scale 7-pin bundle fuel assembly model was fabricated using polymathic methacrylate. Particle image velocimetry (PIV) and computational fluid dynamics (CFD) simulations were used to investigate the velocity distribution in the 7-pin bundle flow channels at Reynolds number of 1250~5000 in the

x
z

plane and Reynolds number of 1500 and 2500 in the

x
y

plane. The deviation between CFD simulation results and PIV experimental data was small, and the Reynolds Average Navier-Stokes model could accurately simulate the flow characteristics of the wire-wrapped fuel rod bundle channels. The maximum crossflow velocity caused by helical wires was about 40% of the axial bulk velocity. The normalized crossflow velocity at the subchannel interface varied approximately sinusoidally with the axial height. As the Reynolds number increased, the velocity distribution trend and the loss rate of axial velocity in flow channels remained essentially constant while the peak value of crossflow velocity increased. The contour images of velocities with different axial heights were obtained from the

x
y

plane, and their velocity distribution had a certain periodicity. The axial velocity loss rate in each subchannel caused by wire-wrap spacer resistance was between 7.35% and 38.51%, and the axial velocity loss rates in inner subchannels were usually higher than those in edge subchannels.
Allelic and Genotype Frequencies of CYP2B6∗2 (64C > T) and CYP2B6∗3 (777C > A) in Three Dominant Ethnicities of the Iranian Population
Authors: Khavandegar Armin , Tavakoli-Far Bahareh , Ansari Sarina , Veis-Karami Parisa , Ghasemi Faezeh , Sheibaninia Samira , Jazayeri Roshanak , Houshmand Massoud
Published: February 2023

Background. Cytochrome P450 complex plays a key role in drug metabolism. CYP2B6 has an essential part in Cytochrome P450 complex metabolism. This study aims to determine the allelic distribution of CYP2B6∗2 and CYP2B6∗3 in three main Iranian ethnicities: Fars, Turk, and Kurd. Methods. The study was conducted on 174 unrelated healthy volunteers from three main Iranian ethnicities. After DNA extraction from peripheral blood samples, genotyping of CYP2B6∗2 and ∗3 was performed using tetra ARMS and ARMS PCR, respectively. Results. The average age of 174 cases was 40.69

±

11.87 (mean

±

SD) and 39.06

±

11.63 (mean

±

SD) for males and females. In the CYP2B6∗2 variant, the genotyping frequency of wild type (C/C), heterozygous (C/T), and homozygous mutant (T/T) was 8.7%, 86%, and 5.2%, respectively. The CYP2B6∗2 (c.64C > T) allele frequency was 48.2% (95% CI: (37.8–58.6)). In the CYP2B6∗3 variant, the frequency of wild type (C/C), heterozygous (C/T), and homozygous mutant (T/T) was 75.3%, 11%, and 13.6%, respectively. The CYP2B6∗3 (c.777C > A) allelic frequency was 19.1% (95% CI: (17.5–20.7)). Conclusion. Allelic distribution in three main Iranian ethnicities, i.e., Turk, Kurd, and Fars, is remarkably higher than that in other populations, even that in Southern Iran. High frequencies of CYP2B6∗2 and ∗3 in the Iranian population highly affect drug responsiveness. Understanding such variability could help to increase drug efficacy and reduce its toxicity.
Analysis of the Change Feature and Action Mechanism of Coal Pore Structure under the Action of Supercritical CO2
Authors: Li Bo , Jian Wang , Zhang Junxiang , Wang Bo , Zhu Daohe
Published: February 2023

In this study, supercritical CO2- (ScCO2) induced permeability enhancement tests were performed on two different-rank coal samples (i.e., coking coal and anthracite) by a self-developed ScCO2-induced permeability enhancement test device for the purpose of exploring the change feature and action mechanism of ScCO2 on coal pore structure during the improvement of coalbed methane extraction. The following results were obtained: after the injection of ScCO2, the original pore structure of coal changes. Specifically, the connectivity between macropores and fractures increases, that between mesopores and small pores decreases and that between small pores and micropores increases. Besides, the total pore volumes of the two types of coal samples both grow primarily due to the increase in macropores and mesopores, and the sample of a higher rank corresponds to a higher growth rate. The growth in the number of effective pores conduces to dredging and enlarging pores in some ways, promoting the surface roughness of macropores and mesopores and reducing that of small pores and micropores. With respect to the action mechanism, ScCO2-induced changes in the coal pore structure are jointly induced by pore adsorption swelling, dissolution-migration, and dissolution-precipitation. Among them, the internal cause of pore adsorption swelling is the surface-free energy of fine pores. The sample of a higher rank contains more fine pores and greater surface-free energy; resultantly, it experiences stronger adsorption swelling and thus greater changes in its pore structure. The carbonic acid generated by ScCO2 and the strong acid minerals existing in the coal matrix and pore space dissolute and migrate, which stands to dredge and expand pore space and meanwhile promote pore connectivity and volume. Moreover, dissolution-precipitation leads to the blockage of pore space and pore channels, hence reducing pore connectivity and pore volume.
An Efficient and Accurate 2W-PE Method for Solving Spatial Field Strength Based on CVNN and PINN
Authors: Li An-Qi , Yin Cheng-You , Zhang Qian-Qian , Liu Han
Published: February 2023

A two-way parabolic equation (2W-PE) method based on complex-valued neural networks (CVNNs) and a physics-informed neural network (PINN) is proposed to predict the spatial field in the environment of dielectric obstacles with high efficiency and accuracy. In the framework of the 2W-PE method, CVNNs are used to calculate the lumped transmission field and the lumped reflection field considering the influence of the obstacle, thus avoiding the long calculation time caused by the internal multilayered reflection processes. The incident directions and field strength of the waves on the regional boundaries vary greatly with the propagation environment, so coefficients of the boundary conditions are obtained by using the PINN. Next, the training results are applied to the examples using the continuation method and compared with the numerical results of the method of moments (MoM). The proposed 2W-PE method has high computational accuracy and efficiency, which reflects the applicability of machine learning in solving the computational efficiency problem of radio wave propagation. Therefore, this study provides a very effective and reliable method for solving the spatial field in the obstacle environment.
Three-dimensional Smith Chart and long blade design for axial flow turbine
Authors: Wang Naian , Yang Huan , Luo Dan , Qi Yinke , Huang Diangui
Published: February 2023

Conventional 1D turbine aerodynamic designs are usually completed by using 2D Smith Chart, which has many limitations (especially the reaction degree of blade is restricted to be about 0.5), and significantly limits design efficiency. In order to eliminate the limitations of the traditional Smith Chart, this paper proposes to take the reaction degree as a third axis, to expend the original 2D Smith Chart to a 3D diagram, which could be used to guide the blade profile design under different blade reaction degrees. The design and numerical calculations of blade profiles are carried out for some operating points in the 3D Smith diagram. It is numerically verified that the relationship between load coefficient, flow coefficient, and efficiency of blade profile under different reaction degrees (0.1–0.7) are consistent with the newly proposed Smith diagram. In addition, a new method of long blade design is proposed: using the 3D Smith diagram to guide the design of blade profiles corresponding to the given radial reaction degree distribution law of the blade, then the long blade is obtained by stacking these blade profiles along the center of gravity. After that the 3D numerical simulation of the obtained 3D blade is carried out to obtain a new radial reaction degree distribution law. The above steps must be repeated until the radial reaction degree distribution can meet the design requirements. The design parameters of high pressure single-stage axial turbine (expansion ratio is about 4.3) are used for the long blade design. The whole stage is calculated by a 3D steady numerical simulation method. The results are consistent with the 1D design value, and the error between total to static and total to total efficiency is less than 3%. It is shown that the 3D design method is instructive for axial turbine long blade design.
A humification-based method toward refining Holocene radiocarbon chronologies: Wetland records from southeastern China
Authors: Li Nannan , Yu Fengling , Chambers Frank M , Huang Zhaoquan , Lin Wenmin , Zhu Zilong , Yang Huanjie , Lin Jiaqi
Published: February 2023

Holocene paleoclimate reconstructions and comparisons largely rely on accurate age-depth modeling. However, uncertainties in chronology, such as those caused by sparse radiocarbon dates, will hamper inter-core comparisons and correlations, and might result in misleading “cause and consequence” conclusions. This study aimed to find a solution to increase the comparability and minimize the uncertainty of wetland chronology as much as possible. Sediment cores were recovered and radiocarbon dated from the Lianhuachi wetland located in Southeastern China. Humification degree and loss-on-ignition (LOI) were determined using colorimetric and combustion methods respectively. Our data were compared with previously published datasets obtained in the same wetland. The results show that independent humification profiles from the Lianhuachi wetland displayed high similarities. This high similarity between the humification profiles allowed us to transfer radiocarbon ages from one core to another using sequence slotting correlation. Applying the humification-based chronology refinement method to all sediment cores resulted in an improvement in the correlation coefficients between the same but independently measured proxy sequences from the wetland, which suggests both the inter- and intra-core comparability was improved. Because determining peat humification degree is easy, inexpensive, and time-saving, we suggest that humification can serve as a tool that can be used to correlate different cores and to transfer published radiocarbon ages within the same wetland (peatland) or in a comparable geological setting, to establish a more robust chronology of these comparable cores. The degree of peat humification can thus serve as a relative dating technique to refine the chronology of wetland (including peatland) records.