bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the scope and costs of dental treatment provided under general anaesthesia among children with congenital heart disease
Authors: Nikolovski Jana , Chapman Emily E , Widmer Richard P , Ayer Julian G
Published: April 2023

Aim

To identify the types of dental treatment provided under general anaesthesia for children diagnosed with congenital heart disease (CHD), quantify the costs within a publicly funded tertiary paediatric hospital setting and identify factors which affect the cost.

Methods

A retrospective analysis of dental records (July 2015 to June 2019) was conducted for children with CHD who had undergone a dental general anaesthetic procedure at The Children's Hospital at Westmead, Australia. Patient and treatment‐related information were collected, and a costing analysis was performed on 89 dental general anaesthetic procedures.

Results

Mean age at the time of the general anaesthetic was 8.15 years. About 27% of children with CHD had a history of dental infection. Dental extractions and restorations comprised the majority of treatments provided, with extractions performed in 86% of procedures. The mean number of days in hospital was 1.43 and the mean cost was $4395.14. The cost was significantly greater when children presented with a facial swelling compared to any other reason.

Conclusions

Dental extractions are performed in the majority of general anaesthetics. Not only is there an economic burden to the public health system in providing dental treatment under general anaesthesia for children with CHD, the health impacts also appear to be substantial. A considerable proportion required overnight hospitalisation and days in hospital was strongly related to the cost of the dental general anaesthetic. Systematic referral pathways for accessing dental care are an important consideration for children with CHD.
Melatonin inhibits chondrosarcoma cell proliferation and metastasis by enhancing miR‐520f‐3p production and suppressing MMP7 expression
Authors: Nguyen Bao Tran , Lin Chih‐Yang , Chang Ting‐Kuo , Fong Yi‐Chin , Thadevoos Louis Anoop , Lai Chao‐Yang , Huang Yuan‐Li , Tsai Chun‐Hao , Ko Chih‐Yuan , Liu Ju‐Fang , Yang Shun‐Fa , Tang Chih‐Hsin
Published: April 2023

Chondrosarcoma has a high propensity to metastasize and responds poorly to chemotherapy and radiation treatment. The enzymatic activity of matrix metalloproteinases (MMPs) is very important in chondrosarcoma metastasis. Melatonin exhibits anticarcinogenic activity in many types of cancers by suppressing the expression of certain MMP family members, but this has not yet been clearly determined in chondrosarcoma. Our study demonstrates that MMP7 plays an essential role in chondrosarcoma cell proliferation, migration, and anoikis resistance. We also found that MMP7 is highly expressed in chondrosarcomas. Our in vitro and in vivo investigations show that melatonin strongly inhibits chondrosarcoma cell proliferation, migration, and anoikis resistance by directly suppressing MMP7 expression. Melatonin reduced MMP7 synthesis by promoting levels of miR‐520f‐3p expression, which were downregulated in human chondrosarcoma tissue samples. Pharmacological inhibition of miR‐520f‐3p markedly reversed the effects of melatonin upon chondrosarcoma proliferation and metastasis. Thus, our study suggests that melatonin has therapeutic potential for reducing the tumorigenesis and metastatic potential of chondrosarcoma via the miR‐520f‐3p/MMP7 axis.
Insomnia trajectories predict chronic inflammation over 2 years at the transition to adulthood
Authors: Zhai Shuang , Li Tingting , Zhang Dan , Qu Yang , Xie Yang , Wu Xiaoyan , Zou Liwei , Tao Fangbiao , Tao Shuman
Published: April 2023

Insomnia in adolescents is an important public health concern, as its impacts on both their current and future physical and mental health has been discussed. However, few longitudinal studies have examined insomnia and chronic inflammation at the transition from adolescence to adulthood. This study aimed to examine the predictive effects of insomnia and insomnia trajectories on inflammation in college students by using a prospective design. Using data from the College Student Behaviour and Health Cohort Study, which was conducted between April 2019 and April 2021, with an interval of 6 months. We investigated the associations between insomnia trajectories from Year 1 to Year 3 and five inflammatory biomarkers (C‐reactive protein [CRP], tumour necrosis factor [TNF]‐α, interleukin [IL]‐6, IL‐1β, IL‐10) at Year 3. The association of insomnia symptoms at baseline, Wave 1 or Wave 2 with inflammatory biomarkers at Wave 4 were also assessed. A total of 312 college students (males: 51.6%) aged 16–26 years (mean [SD] 18.82 [1.22] years) were analysed. We identified two insomnia trajectory classes: increasing insomnia (n = 63 [20.2%]) and decreasing insomnia (n = 249 [79.8%]). Generalised linear model analysis revealed that insomnia symptoms at Wave 1 were associated with significantly elevated CRP and TNF‐α levels at Wave 4. Increasing insomnia trajectories predicted consistently higher levels of CRP, TNF‐α and IL‐10. However, after adjusting for potential confounders, these associations were significantly attenuated. Overall, the findings suggest that insomnia symptoms affect chronic inflammation at the transition to adulthood. Our study needs to be replicated in larger cohorts to further explore how inflammation interacts with insomnia to increase the susceptibility to adverse health conditions.
Plasma and urinary metanephrine and normetanephrine concentrations using liquid chromatography with tandem mass spectrometry in healthy cats and in a cat with pheochromocytoma
Authors: Prego Maria Teresa , Dias Maria Joana , Ferreira Rui Lemos , Gonçalves Salomé , Dias Domingues Tiago , Junius Greet , Van den Steen Evi , Galac Sara , Leal Rodolfo Oliveira
Published: April 2023

Background

Pheochromocytoma (PCC) is rare in cats and plasma (PL) and urinary (U) metanephrines (metanephrine [MN]; normetanephrine [NMN]) measurement is rarely described in cats.

Objectives

We evaluated the utility of PL and U MNs measurement in 10 healthy cats and a cat with a confirmed diagnosis of pheochromocytoma (PheoCat), using liquid chromatography with tandem mass spectrometry (LC‐MS‐MS).

Methods

Urine and EDTA PL samples collected from each of the 10 cats and the PheoCat were promptly stored at −80°C and remained frozen until analysis. To evaluate U MNs stability, an additional urine sample collected from the healthy cats was refrigerated for 24 hours before freezing. Urinary creatinine concentration (Creat) was assessed using the same spot urine samples to calculate U MNs‐to‐creatinine ratios.

Results

The PL‐MN and PL‐NMN median concentrations of the healthy cats were 2.73 and 7.02 nmol/L, respectively. The median U‐MN/Creat and U‐NMN/Creat ratios were 70 and 139 μg/g, respectively. The PheoCat had a PL‐MN of 3.68 nmol/L, PL‐NMN of 66.27 nmol/L, U‐MN/Creat of 179 μg/g, and U‐NMN/Creat of 1262 μg/g. The PheoCat had markedly increased concentrations of both PL and U MNs when compared to the healthy cats. No significant difference was found between U MNs measured in urine samples that underwent 24 hours of refrigeration in comparison to those that were frozen immediately.

Conclusions

We report preliminary reference intervals for PL and U MNs in cats using LC‐MS‐MS and the potential clinical applicability of these biomarkers for the diagnosis of PCC in cats.
Trust plays no role in regional U.S. economic development—And five other problems with the trust literature
Authors: Forrester Andrew C. , Nowrasteh Alex
Published: April 2023

Economists have developed a vast empirical literature on how cultural traits like generalized trust affect economic output. Much of this literature finds a positive causal relationship between measures of generalized trust, as gathered by international surveys, and economic output. However, the trust literature commits five deadly empirical and theoretical sins that undermine many of its findings. From the quality of the survey questions and responses to the paucity of theoretical models used to explain how trust affects economic outcomes to the radically different results from experimental evidence and others, the trust literature is riven with poor methods and bad data. Even so, applying common methods used in the trust literature to regional level analysis in the United States during the 1972–2018 period reveals no statistically significant correlation between economic output and trust. Given our lack of findings at the subnational level, we find further evidence to be skeptical of the trust literature.
Addressing disparities in capital to promote social equity in medical education
Authors: Mosley Marcus
Published: April 2023

Mosley argues that disparities in differential attainment for minoritized groups can be addressed by focusing on the unequal distribution of social, economic and cultural capital.
Anatomical drivers of stomatal conductance in sorghum lines with different leaf widths grown under different temperatures
Authors: Al‐Salman Yazen , Cano Francisco J. , Pan Ling , Koller Fiona , Piñeiro Juan , Jordan David , Ghannoum Oula
Published: April 2023

Sustaining crop productivity and resilience in water‐limited environments and under rising temperatures are matters of concern worldwide. We investigated the leaf anatomical traits that underpin our recently identified link between leaf width (LW) and intrinsic water use efficiency (iWUE), as traits of interest in plant breeding. Ten sorghum lines with varying LW were grown under three temperatures to expand the range of variation of both LW and gas exchange rates. Leaf gas exchange, surface morphology and cross‐sectional anatomy were measured and analysed using structural equations modelling. Narrower leaves had lower stomatal conductance (gs) and higher iWUE across growth temperatures. They also had smaller intercellular airspaces, stomatal size, percentage of open stomatal aperture relative to maximum, hydraulic pathway, mesophyll thickness, and leaf mass per area. Structural modelling revealed a developmental association among leaf anatomical traits that underpinned gs variation in sorghum. Growing temperature and LW both impacted leaf gas exchange rates, but only LW directly impacted leaf anatomy. Wider leaves may be more productive under well‐watered conditions, but consume more water for growth and development, which is detrimental under water stress.
Pattern of MUC6 expression across 119 different tumor types: A tissue microarray study on 15 412 tumors
Authors: Dwertmann Rico Sebastian , Schliesser Sebastian J. A. , Gorbokon Natalia , Dum David , Menz Anne , Büscheck Franziska , Hinsch Andrea , Lennartz Maximilian , von Bargen Clara , Bawahab Ahmed A. , Luebke Andreas M. , Hube‐Magg Claudia , Fraune Christoph , Lebok Patrick , Clauditz Till S. , Jacobsen Frank , Sauter Guido , Uhlig Ria , Steurer Stefan , Minner Sarah , Marx Andreas H. , Simon Ronald , Burandt Eike , Hoeflmayer Doris , Krech Till , Bernreuther Christian
Published: April 2023

Mucin 6 (MUC6) is a secreted gel‐forming mucin covering the surfaces of gastrointestinal and other tissues. Published work demonstrates that MUC6 can also be expressed in several cancer types and can aid in the distinction of different tumor entities. To systematically analyze MUC6 expression in normal and cancerous tissues, a tissue microarray containing 15 412 samples from 119 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. At least a weak MUC6 positivity was seen in 50 of 119 (42%) tumor entities. Thirty‐three tumor entities included tumors with strong positivity. MUC6 immunostaining was most frequent in mucinous carcinomas of the breast (44%), adenocarcinomas of the stomach (30%–40%) and esophagus (35%), and neuroendocrine carcinomas of the colon. Strong MUC6 staining was linked to advanced pT stage (p = 0.0464), defective mismatch repair status and right‐sided tumor location (p < 0.0001 each) in colorectal cancer, as well as to high tumor grade (p = 0.0291), nodal metastasis (p = 0.0485), erb‐b2 receptor tyrosine kinase 2 positivity (p < 0.0001) and negative estrogen receptor (p = 0.0332)/progesterone receptor (p = 0.0257) status in breast carcinomas of no special type. The broad range of tumor types with MUC6 expression limits the utility of MUC6 immunohistochemistry for the distinction of different tumor types.
Bank on it: Do Local Banks Contribute to Rural Community Prosperity?*
Authors: Mencken F. Carson , Carpenter Craig Wesley , Lotspeich‐Yadao Michael , Tolbert Charles M.
Published: April 2023

Recent research on the restructuring of the financial industry from local banks to interstate conglomerates has raised questions about the impact on nonmetropolitan economies. In this paper, we develop two competing hypotheses and scrutinize the impact of local bank concentration (percent banks that are locally headquartered) on four measures of economic growth from 1980 to 2010 in metropolitan, micropolitan, and non‐core Commuting Zones (CZs). We employ fixed effects panel regression models for the 1980–2010 time frame. We find that local bank concentration is positively related to business births and establishment dynamics in non‐core and micropolitan CZs. The effects of local banking on measures of income and wages fail to show consistent effects. There are no positive local banking concentration effects on economic growth in metropolitan CZs during this time frame. Implications for theory, research, and policy are discussed.
Characterization of the novel HLA‐A*24:587 allele by sequencing‐based typing
Authors: Cargou Marine , Elsermans Vincent , Top Isabelle , Wojciechowski Elodie , Visentin Jonathan
Published: April 2023

HLA‐A*24:587 differs from HLA‐A*24:02:01:01 by one nucleotide substitution in codon 220 in exon 4.
A prospective assessment of the time required to obtain one unit of fresh whole blood by civilian phlebotomists and Army laboratory technicians (68 K)
Authors: Mancha Fabiola , Mendez Jessica , April Michael D. , Fisher Andrew D. , Hill Ronnie , Bynum James , Cap Andrew P. , Corley Jason B. , Schauer Steven G.
Published: April 2023

Background

Resuscitation with blood products improves survival after major hemorrhage. Blood product administration at or near the point‐of‐injury (POI) amplifies this benefit. Size, weight, and cold‐chain management challenges all limit the amount of blood medics can carry. Warm fresh whole blood (WFWB) transfusions from a pre‐screened donor within the unit represent an alternative source of blood at the POI. We measured the time required for civilian and Army technicians performing phlebotomy frequently to obtain one unit of blood to serve as a goal metric for combat medics being trained in this skill.

Methods

We gathered demographic and experience data along with proportion of first intravenous cannulation attempt success, time to blood flow initiated, and time to unit draw complete.

Results

We prospectively enrolled 12 civilian phlebotomy technicians and 10 Army laboratory technicians performing whole blood collections on 50 and 68 donors respectively. The mean time from setup to needle insertion was 3.7 min for civilians versus 4.2 min for Army technicians. The mean time from blood flowing to the bag being full was 10.7 min versus 8.4 min for civilians versus Army technicians respectively. The mean bag weights were 514 g versus 522 g. First‐pass intravenous cannulation success was 96% versus 98% respectively.

Conclusions

We found a high first intravenous cannulation attempt success among both the civilian and Army technicians. Medians times were <5 min to obtain venipuncture and <11 min to obtain one unit. These findings provide time‐based benchmarks for potential use during transfusion training among military medics.
Novel fibroblast phenotypes in homeostasis and chronic inflammation: From functions to potential regulators
Authors: Miki Haruka , Manresa Mario C.
Published: April 2023

Fibroblasts are essential components of the stroma, sustaining a variety of tissues and being key to the process of tissue repair after injury. Their role in tissue repair has been attributed to their ability to acquire a contractile, extracellular matrix‐producing phenotype known as myofibroblasts. This property is primarily dependent on their response to the pleiotropic cytokine transforming growth factor‐β1. Until recently, the potential role of fibroblasts in other homeostatic and disease‐related processes was less well understood. Although in vitro studies indicated that fibroblasts are able to respond to and secrete inflammatory mediators, definitive evidence of their contribution to chronic inflammation was limited. However, the emergence of techniques that allow exploration of tissues at the single cell level has challenged the previous paradigms on fibroblast identity and functions, and has led to the discovery of significant diversity, showing the presence of fibroblasts with alternate transcriptional profiles in a variety of tissues. These studies have also suggested potential roles of novel fibroblast subtypes as regulators of epithelial homeostasis and renewal, inflammatory cell infiltration and activation, and antigen presentation. Here, we provide a comprehensive review of the recent literature on fibroblast diversity in the digestive tract, skin, lungs and joints. We also review evidence of their contribution to the regulation of homeostasis and chronic inflammation, as well as their interactions with other cells in various tissue compartments. We discuss evidence of different factors involved in the control of fibroblast function, addressing the role of various cytokines, transcription factors and epigenetic changes, as well as microenvironmental factors, including extracellular matrix stiffness, hypoxia, and metabolic shifts.

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Transmission of Visible, Infra-Red, and Ultra-Violet Radiation Through Fog: With Reference to Developing Aids in Fog Aviation
Authors: Anderson S. Herbert
Published: April 2023

Fog menaces all forms of transportation, particularly air travel. To study the visibility of beacons through fog, a laboratory method of producing fog was developed. Fogs of two types have been made with a range of densities corresponding to natural fogs in which the visibility varies from 20 ft. to 2000 ft. Transmission of radiation through these fogs has been measured, covering a wave-length range of 0.30 to 0.40 micron in the ultra-violet, 0.40 to 0.75 micron in the visible, and 0.75 to 2.6 microns in the infra-red parts of the spectrum. The conclusion is that the penetration of infra-red through fog is many times that of visible light, the ratio depending upon the distance and the nature of the fog, and consequently infrared gives promise in developing aids for fog landing, especially in localizing a fog-obscured airport.
Engine Cowl Rings
Authors: Boyd Paul M.
Published: April 2023

The radial air-cooled engine is a popular power plant. Its reputation with the public can be said to date from the summer of 1927, when it demonstrated its reliability and ruggedness in the hazardous long-distance flights of that year. Since then many refinements and improvements have been brought forth, but the drag of the radial engine has always been high. Large frontal areas are inherent with the radial engine, and as the power output of the present radial has increased, so has its frontal area. Until recently it did not seem likely that the radial engine could ever successfully compete with the liquid-cooled type as the power plant for use in high-speed airplanes. However, with the development of the N.A.C.A. type of cowling and the engine cowl ring by various aerodynamical laboratories, the big gap existing in actual ship’s performance between these two widely divergent power plants has been eliminated.
Some Design Factors Which Influence Aviation Insurance Rates
Authors: Lederer Jerome
Published: April 2023

The five principal factors which insurance underwriters consider when they are asked to estimate aviation hazards are: (1) the aircraft itself, (2) operational management, (3) the pilot, (4) the geographical limits, and (5) the uses for which the aircraft will be insured. The relative importance of these factors depends on the coverage being considered, and the connection of various aircraft design factors with these coverages is set forth.
Airship Factory and Dock of the Goodyear Zeppelin Corporation
Authors: Watson Wilbur J.
Published: April 2023

The paper describes the airship factory and dock at Akron of the Goodyear Zeppelin Corporation, covering its design and construction, a study of wind pressures, a comparison with other hangars, the docking problem, the design of the doors and the roof covering, with the details of the preparation of the site, the substructure, the structural-steel fabrication and the erection methods employed, the mechanical and the electrical equipment, and the floors, the fire protection, and the helium storage.
The Hydraulic Jump and Related Phenomena
Authors: Bakhmeteff Boris A.
Published: April 2023

In this paper the author presents certain results which were obtained by him in studying the hydraulic jump over a period of years. A general characteristic of the “state” of flow is introduced through the notion of “Kineticity of Flow,” expressed numerically by a “Kinetic flow factor.” The fundamental relations, referring to the jump, are presented in generalized form. A physical basis is offered to explain the different forms in which the jump occurs. The practical important cases of a jump below a sluice and at the foot of a weir are studied in detail. Formulas are devised and charts given which make it possible to solve different problems of engineering practice.
Celluloid as a Medium for Photoelastic Investigation
Authors: Edmonds R. H. G. , McMinn B. T.
Published: April 2023

This paper deals with the physical properties of celluloid and their bearing on its use in the photoelastic method of stress determination. The authors present curves and test data on American-made celluloid, showing stress-strain and time-creep relations. Their results indicate that the physical constants for this material are not fixed, but have a consistent variation with speed of loading. Their work shows that celluloid is not perfectly elastic under any condition of loading. They point out some important peculiarities in the interrelation between photoelastic color and stress and strain.
Design of Columns of Varying Cross-Section
Authors: Dinnik A.
Published: April 2023

In this paper the author develops formulas for special cases of columns of varying cross-section. The uses of these formulas are illustrated by many problems from practice, and tables of constants for every special case facilitate the application of the theory without going into the solution of differential equations.
Conversion of Coal-Fired Boilers and Furnaces to Gas Firing
Authors: Edwards William D.
Published: April 2023

This paper deals with the use of natural gas in the City of Memphis, the methods and data used in making estimates of gas consumption, the application of the degree-day to this end, and the actual operating data for various types of plants converted to gas fuel.
Solubility of Calcium Salts in Boiler Water
Authors: Straub Frederick G.
Published: April 2023

The purpose of this investigation has been to determine the behavior at elevated temperatures of the various chemical compounds found in boiler waters. This includes a study of the solubility of the various compounds under conditions simulating those found in high-pressure boilers. Such a study involves the determination of the solubility of the more insoluble compounds such as calcium carbonate and calcium sulphate separately and combined, as well as in the presence of the more soluble salts such as sodium carbonate, sodium sulphate, and sodium hydroxide. These results should aid materially in determining the proper water treatment for high-pressure-boiler operation.
Automatic Internal Grinder
Authors: Blood H. L.
Published: April 2023

Internal grinding, originally a toolroom operation, has been demanded for such a large number of parts that it has become necessary to develop machines that would grind the holes at the lowest possible cost. This development has culminated in the automatic internal-grinding machine which positively determines the size of the hole and which requires no gaging on the part of the operator, who merely puts the work into the chuck and starts the cycle of operations. The improvements on the machines and their adaptation for special grinding jobs are described.
Small Tools and Gaging for Interchangeable Manufacture
Authors: Bryant E. J.
Published: April 2023

To secure interchangeable parts in continuous production, proper gaging is necessary. The author describes the specifications by which the design of the correct gage can be greatly simplified. The methods by which the manufacture of reamers, taps, threading dies, drills, etc., can be held to uniformity, within proper tolerances, are covered in the paper.
Conventional Gages and Their Application to Duplicate Production
Authors: MacLaren Thomas F.
Published: April 2023

The attainment of greater accuracy in present-day machines has necessitated improved gaging facilities. This article briefly treats of some important considerations in the design of gages, a description of a few special applications, and the need for standardization in gaging methods relative to machine-shop practice.
Properties of Hydrocarbon Mixtures at High Pressures
Authors: Lewis W. K. , Luke C. D.
Published: April 2023

The paper provides a comparatively simple method for the design of apparatus handling complex hydrocarbon mixtures at extraordinary pressures. The computation methods outlined enable one to calculate the density of any vapor, mixed or otherwise, at any temperature and pressure; the heat effect of any heating or cooling operation, whether conducted at constant pressure or changing pressure; the equilibrium between vapor and liquid at any temperature and pressure; the equilibria and changes in concentration throughout the tower in any operation of rectification or absorption, at whatever pressures they may be conducted; and the isothermal reversible work of compression of vapor mixtures, whatever the pressure range. These computation methods enable the refining engineer to design high-pressure equipment and operations with a high degree of precision.
A Study of Primary Metering Elements in 3-In. Pipe
Authors: Beitler S. R. , Bucher Paul , Barnes T. C.
Published: April 2023

This paper presents part of the results of a study of the performance of a complete series of primary metering devices in a 3-in. pipe line. The devices tested were as follows: Three types of orifices (concentric, eccentric, and segmental) with diameter ratios varying from 20 to 90 per cent; flow nozzles with diameter ratios varying from 30 to 88 per cent; also two venturi tubes with three throat sections each, with diameter ratios varying from 33 to 50 per cent. Discharge coefficients are given for these elements, using water as the metered fluid, with a wide range of differential heads. Coefficients are given also on some of the elements where superheated steam at various temperatures was the metered fluid. The effect of sharpness of orifice edge, of roughness of approach pipe, and of surface finish of flow nozzle on water coefficients is shown. The effect of temperature upon the diameter of the primary device and upon the coefficient of discharge for steam is also given.
Blood Albumin and the Woodworking Industry
Authors: Smith C. B.
Published: April 2023

Blood-albumin glue is probably the latest commercial adhesive. Its first use apparently was in the making of plywood canoes. The World War created an intensive demand for water-resistant plywood glues, and much of it was used in airplane and boat construction. Its source is beef blood as a by-product of the packing-house industry. It is essentially a hot-press glue. There are several types, all a mixture of blood albumin, water, and an alkali.
How Dry Should Wood Be for Various Industrial Uses?
Authors: Henderson H. L.
Published: April 2023

The testing of wood for industrial uses is stated to be best made on its moisture content. Much wastage in manufacture is declared to be due to lack of knowledge of this fact, and the consequent antiquated test methods in use in the wood-goods manufacturing industries. The effect of climate on the ideal moisture content is said to count for little. Furniture, flooring, and other products are dried to about 6 per cent, wherever manufactured. A table is given of the equilibrium moisture content of wood at various atmospheric conditions and also a table of the dryness requirements for a wide variety of wood products.
Double-End Tenoners and Their Use
Authors: Mansfield J. H.
Published: April 2023

The paper describes the construction, development, and use of the double-end tenoner from the original belt-driven machine with babbitted bearings, with its limited range of cutting stock to length and making tenons, to the present motorized ball-bearing machine, with its broad range of sizing, tenoning, shaping, dadoing, relishing, notching, and dovetailing all rectangular parts in two passes through the machine, and making certain styles of lock joints. It is by far the nearest to a universal use machine yet developed for a production woodworking plant.
The Economics of Air Transport
Authors: Breguet Louis
Published: April 2023

In this up-to-date analysis of the economic problems of aerial transportation, the author presents a revision of the basic formula for calculating the net cost of air transport, gives examples of its application, and discusses the following problems: (a) Application to a simple case; (b) the importance of overhead expense; (c) the influence of speed on net cost; and (d) flight at high altitudes.
Survey of Problems of Thin-Walled Structures: I—The Problem of Elastic Stability
Authors: Donnell L. H.
Published: April 2023

Increasing loading on a structure brings about “failure,” either in the familiar way in which the material does not stand up at some point or by the way in which a part under compression reaches a state of instability and buckling occurs. The first of these modes of failure is a failure of material; the second is of a more structural character. The paper discusses preliminary stress calculations, independence of the two types of failure, characteristics of structures influencing each type of failure, relation of the characteristics to weight saving, secondary failures, experimental and analytical methods of studying buckling problems, comparison of different methods of analysis, the simple strut, column formulas, other stability problems, and possible methods of analysis of monocoque construction.
Principle of Similitude as Applied to Research on Thin-Sheet Structures
Authors: Younger John E.
Published: April 2023

Any program of research on airplane structures must give consideration to the design and stress-analysis requirements of the Army, the Navy, and the Aeronautics Branch of the Department of Commerce. The requirement that the breaking strength of the structure or of its component parts must be the basis of strength calculations places a difficult problem before research men. Hooke’s law of proportionality of stress to strain forms the basis of the mathematical theory of elasticity, and above the proportional limit of the material (which for aircraft metals may be taken as the elastic limit), formulas based on this law do not apply. Formulas are derived from the standpoint of the mathematical theory of elasticity which fit the data quite accurately for stresses within the elastic limit. For stresses above the elastic limit an empirical formula will be necessary. In so far as the practical use of the data is concerned, since stresses above the proportional limit are involved, a derived formula may not be as desirable as the experimental curve. The value of the experimental curve depends very greatly upon the proper selection of the coordinates and the parameters.
The Rolling and Extrusion of Aluminum and Its Alloys
Authors: Streeter Robert L.
Published: April 2023

This paper outlines the history of the development of the manufacture of aluminum sheet, wire, and rod. It then discusses the growth of the demand for aluminum alloys and the problems that research laboratories and engineers had to solve before the manufacture of these alloys became practicable. A description is given of mills for rolling standard structural shapes, with reports on tests made to ascertain the power required to roll strong alloys. The extrusion of aluminum alloys is discussed, touching on the reasons for using extrusion in place of rolling, and explaining the limitations of the extrusion method of manufacturing shapes.
Dissolving of Concentrated Industries
Authors: Coes Harold V.
Published: April 2023

Far-reaching changes in the pattern of industrial organization are discernible from the small changes that are now taking place in the evolutionary process of American industry. These changes, just discernible in some instances, seem to indicate the trend toward a better balance between urban and rural population, the development of new raw materials for industry and new sources for existing materials from agriculture, the location of industrial plants in agricultural communities to permit of lower costs and greater economic security for the workers, the greater use of branch plants and branch assembly plants to afford access to and to better serve the domestic market, a limitation of the concentration of industrial units in the large cities, and the dissolving of some of these concentrated units by scientific relocation to more suitable places. As the process goes on it should result in a better total economic balance, greater economic security to all, and more wholesome enjoyment of life by all. In bringing about and furthering these changes, the engineer, guided by economic and scientific facts, principles, and laws, will be an important factor and will play a leading part. More and more, and more than ever before, the engineer must become economic minded if he is to play his part well and serve society as it should be served.
Planning and Scheduling
Authors: Polakov Walter N.
Published: April 2023

The process of planning presupposes an aim to be attained, and therefore it is a purposeful action. It may or may not have a clearly conceived means for this achievement or a clearly determined order of procedure. These two elements, the means or facilities for the achievement of the aim and the order of their utilization, determine the quality of planning. The author analyzes the requirements, cites the work of Taylor and of Gantt, lists the preferred methods in use, and reaches definite conclusions, summing up with: Planning is a reversible process tending to reduce the element of random.
Fundamentals of Training
Authors: Via G. Guy
Published: April 2023

Fundamental principles involved in a modern training program are outlined. Beginning with an accepted definition of training, certain postulates are set up: (1) The careful selection of the learner. (2) The careful selection of the instructor. (3) The development of a suitable system of grading. (4) The analysis of the business for its training content. (5) The objectives of the training program. In selecting the candidate for training, attention must be focused on (a) physical, (b) manual, (c) mental, and (d) moral qualifications. A certain minimum of each capacity should be evident. The instructor must be a craftsman, a teacher, a psychologist. He must be a leader, an adviser, and a friend. A method of grading somewhat out of the ordinary is developed from Richard’s formula for effective training. This system uses the performance of the average worker as a standard, rather than that of an imaginary ideal worker who has never existed. The instructor should analyze the business thoroughly for its instructional content, regrouping the units according to the learning difficulty from simple to complex. This analysis may often be turned to useful account by the thoughtful executive in comparing the worth of various employees, reviewing the processes of the business, etc. The paper is concluded with the reminder that the perpetuation of a business depends upon the continual absorption of new blood, which gives to the study of training an unusual significance.
Application and Design of the Floating Drive for Conveyors
Authors: Preble N. H.
Published: April 2023

Increasing demand for longer conveyors and conveyors more heavily loaded per foot of length has brought about the necessity of using multiple drives on a single strand of conveyor chain in order to keep the weight and cost of chain and carrier units down to a reasonable point. To meet this requirement there has been developed a floating type of driving mechanism so arranged that two or more drives located at considerable distances from each other will automatically synchronize as to speed so as to maintain proper driving action at each drive point. The paper describes in detail the development of this design and its application to various types of conveyors, pointing out the advantages obtained through its use not only as a synchronizing means, but also in properly distributing the total load, in effecting smoother operation, in replacement of the standard form of shear pin, etc.
Grinding Cemented Tungsten- and Tantalum-Carbide-Tipped Tools Economically
Authors: Highducheck J. M.
Published: April 2023

Present-day speeds and efficiency in handling enormous production have been made possible only by the development of modern tool equipment and set-ups which hasten service and assure quality. In this paper the author outlines a tungsten-carbide-grinding set-up which is efficient and profitable.
A Test Method for Determining the Quantitative Effect of Tube Fouling on Condenser Performance
Authors: Hardie P. H. , Cooper W. S.
Published: April 2023

The purpose of this paper is to show the importance and practicability of adding another vital measurement to condenser tests which will give a specific value for the degree of tube fouling existing at the time of the test. Since the majority of condenser installations are subjected to some type of fouling, and since conventional means of cleaning seldom if ever restore the tubes to their original state, it is evident that the performance of many condensers cannot be correctly appraised without a knowledge of their cleanliness factors. Cleanliness factor is the term used to express the degree of tube fouling, and is defined as the ratio of the heat transmittances of fouled and new tubes subjected to the same operating conditions. Several methods of measuring the cleanliness factor are described, and data from six tests are included. The importance of avoiding inconsistent procedures in making the measurements and computing the data is stressed.
The Pressure of Saturated Water Vapor in the Range 100 C to 374 C
Authors: Osborne N. S. , Stimson H. F. , Fiock E. F. , Ginnings D. C.
Published: April 2023

The method and apparatus employed, and the measurements made in this determination of the vapor pressure of water are described, and the results obtained are given and formulated.

The method used was the “static method” in which the pressure is determined at the stationary boundary between the liquid and vapor phase in equilibrium at a constant temperature in a closed container.

The container for the water sample was a calorimeter specially built for high-pressure work. Pressures were measured by a precision piston gage which balances the pressure by the gravitational force on a piston loaded with weights. Temperatures were measured by platinum-resistance thermometers supplemented by thermoelements.

A total of 394 measurements were made at 38 temperatures so distributed as to facilitate formulation of the pressure-temperature relation.

The formulation was made by using an empirical equation which was fitted to the results in two temperature ranges. Values of pressure and its derivative with respect to temperature are tabulated from this formulation in standard atmospheres, centibars, and kilograms per square centimeter at each degree centigrade, and in pounds per square inch at each degree fahrenheit. This provides a mutually consistent group of vapor-pressure tables in convenient form for practical working tables of fundamental steam data.

It is estimated that the results are reliable to 3 parts in 10,000.
Horsepower and Tractive Effort of Steam Locomotives (Locomotive Ratios)
Authors: Lipetz A. I.
Published: April 2023

Cole’s Ratios, by the use of which the tractive-force curves of locomotives can be calculated and plotted, knowing certain of the locomotive dimensions, have been successfully used for the past 15 to 18 years. The Type E superheater, the feedwater heater, long-travel valve motions, and certain changes and refinements in proportion and design have tended to increase the power of steam locomotives built since 1920. The power calculated by Cole’s method does not therefore accurately represent the actual power of modern steam locomotives. In his paper the author reviews the work of Cole and others, checking it against available test-plant and road-test data, and finds that some of Cole’s constants still hold good in a great many cases. Others he finds it necessary to modify not only as to the figures, but also as to the method itself.

He develops constants for a new, easily applied method, based on boiler evaporation and a factor depending on the number of revolutions of the driving wheels, for use in connection with modern locomotives, and suggests the continued use of Cole’s Ratios for locomotives in the design of which the modern factors are not included.
Canadian Pacific Multi-Pressure Locomotive: Its Machinery, Locomotive Chassis, and Tender
Authors: Ennis J. B.
Published: April 2023

The remarkable thermal efficiency of the multi-pressure locomotive of the German State Railways has commanded the attention of the entire railroad world. The introduction of this type of locomotive to American practice involves far more than the mere reproduction of the German machine, for the difference between the problems of availability, maintenance, and proportionate output on the two continents is profound. The author gives the reasons for the adoption of the type of engine selected to introduce the multi-pressure principle to American service, and describes the leading features of the construction of the chassis and cylinders.
Laminating With Phenolic Resins: Some Practical and Theoretical Considerations Involved
Authors: Merritt Ericsson H.
Published: April 2023

Phenolic resins as wood adhesives have qualities that have been long known, but commercial application has been retarded because of the cost. The method of manufacturing plywood is said to be revolutionary in the manner of applying the adhesive. The paper describes four ways in which these resins may be applied as an adhesive between two or more plies of wood or other material, these being as a varnish, as a film, as a dry powder, and as a colloidal solution. The author concludes that, despite objections raised against the high temperatures employed in laminating with resins, they constitute an ideal adhesive for thin panels.
Fundamentals of Knife-Cutting Veneers
Authors: Roberts John N. , Roberts John R.
Published: April 2023

In the last 25 years the per capita consumption of veneer in the United States has increased nearly 500 per cent. The manufacturers of veneer and its subproduct, plywood, are constantly finding new uses, better processes, and improved equipment. The principal methods of veneer cutting are undergoing marked changes and developments, requiring a clear understanding of the fundamental principles.
Airplane-Wing Trussing
Authors: Mock Richard M.
Published: April 2023

The paper compares and analyzes the existing types of wing bracing in conventional airplanes. The internal structure of airplane wings is closely linked with the external system of support, and therefore the paper covers some of the methods of internal bracing, but is mainly devoted to systems of external bracing. The efficiency of the wing trussing is a function of the size of the machine. For a low-wing design the wire-braced wing seems quite efficient, providing the span is not too great compared with the height of the plane. For a larger span, subject to high wing loadings, the high-wing monoplane is very efficient, though there are many points in favor of both the braced and the cantilever wing. For the very large plane, with a normal fuselage, the biplane bracing is advantageous. On large designs where a part of the load can be carried in the wings the monoplane is better aerodynamically.
Stresses in Retaining and Centering Rings for Turbine-Generator Rotors
Authors: Patterson R. , Harms D. H.
Published: April 2023

In this paper the authors deal theoretically with the distribution of stresses throughout the system of parts enclosing the rotor coil ends of a turbine generator.

This system of parts consists of a disk of uniform cross-section, a cylinder, and a part of the shaft. These parts are fastened together by means of fairly heavy shrink fits and therefore, in the development of formulas for the stresses, the effect of this shrinkage, as well as that of rotation, must be considered.

Since these parts must remain integral for the design considered, the importance of being able to predetermine the speeds at which the various parts may become free is apparent. Therefore formulas were developed for these speeds subject to the boundary conditions which were set up.

An example is given for which the distribution of stresses for two cases is plotted. These two cases are, respectively, for the generator at standstill and at operating speed.

A summary of the significant results is given at the beginning, and a discussion of the main points of interest at the close of the paper.
Thermal Stresses in Thin-Walled Cylinders
Authors: Kent Clarence H.
Published: April 2023

The author, using Föppl’s method, investigates the stresses in (1) a cast-iron cylinder 30 in. long, 20 in. mean diameter, and 1 in. in wall thickness, with the temperature 100 deg. fahr. higher inside than outside; (2) the same cylinder and temperature conditions, but with cylinder supported at the ends; and (3) a steel cylinder of same size with flat heads rigidly attached and subjected to 500 lb. per sq. in. internal pressure. Constant and variable temperature gradients are considered, both in axial and radial directions.
Jets From Manifold Tubes
Authors: Kunz Jakob
Published: April 2023

After a brief reference to previous work on the subject, the author develops an expression for the discharge coefficient. He then determines the flow of a sheet of water through a slot of infinitesimal width in the wall of a pipe by means of a variable and a constant discharge coefficient. The slot is then conceived of as a row of separate holes and the flow problem is solved by means of difference equations for a variable and a constant discharge coefficient. A special case is also considered in which the pipe has a hole through its further (closed) end.
Spiral Springs: A New Theory Regarding Their Stress, Strain, and Energy Functions
Authors: Van den Broek J. A.
Published: April 2023

The paper presents a new theory relative to the stress, strain, and energy functions of spiral springs. This theory differs from the current one in that it takes into account the large deformations implied in the action of spiral springs. In the light of the theory, definite recommendations are made with reference to the design and mounting of spiral springs. It is suggested that springs may be loaded in such a manner as to eliminate all locally overstressed points as well as all friction between leaves. No grease or graphite, therefore, need be employed and the efficiency of spiral springs may thus be increased: (1) By the utilization of space otherwise occupied by a lubricant, from 10 to 20 per cent; (2) by the elimination of all friction between leaves, from 20 to 40 per cent; and (3) by the elimination of locally overstressed points, from 40 to 100 per cent.