bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of sulfur-oxidizing bacteria isolated from mustard (Brassica juncea L.) rhizosphere having the capability of improving sulfur and nitrogen uptake
Authors: Chaudhary Suman , Dhanker Rinku , Singh Kuldeep , Brar Basanti , Goyal Sneh
Published: July 2022

Aims

The present investigation was carried out to isolate, screen and characterize potential sulfur-oxidizing bacteria (SOB) isolated from mustard field's soil.

Methods and Results

A total of 130 bacteria were isolated and after screening five maximum sulfate-producing isolates were optimized for culture conditions. The incubation time of 48 h was found optimum for all bacterial isolates and 30°C was the best temperature for the growth of SSD11, SSR1 and SSG8 whereas 35°C for SSF17. The pH 8 was found best for all four isolates except SSF17 (6 pH). Media having glucose as a carbon source and ammonium sulphate as an N-source were producing maximum sulphate. The isolates SSF17, SSR1 and SSG8 were identified as Burkholderia cepacia (accession no. MT559819), Enterobacter cloacae (accession no. MT559820) and Klebsiella oxytoca (accession no. MT372097), respectively, on the basis of morphological, biochemical and molecular characterization. The isolates were also found to increase N and S uptake efficiently in both wheat and mustard crops.

Conclusion

This study strongly concludes that SOB isolated from the mustard field can oxidize sulfur in vitro and in vivo conditions. The three best isolates come out of the study were identified as Burkholderia, Enterobacter and Klebsiella strains. Also, inoculation of SOB increased the uptake of S and N nutrient in mustard and wheat crops and thus may be proved as an important plant growth-promoting bacteria having the biofertilization capability.

Significance and Impact of the study

As we know, our soil is continuously deteriorating day by day due to excessive utilization and immoderate use of chemical fertilizers. The SOB could minimize the application of chemical fertilizers thus reducing environmental deterioration by improving soil health in sustainable agricultural practices.
Effectiveness of combined use of targeted pressure energy, radiofrequency, and high‐intensity focused electromagnetic fields to improve skin quality and appearance of fat and muscle tissue in different body parts
Authors: Duncan Diane Irvine , Busso Mariano
Published: July 2022

Background

Inevitable signs of aging are especially noticeable in middle to elder age when stretch marks, loose skin, cellulite, and body‐contour changes naturally appear.

Aims

To verify efficacy of high‐intensity focused electromagnetic field (HIFEM), radiofrequency (RF), and Targeted Pressure Energy (TPE) combination treatment to address unfavorable changes in skin, fat, and muscle tissue.

Methods

The device simultaneously emitting monopolar RF and TPE energies was consecutively combined with simultaneous HIFEM+RF procedure in 32 subjects (21–64 years, 17.4–33.5 kg/m2) for treatment of thighs (N = 15; back, inner, or front), buttocks/saddlebags (N = 7), abdomen (N = 8), and upper arms (N = 2). All patients underwent four weekly, combined treatments of 30‐min HIFEM+RF procedure followed by 15–30 min RF+TPE, depending on treatment area. Circumferential measurements, digital photographs, subject satisfaction, and comfort questionnaires were assessed up to 3‐months post‐treatment.

Results

Majority of participants found treatments comfortable, no adverse events occurred. Subjects showed substantial improvement in all treated areas from 1‐month follow‐up. Combination of HIFEM+RF, monopolar RF, and TPE resulted in significant circumference decrease. Generally, more pronounced results were seen at 3 months when subjects showed −5.2 cm on abdomen, −3.0 cm on thighs, and −5.5 cm on saddlebags, respectively. Ninety‐four percent of subjects were satisfied with treatment results, most noticed improvement in cellulite, skin laxity, and muscle definition.

Conclusions

Results showed high patient satisfaction and efficacy in improving body contour and skin quality. Combining simultaneous HIFEM+RF procedure with simultaneous monopolar RF+TPE treatments considerably enhanced body contour and skin tissue. The procedure proved versatile and may effectively treat multiple body parts.
Vaginal preparation with different antiseptic solutions before cesarean section for preventing postoperative infections: A systematic review and network meta‐analysis
Authors: Fadlalmola Hammad Ali , Al‐Sayaghi Khaled Mohammed , Al‐Hebshi Abdulqader Abdlah , Alshengeti Amer Mohammad , Almohammadi Nawal H. , Alawfi Abdulsalam Dakheel , Aljohani Maher M. , Elhaddad Nourhan F.
Published: July 2022

Aims

We aimed to investigate the effect of various vaginal wash solutions on reducing risks of post‐cesarean endometritis, wound infections, fever, and hospital stay duration.

Methods

Scopus, Web of Science, PubMed, and Cochrane Library were searched for randomized clinical trials that compared different vaginal wash solutions to each other or to “no vaginal cleaning”; without restriction on the age of parturients or site where trials were conducted. We analyzed this frequentist network meta‐analysis using the netmeta package in R software version 4.1.2; synthesized data as mean difference or risk ratio with their 95% confidence intervals.

Results

Our network meta‐analysis included 29 RCTs with a total sample size of 9311 women undergoing CS. Regarding post‐cesarean endometritis, we found that povidone‐iodine had the highest significant risk reduction compared to “no vaginal cleaning” (RR = 0.08, 95% CI [0.01, 0.69]). While regarding post‐cesarean reduction of wound infection, fever, and hospital stay duration, we found that chlorhexidine 4% (RR = 0.17, 95% CI [0.05, 0.65]), saline 0.9% (RR = 0.12, 95% CI [0.03; 0.48]), and saline 0.9% (MD = −1.29, 95% CI [−2.18; −0.39]), respectively, had the highest significant risk reduction compared to “no vaginal cleaning.”

Conclusion

Vaginal wash solutions were associated with a significant reduction of post‐cesarean endometritis, wound infection, fever, and hospital stay duration. Since povidone‐iodine had the highest significant reduction of post‐cesarean endometritis, we recommend setting povidone‐iodine as the standard practice as pre cesarean vaginal wash solution; consistent practice guidelines of Enhanced Recovery After Surgery (ERAS).
Age‐friendly Universities (AFU): Combating and inoculating against ageism in a pandemic and beyond
Authors: Montepare Joann M. , Brown Lisa M.
Published: July 2022

Manifestations of ageism during the recent COVID‐19 pandemic call for ways to combat persistent negative views of older adults and the disparities they fuel, especially in light of the aging of populations. We discuss the pioneering Age‐Friendly University (AFU) initiative that takes a systems‐level approach and offers guiding principles for advancing age inclusivity, which in turn can combat and inoculate individuals against ageism. In particular, the principles advocate that older adults be enabled to participate in core educational activities in higher education for personal and professional development and that institutions extend aging education, research on aging, and intergenerational exchange. The need for educational institutions to be more age‐friendly has become even more clear and pressing during the pandemic, where ageism has been exacerbated. Drawing on empirical evidence, we show how AFU principles can be applied to disrupt the roots of ageism and age biases, and disparities in healthcare and work environments. Connections between the AFU initiative and the Age‐Friendly Communities, Age‐Friendly Health Systems, and Age‐Friendly Employers initiatives are suggested as a collective move toward a more age‐inclusive ecosystem that fosters the well‐being of all people as they age.
Regulating emerging technology in times of crisis: Digital contact tracing in Norway during the COVID‐19 pandemic
Authors: Lund‐Tønnesen Jonas
Published: July 2022

In times of crisis, emerging technology can pose major challenges for regulators. They must deal with great uncertainty and urgency related to both the crisis and the technology. To understand such situations, this article studies the revelatory case of privacy regulation of a contact‐tracing application called Smittestopp, created in Norway during the COVID‐19 crisis. Based on public and organizational documents and 48 interviews, the analysis shows that the Norwegian Data Protection Authority faced several options for regulatory intervention throughout the crisis, and adapted its approach based on intra‐crisis experience, regulatees' responses, and different levels of uncertainty and urgency. Building on these findings, the study formulates propositions regarding the regulation of emerging technology during a crisis and regulatory agencies' use of rule‐based, idea‐based, and norm‐based interventions. This study provides insight into how these three types of intervention relate to different aspects of a crisis situation. Furthermore, it stresses the importance of idea‐based intervention as a key site of analysis in studying technology that emerges during a crisis.
Interaction of PKR with STCS1: an indispensable step in the biosynthesis of lunularic acid in Marchantia polymorpha
Authors: Zhu Ting‐Ting , Sun Chun‐Jing , Liu Xin‐Yan , Zhang Jiao‐Zhen , Hou Xu‐Ben , Ni Rong , Zhang Jing , Cheng Ai‐Xia , Lou Hong‐Xiang
Published: July 2022

Unlike bibenzyls derived from the vascular plants, lunularic acid (LA), a key precursor for macrocyclic bisbibenzyl synthesis in nonvascular liverworts, exhibits the absence of one hydroxy group within the A ring. It was hypothesized that both polyketide reductase (PKR) and stilbenecarboxylate synthase 1 (STCS1) were involved in the LA biosynthesis, but the underlined mechanisms have not been clarified.

This study used bioinformatics analysis with molecular, biochemical and physiological approaches to characterize STCS1s and PKRs involved in the biosynthesis of LA.

The results indicated that MpSTCS1s from Marchantia polymorpha catalyzed both C2→C7 aldol‐type and C6→C1 Claisen‐type cyclization using dihydro‐p‐coumaroyl‐coenzyme A (CoA) and malonyl‐CoA as substrates to yield a C6‐C2‐C6 skeleton of dihydro‐resveratrol following decarboxylation and the C6‐C3‐C6 type of phloretin in vitro. The protein–protein interaction of PKRs with STCS1 (PPI‐PS) was revealed and proved essential for LA accumulation when transiently co‐expressed in Nicotiana benthamiana. Moreover, replacement of the active domain of STCS1 with an 18‐amino‐acid fragment from the chalcone synthase led to the PPI‐PS greatly decreasing and diminishing the formation of LA. The replacement also increased the chalcone formation in STCS1s.

Our results highlight a previously unrecognized PPI in planta that is indispensable for the formation of LA.
Synthesis and Photophysical Characterizations of Pyrroloquinolone Photosensitizers for Singlet Oxygen Production†
Authors: De Bonfils Paul , Sandoval‐Altamirano Catalina , Moreau Xavier , Nun Pierrick , Laurent Adèle D. , Gunther German , Coeffard Vincent
Published: July 2022

A series of pyrroloquinolone photosensitizers bearing different halogen substituents (Cl, Br, I) on the heterocyclic framework was studied. These structures were readily prepared through a multi‐step synthetic sequence involving an oxidative protocol as an important step to access the quinolone framework. Spectroscopic characterizations and computational investigations were carried out to study the dyes before and after the oxidative step. Interestingly, the fluorescence emission was significantly reduced upon oxidation. In spite of a low photostability under UV light, the pyrroloquinolone photosensitizers proved effective to produce singlet oxygen. Higher singlet oxygen quantum yields were obtained with photosensitizers bearing halogen atoms with a higher atomic number.
Progress towards reestablishing Latin America as a major pearl producing region: A review
Authors: Saucedo Pedro E. , McLaurin Douglas , Lodeiros César , Freites Luis , León Luis , Cáceres‐Puig Jorge I. , Albuquerque Marcos C. P. , Southgate Paul C. , Acosta‐Salmon Héctor
Published: July 2022

Globally, pearl culture is a profitable sector generating significant export incomes for producer countries, as well as livelihood opportunities for local communities. Latin America has a long history as a pearl producer from extensive fisheries that date back to the 15th century. The presence of pearl oyster beds on the Pacific and Caribbean coasts of many Latin American countries was a major incentive for colonisation of the region and subsequent social and economic development of areas in the Gulf of California and the Caribbean. This review presents the historic background of the pearl fishery in this region since the arrival of the Spanish in the 16th century, describes the current status of pearl culture in Latin America, and outlines future opportunities for sector development. Information on the current status of pearl culture in Latin American countries is divided between two major categories: commercial and pilot‐scale. Commercial pearl production currently occurs only in Mexico and production updates are provided for bead‐nucleated, half pearls (mabé) and non‐nucleated (keshi) pearls from the two pearl farms operating in the Gulf of California. The second category comprises countries whose pearling activities were relevant in the past (Venezuela, Panama) and others that are emerging, but still maintain pilot‐scale production of mabé pearls using Pteria sterna (Ecuador, Peru), Pinctada mazatlanica (Panama) and Pteria hirundo (Brazil). Finally, this review discusses future prospects for pearl culture in Latin America, analysing technology gaps and challenges to be addressed if the cultured pearl sector is to achieve its full potential in this region.
Astaxanthin alleviates palmitic acid‐induced hindrance of porcine oocyte maturation
Authors: He Xu , Wang Dayu , Zhu Fuquan , Jiang Yuan , Bi Jiaying , Lu Xinyue , Zhao Mingyue , Wu Weidong , Li Juan
Published: July 2022

Increased palmitic acid (PA) levels have been found in females with reduced fertility due to metabolic disorders. However, effective antioxidant astaxanthin (AXE) might positively affect animal reproduction. Therefore, the present study was designed to evaluate the impact of a high concentration of PA on oocyte maturation and the possible protective effect of AXE against high PA concentration in pigs. Firstly, different concentrations (0.2, 0.5, 0.8 mM) of PA were conducted on in vitro maturation (IVM) of pig oocytes (PA0.2, PA0.5, and PA0.8), while no addition of PA was performed as the control group (Ctrl). Results showed that the cumulus cell expansion index (CCEI) was lower in PA0.5 and PA0.8 groups compared to Ctrl group (p < .05). In PA0.5 group, not only did the percentage of matured oocytes with the first polar body (PB1) reduced, that with more oocytes arrested at germinal vesicle (GV) stage (53.44% ± 7.16% vs. 20.93% ± 5.16%, p < .05), but also a higher number of transzonal projections (TZPs) was observed in PA0.5 than Ctrl group. Besides, supplement of PA resulted in a dose‐dependent decrease in mitochondrial activity. Although no difference of lipid content was observed between PA0.5 and Ctrl groups, the lipid content was at a higher level in PA0.2 group than in the other three groups. Hence, concentration of 0.5 mM of PA was performed in the following experiments, and 2.5 μM AXE carried out to investigate the possible relief effects of PA (PA0.5 + AXE). Results showed that the percentage of matured oocytes with PB1 was higher in PA0.5 + AXE than in PA0.5 group (63.43% ± 1.50% vs. 55.33% ± 0.81%, p < .01), and ROS levels both in oocytes and their cumulus cells (CCs) reduced in PA0.5 + AXE when compared to PA0.5 group. In addition, the rate of CCs with apoptosis decreased in PA0.5 + AXE, and the expression level of caspase 3 and BAX was lower than PA0.5 group. In conclusion, the maturation of pig oocytes was inhibited by the high concentration of PA; however, this negative effect of PA‐induced might be relieved by the supplement of AXE.
Chemical and short‐wave infrared characteristics of white mica associated with the Gajah Tidur porphyry copper system at the deep Grasberg Cu—Au—(Mo) deposit, Indonesia
Authors: Al Furqan Reza , Watanabe Yasushi , Arribas Antonio , Leys Clyde , Echigo Takuya , Putri Rici Anggun , Sevirajati Renanda
Published: July 2022

The Grasberg Cu—Au—(Mo) deposit comprises the shallower Main Grasberg porphyry Cu—Au and the deeper Gajah Tidur (GT) porphyry Cu—Mo—(Au) systems. The GT porphyry preserves various types of white mica whose geochemical variations provide insights into the white mica‐dominated alteration of porphyry systems. The white mica assemblages within the GT porphyry system comprise: (1) muscovite‐anhydrite‐chlorite (MAC), (2) muscovite‐chlorite‐anhydrite (MCA), and (3) muscovite‐quartz ± pyrophyllite (MQP). These assemblages display zonation from central and deep parts of the system to its shallower and peripheral parts. The MAC alteration white micas are characterized by high Na, Fe, Ti, and V concentrations, and with short‐wave infrared Al—OH absorption wavelengths of 2203–2208 nm. The MCA white micas have higher Mg content than the other two GT white mica assemblages but similar Al—OH absorption wavelengths to the MAC white micas. The MQP alteration white micas have low Na, Fe, Mg, and Ti, but relatively high Si, Al, and F, and Al—OH absorption wavelengths are largely shorter than 2202 nm. We interpret that the high Fe and Ti content of the MAC white micas is due to inheritance of these elements from mafic minerals they replaced. The higher Fe content of these white micas explain their longer wavelength Al—OH absorption positions relative to the MQP white micas. In contrast, lower Fe content and shorter Al—OH wavelengths of the MQP white micas are caused by their higher Si and Al content, which reduces iron occupancy in the white mica crystal structure. White micas in this assemblage formed at lower temperature and probable lower pH condition that may have led to a replacement of Fe by Al. The short‐wave infrared Al—OH position of white mica together with the associated hydrothermal assemblage can be used as a proximitor for porphyry Cu hydrothermal centres. White mica associated with chlorite, anhydrite, and chalcopyrite, which commonly occur overprinting or adjacent to the potassic alteration center, are characterized by Al—OH absorption positions at 2200–2215 nm. By contrast, white mica associated with quartz‐pyrite are characterized by Al—OH wavelengths shorter than 2202 nm. In the distal part of porphyry Cu system, white micas may be associated with chlorite and have Al—OH absorption positions longer than 2204 nm.
Network Hawkes Process Models for Exploring Latent Hierarchy in Social Animal Interactions
Authors: Ward Owen G. , Wu Jing , Zheng Tian , Smith Anna L. , Curley James P.
Published: July 2022

Group-based social dominance hierarchies are of essential interest in understanding social structure (DeDeo & Hobson in, Proceedings of the National Academy of Sciences 118(21), 2021). Recent animal behaviour research studies can record aggressive interactions observed over time. Models that can explore the underlying hierarchy from the observed temporal dynamics in behaviours are therefore crucial. Traditional ranking methods aggregate interactions across time into win/loss counts, equalizing dynamic interactions with the underlying hierarchy. Although these models have gleaned important behavioural insights from such data, they are limited in addressing many important questions that remain unresolved. In this paper, we take advantage of the observed interactions' timestamps, proposing a series of network point process models with latent ranks. We carefully design these models to incorporate important theories on animal behaviour that account for dynamic patterns observed in the interaction data, including the winner effect, bursting and pair-flip phenomena. Through iteratively constructing and evaluating these models we arrive at the final cohort Markov-modulated Hawkes process (C-MMHP), which best characterizes all aforementioned patterns observed in interaction data. As such, inference on our model components can be readily interpreted in terms of theories on animal behaviours. The probabilistic nature of our model allows us to estimate the uncertainty in our ranking. In particular, our model is able to provide insights into the distribution of power within the hierarchy which forms and the strength of the established hierarchy. We compare all models using simulated and real data. Using statistically developed diagnostic perspectives, we demonstrate that the C-MMHP model outperforms other methods, capturing relevant latent ranking structures that lead to meaningful predictions for real data.
The skeletal muscle microbiopsy method in exercise and sports science research: A narrative and methodological review
Authors: Newmire Daniel E. , Willoughby Darryn S.
Published: July 2022

Background

The skeletal muscle microbiopsy protocol was introduced to the Exercise and Sports Science (ESS) research field in 1999 and has been used as a protocol to directly examine muscular structural and biochemical changes. There is much variation in the reporting of the microbiopsy protocol and its related pre‐ and post‐procedure for participant care and sample collection. The purpose of this narrative and methodological review is to compare the microbiopsy to the traditional Bergström protocol used in the ESS field, identify and summarize all related microbiopsy protocols used in previous ESS studies and determine the most frequently used microbiopsy protocols aspects and associated pre‐ and post‐biopsy procedures.

Methods

A review of literature up to January 2022 was used following the PRISMA and Cochrane Methodological Review Guide to determine frequently used methods that may facilitate optimal and potential recommendations for muscle microbiopsy needle gauge (G), concentration or dose (% or ml) and administration of local anesthetic, co‐axial/cannula introducer gauge (G), muscle depth (cm), muscle sample size collected (mg), passes to collect samples, time points of muscle sampling, and promotion of participant compliance and minimization of adverse events.

Results

Eighty‐five articles were selected based on the inclusionary requirements related to the ESS field or methodological considerations. The most frequently reported aspects in previous research to suggest the location of the vastus lateralis is the midpoint between the patella and the greater trochanter of the femur or 1/3 or 2/3 the distance from the patella to anterior superior iliac spine, 14 G biopsy needle, subcutaneous injected lidocaine administration (2 ml, 1%), 13 G co‐axial/cannula, 1–2 cm muscle depth, 10–20 mg of muscle sample, ~3‐time points, and 2–3 passes.

Discussion

There is much variation in the reporting of the microbiopsy protocol and its related pre‐ and post‐biopsy procedures. Standardization in reporting may promote recommendations to optimize data integrity, participant safety, participant adherence to the study design, and increase reproducibility. Recommendations are made for the microbiopsy procedure based on frequently reported characteristics.
He reshaped the forefront of xenotransplantation: Agustin Pasqual Dalmasso (1933–2021)
Authors: Platt Jeffrey L. , Vercellotti Gregory M.
Published: July 2022

Agustin Pasqual Dalmasso died in December 2021. He was 88 years old and an Honorary Member of the International Xenotransplantation Association. Gus made seminal contributions to understanding and overcoming the barrier complement system poses to xenotransplantation. Those endeavoring to advance xenotransplantation to clinical application and those seeking the most topics in which to devote their life's work could do no better than examining how Gus approached the subjects of his life's work.
Reviewer Acknowledgements (Vol. 5, No. 1)
Authors: Brown Bennett
Published: July 2022

International Journal of Law and Public Administration (IJLPA) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this volume. Many authors, regardless of whether IJLPA publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this volume.Reviewers for Volume 5, Number 1Antonio Fortes Martín, Carlos III University of Madrid, SpainDiane M. Hartmus, Oakland University, USAJohn Mark R. Asio, Gordon College, PhilippinesJosé Sebastián Kurlat Aimar, University of Buenos Aires, ArgentinaTatiana Bachvarova, Special Tribunal for Lebanon, BulgariaTaylisi de Souza Corrêa Leite, Anhanguera University, BrazilYusra, University Utara Malaysia, Malaysia
A numerical scheme for the one-dimensional neural field model
Authors: Gokce Aytul , Gurbuz Burcu
Published: July 2022

Neural field models, typically cast as continuum integro-differential equations, are widely studied to describe the coarse-grained dynamics of real cortical tissue in mathematical neuroscience. Studying these models with a sigmoidal firing rate function allows a better insight into the stability of localised solutions through the construction of specific integrals over various synaptic connectivities. Because of the convolution structure of these integrals, it is possible to evaluate neural field model using a pseudo-spectral method, where Fourier Transform (FT) followed by an inverse Fourier Transform (IFT) is performed, leading to a new identical partial differential equation. In this paper, we revisit a neural field model with a nonlinear sigmoidal firing rate and provide an efficient numerical algorithm to analyse the model regarding finite volume scheme. On the other hand, numerical results are obtained by the algorithm.
An Energy Basis for Comparison of Performance of Combustion Chambers
Authors: Nichols J. B.
Published: July 2022

The energy loss in a combustion chamber, as a result of pressure drop, is generally found to be of relatively greater importance than the losses from combustion inefficiency. Therefore it must be included in any parameter which claims to state the efficiency of the burner. Combustion efficiency alone does not serve this purpose. A method of comparison is suggested and developed which allows combustion chambers to be compared on an over-all basis. By this method, any combustion chamber is assigned a single energy efficiency for each inlet condition, which includes the effects of both combustion efficiency and pressure drop.
Use of the Centrifugal Governor Mechanism as a Torsional Vibration Absorber
Authors: Pringle O. A.
Published: July 2022

The centrifugal governor mechanism, suitably modified, is shown to be a practical torsional vibration absorber. Equations for predicting its performance are developed, and comparisons are made with other types of absorbers.
Operating Experiences With Mechanical Joints in High-Pressure High-Temperature Steam Piping
Authors: Bailey E. C. , Schroeder H. C. , Carlson I. H.
Published: July 2022

Because of the uncertain life expectancy of austenitic-ferritic steel welds for joining the 2¼ per cent chromium, 1 per cent molybdenum alloy-steel main steam piping to Type 347 stainless alloy steel at the throttle valves of the turbines, two types of mechanical transition joints were installed in the Ridgeland Station of the Commonwealth Edison, Chicago, Ill. The joints, the pressure-seal and the bellows-type were designed for operation on steam at 1800 psig and 1050 F. These joints have operated satisfactorily since the units were put in service. The pressure-seal joints have been in service a total of 1 year and 5 months and the bellows-type joints 1 year.
Comparisons at Elevated Temperatures of Some Commercial Grades of Ferritic Cast Steels
Authors: Wyatt H. W. , Bolton J. W. , Steinbuch M. L.
Published: July 2022

This paper presents some direct elevated-temperature test comparisons of cast steel Grades WC4, WC5, WC6, and WC9 of ASTM Specification A217-49T. The materials studied are from commercial heats. Care has been taken to hold all variables in manufacture, treatment, and composition (aside from prescribed “alloy elements”) as closely alike as possible. The tests show that at the temperatures under consideration the nominal 1 per cent molybdenum grades WC5 and WC9 are higher in “creep strength” than the nominal ½ per cent molybdenum grades, WC4 and WC6. Grade WC5 has shown, in this direct comparison, higher “stress-rupture strength” than the other three grades.
Design and Development of a Broad-Range, High-Efficiency Centrifugal Compressor for a Small Gas-Turbine-Compressor Unit
Authors: Speer Ivan E.
Published: July 2022

The compressor requirements for a small gas-turbine-compressor unit imposes factors with regard to broad flow range and efficiency that form the basic objectives for the design and development. Highly backwardly curved impellers, designed according to the reasoning presented, are shown to evidence the required characteristics. Results of the development program show that the objectives can be met and exceeded.
Engineering Features of the Union Oil-Shale Retort
Authors: Reed H. C. , Berg Clyde
Published: July 2022

The retorting of shale requires an operation combining very good heat and fuel economy with low capital investment. In order to meet these demands the Union Oil Company developed its novel underfeed retorting method, which was publicly demonstrated in 1950 in a 50-ton per day unit. The retorting unit employs countercurrent flow of shale and air in a kiln utilizing bottom feed of solids. Ash and clinkers are removed overhead, and the oil drained from the bottom of the unit is cooled by countercurrent heat exchange with the incoming shale. No water is required for process operation. Movement of the shale through this unit is effected by a hydraulically operated underfeed mechanism. The shale kiln employs an external retorting section with cowling to direct air flow over the fins and to control shell temperature. Unlike conventional retorts, fusion of ash is not considered a problem in the operation of the Union retort since specially designed sodium-filled plows carry out a scraping action in the plastic ash-fusion zone, maintaining uniform bed porosity and size range of the discharged ash. It has been estimated that a typical commercial shale mine can produce approximately 20,000 tons per day of shale. The shale-retorting plant designed to handle this production would employ a battery of retorts, each having a capacity of 1000 tons per day, and centralized gas-handling and hydraulic power-supply systems.
Full-Scale Fatigue Testing of Compressor Cylinders
Authors: Kuivinen T. O.
Published: July 2022

Present needs for higher-pressure compressor cylinders for natural-gas pipe lines introduce complexities of design and manufacture. Through full-scale fatigue testing, designs incorporating high-strength cast irons are proved suitable at considerable saving to the user. Comparison of the fatigue-test failure of the design to the fatigue strength of the material used indicates the maximum safe working pressures permissible for various suction pressures. In this manner a new design is evaluated, eliminating the risks involved in former practice where field service was the only criterion of performance.
On the Solution of the Reynolds Equation for Slider-Bearing Lubrication—III: Effect of Transverse Curvature
Authors: Charnes A. , Saibel E. , Ying A. S. C.
Published: July 2022

The effect of transverse curvature on the properties of a rectangular slider bearing with side leakage is studied for film thickness varying exponentially in the direction of motion and symmetrically perpendicular to this direction. A perturbation technique allows the expression of the results in terms of the same type of simple solution previously obtained without transverse curvature. Thus the solution is convenient for all length to width ratios and entrance to exit clearances.
Vibrations in Knee-Type Horizontal Milling Machines
Authors: Bendixen Ivar
Published: July 2022

This paper outlines a series of tests on vibrations in knee-type horizontal milling machines, especially in the knee system. The amplitude of the vibrations was determined by means of a capacitive pickup. Systematic investigations on the importance of clamping and unclamping the various elements are made. The influence of damping in the case of resonance is pointed out. An explanation of the vibration accompanying entrance and exit of the milling cutter is indicated. A theory for the presence of low natural frequencies in the knee system is developed. Up- and down-milling are compared.
Mechanical Properties of Glass-Cloth Plastic Laminates as Related to Direction of Stress and Construction of Laminate
Authors: Werren Fred
Published: July 2022

Methods are available for predicting the directional properties of glass-cloth plastic laminates from a knowledge of the properties associated with their natural axes. The mechanical properties of cross-laminated or composite laminates may also be calculated from the basic properties of parallel laminates made of the component fabrics. Tests at the Forest Products Laboratory have shown that the suggested methods are reasonably correct for the range of glass-cloth plastic laminates presently being used in aircraft.
Contamination of Condensate by Heat-Exchanger-Tube Alloys
Authors: Ristroph J. D. , Powell E. B.
Published: July 2022

Results are presented from condensate contamination studies conducted at two steam power stations to evaluate the influence of temperature of condensate, of differing dissolved gas content, and of cumulative service time upon the degree of metallic contamination to be expected in steam condensate of the general character described from flowing contact with tubing of twelve alloys commercially used in power-plant heat exchangers. The influence of cyclohexylamine on the rates of contamination is also indicated. The testing procedures are briefly described.
Creep of Neoprene in Shear Under Static Conditions; Ten Years
Authors: Keen W. Newlin
Published: July 2022

This paper, representing more than a decade of research on the static creep of neoprene vulcanizates, supplements a previous paper by the author. The test procedure is given, and the effects of composition, age, and temperature on the creep characteristics of the vulcanizates are reported. The author’s data indicate that neoprene vulcanizates can be designed with creep-resistant properties equal to or superior to those of natural rubber.
The Venturi as a Meter for Gas-Solids Mixtures
Authors: Farbar Leonard
Published: July 2022

This investigation was undertaken to determine the behavior of a Venturi tube when metering the solids phase in a gas-solids mixture for the condition of constant gravimetric gas-flow rate. The Venturi tubes were used in both a horizontal and vertical section of 17-mm-ID glass conduit and had throat diameters of 0.500 in. and 0.375 in., respectively. The gas-solids mixtures consisted of air and alumina-silica catalyst (an aggregate mixture containing a size range varying from 10 to 220 microns) with solids loadings as high as 10 lb of solids per lb of air. Results on four different gas-flow rates indicated a linear relationship between the Venturi pressure differential and the solids-flow rate over the range of loadings attainable with the experimental equipment. The linear relationship was observed for each Venturi size in both the horizontal and vertical location; the slope of these lines increased with increased air-flow rate and decreasing Venturi throat diameter. Pressure recovery in the diffuser section of the Venturi was observed and found to vary in nonlinear fashion with the solids rate. It appears that the Venturi may be used with satisfactory results in the metering of a solids phase in a gas-solids mixture when the gravimetric gas-flow rate is held constant. In plants and pilot plants handling powdered solids by pneumatic conveyance, the Venturi may serve as a useful tool in indicating any instantaneous changes in the solids-flow rate as well as the gas-flow rate.
Pressure Distributions on the Blade of an Axial-Flow Propeller Pump
Authors: Morelli D. A. , Bowerman R. D.
Published: July 2022

Propeller pumps with small numbers of blades are usually designed by applying airfoil-strip theory using the tabulated properties of airfoils in a linear flow field of infinite extent. The velocity at each radius is taken as the relative velocity obtained by vector combination of the tangential velocity, the axial velocity, and the induced velocity at the mid-chord of the blade. For few blades the induced velocity at a blade resulting from the presence of other blades usually is ignored. Since the facilities and techniques at the authors’ disposal make it relatively easy to obtain pressure distributions on the moving elements of hydraulic machinery, a comparison was made between the calculated and measured pressure loading on a single-bladed axial-flow impeller. The results show that the design method used, which differs only in a minor way from the usual method given in the technical literature, gives a close approach to the actual loading at the design point. The experimental data are presented in sufficient quantity to show how the blade loading varies with flow rate over the whole of the blade and that the free-vortex condition is fairly well achieved in the neighborhood of the design point. Generally, it is concluded that the airfoil theory can give a close approximation to the performance and loading of a blade of a propeller pump in spite of the considerable departure from the ideal conditions for which it was developed.
A Lathe Test for the Evaluation of Cutting Fluids
Authors: Oathout J. D. , Howell W. C. , Hamer J. P. , Leland H. L.
Published: July 2022

A full-scale lathe test procedure is described which offers a sound and reproducible laboratory method for evaluating cutting-fluid performance. This test is based on tool-life measurements in a single-point turning operation on steel. Testing technique and data treatment are presented. Results show excellent general correlation with field-performance tests under widely varied cutting conditions.
Power Required by Carbide-Tipped Face-Milling Cutters
Authors: Gilbert W. W. , Boston O. W. , Siekmann H. J.
Published: July 2022

Fundamental data on high-speed milling were derived from two research projects conducted in the period 1944–1946, the results of which were made available by this Society in the form of data sheets. However, these individual data sheets have been difficult to use because of their large mass and lack of correlation. The data dealing with the power requirements as influenced by the setup conditions when face-milling with sintered-carbide tools have been organized and are presented in this paper.
The Lubrication of Gyroscopes
Authors: Brophy J. E. , Romans J. B.
Published: July 2022

The lubrication requirements of a number of gyroscopes have been studied as a prerequisite to the development of improved rotor-bearing lubricants and with the additional objective of replacing proprietary lubricants by one or more lubricants to be specified in the future. The gyroscopes studied included both air-driven and electrically driven types. Measurements were made of bearing temperatures, rotor speed, rate of deceleration, power input, and bearing noise level, the noise components being analyzed. A small high-speed evacuated gyro failed by the time 650 hr of operation had been reached. The other gyros studied all operated without bearing failure for a minimum of 10,000 hr on the specified lubricants. Two electric gyros have operated satisfactorily for 10,000 hr on synthetic diester-type lubricants. Gyro repair facilities reported that the paramount problem in overhaul work is that of obtaining suitable replacement bearings. It has become evident that causes of abnormally short rotor-bearing life include the use of inferior replacement bearings, poor overhaul techniques, and careless handling of equipment. Some of the proprietary lubricants are not suitable for use in instruments which are in storage for long periods.
Design of Shrink Fits
Authors: Paslay P. R. , Plunkett R.
Published: July 2022

A method is set up for the rational design of shrink fits, and it is shown that this type of fit is stronger than that obtained with the force fit. The authors describe and evaluate tests conducted on steel collars and shafts which were selected to give interferences covering the range of interest.
Some Vibration Effects on Surfaces Produced by Turret Lathes
Authors: Eisele P. T. , Griffin R. F.
Published: July 2022

This paper shows the nature of the turned surface produced by a turret lathe under some low-frequency vibration conditions. In shop language the surface is referred to as a “barber-pole finish” or a “spiral cut.” Conditions causing this type of surface are shown together with a theoretical analysis. Some data on vibration magnitude and surface roughness are given. A discussion is included on the degree of balance obtained in commercial motors and its effect on surface finish.
Calculation of Transpiration-Cooled Gas-Turbine Blades
Authors: Livingood J. N. B. , Eckert E. R. G.
Published: July 2022

Methods for an analytic determination of the local coolant flow required to maintain a constant prescribed wall temperature for a transpiration-cooled gas-turbine blade are discussed. In the laminar-flow region, approximations for bodies of arbitrary shape obtained at NACA from wedge-type flow solutions are employed. In the turbulent-flow region, the Rannie-Friedman theory for a transpiration-cooled flat plate is used. Calculations for an arbitrarily chosen transpiration-cooled gas-turbine blade are presented. Recovery factors for a transpiration-cooled flat plate and verification of an existing method for correlating flow data for porous surfaces are included. Finally, a discussion of some of the difficulties associated with the problem of obtaining the proper local coolant flow is given.
Local Heat-Transfer Coefficients on Surface of an Elliptical Cylinder, Axis Ratio 1:3, in a High-Speed Air Stream
Authors: Drake R. M. , Seban R. A. , Doughty D. L. , Levy S.
Published: July 2022

Local heat-transfer coefficients and thermal-recovery factors from a 1:3-axis-ratio elliptical cylinder to air are presented for angles of attack of +6 deg, 0 deg, and −6 deg with reference to the wind-tunnel center line. Air speeds ranged from 150 to 440 fps, yielding Reynolds numbers based on the major axis of the cylinder of 4.34 × 105 to 1.28 × 106. The heat transfer was measured experimentally for the primary purpose of providing results which would be a basis for a check of the approximate methods for predicting the heat transfer in the laminar-boundary-layer region. This check has been made for one method of prediction with satisfactory results for the various flow geometries.
Investigation of Flame Temperatures in a Single-Cylinder Spark-Ignition Engine
Authors: Potter J. H. , Dillaway R. B.
Published: July 2022

The measurement of flame temperatures in the cylinder of an internal-combustion engine has enlisted the interest of many researchers. This paper reports on experimental flame-temperature determinations in a spark-ignition engine using the electro-optical system proposed originally by Graff. For calibration, the sodium D-line-reversal technique was employed. Statistical methods were applied to the temperature-crank angle and pressure-crank angle oscillograms obtained from the electro-optical technique, to reduce individual cycle values to average engine levels. The importance of the Graff method as a research tool is reviewed.
Dynamic Operation of a Force-Compensated Hydraulic Throttling Valve
Authors: Bower J. L. , Tuteur F. B.
Published: July 2022

If the characteristics of a hydraulic control valve are fairly regular, a linear analysis can be applied provided that the input is of low amplitude. Such an analysis reveals that the valve can be considered as a fairly simple feedback loop, particularly if valve and load are approximately symmetrical. Application of standard techniques used in feedback circuits indicates one cause for valve instability and also yields an expression for the valve-transfer function. The analysis may be broadened considerably by use of analog computing techniques which make it possible to remove the requirement on small input amplitudes.
Quick-Starting of Large High-Pressure High-Temperature Boilers
Authors: Falkner Jefferson C.
Published: July 2022

In the near future the Consolidated Edison’s generating stations will be faced with routine week-end 24 and 48-hr shutdowns of large, single-unit, high-pressure, high-temperature turbines and boilers. As a result of week-end load drop and the opening of the new Astoria Station— with heat rates approximately 20 per cent better than those of existing plants—the annual number of starts from cold on high-pressure boilers will increase greatly. It is with this prospective situation in mind together with a conviction that quick-starting from cold of large high-pressure boilers, when properly handled, is less rigorous on the expanding boiler structure than present 5 to 6-hr starts, that this investigation was carried out. By means of test results this paper demonstrates that safe operating procedures can be developed to bring 1,000,000 lb of steam per hr, high-pressure, high-temperature boilers equipped with high-pressure-drop superheaters from a cold condition to on-the-line in 1 to 2 hr. The paper explains some of the operational techniques and fundamental concepts relative to such accelerated starts. It also presents data on the handling of both the topping and condensing turbines in connection with cold boiler starts.
Quick-Starting of High-Pressure Boilers—Discussion: Factors Involved in Starting and Subsequent Loading of Modern Steam Turbines
Authors: Elston C. W.
Published: July 2022

Increasing numbers of high-pressure high-temperature turbines are being subjected to frequent shutdowns, in many cases nightly. Designers and operators of these units must give careful consideration to the factors involved and by co-operative effort develop optimum techniques and procedures for starting and loading steam turbines. Suggestions are given in this paper of such procedures.
Quick-Starting of High-Pressure Boilers—Discussion: Quick-Starting of Steam Turbines
Authors: Wilson C. D.
Published: July 2022

The problem of quick-starting steam turbines can be solved by careful design and careful operation, both of which are equally important. The paper includes typical illustrations and a brief description of the various factors.
Large-Extrusion-Press Operation and Production Problems
Authors: McCormick T. F.
Published: July 2022

Giant presses now under construction or planned in this country will enlarge by severalfold the size of light-metal shapes and tubes that may be extruded. The operation of the new presses will present many production problems, both predicted and unpredicted, but at the same time will permit the extrusion of large or intricate shapes which lead to economy and versatility in aircraft construction. A review of operating techniques and problems associated with present large extrusion presses points out some of the expected problems and emphasizes the increased scope of the extrusion process to provide metal shapes designed for the utmost usefulness.
Forces in Dry Surface Grinding
Authors: Marshall E. R. , Shaw M. C.
Published: July 2022

A dynamometer is described for measuring independently the normal and tangential forces in surface grinding. These forces are correlated with such variables as wheel speed, table speed, depth of cut, direction of table motion, grit material and size, specimen hardness and dressing technique. Specific energy is found to be the best criterion for interpreting grinding data. X-ray diffraction methods are employed to study the surface stresses and the depth of cold work induced by grinding.