bluuebunny/crossref_metadata_2025 huggingface dataset:
Encapsulation of chia (Salvia hispanica) oil on an industrial scale to protect the omega‐3 against ultra‐high‐temperature (UHT) damage and lipid oxidation
Authors: Rodrigues Juliana Burger , Prata Ana Silvia , Bollini Helena Maria André
Published: December 2022

Chia oil has a high content of α‐linolenic acid that is susceptible to oxidation and can hamper its application in thermally processed food. A complex coacervation was tested as an alternative to minimize the impact of processing on chia oil quality. These particles were also produced on an industrial scale and had no chemical or enzymatic cross‐linking. Instead, gradual ethanol baths were used for matrix solidification. The particles produced with gelatin and gum Arabic (4%wt. of polymers) had 84.66% of encapsulation efficiency, with an average size of 27.9 μm, and they resisted the oven drying process, fully recovering their original shape after the rehydration process. These particles were added to chocolate milk, which was submitted to an ultra‐high‐temperature treatment. Morphological analysis revealed the presence of whole particles in the milk after the heat treatment, indicating that these microparticles can withstand high temperatures and pressure. Monitoring the oxidative process in free chia oil and encapsulated chia oil samples showed that these particles were effective in protecting against lipid oxidation of the oil.

Practical Applications

Chia oil is a rich plant‐derivated source of omega‐3. As a sensitive component, it must be protected from being incorporated into food products. Many studies in the literature purpose encapsulation as a tool to overcome the sensitivity of such compounds, but there is no investigation of the resistance of the particle when submitted to industrial processing such as heat treatment. Here, chia oil was successfully encapsulated by complex coacervation on the biggest scale than normally is done, and the resistance of such particles in chocolate milk was proved after an industrial heat process (ultra‐high‐temperature treatment). This paper may give support to researchers or industry experts for product development.
Determinants of dietary diversity among children 6–23 months: a cross‐sectional study in three regions of Haiti
Authors: Sebai Ines , Decelles Stéphane , Batal Malek
Published: December 2022

Background

The prenatal, perinatal, postnatal and nutritional (A3PN) support study was a 4‐year initiative aimed to reduce maternal mortality in Haiti. A cross‐sectional study was developed to collect the baseline data for evaluation purposes of the A3PN. This study aimed to determine the factors contributing to dietary diversity (DD) in Haitian children aged 6–23 months.

Methods

A cross‐sectional study during two seasons (the lean season and the harvest season) was carried out in Haiti to assess the DD of children and their mothers using non‐quantitative 24‐h recalls. Indicators of DD were minimum dietary diversity for children (MDD‐C) and minimum dietary diversity for women (MDD‐W). Mid‐upper arm circumference was measured in women and children, and food security was assessed using the Household Hunger Scale. Focus groups were also conducted to gain a better understanding of the quantitative findings.

Results

Only 7.3% of the children included in this study met the MDD‐C. Factors associated with MDD‐C were the season (odds ratio [OR]: 0.141 [0.039–0.513]), land ownership or rental (OR: 4.603 [1.233–17.188]), maternal education (OR: 0.092 [0.011–0.749]), the mother's responsibility for the main or secondary source of income for the household (OR: 2.883 [1.030–8.069]) and her DD (OR: 5.690 [1.916–16.892]). Focus groups revealed the existence of various food restrictions.

Conclusions

The results indicated that the low prevalence of MDD‐C in three regions of study in Haiti is indicative of a serious public health concern that might be further aggravated by local food taboos. They also suggest that to fight against hunger, it is necessary to focus on women's well‐being.
Principal Portfolios
Authors: KELLY BRYAN , MALAMUD SEMYON , PEDERSEN LASSE HEJE
Published: December 2022

We propose a new asset pricing framework in which all securities' signals predict each individual return. While the literature focuses on securities' own‐signal predictability, assuming equal strength across securities, our framework includes cross‐predictability—leading to three main results. First, we derive the optimal strategy in closed form. It consists of eigenvectors of a “prediction matrix,” which we call “principal portfolios.” Second, we decompose the problem into alpha and beta, yielding optimal strategies with, respectively, zero and positive factor exposure. Third, we provide a new test of asset pricing models. Empirically, principal portfolios deliver significant out‐of‐sample alphas to standard factors in several data sets.
Metabolic effects of kidney donation: A Bayesian analysis of matched cohorts
Authors: Wuttiputhanun Thunyatorn , Udomkarnjananun Suwasin , Hanprathet Nitt , Jiamjarasrangsi Wiroj , Townamchai Nattavudh , Avihingsanon Yingyos , Katavetin Pisut
Published: December 2022

The kidney is a notable site of glycolysis, gluconeogenesis, and fatty acid oxidation. Loss of a kidney after kidney donation might, therefore, affect the glucose and lipid metabolism of the donors. This matched cohort study investigated the effect of nephrectomy on glucose and lipid metabolisms using Bayesian hypothesis testing. There were 77 pairs of matched donor‐control pairs in the present study. Clinical and laboratory data of the participants, at baseline and 1‐year, were extracted from electronic medical records. Comparisons between donor and control groups were performed using the Bayesian independent samples t‐test or Bayesian Mann–Whitney test. The Bayes Factor for alternative hypothesis over null hypothesis (BF10) was used to compare the two competing hypotheses. The BF10 of 3 or more was considered evidence for the alternative hypothesis. Comparing changes from baseline to 1‐year between donors and controls, the BF10 of triglycerides, high‐density lipoprotein cholesterol (HDL‐C), triglyceride‐glucose (TyG) index of insulin resistance, and estimated glomerular filtration rate (eGFR) were 7.95, 3.96, 30.13, and 1.32 x 1041, respectively signifying that the change of these variables in the donors differed from those in the controls (alternative hypothesis). Triglyceride, HDL‐C, and TyG index of the donors increased more than those of the controls while eGFR of the donor decreased more than that of the controls. Our data suggest that triglycerides and insulin resistance increase after donor nephrectomy. Kidney donors should be informed about these metabolic changes and should adhere to lifestyle recommendations that may mitigate insulin resistance.

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Brain alterations in sensorimotor and emotional regions associated with temporomandibular disorders
Authors: Yin Yuanyuan , He Shushu , He Ning , Zhang Wenjing , Luo Lekai , Chen Lizhou , Liu Ting , Tian Mi , Xu Jingchen , Chen Song , Li Fei
Published: December 2022

Objectives

Temporomandibular disorders (TMD) are characterized by sensorimotor and psychological dysfunction, with evidence revealing the implication of a dysfunctional central nervous system. Previous magnetic resonance imaging (MRI) studies have reported brain alterations in TMD, but most studies focused on either structure or function by a single modality of MRI and investigated static functional connectivity (FC) in TMD. By combining structural and functional MRI data, the present study aimed to identify brain regions with structural abnormalities in TMD patients and examine static and dynamic FC seeded by these regions to investigate structural brain alterations and related disrupted FC underlying the pathophysiology of TMD.

Methods

We recruited 30 TMD patients and 20 healthy controls who underwent 3.0 T MRI scanning with T1‐weighted images using a three‐dimensional magnetization‐prepared rapid gradient‐echo sequence and resting state functional images using a gradient‐echo echo‐planar imaging sequence. Cortical thickness, volume, surface area, and subcortical volume were calculated, where brain areas with significant structural between‐group differences were treated as seeds for static and dynamic FC analyses.

Results

In this preliminary study, we found between‐group alterations in sensorimotor regions including decreased cortical thickness in the right sensorimotor cortex as well as decreased volume in the left putamen and associated reduced dynamic FC with the anterior midcingulate cortex; and alterations in emotion processing and regulation regions including decreased volume/surface area in the left posterior superior temporal gyrus and associated increased dynamic FC with the precuneus in TMD patients than controls, having all p < 0.05 with corrections for multiple comparisons.

Conclusion

Our findings of structural and functional abnormalities in brain regions implicated in sensorimotor and emotional functions provided evidence for the biopsychosocial model of TMD and facilitated our understanding of the pathophysiological mechanism underlying TMD. The associations between neuroimaging results and clinical measurements of TMD warrant further exploration.
One‐Stage Arthroscopic Multiple Ligament Reconstruction for Schenck IV Knee Dislocation
Authors: Li Chao , Liu Yubo , Zheng Runlong , Sun Jitong , Peng Wei , Deng Xiang‐Hua , Huang Xunwu
Published: December 2022

Purpose

Schenck IV knee dislocation patients have dissatisfactory knee function and return‐to‐sport rate with the existing treatment methods. The purpose of this study was to illustrate a one‐stage arthroscopic multiple ligament reconstruction method for treating Schenck IV knee dislocations.

Methods

A retrospective case series study was performed. All patients with a history of Schenck IV knee dislocation who underwent one‐stage arthroscopic multi‐ligament reconstruction from 2010 to 2018 were followed for 24 months. The outcomes, including general patient data, Lysholm scores, International Knee Documentation Committee (IKDC) scores, visual analog scale (VAS) pain scores, knee active range of motion, and complications, were reviewed. The data was analyzed with paired‐samples t‐test.

Results

A total of 12 patients, comprising nine males and three females, were followed up and reviewed. The mean age at the time of the surgical procedure was 40.3 ± 9.0 (22–57) years. The mean body mass index (BMI) was 24.6 ± 4.9 (15.2–32.5) kg/m2. The mean IKDC score and Lysholm score before surgery were 30.4 ± 6.1 (21–42) and 28.2 ± 6.2 (22–39), respectively. The average operation time was 121.8 minutes. The mean IKDC score and Lysholm score at the 24‐month follow‐up were 80.6 ± 6.5 (68–92) and 82.0 ± 7.5 (72–95), respectively. There were significant differences in the IKDC and Lysholm scores between the preoperative and 24‐month postoperative time points (p < 0.01). The mean knee range of motion was 124.6° ± 6.6° (115°–135°) at the 24‐month follow‐up. No major complications occurred.

Conclusions

The results of this retrospective study suggest that the new arthroscopic one‐stage multi‐ligament reconstruction technique is an effective way to treat Schenck IV knee dislocation with satisfactory postoperative knee function.
Cardiovascular imaging in conduction system pacing: What does the clinician need?
Authors: Ye Yang , Lv Yuan , Mao Yankai , Li Lin , Chen Xueying , Zheng Rujie , Hou Xiaofeng , Yu Chan , Gabriella Captur , Fu Guo‐sheng
Published: December 2022

Permanent pacemakers are used for symptomatic bradycardia and biventricular pacing (BVP)‐cardiac resynchronization therapy (BVP‐CRT) is established for heart failure (HF) patients traditionally. According to guidelines, patients’ selection for CRT is based on QRS duration (QRSd) and morphology by surface electrocardiogram (ECG). Cardiovascular imaging techniques evaluate cardiac structure and function as well as identify pathophysiological substrate changes including the presence of scar. Cardiovascular imaging helps by improving the selection of candidates, guiding left ventricular (LV) lead placement, and optimization devices during the follow‐up. Conduction system pacing (CSP) includes His bundle pacing (HBP) and left bundle branch pacing (LBBP) which is screwed into the interventricular septum. CSP maintains and restores ventricular synchrony in patients with native narrow QRSd and left bundle branch block (LBBB), respectively. LBBP is more feasible than HBP due to a wider target area. This review highlights the role of multimodality cardiovascular imaging including fluoroscopy, echocardiography, cardiac magnetic resonance (CMR), myocardial scintigraphy, and computed tomography (CT) in the pre‐procedure assessment for CSP, better selection for CSP candidates, the guidance of CSP lead implantation, and the optimization of devices programming after the procedure. We also compare the different characteristics of multimodality imaging and discuss their potential roles in future CSP implantation.
Detection of a unidirectional epicardial connection between the right‐sided pulmonary venous carina and the right atrium by pacing from a high‐density mapping catheter
Authors: Umemoto Shintaro , Takemoto Masao , Koga Tokushi , Tsuchihashi Takuya
Published: December 2022

We report a case of recurring, persistent atrial fibrillation (AF) in a patient with a unidirectional epicardial connection (EC) between the right‐sided pulmonary venous (PV) carina and the right atrium detected using a high‐density mapping catheter with a steerable introducer support, but not a conventional circular mapping catheter. This unidirectional EC could be steadily abolished by a radiofrequency delivery. Finally, we were able to successfully achieve complete PV antrum isolation. Thereafter, he has remained well without any AF.
Apium graveolens PI 181714 is a source of resistance to Fusarium oxysporum f. sp. apii race 4 in celery (A. graveolens var. dulce)
Authors: Epstein Lynn , Kaur Sukhwinder
Published: December 2022

Celery has little genetic diversity and is highly susceptible to the new fungal pathogen Fusarium oxysporum f. sp. apii (Foa) race 4. After screening an Apium graveolens germplasm collection for resistance to Foa race 4, we crossed celery cv. 'Challenger', which is Foa race 2‐resistant but Foa race 4‐susceptible and A. graveolens PI 181714, which is Foa races 2‐ and 4‐resistant but non‐celery type. After selfing F1s, we screened the F1S1 for race 4‐resistance and celery‐type and then selfed selected F1S1. Greenhouse and field trials indicate that three selected F1S2 families (76–8‐4, 76–8‐27 and 76–8‐36) are suitable as germplasm for celery breeders for resistance to Foa race 4. A F1S3 76–8–36‐124 is either fixed or nearly so for resistance to Foa races 4 and 2. Furthermore, quantitative PCR indicates that PI 181714 is resistant, rather than tolerant, to Foa races 4 and 2, and that this resistance has been introgressed into F1S3 76–8–36‐124.
ZmBET5L1 inhibits primary root growth and decreases osmotic stress tolerance by mediating vesicle aggregation and tethering in maize
Authors: Zhao Ran , Li Nan , Lin Qianrun , Li Manfei , Shen Xiaomeng , Peng Yong , Du Yanfang , Ning Qiang , Li Yunfu , Zhan Jimin , Yang Fang , Xu Fang , Zhang Zuxin , Liu Lei
Published: December 2022

Improving osmotic stress tolerance is critical to help crops to thrive and maintain high yields in adverse environments. Here, we characterized a core subunit of the transport protein particle (TRAPP) complex, ZmBET5L1, in maize using knowledge‐driven data mining and genome editing. We found that ZmBET5L1 can interact with TRAPP I complex subunits and act as a tethering factor to mediate vesicle aggregation and targeting from the endoplasmic reticulum to the Golgi apparatus. ZmBET5L1 knock‐out increased the primary root elongation rate under 20% polyethylene glycol‐simulated osmotic stress and the survival rate under drought stress compared to wild‐type seedlings. In addition, we found that ZmBET5L1 moderates PIN1 polar localization and auxin flow to maintain normal root growth. ZmBET5L1 knock‐out optimized auxin flow to the lateral side of the root and promoted its growth to generate a robust root, which may be related to improved osmotic stress tolerance. Together, these findings demonstrate that ZmBET5L1 inhibits primary root growth and decreases osmotic stress tolerance by regulating vesicle transport and auxin distribution. This study has improved our understanding of the role of tethering factors in response to abiotic stresses and identified desirable variants for breeding osmotic stress tolerance in maize.
The effect of temperature, light‐spectrum, desiccation and salinity gradients on the photosynthetic performance of a subtidal brown alga, Sargassum macrocarpum, from Japan
Authors: Ito Tomohiro , Yoshioka Toui , Shimabukuro Hiromori , Nishihara Gregory N. , Endo Hikaru , Terada Ryuta
Published: December 2022

The effect of temperature, light‐spectrum, desiccation and salinity gradients on the photosynthesis of a Japanese subtidal brown alga, Sargassum macrocarpum (Fucales), was determined using a pulse amplitude modulation‐chlorophyll fluorometer and dissolved oxygen sensors. Temperature responses of the maximum (Fv/Fm in darkness) and effective (ΔF/Fm′ at 50 μmol photons m−2 s−1; = ΦPSII) quantum yields during 6‐day culture (4–36°C) remained high at 12–28°C, but decreased at higher temperatures. Nevertheless, ΔF/Fm′ also dropped at temperatures below 8°C, suggesting light sensitivity under chilling temperatures because Fv/Fm remained high. Photosynthesis–irradiance responses at 24°C under red (660 nm), green (525 nm), blue (450 nm) and white light (metal halide lamp) showed that maximum net photosynthesis under blue and white light was greater than under red and green light, indicating the sensitivity and photosynthetic availability of blue light in the subtidal light environment. In the desiccation experiment, samples under aerial exposure of up to 8 h under dim‐light at 24°C and 50% humidity showed that ΔF/Fm′ quickly declined after more than 45 min of emersion; furthermore, ΔF/Fm′ also failed to recover to initial levels even after 1 day of rehydration in seawater. Under the emersion state, the ΔF/Fm′ remained high when the relative water content (RWC) was greater than 50%; in contrast, it quickly dropped when the RWC was less than 50%. When the RWC was reduced below 50%, ΔF/Fm′ did not return to initial levels, regardless of subsequent re‐hydration, suggesting a low capacity of photosynthesis to recover from desiccation. The stenohaline response of photosynthesis under 3‐day culture is evident, given that ΔF/Fm′ declined when salinity was beyond 20–40 psu. Adaptation to subtidal environments in temperate waters of Japan can be linked to these traits.
Generalizing the Stochastic Approach to Price Indexes
Authors: Gorajek Adam
Published: December 2022

I show that conventional price index formulas and time‐dummy hedonic regression techniques all consistently estimate growth parameters in the same generalized model of product pricing. I then use that result to make two points. First, the “stochastic approach” is not a helpful tool for choosing price index formulas, because in its complete form it can justify any of them. Second, the literature uses flawed arguments for replacing time‐dummy hedonic regression with hedonic imputation. The time‐dummy method is an excellent, underrated option.
Artificial intelligence 101 for veterinary diagnostic imaging
Authors: Hespel Adrien‐Maxence , Zhang Youshan , Basran Parminder S.
Published: December 2022

The prevalence and pervasiveness of artificial intelligence (AI) with medical images in veterinary and human medicine is rapidly increasing. This article provides essential definitions of AI with medical images with a focus on veterinary radiology. Machine learning methods common in medical image analysis are compared, and a detailed description of convolutional neural networks commonly used in deep learning classification and regression models is provided. A brief introduction to natural language processing (NLP) and its utility in machine learning is also provided. NLP can economize the creation of "truth‐data" needed when training AI systems for both diagnostic radiology and radiation oncology applications. The goal of this publication is to provide veterinarians, veterinary radiologists, and radiation oncologists the necessary background needed to understand and comprehend AI‐focused research projects and publications.
Wood-Cloth and Wood-Paper Laminates
Authors: Delmonte John
Published: December 2022

A growing tendency exists for the use of wood and resin-impregnated cloth or paper, which is an outgrowth of laminated - plywood developments. Combinations of cloth and paper with wood, in addition to serving as vehicles for the bonding glue in the manufacture of the laminates, also help stabilize the wood assemblies and provide structural advantages, as demonstrated by test data given in the paper. For example, when a reasonably large number of paper laminates are used, there is an apparent increase in the tensile properties of wood, attributable to prestressing of the wood resulting from differences in coefficients of thermal contraction as parts are cooled upon removal from the press. Dimensional stability in plywood faced with phenolic-resin-treated cloth and paper is found to be far superior to unprotected plywood.
The Theory and Design of Electronic-Control Apparatus
Authors: Cockrell W. D.
Published: December 2022

Since the mechanical engineer is vitally concerned with control mechanisms involving electronics in some form, the author believes the explanation of theory involved and design of electronic apparatus given in this paper should be helpful. The almost infinitely fast and inertialess electronic tube can supplement mechanical control to produce many results hitherto considered impossible. After outlining the fundamental conceptions of the electronic tube, describing the types of tubes used, and explaining something of the operation of individual control circuits, the author indicates practical applications of electronics to standard control circuits. Examples of such controls are the photoelectric relay, electronic timer, motor control, resistance welding, photoelectric register control, and others.
Fluid Flow Through Two Orifices in Series—II
Authors: Stuart Milton C. , Yarnall D. Robert
Published: December 2022

This is the second of a series of papers on the characteristics of fluid flow through two orifices in series. The first paper (l) presented a theoretical analysis of the flow of water and steam through two orifices in series over a wide range of pressures and temperatures. This paper presents the results of experimental investigations on this subject using water at an initial pressure of 100 psia and over a range of temperatures from room temperature to saturation temperature. The principal data sought were the pressures established in the intermediate chamber between the two orifices, and especially the variations of this intermediate pressure with reference to the temperature of water supplied and the type of orifice. One of the most significant facts revealed by these researches is that under certain conditions of flow the fluid assumes a metastable state which greatly influences the characteristics of the process. Finally, a device responsive to the pressure variations obtained between two orifices in series constitutes a control element, useful, among other things, to control flow in response to the state of the fluid supplied.
Notch-Toughness Tests of Carbon-Molybdenum Pipe Material
Authors: Kinney W. F. , Rohrig I. A. , Walker H. S.
Published: December 2022

The development of materials for high-temperature-steam piping is of considerable importance in view of the upward trend in power-plant operating temperatures. Chemical composition, steel-melting practice, and heat-treating procedure, and their effects upon physical properties and microstructure are important factors in appraising the probable behavior of a material in service. The metallurgist and power-plant engineer are particularly interested in the influence of these factors upon notch toughness of the material. Starting with the premise that there may be some correlation between notch toughness and performance of high-temperature pipe and that significance should be attached to the interpretation of notch toughness with respect to the behavior of carbon-molybdenum pipe material in power-plant service, the authors give details of an investigation conducted in The Detroit Edison Company laboratory on notch-toughness testing. The specific problem studied was to determine the influence of the uniformity of test results and on the magnitude of average notch-toughness values, both at room temperature and at 925 F, of three variables, namely, (a) the type of specimen, (b) the heat of steel, and (c) the condition of the steel. In connection with this testing program, a survey of the literature was conducted and inquiries were directed to various authorities regarding their experience with this problem. The authors conclude that when the significance of notched-bar testing of carbon-molybdenum pipe material is fully understood, it may be possible to select material of the best quality for high-temperature service of the basis of notched-bar tests.
Efficiency Analysis of Pelton Wheels
Authors: Lowy Robert
Published: December 2022

This paper is devoted to a discussion of the various flow losses in a Pelton bucket. Special attention is given to whether or not such losses are avoidable. Three phases of flow are investigated in detail, i.e., theentrance, the main flow, and the outlet. The author describes the application of a new method to study such movements. The investigation is carried out on a stationary bucket with a jet having the same entrance conditions as the jet on a rotating bucket. The influence of the lip on the entrance conditions is shown by example, and the conditions in the deflected part of the jet are indicated. The loss through the deflected jet is shown in kinetographic representation. A notable loss due to crossing of streamlines on a bucket is discussed. Finally, a list of all possible losses is tabulated.
Range of Operation of Steam Plants in a Combined System of Steam and Hydro
Authors: Hutchins A. T. , Duryea Howard
Published: December 2022

The balance between hydro- and steam-plant power generation on the southeastern group of The Commonwealth & Southern Corporation during the postdepression period and later the period of peak war demands is explained in this paper for an understanding of the system’s approach to the installation of steam plants. The discussion includes such data as area of the system, loads, plant capacities, and such pertinent factors as ratio of steam to hydro generation, the relation of steam to hydro capacity, etc. The unit principle is used in the steam-plant installations, i.e., one boiler supplies all steam requirements for one turbine unit. Details of the boilers, auxiliary equipment, operating experience, and results attained are comprehensively treated.
The Modern Hydraulic Reservoir: How It Provides Micron-Range Filtration and Pump Supercharging
Authors: Thayer W. W.
Published: December 2022

At the present time, the term “high pressure,” with reference to aircraft hydraulic systems, means 3000 psi. Successful design of such systems, now in quantity production by the author’s company, depends upon careful consideration of details, rather than upon the adoption of any features that might be classed as unorthodox. For instance, detailed attention has been given to an improvement in service life of certain hydraulic units whose operation depends upon close-fitted sliding parts. This consideration, resolving into a study of methods for com-bating abrasion and cavitation, has led to the development of a filter for the removal of particles as small as 10 microns, and a simple arrangement for reducing pump cavitation by building up a supercharging pressure in the hydraulic-system reservoir.
Draft-Gear Action in Train Service
Authors: Wikander O. R.
Published: December 2022

In order to investigate the most desirable characteristics of a draft gear by mathematical analysis, a study has been made of the mechanics of an elastic bar, which is subjected to external forces that correspond to those acting in trains under various service conditions. The results of this study, including the derivation of the various equations governing the behavior of an elastic bar, solid or with free slack, are given in another paper by the author. The present paper contains substantially the same equations but transcribed so as to apply to railway trains. Numerical examples are given showing the applications of these equations to assumed test trains.
New Method of Calculating Natural Modes of Coupled Bending-Torsion Vibration of Beams
Authors: Myklestad N. O.
Published: December 2022

Recently the author developed a new method of calculating natural modes of uncoupled bending vibration of beams, the present paper being an extension of this work to take care of coupled bending-torsion vibrations as well. This latter problem has lately taken on considerable importance as a means of interpreting ground-vibration tests on airplane wings, which may be considered as a symmetric beam with free ends. The author’s method also makes it possible to consider the entire airplane as an elastic body both in symmetric and in antisymmetric vibration, and to find the effective inertia of an airplane propeller in determining the torsional vibration characteristics of the engine. It may be readily applied to the vibration of turbine blades and propellers in general, when the centrifugal force is taken into consideration. This method possesses the advantage that the computations may be performed by inexperienced calculators as only the routine completion of a tabular form is required.
Electrical-Analogy Method for Fundamental Investigations in Automatic Control
Authors: Eckman D. P. , Wannamaker W. H.
Published: December 2022

The purpose of this paper is to demonstrate an approach to automatic-control investigation through the use of an electrical-analogy method. A complete description of the apparatus is included, each unit being related to a counter-part in an industrial control application. Diagrams and calibrations of the various units comprising the electrical process analog are given. For illustration of the manner of setting up a problem, the effect of controller scale span upon controller adjustment is shown.
Economic Thickness of Thermal Insulation for Intermittent Operation
Authors: Bradley C. B. , Ernst C. E. , Paschkis V.
Published: December 2022

Economic thickness of an insulation is defined as that thickness yielding the smallest sum of cost of heat loss and fixed cost of insulation. The difficulties in determining the economic thickness for intermittent operation are reviewed. By means of the electrical-analogy method, curves have been developed which permit the ready determination of the heat losses in intermittent operation for any temperature, any single-material wall, any intermittency, any length of period, and any film conductance. These curves permit the determination of the economic thickness for intermittent operation. The application of the curves is illustrated by an example. The influence of intermittency on the economic thickness is discussed for one specific case. The limitations of the method and prospect of obtaining results avoiding the limitations are considered.
Effect of Aeration on Gear-Pump Delivery and Lubrication Ceiling
Authors: Schweitzer P. H.
Published: December 2022

Gear-pump delivery falls off with altitude and, above a certain point, it fails to provide the necessary engine lubrication. By deductive reasoning, an equation has been developed for calculating the gear-pump delivery with aerated oil and also the “lubrication ceiling.” Charts are presented to show the effect on lubrication ceiling of (1) entrained air, (2) dissolved air, (3) pipe length, (4) pipe diameter, (5) tank height, pressure boost, valves, and ells, (6) oil viscosity, (7) pump speed. According to results obtained, a reduction of dissolved air and reduced pipe resistance between oil tank and pressure pump have relatively small effects on the lubrication ceiling. Effective ways to raise the ceiling are pressurizing the oil tank and reducing the pump speed.
Carry-Over in Locomotive Boilers
Authors: Williams Arthur
Published: December 2022

While tremendous advances in feedwater treatment to protect boiler heating surfaces from scale, corrosion, and embrittlement have been made, the methods commonly used on railroads have been accompanied by an increasing degree of foaming troubles. According to statements of the American Railway Engineering Association, the introduction of alkaline sodium compounds, while reducing the scale problem, has increased the foam-producing capacity of the water supplies. This paper approaches a solution to the problem of carry-over by discussing the mechanisms which cause other than dry steam to leave the boiler. The most important type of carry-over is probably that due to foaming. Carry-over by effervescence is also discussed. The effects of carry-over and methods of prevention are treated in detail. In the study of the problem and its correction numerous tests have been conducted by the author’s company, and by the A.R.E.A., and individual railroads. These are reported at some length, the results showing that proper control of feedwater treatment will help minimize foaming. Antifoam compounds increase the concentrations that may be carried in the boiler, but concentration must be controlled either manually or by automatic blowing. Apparatus of various types for this purpose is described, as well as a suitable design of steam separator, which is essential to separate the carry-over from the steam, and discharge the carry-over to the atmosphere.
On Fatigue Failure Under Triaxial Static and Fluctuating Stresses and a Statistical Explanation of Size Effect
Authors: Fowler F. H.
Published: December 2022

The purpose of this paper is to develop a framework for establishing a criterion of safe fatigue characteristics of manufactured units. In addition a statistical theory of fatigue has been indicated. Provision can be made for a study of combined stresses, static and vibratory stresses, and variations in amplitude. Interesting explanations of scale effect and stress gradient effect are given. It is hoped that this will provide a useful framework to improve the designer’s judgment and upon which to build additional work on fatigue.
Effect of Some Environmental Conditions on the Permanence of Cellulose-Acetate and Cellulose-Nitrate Sheet Plastics
Authors: Lawton T. S. , Nason H. K.
Published: December 2022

The effect of outdoor exposure, both in Florida and in Massachusetts, on the tensile properties, impact strength, optical properties, and shrinkage of cellulose-acetate and cellulose-nitrate sheet plastics is shown in detail, and the general nature of these effects is summarized. The effect of outdoor exposure on the composition of these plastics and on the molecular weight of the base cellulose esters is shown quantitatively. Moisture pickup and dimensional change upon immersion in water are reported.
Application of Controlled Atmospheres to the Processing of Metals
Authors: Peck C. E.
Published: December 2022

The development and application of separately controlled atmospheres for use in conjunction with heat-treating processes has been rapid during recent years. By means of controlled atmospheres, finished machine parts which require heat-treatment can be processed without loss of surface hardness during heating, and without further grinding or cleaning. Many other applications in the treatment of metals, such as welding, forging, melting, sintering, and the like, are possible although at present somewhat limited. This paper outlines the principal types of atmospheres and describes briefly the equipment available for producing these atmospheres. A summary is given of the application of these atmospheres to a wide variety of heat-treating processes now in active commercial use.
A Graphical Solution of Windshield Heat Deicing Problems
Authors: Hauger H. H.
Published: December 2022

It is the purpose of this paper to present the problem behind the design of an air-heated double-paneled windshield for aircraft. A windshield ice-prevention nomograph is proposed as a rapid accurate method of making a design analysis of the air-heated windshield. With its use the designer has at his disposal a visual means of determining the relative importance of the variables included within the design, so as to arrive at the optimum solution for a given installation under the conditions imposed. The sample problems analyzed in this paper indicate that the required windshield strength be designed into the inner panel with an outer panel of tempered glass so as to obtain the highest outer-surface temperatures.
Critical Shearing Stress in Skin-Stressed Boxcar Sides
Authors: Green V. L. , Drinka J. J.
Published: December 2022

Developments in boxcar construction are traced through the period of the 1920’s and early 1930’s, leading to design work by K. F. Nystrom on The Milwaukee Road in which 15-gage side sheets, stiffened by six longitudinals of the lapped type formed integrally with the side sheet, were found to be entirely satisfactory for car-side construction, and accomplished a saving in weight of 600 lb. In order to determine the possibility of further weight reduction without sacrificing strength, a study was made of the elastic stability of various types of car sides, and tests were conducted to correlate the theoretical study with actual test results. This paper includes a discussion of shearing stress in thin-webbed girders, the test procedure, a theoretical analysis of a number of panels tested, and the results obtained for the panels tested.
A General Correlation of Friction Factors for Various Types of Surfaces in Crossflow
Authors: Gunter A. Y. , Shaw W. A.
Published: December 2022

This paper is the elaboration of an unpublished one by the late E. S. Davis and A. Y. Gunter, which was released only to the National Advisory Committee for Aeronautics. The present work, using the friction-factor correlation proposed for bare tubes by Davis and Gunter, demonstrates its merit as a general method for correlating on a single line, pure crossflow friction over both bare and extended surfaces. This result is made possible through the use of an equivalent volumetric hydraulic diameter Dv, in both the Reynolds number and the ordinate, plus configuration ratios of the form (Dv/ST)n and (SL/ST)n in the ordinate. Friction factors for bare tubes of diameters from 0.02 in. to 2 in. are included, with transverse and longitudinal pitches ranging from 1.25 to 5 diam. Extended-surface crossflow friction reported on herein covers external round and square cross fins, both meshed and unmeshed, finned cylinders, radiator core-type surface, and one sample of internal wire-mesh fins. It is shown that flat plates and core-type surface with turbulence promoters do not correlate well on the proposed curve.
Heat Transfer Through Tubes With Integral Spiral Fins
Authors: Katz D. L. , Beatty K. O. , Foust A. S.
Published: December 2022

Heat-transfer data are presented for a group of tubes having integral spiral fins. The group includes tubes with a range of from 4 to 24 fins per in. and from 0.05 to 0.38 in. fin height. Seven series of measurements were made, using steam, air, water, and oil as fluids. The data are compared, when possible, with theoretical equations which apply to the particular heat transfer. The performance of tubes with the extended surface is compared in all cases with that of plain tubes tested under similar conditions.
Numerical Methods for Transient Heat Flow
Authors: Dusinberre G. M.
Published: December 2022

This paper deals with the application of numerical methods for the solution of heat-conduction problems, their generality being extended in the following ways: (a) A modulus is developed by choice of which the worker may proceed most rapidly to a solution, or may proceed more slowly and with greater precision; (b) criteria are developed for the choice of modulus to insure convergence. This is most important at a convective surface; (c) a method is developed for handling k and c when these properties vary independently with temperature. A comprehensive Appendix gives the derivations, and the use of equations and charts is demonstrated by typical examples.
Rate of Temperature Change in Short-Length Round Timbers
Authors: MacLean J. D.
Published: December 2022

This paper discusses factors affecting the rate of temperature change in wood and includes time-temperature curves for use in determining the temperature obtained at different points in short-length log sections when heated in steam or hot water. One group of curves shows the temperature distribution from the ends to the mid-length and at different points between the circumference and axis, of logs 12, 24, 36, 48, and 60 in. in diameter. Other charts show the time-temperature distribution at various points between the circumference and axis at the mid-length of log sections of any diameter between 12 and 60 in. Examples are given illustrating the procedure for using the charts in finding the temperature at a parcular point, under different heating conditions.
Measurements of Temperatures in Metal Cutting
Authors: Schmidt A. O. , Boston O. W. , Gilbert W. W.
Published: December 2022

Measurements of the heat developed in a metal-cutting operation, as well as investigation of cutting and chip temperatures by the authors have brought out that the chip temperature is uniform at the higher cutting speeds when all other conditions are kept constant. The temperature of the tool increases with the cutting speed, and the amount of metal removed before tool failure will generally be inversely proportional to the cutting speed.
Certain Aspects of High-Pressure Centrifugal Pumping Cycles
Authors: Karassik I. J.
Published: December 2022

The author discusses the hydraulic and mechanical limitations imposed upon centrifugal boiler feed pumps by certain features of the modern regenerative feedwater heating cycles, as well as the influence of the practical limitations of pump design on the cycles themselves.
The Influence of Tube Shape on Heat-Transfer Coefficients in Air to Air Heat Exchangers
Authors: Green F. H. , King L. S.
Published: December 2022

Heat-transfer coefficients are reported for air passing through round tubes, through partially flattened tubes, and through partially flattened tubes which have also been dimpled. It was found that flattened tubes maintained fully turbulent flow and, consequently, a higher heat-transfer coefficient at lower Reynolds number values than did round tubes. The addition of dimples to the flattened tubes maintained fully turbulent flow from the transition point and increased the heat-transfer coefficient substantially. The addition of the dimples also improved the relation between heat transfer and pressure drop in the flattened tubes.
The Control of Fouling Organisms in Fresh- and Salt-Water Circuits
Authors: Dobson John G.
Published: December 2022

The difficulties encountered by industrial water users due to fouling organisms are discussed. To control such fouling, a knowledge of the organism’s life cycle and reactions to stimulus is necessary. Typical mollusks, Bryozoa, sponges, barnacles, and tunicates are considered. Their control can be effected by heat, change of salinity, change of oxygen content, increased velocity, acids, antifouling paints, screening and poisoning with a number of different poisons. It is concluded that chlorination is the most effective and economical of these methods justifying itself in most plants by improved heat transfer alone. Factors to be considered in designing water systems that may foul are also outlined.
Design Considerations for Welded Machinery Parts
Authors: Snyder G. L.
Published: December 2022

Only some basic considerations for the designer in developing weldments are brought out in this paper, because of the wide scope of the subject. Separately, these basic considerations may seem elementary and self-evident, but when considered collectively in developing a weldment, their complexity becomes apparent. At least twelve different types of components can be utilized by a designer in his weldment and each of these components can be used in several ways. So, the designer must be familiar with limitations in processing weldments and with the scope and limitation of equipment and methods used in their production. These are the factors discussed here. However, this discussion is limited to dynamically loaded welded machinery parts.
Tests of Oil-Film Journal Bearings for Railroad Cars
Authors: Needs S. J.
Published: December 2022

This paper presents results of a special series of tests made with fitted and broached railway-car journal bearings as part of the program of the Journal Bearing Development Committee of the Association of American Railroads. Three recently developed bearings, each containing less bronze than the old standard A.A.R. bearing, were tested. Comparative tests were run with bath, pad, and waste-pack lubrication. Quantitative effects of fitted and broached bearing surfaces and method of lubrication on operating temperature, frictional power loss, and the all-important minimum film thickness are given. An attempt has been made to separate the friction of the bearing from that of the pad or waste-pack lubricator. Total frictional power losses of the box are given in terms of drawbar pull.
Air-Gas Ratio Control Applied to Nonatmospheric-Pressure Furnaces
Authors: McRae H. C.
Published: December 2022

For reasons of economy and efficiency, in the burning of fuel gases in industrial furnaces it is essential to maintain the air-gas ratio at approximately the correct point for perfect combustion. Furthermore it is important to control the ratio of air flow to gas flow because of the effect of burned gases or atmosphere upon material being heat-treated. The author discusses in detail the various control processes available, the equipment developed for the purpose, and analyzes the several control circuits, basing the work on the laws of low-pressure gas flow or noncompressible flow.
A Comparison of Operation of Forced- and Natural-Circulation Boilers
Authors: Ross G. F. , Wilkins Leonard
Published: December 2022

Steam-generating facilities at the Koppers Company, Incorporated, Butadiene Division, Butadiene-Styrene Chemical Plant, at Kobuta, Pa., include two types of units; natural-circulation boilers and the first forced-circulation boiler to be installed in the United States for industrial-plant processes. Since plant operation began in the summer of 1943, this installation has afforded boiler operators an opportunity to compare the operating characteristics of the two types. This paper describes briefly the design and operating features of these steam generators, together with some of the difficulties encountered and how they were overcome.
The Effect of Heat Loss on the Performance of Exchangers With Interconnected Walls
Authors: Trumpler P. R.
Published: December 2022

Equations are derived for the calculation of exchangers in which the passage walls are bonded to each other, providing substantially uniform wall temperature over any cross section normal to the flow. Results are presented for both countercurrent and cocurrent exchangers and an example illustrating the solution is given.
Water Injection in a Spark-Ignition Engine
Authors: Green W. P. , Shreeve C. A.
Published: December 2022

The present war witnessed a revival of interest in the use of water as a coolant and detonation suppressor inside the engine cylinder. Aircraft engines when operated with water injection have been boosted in output above normal sea-level capacity and have functioned satisfactorily. This paper gives a review of past tests on the use of water as a coolant and detonation suppressor in gasoline engines. It presents new data regarding the use of water in very high compression ratio engines to promote increased part-load efficiencies with low octane fuels.