bluuebunny/crossref_metadata_2025_split huggingface dataset:
Boiler-Plant Performance With Natural-Gas Firing
Authors: Philo F. G. 
Published: February 2023

Abstract
With its diversified operations, the Long Beach Steam Station of the Southern California Edison Company, Ltd., using natural gas as fuel has been required to solve many problems. The author presents the boiler-plant performance obtained with this fuel and outlines the methods and equipment adopted to give economic operation. A feature of this paper is the detailed instruction chart developed for the guidance of the boiler-plant operators. During the last fifteen years 120,000,000,000 cu ft of natural gas from three main sources have been burned in the installation. It is the author’s opinion that a properly designed gas-piping system in the hands of competent operators probably presents fewer problems and no greater hazard than does the use of liquid or powdered fuels.
Problems Encountered in the Design and Operation of Impulse Turbines
Authors: Quick Ray S. 
Published: February 2023

Abstract
Because of present-day demands on high-head hydroelectric installations, calling for continuous maximum overload operation of impulse turbines, unusual problems of wear and fatigue of materials have developed. The author discusses such problems frankly and suggests solutions for them. One of the important factors influencing unit efficiency of impulse turbines is the arrangement and design of approach piping due to the effect on the jet of turbulence in the nozzle. Flow-straightening vanes have been developed to correct this turbulence. Various successful forms are illustrated and their characteristics plotted. The form of needle and nozzle tip also has a marked influence upon the appearance and form of the power jet. Another factor affecting the performance of the unit is that of the design, shape, and arrangement of buckets on the water wheel. Investigations have been made on all these elements of the impulse turbine, the results of which have been incorporated in present successful applications. Two outstanding impulse-turbine installations in California are mentioned. A comparison is drawn between field tests on one of these at the Tiger Creek Plant of the Pacific Gas and Electric Company and model tests. The paper concludes with a discussion of the governing problem.
Performance Characteristics of a Mechanically Induced Draft, Counterflow, Packed Cooling Tower
Authors: London A. L. , Mason W. E. , Boelter L. M. K. 
Published: February 2023

Abstract
Predicted and test results of a packed cooling tower are presented in this paper. The geometrical form of the air-water interface may be described as a sheet conforming to the streamlined shape of the tower packing, in contrast with jets and drops encountered in other types of towers. Tower performance is expressed in terms of its effectiveness as an energy exchanger, as compared to the performance of an infinitely high tower. The effectiveness was found to vary from approximately 0.3 at low water rates and high air rates to 0.8 at high water rates and low air rates. Experimentally determined unit conductances for diffusion vary with the 0.48 power of the gas rate, for Reynolds numbers of from 7000 to 24,000, which is in substantial agreement with published thermal-convection data for similar shapes. The height of the transfer unit (HTU) was found to vary from 3.3 to 6.3 ft, depending predominantly upon the fraction of wetted packing area and the air rate. A simple method, analogous to that employed for counterflow heat-exchanger calculations, is presented for predicting tower performance analytically. This method is based upon the integration of the energy and material-balance equations together with the rate equations, subjected to the simplification that the unit over-all conductance for thermal convection may be approximated by the product of the air-water-vapor-mixture unit-heat capacity and the unit over-all conductance for mass transfer.
Wear of Diesel-Engine Cylinders and Rings
Authors: Lane Paul S. 
Published: February 2023

Abstract
This paper considers wear mainly from the viewpoint of cylinder and ring materials, rather than from the design or operating angle. The types of iron used, though important factors, have received only limited attention in published data. Existing wear rates in medium- and heavy-duty Diesel and gas engines in various fields of service are reviewed, followed by several examples of cylinder wear as affected by the hardness and structure of the iron alloy. By means of laboratory wear tests, correlated with service experience, the nature and characteristics of the materials used in cylinders and rings are surveyed and discussed in detail, covering the effects of section size, hardness, analysis, and structure. Initial engine wear, as influenced by bore finishes and wear-resistant or chemical surface treatments, is considered, together with the action of bimetallic or composite rings, in retarding scuffing and over-all wear rates.
A Supersensitive Governor for Hydraulic Turbines
Authors: White W. M. 
Published: February 2023

Abstract
A supersensitive governor is defined in this paper as one that will move the gates of a hydraulic turbine in the corrective direction by reason of a change of speed of 0.02 per cent and will then move the gates back by reason of a change of the speed back to the former speed. The author outlines the elements essential to a supersensitive governor in order to accomplish this fine degree of regulation. The application of these principles to governor design is then outlined.
Constant System Speed and the Steam-Turbine Governor
Authors: Schwendner A. F. 
Published: February 2023

Abstract
The demand for constant system speed is a current problem of power-generating systems. Electrical stability, governor, governing-valve characteristics, and other factors play their part in the problem. In this paper only the effect the governors and governing valves have in maintaining or disturbing the system speed is discussed. New governing systems are described to show the extent to which the turbine manufacturers go in trying to meet the demand for better system speed. The author points out that, when the governor characteristics of all units in a power-generating system are known, the combination of units used for certain load blocks can be determined not only for the best generating economy but also for better system speed. This information can be used to specify required governor characteristics for new units to further improve the system speed. Attention is called to the need for uniform governor performance and testing specifications.
Automatic Control in the Presence of Process Lags
Authors: Mason C. E. , Philbrick G. A. 
Published: February 2023

Abstract
In this paper, the methods of “Quantitative Analysis of Process Lags” developed in a previous paper are extended to include automatic control. Carrying on the idea of representation by liquid-level systems, a specific system is postulated as a model for a typical industrial process which may or may not be thermal. Continuing the quantitative approach, the mathematical machinery is demonstrated by which the operation of control on processes may be investigated. A selected succession of controllers, characterized by the laws of control which govern them, are considered in connection with their performance on the model system. Although no attempt has been made to formulate rules governing the proper application of the various types of controllers considered or governing the adjustment of any of these individual types, the authors consider that analyses of this sort may well serve as a guide to practical theorems in a technology of automatic control.
Photoelastic Analysis of Stresses in a Steam-Turbine Blade Root
Authors: Ryan J. J. , Rettaliata J. T. 
Published: February 2023

Abstract
The analysis of the stresses in steam-turbine blade roots by photoelastic methods has particular reference to the determination of the loadings on the multiple steps. In this paper, from a comparison of test and calculated values, the stress-concentration factors are obtained for the neck and step sections.
Laminar-Flow Heat-Transfer Coefficients for Ducts
Authors: Norris R. H. , Streid D. D. 
Published: February 2023

Abstract
In this paper, theoretically derived values of the heat-transfer coefficient for flat ducts with constant surface temperature are presented and compared with the corresponding results for round ducts which have been previously published. A few test data for air in flat ducts are compared with the theoretical results. For both flat ducts and round ducts the results are presented both in customary terms and in terms of the logarithmic-mean temperature difference. The latter results provide a consistent basis for comparisons with heat-transfer data for turbulent flow. Some limiting values of the local heat-transfer coefficient for both constant surface temperature and constant heat input per unit length are tabulated, and some equations pertinent to very short ducts are included.
Fuels for Diesel Engines in Marine Transportation
Authors: Joachim W. F. , Nutt H. V. 
Published: February 2023

Abstract
After reviewing briefly developments in the field of Diesel fuels over the last 30 years, the authors discuss in detail the present-day requirements for marine-Diesel-engine fuels. A summary of engine troubles and casualties caused by unsuitable fuels is also given. The paper includes a series of tables and explanatory matter concerning Diesel-fuel specifications for various types of marine engines.
Properties of Hydrogen Mixtures
Authors: Brunot A. W. 
Published: February 2023

Abstract
With the increased use of hydrogen as a cooling medium in rotating electrical machines, it has become important to know the properties of hydrogen diluted by small amounts of another gas. Using these properties it is possible to predict the operation of the machine in a hydrogen mixture from the results of tests made in air or pure hydrogen. It is the purpose of this paper to present a summation of data on the properties of hydrogen, air, nitrogen, and carbon dioxide, as well as empirical formulas for the properties of the mixture of hydrogen with any of the other three gases, and to show how accurately the performance of a heat exchanger in hydrogen or hydrogen mixtures may be predicted from tests in air.
Heat Transfer to Falling-Water Films
Authors: McAdams W. H. , Drew T. B. , Bays G. S. 
Published: February 2023

Abstract
Data are presented in this paper for heating water as it flows by gravity in turbulent motion down the inner walls of vertical copper pipes, ranging in height from 0.41 to 6.1 ft. Heat balances check within 5 per cent and the temperature of the inlet water ranges from 38 to 146 F. The data are adequately correlated by the equation: h = 120Γ1/3, where Γ ranges from 600 to 15,000 lb of water per hr per ft of width of stream. Steam-side and over-all coefficients are given. The rather inadequate data for streamline flow by gravity over nearly horizontal pipes (trombones) are reviewed.
Steam-Turbine Blading
Authors: Allen R. C. 
Published: February 2023

Abstract
This paper reviews the blading-design practice associated with modern high-pressure high-temperature steam turbines. The design problems encountered in the development of partial-admission impulse blading for topping units are described, as well as the current engineering practice employed in the manufacture of such blading. The stress analysis used in the construction of full-admission blading is reviewed. The design procedure adopted for high-tip-speed last-row blading and the natural limits in capacity imposed on 3600-rpm turbine construction are also discussed. Materials for turbine blading are considered, as well as the metallurgical problems associated with the fabrication and welding of the high-grade alloy steels now available.
Nonlinear Beamforming Based on Amplitude Coherence Applied to Ultrasonic Imaging of Coarse-Grained Steels
Authors: Carcreff Ewen , Laroche Nans , Varray Francois , Nicolas Barbara 
Published: February 2023

Abstract
This paper deals with ultrasonic imaging in a nondestructive evaluation (NDE) context. In particular, we are focused on the inspection of coarse-grained steels having a heterogeneous composition that creates structural noise in the ultrasonic signals and images. The standard way to beamform the acquired ultrasonic data is by delay-and-sum (DAS). This method is fast but suffers from low signal-to-noise ratio (SNR) for coarse-grained steel inspection. In this paper, we propose to adapt a coherence-based beamformer called pDAS from the medical imaging community. pDAS beamforming is based on DAS structure but includes p-root and p-power before and after summations, respectively. It results in an enhancement of the coherent summation of signals that improves both resolution and contrast. Coherence-based beamformers are known to enhance information whose acoustic response correlates with geometrical information, that is why they decrease grating lobes and side lobes, specular echoes, reconstruction artifacts, and noise due to multiple scattering. In this paper, the pDAS beamformer is proposed for two common acquisition schemes employed in NDE that are plane wave imaging (PWI) and full matrix capture (FMC). The beamformers have been efficiently implemented for parallel computing on graphics processing unit (GPU) in a context of real-time imaging and fast part scanning in NDE. First, experimental results are presented from an austenitic-ferritic sample from the power generation industry that contains side drilled holes (SDH) with diameter 0.4 mm at several depths. pDAS (for p from two to three) shows improvements in terms of SNR and resolution compared to standard DAS, both in PWI and FMC modalities. We also show that the computation cost of pDAS is equivalent to DAS. A real application on a sample containing a fatigue crack connected to the backwall is exposed. We show that pDAS beamformer can enhance crack response compared to grains, but it also decreases unwanted information such as backwall specular echoes and reconstruction artifacts.
CD4 binding site immunogens elicit heterologous anti–HIV-1 neutralizing antibodies in transgenic and wild-type animals
Authors: Gristick Harry B. , Hartweger Harald , Loewe Maximilian , van Schooten Jelle , Ramos Victor , Oliveira Thiago Y. , Nishimura Yoshiaki , Koranda Nicholas S. , Wall Abigail , Yao Kai-Hui , Poston Daniel , Gazumyan Anna , Wiatr Marie , Horning Marcel , Keeffe Jennifer R. , Hoffmann Magnus A. G. , Yang Zhi , Abernathy Morgan E. , Dam Kim-Marie A. , Gao Han , Gnanapragasam Priyanthi N. P. , Kakutani Leesa M. , Pavlovitch-Bedzyk Ana Jimena , Seaman Michael S. , Howarth Mark , McGuire Andrew T. , Stamatatos Leonidas , Martin Malcolm A. , West Anthony P. , Nussenzweig Michel C. , Bjorkman Pamela J. 
Published: February 2023

Passive transfer of broadly neutralizing anti–HIV-1 antibodies (bNAbs) protects against infection, and therefore, eliciting bNAbs by vaccination is a major goal of HIV-1 vaccine efforts. bNAbs that target the CD4 binding site (CD4bs) on HIV-1 Env are among the most broadly active, but to date, responses elicited against this epitope in vaccinated animals have lacked potency and breadth. We hypothesized that CD4bs bNAbs resembling the antibody IOMA might be easier to elicit than other CD4bs antibodies that exhibit higher somatic mutation rates, a difficult-to-achieve mechanism to accommodate Env’s N276
gp120
N-glycan, and rare five-residue light chain complementarity-determining region 3. As an initial test of this idea, we developed IOMA germline–targeting Env immunogens and evaluated a sequential immunization regimen in transgenic mice expressing germline-reverted IOMA. These mice developed CD4bs epitope–specific responses with heterologous neutralization, and cloned antibodies overcame neutralization roadblocks, including accommodating the N276
gp120
glycan, with some neutralizing selected HIV-1 strains more potently than IOMA. The immunization regimen also elicited CD4bs-specific responses in mice containing polyclonal antibody repertoires as well as rabbits and rhesus macaques. Thus, germline targeting of IOMA-class antibody precursors represents a potential vaccine strategy to induce CD4bs bNAbs.
Influence of lake-basin morphology on climate-sediment transfer functions: Early Eocene Wilkins Peak Member, Green River Formation, Wyoming
Authors: Walters Andrew P. , Carroll Alan R. , Meyers Stephen R. , Lowenstein Tim K. 
Published: February 2023

Lacustrine strata are often among the highest-resolution terrestrial paleoclimate archives available. The manner in which climate signals are registered into lacustrine deposits varies, however, as a function of complex sedimentologic and diagenetic processes. The retrieval of reliable records of climatic forcing therefore requires a means of evaluating the potential influence of changing sedimentary transfer functions. Here, we use high-resolution X-ray fluorescence core scanning of the Wilkins Peak Member of the Green River Formation to characterize the long-term evolution of transfer functions in an ancient lacustrine record.
Our analysis identifies a shift in the frequency distribution of Milankovitch-band variance between the lower and middle Wilkins Peak Member across a range of temporally calibrated elemental intensity records. Spectral analysis of the lower Wilkins Peak Member shows strong short eccentricity, obliquity, precession, and sub-Milankovitch−scale variability, while the middle Wilkins Peak Member shows strong eccentricity variability and reduced power at higher frequencies. This transition coincides with a dramatic decline in the number and volume of evaporite beds.
We attribute this shift to a change in the Wilkins Peak Member depositional transfer function caused by evolving basin morphology, which directly influenced the preservation of bedded evaporite as the paleolake developed from a deeper, meromictic lake to a shallower, holomictic lake. The loss of bedded evaporite, combined with secondary evaporite growth, results in reduced obliquity- and precession-band power and enhanced eccentricity-band power in the stratigraphic record. These results underscore the need for careful integration of basin and depositional system history with cyclostratigraphic interpretation of the dominant astronomical signals preserved in the stratigraphic archive.
Fetal hemivertebra: a rare form of 18q deletion prenatal presentation
Authors: Laranjo Mafalda , Marinho Márcia , Brito Conceição , Godinho Cristina 
Published: February 2023

The 18q deletion is a rare condition with several described features. A common phenotype includes short stature, microcephaly, facial defects, small feet, intellectual disability and hypotonia.We present a rare case of a fetus with del18q22.1q23 whose diagnosis was obtained by amniocentesis after a routine ultrasound at 20 weeks, where a hemivertebra was detected.Congenital hemivertebra is infrequent and is rarely associated with chromosomal anomalies. Expectant management can be advocated in isolated hemivertebra. This report shows that a hemivertebra can be an isolated prenatal finding in del18 so it is important to screen for, and exclude, chromosomal anomalies.
Knowledge of legal rights as a factor of refugee and asylum seekers’ health status: a qualitative study
Authors: Pilato Tara C , Taki Faten , Sbrollini Kaitlyn , Purington Drake Amanda , Maley Brian , Yale-Loehr Stephen , Powers Jane L , Bazarova Natalya N , Bhandari Aparajita , Kaur Gunisha 
Published: February 2023

ObjectivesTo examine health behaviours of refugees and asylum seekers, in relation to their knowledge of public benefits and legal rights.DesignQualitative study, utilising an open-ended, semi-structured interview guide to ensure information-rich data collection. Thematic content was analysed using qualitative research software.SettingParticipants were drawn from the Weill Cornell Center for Human Rights (WCCHR) in New York City, a single-center, human rights clinic with a globally representative patient population. All interviews were conducted at the Weill Cornell Medicine Clinical and Translational Science Center, a multidisciplinary space within an urban academic medical center.ParticipantsTwenty-four refugees and asylum seekers currently living in the greater New York City area. Eligible participants were 18 years of age or older and had previously sought services from the WCCHR. The recruitment rate was 55%.Primary and secondary outcome measuresThemes and concepts in participants’ health, knowledge, perceptions of and experiences with accessing healthcare and public benefits programmes.ResultsTwenty-four participants represented 18 countries of origin and 11 primary languages. Several impediments to accessing healthcare and public benefits were identified, including pragmatic barriers (such as prohibitive costs or lack of insurance), knowledge gaps and mistrust of healthcare systems.ConclusionsThere is low health engagement by refugees and asylum seekers, as a result of multiple, complex factors impeding the ability of refugee and asylum seekers to access healthcare and other public benefits for which they are eligible—with resultant detrimental health effects. However, there is an opportunity to utilise novel approaches, such as digital technologies, to communicate relevant information regarding legal rights and public benefits to advance the health of vulnerable individuals such as refugees and asylum seekers.
How does portfolio use support self-regulated learning during general practitioner specialty training? A qualitative focus group study
Authors: van der Gulden Rozemarijn , Timmerman Angelique A , Sagasser Margaretha H , Kramer Anneke , Scherpbier-de Haan Nynke , Thoonen Bart , Heeneman Sylvia 
Published: February 2023

ObjectivesPortfolios are used to support self-regulated learning (SRL), but the research literature is still inconclusive on their effectiveness. This study explored experiences with portfolio use among different stakeholders, to answer the research question: How does portfolio use support SRL during general practitioner (GP) specialty training?DesignWe used a qualitative research design, based on phenomenology.SettingThree of the eight training institutes of Dutch GP specialty training participated in this study.ParticipantsThe three stakeholder groups that use the portfolio were included in nine homogenous focus groups: trainees (n=16), supervisors (n=16) and faculty (n=17). All participants had at least 6-month experience with portfolio use.ResultsThree themes were identified: SRL with(out) the portfolio, stakeholder dynamics and ambiguities. Respondents were doubtful about the learning benefits of portfolio use, as most trainees used their portfolio to ‘check off’ what was considered required. Stakeholder dynamics contributed to checking off behaviour in two ways. First, trainees experienced documenting learning activities to be superfluous, since the close relationship with their supervisor already supported SRL sufficiently. Second, faculty often (unintentionally) took portfolio ownership away from trainees, as they instructed trainees to deliver portfolio content that was valuable for assessment. Without ownership, trainees struggled to use the portfolio for SRL. Besides, ambiguities related to portfolio use amplified checking off behaviour.ConclusionsPortfolio use did not support SRL in our setting. The multipurpose use of the portfolio (for the support of SRL and assessment) was identified as the primary obstacle. Underlying is a conflict that is often present in current medical curricula: agency versus accountability. If the support of SRL is considered a valuable and attainable purpose of portfolio use, it is important to realise that deliberate attention for this purpose is required during the design, guidance, assessment and evaluation of the portfolio.