bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Anterior Approach Provides Superior Prosthesis Adaptability in the Early Postoperative Period of Total Hip Arthroplasty
Authors: Shen Jing , Ji Ruiqing , Yao Sai , Ruan Pengfei , Zhu Zhouwei , Wang Xiang , Sun Huihui , Chen Jie , Ruan Hongfeng , Ji Weifeng
Published: December 2022

Objectives

Prosthesis awareness is the perception of foreign bodies, which has a critical effect on the function of the prosthetic joint. In total hip arthroplasty (THA), the direct anterior approach (DAA) has more advantages than the posterior approach (PA), including superior rehabilitation outcomes. This study was to evaluate the recovery of “prosthesis awareness” through these two approaches.

Methods

Three hundred and seventy‐six patients who received THA with either DAA (n = 41) or PA (n = 335) from January 2016 to December 2017 were retrospectively analyzed. The Forgotten Joint Score‐12 (FJS‐12), Harris hip score (HHS), and visual analog scale (VAS) analyses were used to evaluate the recovery of “prosthesis awareness” in these patients 2 weeks, 1, 3, 6, and 12 months after surgery. The student t‐test, Wilcoxon rank sum test, chi‐square test, and MANOVA were used to compare the differences among groups.

Results

We found that DAA patients had higher FJS‐12 scores than PA patients at 2 weeks (42.15 ± 3.36 vs. 38.09 ± 3.28, p = 0.042), 1 month (49.06 ± 5.14 vs. 41.11 ± 5.21, p = 0.038), and 3 months (53.23 ± 4.07 vs. 48.09 ± 3.71, t = 3.152, p = 0.045). And the recovery rates of FJS‐12 scores in DAA and PA groups at 2 weeks, 1 month, and 3 months after surgery were 75.46% ± 6.04%, 84.05% ± 6.57%, 91.37% ± 7.13%, and 74.14% ± 5.54%, 78.16% ± 6.01%, 88.23% ± 6.42%, respectively. To compare the recovery effects of the two procedures in more detail, we classified the 12 items in FJS‐12 that evaluate different types of gravity center motions into three categories: low‐movement group (LG), middle‐movement group (MG), and high‐movement group (HG). Interestingly, DAA patients had significantly higher HG than PA patients at 2 weeks, 1 month, and 3 months after operation (t = 3.225, p = 0.022 at 2 weeks, t = 3.081, p = 0.041 at 1 month and t = 2.783, p = 0.046 at 3 months), whereas no significant differences were observed in LG‐ and MG‐related items. In addition, there were no significant differences in HHS and VAS scores between DAA and PA patients at 2 weeks (p = 0.102, p = 0.093), or from 1 month to 12 months (each p > 0.05).

Conclusions

DAA‐mediated THA is superior to PA in terms of prosthesis adaptability and recovery of hip joint motion in the first 3 months after surgery, especially concerning high‐movement gravity center motions.
Correlation of unipolar electrogram modification with ablation index during pulmonary vein isolation: A pilot study
Authors: Paymard Mohammad , Deyell Marc W. , Laksman Zachary W. , Yeung‐Lai‐Wah John A. , Chakrabarti Santabhanu
Published: December 2022

Background

Pulmonary vein isolation (PVI) using radiofrequency catheter ablation is a widely accepted therapy for drug‐refractory atrial fibrillation patients. Elimination of the negative component of the local unipolar electrogram (UEGM) during PVI is a marker of transmural lesion formation. The ablation index (AI) can predict the quality of ablation lesion. Combining these two parameters could make PVI safer and efficient. The purpose of this pilot study was to examine the correlation between UEGM modification characteristics of the different target areas of left atrium and the associated AI values during PVI.

Methods

We analyzed 10 patients who underwent PVI using radiofrequency energy. The local electrophysiological properties and ablation parameters of 15 designated areas of interest in the left atria targeted by radiofrequency catheter ablation were collected.

Results

Out of the 10 patients, six were men (mean age 66 years) and 80% had paroxysmal AF. The mean time to achieve the UEGM modification in the posterior wall was shorter than that of the anterior wall (8.9 seconds vs. 11.1 s, respectively). The UEGM modification for every lesion was achieved at significantly lower AI values than conventional AIs (p < .001).

Conclusion

During PVI, the AIs deduced according to the local UEGM modification are markedly shorter than those generally recommended AIs in contemporary practice. This indicates that conventionally recommended AIs could be safely reduced while ensuring the efficacy and quality of radiofrequency ablation during PVI. This approach would probably reduce to risk of collateral thermal injuries.
Diversity, classification, and EST‐SSR‐based association analysis of caladium ornamental traits
Authors: Zhou Yiwei , Ye Yuanjun , Zhu Genfa , Xu Yechun , Tan Jianjun , Liu Jinmei
Published: December 2022

Caladium (Caladium × Hortulanum Birdsey) is a popular ornamental plant with a wide range of vibrant leaf color among Araceae. Even after years of breeding, creating new caladium leaf color variations is extremely difficult. Molecular marker‐assisted selection is an effective approach for accelerating breeding, but few studies on the molecular markers associated with caladium traits have been performed. In the current study, 144 caladium accessions were used to examine 12 phenotypic characteristics. The coefficient of variation for four numerical characters ranged from 23.94% to 43.22%, and the Shannon–Wiener indexes for eight descriptive characters ranged from 0.13 to 1.52. Based on L*, a*, b*, C, h° values determined by a colorimeter and hierarchical cluster analysis, the leaf color can be divided into four groups: pale green, green, light pink, and red. Furthermore, 7708 new SSR loci were identified by transcriptome sequencing, and 26 SSR markers with high polymorphism and reproducibility were screened. Genetic structure, NJ clustering, and PCoA analysis revealed that 144 accessions could be divided into three clusters, with genetic structure being closely related to germplasm origin. An association analysis revealed that the SSR markers 2, 1, 1, 1, 1, and 1 were mainly associated with petiole color, main vein color, blade upperside glossiness, and C, b*, and L* of leaf color (p < 0.01). These findings will serve as a valuable reference for evaluating germplasm resources and caladium molecular marker‐assisted breeding.
School dropout and overeducation in developing economies: Feasibility of a budgetary solution†
Authors: Gooptu Sayoree , Mukherjee Vivekananda
Published: December 2022

High rates of school dropout and overeducation are typical problems faced by developing economies. This paper addresses these issues in a unique theoretical model that accounts for complementarity between household and infrastructural investment in education production function on the one hand, and school and higher education on the other hand. The results derived in this paper show that a reallocation of the education budget in favor of school education can solve both problems at the same time if certain conditions are satisfied. Otherwise, reallocation aggravates the problems. This paper questions the efficacy of the widely practiced budget reallocation policy in favor of school education, and in turn, shows that reallocation cannot eliminate school dropouts.
Negotiating Unequal Exchange: Relational Work in Cross‐Class Sibling Relationships1
Authors: Wigen Allison
Published: December 2022

Based on 60 in‐depth, semi‐structured interviews, this article examines exchanges of support in cross‐class adult sibling relationships. Whereas previous studies of family exchange have largely focused on parent–child support and patterns of inequality across families, this study addresses a gap in the literature by focusing on sibling exchanges and within‐family inequality. How is support exchanged when expectations of peer equality are violated—when there is an economic difference between adult siblings? I find that cross‐class siblings engage in relational work to shape and reframe exchanges in ways that are more indirect, often involving third parties. I identify four types of indirect economic support—proxy support, dependent support, compensatory support, and shared resources—which contribute to our understanding of the dynamics of sibling exchange, and point to ways in which inequality can be interactionally managed.
“Ground Zero” for Climate Crisis: Narratives About Climate Adaptation and Implications for Justice in Coastal Louisiana
Authors: Domingue Simone Justine
Published: December 2022

Decisions about climate change adaptation are informed by technical information, but they are also shaped by social and political factors and impacted communities. Given the realities of a changing climate, more research is needed to examine how technically trained practitioners and other actors describe their work in relation to social and political factors. This article contributes to knowledge on this topic by analyzing the narratives of 62 organizational actors in coastal Louisiana. Actors include scientists, engineers, modelers, planners, project administrators, government staff, and non‐profit employees working on climate adaptation and coastal risk reduction projects outlined in Louisiana's Coastal Master Plan. While scholars critique the Master Plan as overly technocratic, I show that people weave morals and values into narratives about science. However, I show how the motivations of acting boldly, morally, and urgently in the face of emergency clash with climate justice. Some individuals within these organizations do advocate for reforming or rethinking Master Plan projects to better serve coastal communities; however, these individuals also face resistance from colleagues who frame this work as secondary or outside of their organizational purview. To conclude, I argue that research connecting technical aspects of climate adaptation planning to power and social justice outcomes has the potential to bridge disciplinary divides.
A STUDY ON NEURO FUZZY ALGORITHM IMPLEMENTATION ON BCI-UAV CONTROL SYSTEMS
Authors: Chu Timothy Scott , Chua Alvin , Secco Emanuele Lindo
Published: December 2022

Brain-Computer Interface (BCI) machines are capable of obtaining brain activities by conducting Electroencephalogram tests. Developments on both BCI and Machine Learning allowed various researchers to develop and study various BCI control systems, mainly varying with the algorithm implementation. This research presents a performance analysis of the Adaptive Neuro-Fuzzy Inference System (ANFIS) for BCI control systems for drone maneuverability. Eye gestures were used to generate the EEG data that were captured using the Emotiv INSIGHT Neuroheadset. The obtained data were transferred to the computing hardware using IEEE 802.15 wirless communication protocol (i.e. Bluetooth connectivity); the data are processed using the 5th order Butterworth Band-Pass filtering and heuristic filtering. The filtered dataset is then fed to the ANFIS and a Support Vector Machine (SVM) algorithm, the latter serving as the basis, for training and quadcopter control implementation. Three flight tests were done, hover test, flight command test, and the flight control test, the final test compared the performance of the BCI control system using the ANFIS algorithm to the performance of a traditional handheld remote controller. Results from the initial two tests showed that the ANFIS performed comparably with the SVM, and even about 2% better. The final test showed that the BCI control system had a maximum variance of 4% compared to the handheld controller, where the latter served as the basis. It was found that between Machine Learning algorithms, ANFIS is as capable as the SVM for BCI control systems. Further developments may focus on employing time-series EEG preprocessing techniques.
SEMICIRCULAR SLOT BASED UWB MICROSTRIP PATCH ANTENNA FOR VARIABLE BAND NOTCHED APPLICATIONS
Authors: Mahfuz M.M. Hasan , Islam Md Rafiqul , Habaebi Mohamed Hadi , Malek Norun Abdul
Published: December 2022

The patch antenna with Ultra-Wide Band (UWB) characteristics is a promising candidate for wireless communication. It is a major research problem to mitigate electromagnetic interference (EMI) with narrowband technologies such as 5G lower band, Wi-MAX, WLAN and satellite band, which are all in the UWB region. This study describes a UWB antenna with variable band rejection that can be used to avoid interference with Wi-MAX and 5G lower band applications. The UWB characteristics of a simple rectangle patch antenna with a faulty ground structure has been designed for operational bandwidth (2.7–13) GHz. A novel method semicircular slot (SCS) at the radiation patch creates a band notched from (3.25–3.80) GHz and (3.4–4) GHz. Variable band rejection between (2.95–4.40) GHz can be achieved by adjusting the “Wa” values. When measured over the band rejection frequency, the return loss (S11) and VSWR values are very close to 0 dB and larger than 2. The simulated and measured results such as return loss, VSWR, 2-D polar pattern and gain have almost similar agreement. The design of the suggested antenna is simple, compact and efficient for Wi-MAX application, this is an ideal UWB antenna with the band notch characteristics.
SHEAR AND BENDING PERFORMANCE OF HORIZONTAL LAMINATED BAMBOO LUMBER BONDED WITH UREA-FORMALDEHYDE AND PRESERVED WITH DELTAMETHRIN
Authors: Syaifudin Tirana Novitri , Irawati Inggar Septhia , Awaludin Ali
Published: December 2022

Deltamethrin has potential to be used for bamboo strip preservation in laminated bamboo lumber (LBL) beam industry. However, there is a lack of information regarding the effect of deltamethrin preservation on the structural performance of the LBL beam. This study was intended to observe shear and bending performance of LBL beam made of Dendrocalamus asper, preserved by deltamethrin, and glued by urea-formaldehyde. The adhesive bonding strength test following ASTM D905 and MD Block method and static bending test based on ASTM D143 were performed toward preserved and unpreserved samples. The performance was observed by calculating adhesive bonding strength, MOE, MOR, ductility index, and investigating failure modes. The results show that the average adhesive bonding strength of the treated sample is 7.28 MPa (ASTM D905) and 7.03 MPa (MD Block), while the average adhesive bonding strength of the untreated sample is 7.67 MPa (ASTM D905) and 7.41 MPa (MD Block). The average MOE (modulus of elasticity) and MOR (modulus of rupture) of the treated specimen is 18,840 MPa and 110 MPa, respectively. The untreated specimen's average MOE and MOR are 18,199 MPa and 109 MPa, respectively. The average ductility index of untreated and treated specimens is 4.8 and 3.9, respectively. The adhesive bonding strength of treated and untreated samples are higher than the bamboo shear strength. The result indicates that deltamethrin has no significant effect on the adhesive bonding strength, MOR, and MOE of the LBL beam. The LBL beams show significant plastic deformation before final beam failure.
PREPARATION OF ACTIVATED CARBON FROM TIRE DERIVED PYROLYTIC CHAR FOR ADSORPTION OF TETRACYCLINE HYDROCHLORIDE
Authors: Chana Khulanuttha , Soisuwan Sasit , Sinpichai Sarawut , Chen Bing-Hung , Na-Ranong Duangkamol
Published: December 2022

Effects of activation variables on performance of the obtained activated carbon (AC) were investigated for removal of tetracycline hydrochloride (TCH).  Pyrolytic char derived from waste tire was chemically activated via two-step of KOH impregnation following by thermal treatment.  According to regression analysis and fitting with second-degree polynomial equation, empirical models were developed to correlate performance of AC in TCH adsorption (percentage removal and adsorption capacity at equilibrium) with three activation variables: impregnation ratio (IR), activation temperature (T) and holding time of thermal treatment (t).  The analysis of variance indicated that only T, T2 and IR2 were significant to the prediction of both percentage removal and adsorption capacity.  According to the developed models, it is suggested that the pyrolytic char should be activated at IR = 6, T = 750 °C and t = 2 h to obtain the highest efficiency of TCH removal in the tested range of activation condition.
THE IMPACT OF UNEVEN JOINT OF BRIDGE APPROACH SLAB AND DECK TO ROAD USERS PERCEPTION AND SPEED: A CASE STUDY IN JAMBATAN PARIT JAMIL AND JAMBATAN PARIT HAJI IBRAHIM, JOHOR
Authors: A. Khalifa Nasradeen , Othman Mohd Hanifi , Kamarudin Muhammad Irfan , Omar Noorliyana
Published: December 2022

Bridge approaches offered a smooth and safe transition for any vehicle from the road pavement to the bridge structure and vice versa. Settlement of the soil that  of Jambatan Parit Jamil results in a slight change of their level which can create a ‘bump’ on the roadway. This uneven joint occurs due to soil settlement under the bridge approach due to the increasing number of rough rides by the driver that cause cracking at the approach slab. Thus, the ‘bump’ or uneven joint between the bridge deck and road pavement will cause driver discomfort, impair driver safety, reduce steering response, and. The purpose of this study is to investigate the perception of the respondents about the shock impact and to evaluate their speed reduction during maneuvering the uneven joint of the approach slab and the bridge deck. Thus, a social survey has been conducted in Kampung Parit Jamil and Kampung Parit Penyengat to investigate the perception of frequent road users about uneven joints. The spot speed study method has been used to evaluate vehicle speed reduction in maneuvering the uneven joint. The speed reduction results were then compared with the speed of vehicles on a good condition bridge as a control sample. The results show that most of the respondents suggest that they are ‘very disturbed’ (70%) with uneven joint. The speed reduction on the uneven joint bridge recorded 13km/h mean speed readings of 13 km / h and possess 5km/h differences with a good condition bridge. The results are expected to highlight the impact of uneven joint issue on road users’ comfort and traffic speed.
PERFORMANCE OF JUTE FIBER REINFORCED CONCRETE IN THE CONTEXT OF BANGLADESH
Authors: AL Mansur A.Z.M. Abdullah , Hossain Arif , Anisha Atia , Tahmid Ahanaf , Chowdhury Sharmin Reza
Published: December 2022

Concrete is a mixture made up of a proportional mixture of water, aggregate (sand or gravel), cement, and admixtures to impart advantageous properties. Despite its high compressive strength, concrete is fragile; compared to its compressive strength, its tensile strength is only about 10%, and it also has a low resistance to cracking, which restricts its application. Fiber-reinforced concrete, which combines concrete with fibrous material to solve these limitations, is a solution. Fiber-reinforced concrete (FRC) has emerged as a new sustainable material for a varied range of applications, including building pavements, huge industrial building floors, and runways. Natural fibers are used in contemporary technologies (jute fiber) and this study explores the use of non-metallic fibers (jute fiber) in concrete. The purpose of this article is to analyze the strength properties of non-metallic fibers in concrete and compare them to standard plain concrete specimens. When Jutes fiber is added to concrete, the compressive strength increases to a certain limit, increasing fiber content. In this study, chopped jute fibers were utilized to create an FRC material to see whether the 28-day strength could be improved. Mixing and casting issues were created by fiber clumping at high fiber concentrations. In this experiment, 10 mm and 15 mm long jute samples (0.1%, 0.2%, and 0.3%) of volumetric weight are mixed with concrete. The mix design followed the American Concrete Institute's recommendations (ACI, 211.1-91). The ratio of water to cement was 0.4. Compressive strength of the concrete decreases, also resulting in poor workability. When compared to ordinary concrete, the compressive strength of 28 days was improved by 64.34%, and the optimal content of jute was determined to be 0.1%. The compressive and tensile strength of the fiber was also affected by its length. The ductile behavior of the FRC improves as the fiber content increases. In this investigation, it was also discovered that the modulus of elasticity of FRC was increased when compared to ordinary concrete
EFFECTS OF EXPANDED POLYSTYRENE BEADS ON THE STRENGTH PROPERTIES OF BRICK AGGREGATE CONCRETE
Authors: Alam Md. Ashraful , Tahmid Ahanaf , Nayeem Abu
Published: December 2022

Bangladesh's construction industry has grown significantly over the past two decades. The construction industry is progressing at a faster speed, which has raised the raw demand for building materials. Finding an alternative to natural aggregate in concrete casting as a partial replacement is a smart concept to protect natural resources. Our environment is severely harmed by the production of bricks. On the other hand, polystyrene, a common plastic packaging material, degrades to harm the environment and produces useless plastic waste. To conserve natural resources, it can be a good idea to use plastic trash as a partial replacement for natural aggregate in concrete casting. The addition of EPS to concrete offers a variety of benefits. These include reduced self-weight in structures, lighter weights during construction, and higher thermal resistance. In this experiment on the characteristics of concrete structure, expanded polystyrene beads have been used in place of coarse aggregate in this experiment. In various combinations (1:1:2), (1:1.5:3), and (1:2:4), EPS beads replace 0%, 10%, 20%, and 30% of the volume of the course aggregate portion. The compressive strength, unit weight and splitting tensile strength of these mixes are all measured for the complete testing procedure. The optimal levels of compressive strength, splitting tensile strength, and unit weight of 12.65 MPa, 1.89 MPa, and 46.28 kg/m3 respectively, and the normal concrete's compressive strength, splitting tensile strength, and unit weight of about 19.16 MPa, 2.05 MPa, and 12.24 kg/m3 are successfully developed in Grade M25 EPS-based concrete with a replacement percentage of 10%. The results indicate that EPS beads have the potential to produce lightweight concrete with a moderate strength grade that might be used in a wide range of applications.
Test and Predicted Oil-Cooler Performance
Authors: London A. L. , Brewster J. I.
Published: December 2022

Air-side heat-transfer and pressure-drop laboratory test data are presented for a shell-and-tube-type oil cooler, employing steam as the shell-heating medium (1). These data are compared with the information existing in the literature. The chief discrepancy observed is the surprisingly high Reynolds number obtained for transition between laminar and turbulent flow; the dip region being in the Reynolds number range 10,000 to 4000 instead of the usually expected range of 4000 to 2000. The test results, together with available oil-side conductance data, are employed to predict oil-cooling performance of the exchanger as a function of air-flow pressure drop.
Pressure Loss in Elbows and Duct Branches
Authors: Vazsonyi Andrew
Published: December 2022

The pressure loss in a duct branch is a function of at least six independent variables, and there is no complete set of data available for correlation. Equations [II] and [III] of this paper are derived on a theoretical and experimental basis. These equations correlate all available data with fair accuracy with the aid of four experimental curves (Figs. 2, 3, and 5). Furthermore, they permit prediction of probable pressure losses for ducts heretofore untested. Similar formulas can be derived for elbows, diffusers, contracting passages, and other configurations, e.g., Equation (1) presents losses for elbows.
Porous Chromium in Engine Cylinders
Authors: Pyles Russell
Published: December 2022

In recent years it has been possible to deposit thick coatings of chromium electrolytically on machined parts, where lubrication is a vital factor. Diesel-engine cylinders and piston rings may be included among the most critical engine parts from a wear standpoint, and in this application, porous chromium has demonstrated its ability to increase the life span of an engine. The author outlines the properties inherent in porous chromium which contribute to its low wear rate in engine cylinders, i.e., hardness, exceeding that of any other cylinder-lining material; high thermal conductivity; low friction coefficient, and low affinity for other metals; corrosion resistance, preventing surface deterioration.
Application and Design of Package Conveyers
Authors: Keller H. C.
Published: December 2022

Conveyers used for material handling are divided into two groups, namely, for bulk materials like ore, gravel, coal, ash, sand, and so on, and for unit loads such as cartons, boxes, barrels, sacked goods, tote boxes, etc. This paper will discuss the latter group, dealing with application and design. In giving the various formulas on design, certain liberties with theory are taken and short cuts are used, but all formulas have been checked and proved by actual performance.
Design Features of Conveying Equipment for the Foundry Industry
Authors: Henry F. B. , Wileman G. N.
Published: December 2022

The design of conveying equipment used in the foundry industry is covered in its general applications, with consideration given to the design of some of the more important details. Emphasis has been placed on equipment used in the handling of sand, molds, and castings, since they offer the major opportunities for economies and savings in manufacturing costs.
Application of Electronic Control
Authors: Vedder E. H.
Published: December 2022

This paper describes typical applications of electronic control. Motor control including an adjustable-speed drive for direct-current motors and a speed-regulator system are shown. The importance of resistance welding in production of sheet-metal assemblies and the use of ignitron equipment for control of time and current are discussed. Many uses for control using light, including loop, tin-flow, and paper-cutting regulation are described, as well as pinhole detection in steel strip, and general-purpose photoelectric relays. The importance of close co-ordination of design of the electrical and mechanical elements of a complete system is emphasized.
High-Speed Multiple-Point Potentiometer Recorder for Measuring Thermocouple Temperatures During Test-Plane Flights
Authors: Stein I. M. , Williams A. J. , Clark W. R.
Published: December 2022

Measuring exhaust-gas temperatures in flight-testing large planes requires the use of thermocouples of special design and requires also an instrument capable of recording rapidly, accurately, and directly a large number of temperatures. This paper describes a multiple-point, null potentiometer for this purpose. It accommodates 140 thermocouples and records each temperature in 1.63 sec. Flexible arrangements are provided for switching the numerous thermocouples, and this switching may be operated manually by push-button control and also automatically by the recorder. Operating characteristics and performance in flight tests are discussed.
The Corrosion of Alloy Steels by High-Temperature Steam
Authors: Hawkins G. A. , Agnew J. T. , Solberg H. L.
Published: December 2022

This paper presents additional test results obtained at the Engineering Experiment Station of Purdue University dealing with the relative resistance to corrosion by steam of unstressed specimens of various alloy steels at temperatures between 1000 F to 1800 F. All of the steels tested, except for the very high chromium-nickel alloys, show rapid corrosion beyond a limiting temperature which increases with chromium content. Data are presented relative to the chemical composition of the scale layers formed during tests at 1500 F and 1800 F.
Development of the Lysholm-Smith Torque Converter
Authors: Lysholm A.
Published: December 2022

The author’s experience in the design and construction of hydraulic transmissions for automotive drives goes back over a 15-year period when the outstanding development was the Föttinger transformer, incorporating a coaxial pump impeller and turbine which was used as a speed reducer for ship propellers. Present-day designs of the Lysholm-Smith torque converter employ the Föttinger coaxial arrangement, but with improved multiple-stage turbine blading which enables the torque-speed range to become automatically variable within a wide range of high efficiency. The paper is concerned principally with the theory of the torque converter, details of early experiments in Sweden, and design features of hydraulic drives of various types as now widely applied in the automotive and railroad fields.
The Combustion of Barley Anthracite
Authors: Johnson Allen J.
Published: December 2022

Because of its availability, excellent combustion qualities, and low cost, “barley” or No. 3 buckwheat anthracite is one of the most economical of all industrial fuels. After giving the analyses and physical properties of this fuel, the author discusses the effect of utilizing barley upon boiler performance. Details of the equipment available for burning this fuel, either by hand or stoker firing, are outlined, as well as practical suggestions for actual operation of the various types.
New Combustion-Control Methods for All Standard Fuels
Authors: Reed Robert
Published: December 2022

As a result of extensive study and field experience with combustion problems, the author offers suggestions for increasing the accuracy of combustion control in all types of furnaces and with all types of standard fuels. This is accomplished by overcoming the existing limitations of flue-gas-analyzing methods either by recorded CO2 concentrations, or by Orsat analysis. Curves are given which provide a simple means for determining “excess air by CO2” and “excess air by O2,” by the use of which excess-air control can be quickly adjusted for any change in fuel to obtain unimpaired combustion. The importance of determining the presence of aldehydes in flue gases is recognized and a positive method for their indication has been developed in the form of a simple apparatus which is described. This check on combustion may save considerable fuel, and a great deal of mechanical difficulty with furnaces.
Firing High-Pressure Furnaces
Authors: Peterson E. G.
Published: December 2022

Developments in the oil-refining industry, particularly in the catalytic-cracking process, have created a need for furnaces capable of carrying high pressures and sustaining high loadings. Direct-fired air heaters are in service which operate at pressures of 45 to 55 psi or higher, with furnace loadings of 500,000 to 2,500,000 Btu per hr per cu ft of volume. The design requirements of such heaters, their details of construction, and operating characteristics are discussed in this paper. The subject is of great importance since the possibility of wide application for this combustion system already exists. One of the most important fields under consideration is that of ship propulsion with power generated by gas turbines and direct-fired air heaters. “Package power” units made up of similar equipment may be used for power generation in small plants.
Heat and Vapor Transfer in the Dehydration of Prunes
Authors: Perry R. L.
Published: December 2022

Quality of prunes is known to be influenced by the temperature and relative humidity of the dehydrator air, and by the time required for drying, long exposures to high temperatures at high humidities resulting in excessive caramelization and cooked taste. To determine the actual temperatures of prunes during dehydration, readings were made by thermocouples inserted at different points in prunes for three test runs at about 166 F, and relative humidities of 15, 27, and 43 per cent. To permit adapting the data obtained to commercial dehydrators, surface thermal conductances were computed. The vapor conductance at the surface was estimated from the thermal conductance, by employing the heat-mass transfer analogy. From the vapor conductance and the evaporation rate, the difference in vapor concentration required to move vapor from the prune surface to the air stream was calculated. Moisture movement within the prune was investigated by cutting the flesh of samples, removed after 3, 6, 10, and 16 hr drying, into two parts, that near the surface, and that near the pit.
Evaluating Importance of the Physical and Chemical Properties of Fly Ash in Creating Commercial Outlets for the Material
Authors: Weinheimer C. M.
Published: December 2022

The paper presents the reasons for emphasizing the physical properties rather than the chemical constituents in outlining an investigational program for fly-ash disposal and outlines the procedure followed in determining the potential consumers of this material. The results of a laboratory and field investigational program are presented and various methods and equipment for modifying the ash to meet special requirements are discussed. Commercial markets and other possible uses for fly ash are discussed together with the handling equipment and the storage facilities necessary in using bulk fly ash. Finally, certain conclusions are presented regarding the general problem of fly-ash disposal.
High- and Low-Pressure Airplane Hydraulics in Europe
Authors: Mercier Jean
Published: December 2022

Development of hydraulic control systems for aircraft began to make progress in Europe about 1936, the trend being toward pressures of 5000 psi and higher. Details of the equipment comprising the hydraulic systems, applications made, and lines of development when the war interrupted the program are treated in this paper.
Some Characteristics of Rotary Pumps in Aviation Service
Authors: Pigott R. J. S.
Published: December 2022

Only within recent years have rotary pumps been accorded a semblance of the technical consideration which has been expended upon the piston or plunger reciprocating type, and the centrifugal and turbine types, between which two groups occurs its sphere of greatest usefulness. The rotary can handle all pumpable viscosities at any pressure up to 1000 psi. It has other qualities such as the ability to handle liquids with considerable gas or vapor present. The present paper is devoted to a discussion of characteristics of gear- and vane-type rotary pumps which make them widely adaptable to lubrication-oil, fuel-oil supply, and other aircraft uses in which they predominate.
Effect of Grain Size and Subzero Treatment on Productivity of Four High-Speed Steels
Authors: Depoy S. M.
Published: December 2022

In the investigation reported, the effect of grain size and subzero treatment on the productivity of four high-speed steels was studied by means of a series of turning tests on one alloy steel at a preselected uniform hardness. The material being cut, the shape of the tool bit, and the speed, feed, and depth of cut on the turning operation were held constant. Standard and subzero treatments were used at different hardening temperatures to develop different grain sizes and different hardening products. The results obtained show that the grain size, carbide solution, and type of martensite formed in the tool have a very marked effect on its cutting ability. It appears that subzero treatment is much more effective, when large grain sizes are developed.
Methods of Joining Aluminum-Alloy Products
Authors: Hartmann E. C. , Hoglund G. O. , Miller M. A.
Published: December 2022

American industry has never fully realized the possible economies that can be achieved by using the light alloys, particularly the aluminum alloys, as structural metal. There were many reasons for this, most of which are no longer valid. The end of the war will find fabricating capacity that can deliver metal in quantity, sizes, and high-strength alloys to meet the most ambitious program to use the metal in all types of transportation, architectural, structural, or other fields that can be foreseen. It is the purpose of the authors to make clear the many procedures that have become established for making joints in these alloys. The discussion will include the common practices of riveting, welding, brazing, soldering, and a promising new possibility, resin-bonding. These methods will be considered as specifically as space permits to provide a comprehensive picture of the subject. Additional and more detailed information and training will be required to put the methods into practice, and further inquiry on any of the methods will be welcomed.
Variable Heat-Transfer Rate Correction in Multipass Exchangers, Shell-Side Film Controlling
Authors: Gardner Karl A.
Published: December 2022

The change in temperature of the fluid streams within a heat exchanger, through the consequent alteration of their physical properties, may cause the over-all heat-transfer coefficient to vary between rather wide limits; this represents the chief source of error in mean temperature difference formulas, most of which are derived on the assumption of constant over-all coefficient. Colburn (3) based a simple method of correcting for this effect in counter- and parallel-flow exchangers on the assumption of a linear variation of rate with fluid temperature. On this same basis, equations are developed in the present paper for multipass exchangers in which the shell-fluid film controls. It is shown that the results are practically independent of the number of tube passes, and the numerical data given are therefore those for the limiting case of crossflow with both fluids mixed, since this proves to be more amenable to direct mathematical treatment. These data are presented graphically and in tabular form as correction factors by which the arithmetic-average over-all heat-transfer coefficient and logarithmic mean temperature difference may be multiplied to obtain the true mean heat-transfer coefficient - temperature difference product; an example of their use is given.
Experimental Confirmation of Predicted Water-Freezing Rates
Authors: Seban R. A. , London A. L.
Published: December 2022

A general approximate method for the solution of the freezing problem, with applications to ice formation at spherical, cylindrical, and plane boundaries, has been presented in a previous paper (1). Numerical examples therein, applying the analysis to similar systems for which test data were available, indicated good agreement between prediction and test results. Test data on an actual system closely analogous to an ideal one of the analysis are presented in the present paper, and the agreement with the predicted values validates the approximations of the analysis. Measurements of times of complete freezing in food products of high water content indicate applicability of the analysis, although with less accuracy than in the case of pure water.
Stabilizing a Suction-Relief Valve
Authors: Smith Ed S.
Published: December 2022

Starting with a less than fully stable conventional valve in aircraft use, a simple analysis is presented which is based upon energy considerations under resonance conditions and involves a minimum of mathematics. This analysis led to the disclosed improvement which renders the valve stable under all installations except the worst, from an acoustic standpoint. A short appendix on acoustic systems is included for the convenience of control engineers who may need in advance to evaluate and, if necessary, correct acoustic difficulties of installations. The analysis of this paper amounts to an informal use of the Nyquist method.
Lubrication Characteristics of Involute Spur Gears: A Theoretical Investigation
Authors: Gatcombe E. K.
Published: December 2022

In this paper the lubricating-oil wedge which separates the tooth surfaces of involute straight spur gears is analyzed mathematically. Expressions are derived for the pressure distribution, the maximum pressuro, the minimum thickness, and the load-carrying capacity of the wedge for any phase of mating. The equation for the load-carrying capacity may give guidance to gear designers and to gear operators who are conscious of the importance of lubrication in their fields of work.
Silica Deposition in Steam Turbines
Authors: Straub F. G. , Grabowski H. A.
Published: December 2022

Laboratory and power-plant tests have been conducted to determine the cause of silica deposition in steam turbines. The tests indicate that the silica leaves the boiler as vaporized silicic acid which later crystallizes on the blades in the lower-pressure stages of the turbine. When the silica in the steam is below 0.1 ppm, no appreciable deposits are found in the turbines. Two methods of preventing deposits are suggested; (1) maintain the silica in the boiler water below 5 ppm; (2) remove the silica from the steam by scrubbing with a pure-grade water.
History of Potassium Boiler-Water Treatment at Springdale
Authors: Hankison L. E. , Baker M. D.
Published: December 2022

Results are given in considerable detail of 2 years’ experience in the treatment of boiler water at Springdale Station, West Penn Power Company, with potassium compounds which were substituted for sodium salts for water conditioning of both the high- and low-pressure boilers. This change in treatment was started August 25, 1942, in an endeavor to prevent the formation of silica scale in the boilers and also to minimize if possible deposits of silica on the turbine blades.
Water-Hammer Analysis by the Laplace-Mellin Transformation
Authors: Rich G. R.
Published: December 2022

The author supplements the pioneer work of Prof. F. M. Wood in applying operational methods to the study of water-hammer phenomena. The Heaviside calculus is replaced by the Laplace-Mellin transformation together with the elementary theory of functions of a complex variable. This substitution facilitates interpretation of a much wider range of operators, is believed to be better adapted to problems starting from a steady-state system in motion, and permits working directly with total pressures and velocities instead of surge pressures and velocities. This third feature operates to eliminate ambiguity concerning reflection coefficients at junction points in branched-conduit problems. When the effect of friction is not included, results are given in the form of simple trigonometric series of rapid convergence. When the abscissas of the two terminal sections of the conduit are inserted in these formulas, the resulting expressions are, in many cases, Fourier representations in the time variable of well-known periodic step or saw-tooth functions. In such instances, almost no computation work is required; it is unnecessary to sum the series, as the value of the summation may be taken at a single reading from a graph of the function, one plot of such a function serving for all particular cases within its domain. In cases where the effect of friction is included, a standard table of Bessel functions, used in conjunction with the formulas developed, affords easy and comparatively rapid solution.
Use of Anthracite Fines in By-Product Coke Production: Factors Influencing the Relative Suitability of Different Anthracites for Blending
Authors: Clendenin J. D. , Barclay K. M. , Wright C. C.
Published: December 2022

The blending of carbonaceous materials, particularly Pennsylvania anthracite, with coking coals as a means of mitigating the acute war shortage of certain types of metallurgical coke, has received considerable emphasis in recent months. However, the desirability of blending anthracite fines with coking coals for by-product coke production has been a matter of considerable controversy. To settle the differences of opinion and judgment, an attempt has been made as reported in this paper to evaluate, at least relatively, some of the variables encountered in the case of anthracite fines. The investigation in question was conducted at the Mineral Industries Experiment Station of The Pennsylvania State College, and was sponsored jointly by the Anthracite Institute and the Commonwealth of Pennsylvania.
Blending Coals Reflects Greater Uniformity of Product
Authors: Stilwell R. F.
Published: December 2022

Coal consumers look for three qualities in their fuel, suitability for their requirements, uniformity in shipments, and proper heating value, as well as suitable chemical and physical characteristics. The present paper gives a broad picture of the part that blending plays in the attainment of these qualities, discussing methods and equipment which have given the best results. Case examples are cited of the improvements achieved by suitable blending practices. Metallurgical engineers have had much wider experience in blending raw materials than have coal-preparation engineers; and the author has incorporated notes on “bedding” or blending with reference to coal, by A. J. Boynton, an authority on the subject. Suitable bin designs for blending purposes are included in the paper.
Prediction of Centrifugal-Pump Performance
Authors: Pigott R. J. S.
Published: December 2022

The author states that the selection of impeller, diffuser, and volute shapes of centrifugal pump designs are largely empirical, because the theory, based mostly upon the classical centrifugal theory, has been incorrect or at least incomplete. In the prediction of performance of small multistage deep-well pumps, some time ago, the author found another course of analysis which gave promise of excellent results. Essentially, the centrifugal pump does not operate as such except at shutoff but does behave as a radial-flow turbine. Consequently, the performance can be more truly analyzed and the hydraulic losses can be treated as if the pump were a pipe with a shock loss at the pickup edge of the blades and a recirculation loss. This method of prediction is explained and illustrated in the course of the paper.
A Study of the Theory of Axial-Flow Pumps
Authors: Wislicenus G. F.
Published: December 2022

The essential aim of this paper is to present the theory of axial-flow pump runners in as simple a form as possible. The results are fairly conclusive in so far as the determination of the flow conditions in individual cylindrical stream surfaces is considered. In addition, it has been found possible to eliminate the controversy between the one-dimensional and the two-dimensional theories. The question of the method to be employed in building up the performance of the machine as a whole is still controversial and has been presented in this form.
Efficiency of Extended Surface
Authors: Gardner Karl A.
Published: December 2022

The work of previous investigators on heat flow through extended surface is briefly reviewed and literature citations are given. General equations are derived for the temperature gradient and fin efficiency in any form of extended surface to which the assumptions listed are applicable. The solution of these equations in terms of Bessel functions is shown to cover practically any form of extended surface whose thickness varies as some power of the distance measured along an axis normal to the basic surface. Curves are presented for the fin efficiency of several forms of straight fins, annular fins, and spines.
Disk Extended Surfaces for High Heat-Absorption Rates
Authors: Tate G. E. , Cartinhour John
Published: December 2022

Four types of disk-on-tube extended-surface heat exchangers are discussed in this paper, i.e., interlocking castiron sections of nine disks each; die-cast aluminum-alloy disks each with shroud and hub; two surfaces die-pressed from wrought-iron sheet, each with a flue; and one a sixteen-pronged star. Data for both the cast-iron and aluminum surfaces were obtained from tests of full-sized economizers in conjunction with boiler tests, while data on the wrought-iron disks were obtained from laboratory studies. Details are given of the testing procedure, and the results in terms of effectiveness of the various surfaces are analyzed and correlated.
Heat-Flux Pattern in Fin Tubes Under Radiation
Authors: Mumford A. R. , Powell E. M.
Published: December 2022

In this paper data are presented showing heat-flux patterns as indicated by temperature-drop curves from field measurements and from an electrical analogy in the laboratory. Data of this kind may become of some importance if the use of tube-surface temperatures in furnace-testing technique is successfully developed.