bluuebunny/crossref_metadata_2025 huggingface dataset:
Ribonuclease H‐like gene SMALL GRAIN2 regulates grain size in rice through brassinosteroid signaling pathway
Authors: Huang Yunshuai , Dong Hui , Mou Changling , Wang Ping , Hao Qixian , Zhang Min , Wu Hongmin , Zhang Fulin , Ma Tengfei , Miao Rong , Fu Kai , Chen Yaping , Zhu Ziyan , Chen Cheng , Tong Qikai , Wang Zhuoran , Zhou Shirong , Liu Xi , Liu Shijia , Tian Yunlu , Jiang Ling , Wan Jianmin
Published: July 2022

Grain size is a key agronomic trait that determines the yield in plants. Regulation of grain size by brassinosteroids (BRs) in rice has been widely reported. However, the relationship between the BR signaling pathway and grain size still requires further study. Here, we isolated a rice mutant, named small grain2 (sg2), which displayed smaller grain and a semi‐dwarf phenotype. The decreased grain size was caused by repressed cell expansion in spikelet hulls of the sg2 mutant. Using map‐based cloning combined with a MutMap approach, we cloned SG2, which encodes a plant‐specific protein with a ribonuclease H‐like domain. SG2 is a positive regulator downstream of GLYCOGEN SYNTHASE KINASE2 (GSK2) in response to BR signaling, and its mutation causes insensitivity to exogenous BR treatment. Genetical and biochemical analysis showed that GSK2 interacts with and phosphorylates SG2. We further found that BRs enhance the accumulation of SG2 in the nucleus, and subcellular distribution of SG2 is regulated by GSK2 kinase activity. In addition, Oryza sativa OVATE family protein 19 (OsOFP19), a negative regulator of grain shape, interacts with SG2 and plays an antagonistic role with SG2 in controlling gene expression and grain size. Our results indicated that SG2 is a new component of GSK2‐related BR signaling response and regulates grain size by interacting with OsOFP19.
Deciphering Eurasian otter (Lutra lutra L.) and seal (Phoca vitulina L.; Halichoerus grypus F.) diet: Metabarcoding tailored for fresh and saltwater fish species
Authors: Boyi Joy Ometere , Heße Eileen , Rohner Simon , Säurich Josefin , Siebert Ursula , Gilles Anita , Lehnert Kristina
Published: July 2022

Long‐lived top predators shape biodiversity structure in their ecosystems and predator–prey interactions are critical in decoding how communities function. Studies on the foraging ecology of seals and Eurasian otters in Western Europe are outdated and most studies solely performed traditional hard part analysis. Molecular metabarcoding can be used as an innovative noninvasive diet analysis tool, which has proven efficient and complementary to hard part analysis, however, lacking application in the wider North Sea area. In this study, DNA from digesta, collected between 2014–2020, were used to identify fish species in the diet of 47 Eurasian otters, 54 harbour seals and 21 grey seals by applying a next‐generation metabarcoding approach. A newly designed 16S rRNA primer, providing the best coverage of >130 local marine and freshwater fish species, was used to amplify prey DNA from seal scats and otter gut content sampled from the North Sea and regional freshwater bodies. Frequent fish species included tench, ninespine stickleback and white bream in otters; hooknose and common roach in grey seals and Pleuronectidae and sand gobies in harbour seals. Bipartite network analysis showed a strong overlap of harbour and grey seal diets. Otter diet intersected with both seal species in terms of freshwater species. This study provides new knowledge about dietary composition and community assemblage of fish prey in otters and seals in the North Sea and regional freshwaters, and a new molecular tool to elucidate predator–prey interactions and interspecies competition in complex and changing ecosystems under pressure from anthropogenic activities.
Impact of variant of concern and vaccination status on COVID‐19 infection virological dynamics in end stage kidney disease patients receiving haemodialysis
Authors: Koh Timothy , Ooi Xi Yan , Vasoo Shawn , Yeo See Cheng
Published: July 2022

Aim

It is unclear if variant of concern and vaccination status impact COVID‐19 infection virological dynamics in haemodialysis patients and affect de‐isolation protocol for dialysis centres.

Method

We performed a retrospective observational cohort study between February 2020 to September 2021, to examine the virological kinetics of vaccinated and unvaccinated haemodialysis patients with polymerase chain reaction (PCR)‐confirmed COVID‐19 infection of the delta and pre‐delta variants.

Results

Of the 38 subjects with PCR‐confirmed COVID‐19 infection, we found that individuals infected during the delta‐variant period had higher viral load at presentation and required longer duration to achieve a negative PCR swab, compared to those infected in the pre‐delta variant period. Time to achieve negative PCR swab was longest in unvaccinated individuals infected during delta‐variant period. However, vaccinated and unvaccinated individuals achieved high PCR cycle threshold value of ≥25 and ≥30 at similar timing.

Conclusion

Our study suggests that patients infected during delta‐variant period of COVID‐19 illness, have higher viral load at presentation and prolonged viral shedding, especially in the unvaccinated cohort. However, prolonged time to negative PCR is likely due to inactive virus shedding, and that conversion to negative PCR may not be a necessary pre‐requisite for de‐isolation.
Kuwaitiella rubra gen. et sp. nov. (Bangiales, Rhodophyta), a new filamentous genus and species from the north‐western Indian Ocean
Authors: Hasan Amal Hajiya , Van der Aa Pierrot , Küpper Frithjof C. , Al‐Bader Dhia , Peters Akira F.
Published: July 2022

A new filamentous marine red alga, Kuwaitiella rubra gen. et sp. nov. (Bangiales, Rhodophyta), is described from Kuwait in the north‐western Arabian Gulf (also referred to as the Persian Gulf). It was found on a submerged fishing line. The intensively red upright thallus of up to 1 cm in length consists of cells containing a single stellate plastid. The thallus is initially uniseriate but becomes biseriate in its distal part upon transformation into globular reproductive cells, possibly archaeospores. The biseriate fertile part is the only morphological difference from other filamentous species of the Bangiales, in which this region is parenchymatous. In culture, bipolar asymmetric germination of the spores of Kuwaitiella led to a new generation of identical erect thalli, fixed to the substratum by colourless rhizoids. According to phylogenetic analyses of partial small subunit nuclear ribosomal DNA (18S) and of the plastid‐encoded ribulose‐1,5‐bisphosphate carboxylase/oxygenase large subunit (rbcL), the new species forms an additional lineage of the Bangiales, genetic similarity with other taxa being limited (maximum 91% in SSU and 90% in rbcL). It was no clear member of any known lineage of the Bangiales but was weakly associated with the filamentous species Minerva and Dione from New Zealand. In a SSU phylogeny, it formed a basal branch in the Bangiales and clustered with M. aenigmata and D. arcuata as sister clade to all other species of the order. In a rbcL phylogeny, it was part of a large polytomy of lineages, its closest relative being D. arcuata. Kuwaitiella forms the 8th lineage of filamentous Bangiales detected so far.
The Shear-Angle Relationship in Metal Cutting
Authors: Shaw M. C. , Cook N. H. , Finnie I.
Published: July 2022

The several analytical solutions that have been presented for the shear angle in metal cutting are described briefly and the underlying assumptions critically discussed. The friction process that obtains in cutting is considered in detail and it is shown that a variable restraint and accompanying variation in the effective hardness of the metal cut constitute a major difference between ordinary friction and that between chip and tool. This variation in relative restraint and effective hardness accounts for the wide variation of coefficient of friction with rake angle observed in metal cutting. Furthermore, this variable restraint constitutes a significant connecting link between shear and friction processes, and is responsible for the shear plane not being in the direction of maximum shear stress in the general case. These new concepts are incorporated with the best features of previous work, and an equation is presented, in which the angle between the shear plane and direction of maximum shear stress figures prominently. The new equation for shear angle is illustrated and discussed with the aid of experimental cutting data covering a wide range of operating conditions.
The Periodic-Flow Regenerator—A Summary of Design Theory
Authors: Coppage J. E. , London A. L.
Published: July 2022

A description is given of the periodic-flow rotary regenerator, and it is contrasted to the other types of heat-exchanger systems which may be employed to “regenerate” or “recuperate” the exhaust-gas thermal energy in a gas-turbine plant. The advantages in principle of the periodic-flow type are considered briefly, and the mathematical complexities of analysis of the more exact theory of its performance are indicated. Available special solutions, obtained by numerical-graphical methods, provided by Hausen, Nusselt, Boestad, Iliffe, and Saunders and Smoleniec are reviewed and their limitations pointed out. An algebraic equation solution corresponding to the special case of high rotative speeds is shown to be exactly the same as the well-known equation for a direct-transfer-type counterflow exchanger. These results are supplemented with an “approximate theory” solution which has the advantage of being in closed form, and the limitations on accuracy of this solution are considered. Recommended design curves are presented using a set of simple nondimensional parameters, of the same nature as those employed for direct-transfer-type exchangers, and which are readily usable for the gas-turbine regenerator-design problem. The curves result from a rational extrapolation of the special case solutions of Hausen, employing the approximate theory as well as the results of Iliffe, to other situations of interest to the gas-turbine designer. An illustrative problem is included.
Pulverized-Coal Gasification Ruhrgas Processes
Authors: Traenckner Kurt
Published: July 2022

After reviewing briefly the situation of Germany’s gas demand and supply which makes it highly desirable to set free larger amounts of coke-oven gas by firing coke ovens with producer gas, the general program of research and development of the Ruhrgas A-G is explained. Main efforts were directed toward the development of two gas producers using low-grade pulverized coal or coal dust obtained from the coal-cleaning operations. The first process, involving gasification of pulverized coal in a vortex-type system, with slagged-ash removal, has reached the state of commercial applicability, and the results obtained exceed those of conventional gas producers gasifying coke. The second process described in some detail, the coal-dust pulse-jet gasifier, is in the experimental stage, but already has shown promising results. Further work is in progress to improve operations and efficiencies.
On the Solution of the Reynolds Equation for Slider-Bearing Lubrication—IV: Effect of Temperature on the Viscosity
Authors: Osterle F. , Charnes A. , Saibel E.
Published: July 2022

Treating viscosity as a function of temperature and pressure, the problem of the slider bearing without side leakage and with film thickness varying exponentially is solved exactly for the case of adiabatic flow. An approximate solution is developed, applicable to both finite and infinite sliders. This approximate solution is found to check very closely with the exact solution for the infinite-slider case.
On the Solution of the Reynolds Equation for Slider-Bearing Lubrication—VI: The Parallel-Surface Slider Bearing Without Side Leakage
Authors: Osterle F. , Charnes A. , Saibel E.
Published: July 2022

Treating the density of the lubricant as a function of temperature and the viscosity as a function of pressure and temperature, the problem of the parallel-surface slider bearing without side leakage is solved exactly for the case of adiabatic flow. The theory permits rapid evaluation of the maximum film pressure, the point in the film where the maximum pressure occurs, the film temperature at this point, and the film temperature at outlet.
Contributions to Hydraulic Control: 5—Lateral Forces on Hydraulic Pistons
Authors: Blackburn J. F.
Published: July 2022

Sticking or excessive friction of pistons or valves in their bores has always caused trouble to designers and users of hydraulic equipment. The phenomena involved are complex and incompletely understood. This paper shows that large lateral forces may be caused by hydrodynamic phenomena alone, without the complicating effects of dirt in the oil. It presents expressions describing the lateral force for certain cases of simple geometry, with experimental verification, and discusses other cases qualitatively. Finally, it summarizes briefly present ideas concerning the frictional phenomena involved and lists several questions to which the answers must be obtained by further investigation.
An Investigation of Cemented Tungsten Carbide as Bearing Material
Authors: Kozacka J. S. , Erickson H. A. , Highriter H. W. , Gabriel A. F.
Published: July 2022

There have been many inquiries for application of cemented tungsten carbide as bearing material in designs where high pressures exist and where lubrication is a problem. Considerable interest exists in application of cemented tungsten carbide to precision-grinding spindle bearings, where the life of other bearings is short, a factor resulting in excessive replacement time. There are inquiries for technical data, which up to this time are very scant. To test the feasibility of using cemented tungsten carbide as bearing material, a research project was organized by the Vascoloy-Ramet Corporation, a manufacturer of tungsten-carbide cutting tools, wear parts, and wiredrawing and stamping dies; the Acme Industrial Company, manufacturer of precision-finished parts, and the D. A. Stuart Oil Company, processor and distributor of metalworking lubricants, and extreme-pressure additives. Tests were arranged and co-ordinated by Prof. J. S. Kozacka. This is the first progress report of an investigation to measure cemented-tungsten-carbide bearings performance using different lubricating oils under varying load conditions.
Aerodynamic Design of Efficient Two-Dimensional Channels
Authors: Stanitz J. D.
Published: July 2022

A general design method is presented for two-dimensional channels with arbitrary prescribed velocity distributions along the channel walls. The design method is developed for compressible or incompressible fluids and is applied to the design of channels with relatively thin boundary layers. Maximum deceleration rates that avoid turbulent boundary-layer separation are discussed and it is shown that linear variations in a certain velocity parameter along the channel walls give a suitable engineering approximation to the velocity distribution resulting from boundary-layer considerations. For these linear variations in velocity parameter the design method is rapid. Eleven numerical examples are presented for compressible and incompressible flow in elbows and diffusers. In addition, some experimental results are presented which show that, provided the initial boundary layer is sufficiently thin, efficient two-dimensional channels can be designed for prescribed velocity distributions that avoid boundary-layer separation.
New Aspects of Natural-Convection Heat Transfer: Preliminary Study of Effect of Frictional Heating
Authors: Ostrach Simon
Published: July 2022

An analysis of the natural-convection process shows that in many new practical cases, the compression work and frictional heating may affect this mode of heat transfer appreciably, depending on the magnitude of a new parameter K¯=GrβfXlcp Study of a simplified problem, namely, the flow between two parallel infinite plates oriented parallel to the direction of the generating-body force shows, in particular, that the frictional heating appreciably alters the velocity and temperature distributions, and hence the heat transfer. Consideration of the frictional heating also leads to the predictions that two states of flow and heat transfer are to be expected for a given set of conditions and also that there exists a critical set of conditions which is analogous to that for thermal choking.
Piping Flexibility Analysis by Model Test
Authors: Andrews Lale C.
Published: July 2022

During the past 10 years, model-test flexibility analyses of piping systems have been made, under the author’s direction, for nearly a hundred oil, power, and chemical companies, and for two navies. Herein are described briefly the scope of the work, the apparatus and methods employed, and a few observations on design.
Fatigue Tests of Piping Components
Authors: Markl A. R. C.
Published: July 2022

This paper presents a compilation of available fatigue-test data on piping components and derives therefrom stress-intensification factors relative to straight pipe. These factors are strictly applicable only to the limited range of sizes for which fatigue tests were made. In view of the importance of proper consideration of stress intensifications in cyclically stressed piping and the lack of theoretical developments which would serve to evaluate their magnitude for all shapes involved, the author has taken it upon himself to suggest empirical correlations by which the application of the available data can be expanded to a wider range of sizes and conditions.
The Theory and Design of Long-Deflection Constant-Force Spring Elements
Authors: Votta F. A.
Published: July 2022

A thorough study of the “neg’ator,” its present and predictable applications and design procedures are discussed in the light of two years’ experience in neg’ator development, research, and testing. The neg’ator is characterized by properties which permit it to exert constant or controlled varying force through theoretically infinite deflection. Design formulas and operation of the three major forms of the neg’ator, (1) extension member, (2) A-motor, and (3) B-motor, are discussed and illustrated. The major existing applications of the neg’ator are examined in terms of form, function, field, and type of mechanism and are illustrated by several representative designs.
Single-Stage Radial Turbines for Gaseous Substances With High Rotative and Low Specific Speed
Authors: von der Nuell W. T.
Published: July 2022

The turbine with radial inward flow, long known and in use as a water-power plant (1), is rapidly gaining interest for gaseous energy carriers. Single-stage versions with wheels of shapes well known from aircraft-engine superchargers are now generally accepted in gas and air turbines when, relatively speaking, low mass flow in conjunction with high energy content per weight unit of the working substance characterize the available energy supply. Combining efficiency of 80 per cent and upward with attractive simplicity, this turbine type is bound to conquer its field. At present, aircraft auxiliary-power units represent its predominant application.
A Time-Temperature Relationship for Rupture and Creep Stresses
Authors: Larson F. R. , Miller James
Published: July 2022

A relation which evaluates the relative effects of time and temperature on the tempering of steels has been developed by previous investigators. In this paper this relation has been adapted to rupture and creep behavior and applied to existing data on several widely different alloys with outstanding results. Methods are described by which short-time tests can be used to determine long-time properties.
Discharge Measurements by Means of Cylindrical Nozzles
Authors: Jorissen A. L. , Newton H. T.
Published: July 2022

Cylindrical nozzles maintain a constant coefficient of discharge at Reynolds numbers lower than standard pressure-difference devices of flow measurement. Tests on nozzies of various opening ratios have indicated the optimum proportions for each ratio.
Oil Flow in Plain Journal Bearings
Authors: McKee S. A.
Published: July 2022

An analysis is given of the factors affecting the leakage of oil from the ends of plain journal bearings fed either through an oilhole or an axial groove on the unloaded side, or a circumferential groove. With bearings having an oilhole or an axial groove, the oil flow consists of two components, one resulting from the oil-feed pressure, and the other from the hydrodynamic-film pressures supporting the load. For bearings having a circumferential groove, the flow is primarily from the oil-feed pressure. The data given indicate that for any given bearing the oil flow may be expressed in terms of two dimensionless factors involving the oil-feed pressure and the bearing load. The relations between these factors and the generalized operating variable, μN/P, are given for bearings having each of the three designs of oil feed. Further investigations are suggested to provide a more complete understanding of the factors affecting end leakage of oil from plain journal bearings.
Contributions to Hydraulic Control: 1—Steady-State Axial Forces on Control-Valve Pistons
Authors: Lee Shih-Ying , Blackburn J. F.
Published: July 2022

A theory is given of the origin of the steady-state force exerted upon a piston by fluid flowing past its corner, brief reference is made to a considerable body of experimental evidence in support of that theory, and a practical valve construction is described which very nearly eliminates that force.
The Mechanics of Three-Dimensional Cutting Operations
Authors: Shaw M. C. , Cook N. H. , Smith P. A.
Published: July 2022

The oblique tool, which has a cutting edge that is inclined to the direction of motion of the workpiece at an angle other than 90 deg, represents the most general type of cutting tool. The more complex three-dimensional tools of production may be related to an equivalent oblique tool having a given inclination angle and a corresponding effective rake angle. In this investigation the chip-flow direction and the velocity and force relations for an oblique cutting tool were compared with experimental results. The angle between the direction of chip flow and a normal to the cutting edge was found to be approximately equal to the inclination angle for ordinary friction conditions, but to be progressively larger than the inclination angle as the friction decreased. The effective rake angle for an oblique tool is found to increase without a corresponding decrease in the included tool angle. The direction of the force component in the tool face was found to deviate considerably from the chip-flow direction, particularly for larger values of inclination angle. However, the directions of maximum shear stress and shear strain on the shear plane were found to be nearly colinear for values of inclination up to 30 deg. The analytical consequences of these observations are discussed. The method of applying the oblique-tool results to three-dimensional tools is illustrated by three examples involving a lathe tool, a face-milling cutter, and a drill point. The drill-point discussion is extended to illustrate the value to be derived from a qualitative application of basic oblique-tool mechanics to the interpretation of drill test data.
The Influence of Aging on the Bauschinger Effect in Inelastically Strained Beams
Authors: Elsesser T. M. , Sidebottom O. M. , Corten H. T.
Published: July 2022

In many engineering applications the elastic-limit loads for members are increased by overloading the members until inelastic deformation occurs in regions of peak stresses. The extent of the inelastic deformation may be of the order of magnitude of the elastic-limit strain in such members as overstrained beams and autofrettaged thick-walled cylinders. An increase in the elastic-limit loads for these members is possible because of the beneficial macroscopic (measurable) residual stresses resulting from the inelastic deformation. However, the full theoretical beneficial effect of the residual stresses is never realized since they are reduced by the inelastic deformation caused by the Bauschinger effect which occurs when the member is unloaded. This investigation was undertaken to determine whether the full benefit of the macroscopic residual stresses could be retained by aging the member while loaded, and in this way eliminate the Bauschinger effect before its detrimental influence could occur. Tests were conducted on beams of rectangular cross section made from annealed mild (SAE 1020) and high-carbon (rail) steels. An aging treatment of 180 F for 20 hr was found to be sufficient to remove practically all of the Bauschinger effect in the mild steel but was not sufficient to remove all of the Bauschinger effect in the high-carbon steel.
The Effect of Slightly Elevated-Temperature Treatment Upon Microscopic and Submicroscopic Residual Stresses Induced by Small Inelastic Strains in Metals
Authors: Corten H. T. , Elsesser T. M.
Published: July 2022

Inelastic deformation of metals introduces structural changes which during unloading and reversed loading cause the Bauschinger effect. This effect may be interpreted in terms of microscopic and submicroscopic residual stresses. A slightly elevated-temperature treatment applied to an overstrained tension specimen at zero load allows two mechanisms to occur, namely, (a) relaxation of microscopic residual shear stresses in slip bands, and (b) a reduction of submicroscopic residual forces around flaws and disordered regions by the place change of atoms. Each of these mechanisms, (a) and (b) partially or completely removes the Bauschinger effect. In brass and low-carbon steel, the application of a slightly elevated-temperature treatment at a high stress level, during which mechanism (a) does not occur, very nearly or completely removes the Bauschinger effect. It appears therefore that the removal of the Bauschinger effect can be attributed, under these conditions to mechanism (b). This fact means that in load-resisting members made of these metals and containing favorable macroscopic residual stresses induced by inelastic deformation, the undesirable microscopic and submicroscopic residual stresses which cause the Bauschinger effect may be removed, thereby retaining the full theoretical value of the favorable macroscopic residual stresses.
Additional Measurements of Heat Conductivity of Nitrogen, Carbon Dioxide, and Mixtures
Authors: Keyes F. G.
Published: July 2022

Since the Annual Meeting of 1950, measurements of the heat conductivity of three mixtures of nitrogen-carbon dioxide have been continued to higher temperatures and the earlier reported measurements repeated. It is now established for the N2–CO2 mixtures at low pressure that the sign of the deviation of the observed heat conductivities, relative to the conductivities computed on the basis of the linear composition proportionality, changes, passing from negative at room temperature to zero at about 150 C, and becoming increasingly positive at higher temperatures. This behavior is unexpected and appears not to have been hitherto observed. The Enskog theory of the conductivity of mixtures does not predict the observed trend nor does the empirical formula of Lindsay and Bromley. The data have been formulated at each of the three constant concentrations of constituents using the same type of equation that has proved useful for the pure components. A new installation for low-temperature measurements has been completed and tested in the course of calibrating the copper-constantan thermocouples to be used for measuring the temperature gradient and absolute temperature from 30 to −180 C of the fluids whose heat-conductive properties are of interest. The N2–CO2 mixtures will be measured along with a series of pure gases and liquids. The measurement of the pressure effect for the heat conductivities of the N2–CO2 mixtures has been attempted but without satisfactory results above 50 C. The difficulty consists of failure of the fluid in the cell to arrive at a steady state above a comparatively low pressure. The cause of the phenomenon is believed, as expressed in last year’s report, to be directly related to the known tendency of the constituents of a mixture to separate in a temperature gradient.
Photographic Study of Surface-Boiling Heat Transfer to Water With Forced Convection
Authors: Gunther F. C.
Published: July 2022

To investigate the effect of forced convection on the mechanism of heat transfer with surface boiling, a high-speed, high-resolution photographic study was made. The test section was a transparent channel of rectangular cross section 3/16 × 1/2 × 6 in., with an electrically heated metal strip 1/8 in. wide suspended lengthwise to divide the channel into two flow passages. To facilitate photography of boiling on the metal strip near burnout conditions, the burnout limits for this section were determined experimentally. An empirical equation was fitted to the points.
Comparative Strengths of Some Adhesive-Adherend Systems
Authors: DeLollis N. J. , Rucker Nancy , Wier J. E.
Published: July 2022

The strength properties of various adhesive-adherend combinations were determined as one phase of an investigation of the nature of adhesion. The adhesives were polyvinyl acetate, cellulose nitrate, resorcinol resin, casein, gum arabic, natural rubber, and neoprene. The adherends were stainless steel, aluminum alloy, paper-phenolic laminate, glass, birchwood, and hard rubber. The properties studied were double-lap shear, tensile, long-time loading shear, and impact strengths. The tensile-adhesion and shear-strength values for a given adhesive-adherend combination did not differ greatly except for wood and paper-phenolic laminate, which are nonisotropic. The highest values (up to 3600 psi) were obtained with polyvinyl-acetate and cellulose-nitrate adhesives. The thermosetting resorcinol resin showed no appreciable flow in supporting a load of 680 psi for 6 months, whereas the thermoplastic polyvinyl acetate failed in 45 days under a load of 200 psi. The rubber-type adhesives which were weak compared with the other adhesives in the static load tests were definitely superior in the impact tests. Better correlation of shear strengths was observed with the moduli of elasticity than with the dielectric constants of the materials used in the various adhesive-adherend combinations.
Principles of Foundation Design for Engines and Compressors
Authors: Newcomb W. K.
Published: July 2022

This paper discusses the elastic character of the ground and shows that foundations for reciprocating machines can be treated as spring-supported masses, the machine and foundation representing the mass, and the ground the spring. Such elastic systems have natural periods of vibration; if the frequency of unbalanced inertia or other exciting force is near the natural frequency of the foundation, resonance will occur producing excessive vibration. Examples of this phenomenon are given and tests on foundations having resonance are described. Also, the nature of inertia forces found in reciprocating machines is explained. Examples of good and bad foundation design are shown and a rational method for foundation design is outlined.
An Investigation of Flow Through Screens
Authors: Baines W. D. , Peterson E. G.
Published: July 2022

Analytical and experimental studies on the three principal aspects of flow through screens are described: (a) The relative drop in pressure as a function of screen form and solidity ratio; (b) the capacity of screens to modify the velocity distribution; and, (c) the characteristics of the turbulence which screens produce. Because of their frequent hydraulic application, primary attention is given to relatively coarse lattices and perforated plates. Results are presented in dimensionless graphs which are immediately usable for design purposes.
A Design Procedure for Integral Flanges With Tapered Hubs
Authors: Jaep W. F.
Published: July 2022

This paper develops a simplified method of applying the ASME flange-stress formulas to the design of integral flanges with tapered hubs. In the course of this development, the hub shape is predetermined and graphs are presented to permit a rapid solution of the stress equations.
Orifice Meters With Supercritical Compressible Flow
Authors: Cunningham R. G.
Published: July 2022

The discharge characteristics of orifices at low pressure ratios were investigated. Probe measurements of high-velocity jets confirm and extend the work of Stanton. Expansion factors (Y) at pressure ratios down to r = 0.13 were measured for the flow of air in a 2-in. pipe meter and for the flow of steam in a 3-in. pipe meter. Both meters were installed in accordance with ASME specifications, and operated at a diameter ratio of 0.15. The effects of high approach velocity on the discharge characteristics of square-edged orifices at low pressure ratios were investigated; expansion factors were determined for diameter ratios from 0.2 to 0.8 over a range of pressure ratios from unity to 0.2. A linear Y-r correlation is shown to exist at low pressure ratios; a change of flow regime occurs at a pressure ratio of 0.63. A theoretical solution for supercritical flow, previously established by the author, is further compared with experimental results.
Strength Behavior of Adhesive Bonds
Authors: Meissner H. P. , Baldauf G. H.
Published: July 2022

Practically all adhesive systems show an increase in strength with decreasing thickness of the adhesive layer. At least five different explanations for this “thickness-strength” rule have been proposed, based upon the following concepts: (a) Molecular orientation of the adhesive. (b) Differences in physical structure. (c) Theory of flaws. (d) Reduction of plastic flow during test. (e) Distribution of internal stresses. An investigation of these alternatives was made by testing butt joints between metal cylinders using eutectic solder, wax, and polystyrene as adhesives. Evidence indicating the correct explanation of the thickness-strength rule was obtained from a study of the effect on bond strength of bond geometry, from the location of bond failure, and from the relations between bond strength and bulk strength.
Basic Factors in Hot-Machining of Metals
Authors: Krabacher E. J. , Merchant M. E.
Published: July 2022

This paper presents the results of research on the influence of basic metal-cutting quantities when machining metals at elevated temperatures. Much of the investigation centered around some of the commoner high-temperature alloys. Studies on the mechanics of cutting at elevated temperatures were made in which such basic quantities as chip friction, shear strength, and machining constant were measured. In addition, tool-chip interface temperatures were calculated. These data were correlated with data obtained from milling tool-life tests on the same materials. Two main factors oppose each other in their effect on tool life in hot-machining. These are the increased ease with which the heat-softened tool material can be abraded away and the decreased ability of the heat-softened chip and workpiece to produce such abrasion. It was found that these two factors can be evaluated roughly from tool-temperature data taken in combination with data on the mechanics of cutting.
Simplified Process for Determining Steam Purity
Authors: Powell S. T. , McChesney I. G.
Published: July 2022

A method and apparatus are described for measuring electrical conductivity of steam from boilers and vapor from evaporators. The stainless-steel capillary sampling line throttles the flow and condenses part of the sample by radiation, normally requiring no cooling water. The condensed part of the sample is kept at the boiling point and continuously swept by uncondensed vapor so that gases cannot go into solution. No reboiling or degassing is required. Design and operating details are given, based upon successful operation for many months, with no attention or adjustment required.
Review of Combustion Phenomena for the Gas Turbine
Authors: Shepherd D. G.
Published: July 2022

Combustion-chamber design information is comparatively meager except for over-all performance data from existing gas turbines, such as combustion intensity and fractional pressure loss. Some information is available from established practices in other fields but many new or intensified problems remain. However, there is a rapidly increasing interest in the basic mechanism of combustion from the viewpoint of the physical chemistry of ignition, flame propagation, and burning, which together with reconsideration of the older empirical data of a fundamental nature shows promise of being fruitful. The purpose of this paper is to present a survey of some of this basic material as a step in helping the combustion engineer to correlate it with his knowledge of existing over-all performance.
Some Biological Fundamentals of Marine Fouling
Authors: Clapp William F.
Published: July 2022

The common mussel is identified as the organism most important in the fouling of sea-water conduits and most difficult to control. Relevant features of its construction, living habits, rates of propagation and growth, and methods of locomotion and self-protection are described. While very young organisms, in general, are less resistant to unfavorable conditions than the mature of their respective kinds, and the mussel is probably no exception; in the case of the young mussel very high resistance is found very shortly after the permanent shell takes complete formation. Chlorination tests on mussels at Kure Beach, N. C., are described and results quoted.
Density-Pressure Relationships for Two Low-Viscosity Dimethyl Siloxanes
Authors: Gunst S. B.
Published: July 2022

An instrument used to determine liquid compressibilities is described as is its use in the determination of density versus pressure for hexamethyldisiloxane and octamethyltrisiloxane. Results at pressures to 10,000 psi, and at temperatures to 200 F for the hexamethyldisiloxane and to 300 F for the octamethyltrisiloxane are shown. The densities are precise within 0.3 per cent.
An Automatic Degasser for Steam Sampling in Power Plants
Authors: Rivers H. M. , Trautman W. H. , Gibble G. W.
Published: July 2022

Electrical conductivity procedures are widely preferred for measuring the purity of condensed steam. Because gases such as carbon dioxide and ammonia contribute to the conductivity as do dissolved salts carried over from the boiler, interpretation of conductivity measurements may be somewhat uncertain. A new degasser has been developed which automatically splits a steam sample into two approximately equal streams of condensate, one containing all solid impurities, the other containing all gaseous impurities in the original sample. Heat-exchange elements are combined in a unique way which guarantees that the weight ratio of one stream to the other will remain substantially constant. Both streams pass through conductivity flow cells so the degree of contamination can be measured continuously by conductometric means.
Surge Problems in Pipe Lines—Oil and Water
Authors: Kerr S. Logan
Published: July 2022

This paper outlines the work done by the Water Hammer Committee of the Society, outlining the publications involved. A general review and summary are given of water-hammer studies as they can be applied to the petroleum pipe-line surge problem.
Zero-Pressure Thermodynamic Properties of Some Monatomic Gases
Authors: Goff J. A. , Gratch Serge , Van Voorhis S. W.
Published: July 2022

This paper presents definitive values of the zero-pressure thermodynamic properties of the stable naturally occurring isotopes and the normal isotopic mixtures of the following monatomic gases: Hydrogen (H), helium (He), carbon (C), nitrogen (N), oxygen (O), fluorine (F), sulphur (S), chlorine (Cl), argon (A), bromine (Br), iodine (I), mercury (Hg). These values cover the range 100 to 5000 deg R at the intervals indicated by the numbers in parentheses: 100(5)130(10)240(20)500(50)1000(100)2000(200)5000. They have been computed by the methods of quantum statistical mechanics from present best values of the relevant (a) general physical constants, (b) isotopic weights and fractional abundances, (c) spectroscopic data. Computational accuracy well beyond present physical accuracy has been maintained for practical reasons, final results being given to seven significant figures. Present physical accuracy is indicated by charts of estimated uncertainties. For some of the monatomic gases here considered, accurate values of their zero-pressure thermodynamic properties hitherto have been unavailable; for others the data presented are the first based upon recent spectroscopic and other input data to be made available at temperatures sufficiently close for convenient practical application.
Pressure-Volume-Temperature Relationships of Gaseous Normal Hydrogen From Its Boiling Point to Room Temperature and From 0–200 Atmospheres
Authors: Johnston H. L. , White David
Published: July 2022

This paper presents a summary of accurate measurements on data of state for normal hydrogen gathered over a period of years by a group of investigators in The Ohio State University Cryogenic Laboratories. Results cover a wide range of temperature and pressure.
Heat-Transfer and Flow-Friction Characteristics of Some Compact Heat-Exchanger Surfaces: Part 1—Test System and Procedure
Authors: Kays W. M. , London A. L.
Published: July 2022

This paper describes a test apparatus and method of analysis used for the accurate determination of the basic heat-transfer and flow-friction characteristics of compact heat-exchanger surfaces. The experimental accuracy is discussed and the results of test of a typical louvered-plate-fin heat-exchanger surface are included to illustrate the quality of data obtainable. It is hoped that the experience presented here may lead to a standardization of test methods so that more accurate design data will be forthcoming.
Do Cognitive, Physical, and Combined Tasks Induce Similar Levels of Mental Fatigue? Testing the Effects of Different Moderating Variables
Authors: Rubio-Morales Ana , Díaz-García Jesús , Barbosa Carlos , Habay Jelle , López-Gajardo Miguel Ángel , García-Calvo Tomás
Published: July 2022

Experts have highlighted the importance of coaches knowing the level of mental fatigue (MF) induced by different tasks. This study aimed to compare the mentally fatiguing nature of cognitive, physical, and combined tasks and, additionally, assess the effect of different moderating variables on MF. Twenty-three physically active (16 males: Mage = 24 years; seven females: Mage = 22.57 years) participants performed three experimental sessions: (a) physically fatiguing: 30 min of cycloergometer work (at 65%–75% of maximum heart rate), (b) mentally fatiguing: 30 min of an incongruent Stroop task, and (c) mixed fatiguing: 30 min of combining the physically and mentally fatiguing protocols. Subjective MF (visual analog scale), reaction time (psychomotor vigilance task), and cognitive performance (Stroop) were measured throughout the different protocols. Results showed significant increments in subjective MF after all tasks, with the mental and mixed protocols showing significantly higher increases. Only the mentally fatiguing protocol caused significant impairments in reaction time. No significant effects of sex, years of experience, or degree of mental toughness were observed. These results suggest that the use of all these tasks, and especially the mentally fatiguing exercises, should be avoided immediately prior to competitions due to the negative consequences of MF on performance. Moreover, this effect seems to be independent of the sex, years of experience, or mental toughness of athletes.
Amphiphilic and fatigue-resistant organohydrogels for small-diameter vascular grafts
Authors: Hou Jinfei , Zhang Xu , Wu Yuqiong , Jie Junjin , Wang Zhenxing , Chen Guo-Qiang , Sun Jiaming , Wu Lin-Ping
Published: July 2022

Hydrogels are used in vascular tissue engineering because of their good biocompatibility. However, most natural hydrogels exhibit high swelling ratio, poor mechanical stability, and low durability, which are key limitations for wider applications. Amphiphilic and fatigue-resistant organohydrogels were fabricated here via the click chemical reaction of unsaturated functional microbial polyhydroxyalkanoates and polyethylene glycol diacrylate and a combination of two-dimensional material graphdiyne. These organohydrogels were maintained stable in body fluids over time, and their tensile moduli remained unchanged after more than 2000 cycles of cyclic stretching. The tubular scaffolds presented good biocompatibility and perfusion in vitro. After transplantation in vivo, the vascular grafts exhibited obvious cell infiltration and tissue regeneration, having a higher patency rate than the control group in 3 months. This fabrication method provides a strategy of improving and promoting the application of organohydrogels as implant materials for small-diameter vascular graft.
Momentum-matching and band-alignment van der Waals heterostructures for high-efficiency infrared photodetection
Authors: Chen Yunfeng , Tan Congwei , Wang Zhen , Miao Jinshui , Ge Xun , Zhao Tiange , Liao Kecai , Ge Haonan , Wang Yang , Wang Fang , Zhou Yi , Wang Peng , Zhou Xiaohao , Shan Chongxin , Peng Hailin , Hu Weida
Published: July 2022

Two-dimensional (2D) infrared photodetectors always suffer from low quantum efficiency (QE) because of the limited atomically thin absorption. Here, we reported 2D black phosphorus (BP)/Bi
2
O
2
Se van der Waals (vdW) photodetectors with momentum-matching and band-alignment heterostructures to achieve high QE. The QE was largely improved by optimizing the generation, suppressing the recombination, and improving the collection of photocarriers. Note that momentum-matching BP/Bi
2
O
2
Se heterostructures in

k

-space lead to the highly efficient generation and transition of photocarriers. The recombination process can be largely suppressed by lattice mismatching–immune vdW interfaces. Furthermore, type II BP/Bi
2
O
2
Se vdW heterostructures could also assist fast transport and collection of photocarriers. By constructing momentum-matching and band-alignment heterostructures, a record-high QE of 84% at 1.3 micrometers and 76.5% at 2 micrometers have been achieved in BP/Bi
2
O
2
Se vdW photodetectors.
Supplemental Material: Migration and localization of faulting near the intersection of the Dead Sea Fault and the Carmel–Gilboa–Faria Fault System
Authors: Hamiel Yariv , et al.
Published: July 2022

Text: Seismological observations. Figure S1: Topography map showing the area of the current active intersection between the Dead Sea Fault and the Carmel-Gilboa-Faria Fault System. Figure S2: The new geological map of the study area. Figure S3: An Image showing the Wadi Malih Fault, which ruptures the ancient Wadi Malih alluvial fan.
Treatment of diaphragmatic dystonia with pallidal deep brain stimulation
Authors: Rahimpour Shervin , Calakos Nicole , Turner Dennis A , Mitchell Kyle T
Published: July 2022

We present the case of a 70-year-old woman with treatment-refractory diaphragmatic dystonia. Patient initially presented with blepharospasms followed by development of involuntary inspiratory spasms during speech. Her symptoms were drug-refractory, and she therefore underwent awake bilateral pallidal deep brain stimulation with microelectrode recording. No intraoperative or postoperative complications or adverse events occurred, and there were no undesired effects of stimulation. Using contacts in bilateral dorsal globus pallidus interna and ventral globus pallidus externa, symptoms alleviated after a latency period of 2–4 weeks. At 5-month follow-up, the patient maintained a 16.5-point reduction in Burke-Fahn-Marsden movement scale (from 20/120 to 3.5/120) with resolution of blepharospasm, irregular inspirations and broken and irregular speech.
One-off physiotherapy and at-home exercise are effective in treating shoulder pain
Authors: Saul Helen , Gursul Deniz , Hopewell Sally
Published: July 2022

The study

Hopewell S, Keene DJ, Marian IR, et al. Progressive exercise compared with best practice advice, with or without corticosteroid injection, for the treatment of patients with rotator cuff disorders (GRASP): a multicentre, pragmatic, 2 × 2 factorial, randomised controlled trial.
Lancet
2021;398:416-28.

To read the full NIHR Alert, go to:
https://evidence.nihr.ac.uk/alert/one-off-physiotherapy-session-effective-for-shoulder-pain/