Higher Rpm Research Articles

Weeding Efficacy of Melanized Formula with Epicoccosorus nematosporus on Eleocharis kuroguwai in the Field

The study was conducted to determine the cultural conditions and the effect of inert fillers for melanization and sporulation abilities of sodium alginate pellets, and the weeding efficacy of the formula in the field. Melanin production of E. nematosporus was affected by striking frequency. Percentage of melanized beads was increased to 80.6% at higher rpm up to 180. The melanized pellets produced more conidia with abundant mucilage than unmelanized pellets. Shaker culture of Epicoccosorus nematosporus with sodium alginate yielded a total of 55 mg per 100 pellets. Percentage of melanized pellets was highest with 81.0% and 83.3% of melanization, when wheat bran and rice polish were amended and produced the conidia with 65.4 and 68.4 mg per 100 pellets, respectively. When 1 L of conidial suspension of 6.0<TEX>$\times$</TEX><TEX>$10^5$</TEX> conidia per ml was applied on 30-day-old plants in a plot, 74.5% of the plants were killed within 20 days, whereas, its melanized sodium alginate pellets killed 57.8% of the plants in the same period. The number of tuber formation of Eleocharis kuroguwai in the untreated control plots was 128.5 per plot, but those of the plots treated with conidial suspension and melanized pellets were 22.1 and 39.7, respectively, at the end of the season. Results of this study showed that melanization of mycelia-mixed sodium alginate are an important sporulation factor in E. namatosporus as a mycoherbicide.

Application of an ideal model to the scaling up of a laboratory extruder

The application of an ideal model to the scaling up of a laboratory single screw food extruder is analysed. The method proposed by Harper (case 3) with a scale up factor of 2.25 was used. Experiments were carried out using a commercial corn grits sample. To compare the extruders performance, the following parameters were measured in each experiment: output ( Q), measured as the solids (at feeding moisture level basis) coming out from the extruder; the die pressure ( P), measured at the cylindrical head which supports the die and degree of cooking (DC), which is taken as product characteristic. DC was estimated by two parameters, the water solubility ( S) and the amylographic retrogradation ( R). Two grits feeding moisture levels were selected for the extrusion (15% and 30 %) in order to produce products having two different degrees of cooking levels, high and low, respectively. Three screw speeds for each extruder and two different die l/ d ratio: l/ d=10 and l/ d=20. were used in the experiments. The results show that the scaled up extruder (SE) gives lower Q values than the predicted by the model. This is due, mainly because a higher DC is obtained with the SE. The differences in DC are more significant in the case of 15% moisture and even more noticeable for the longer die and higher rpm. We conclude that, considering the simplicity of the model used, it could be applied to the scaling up of a single food extruder providing that a new set of processing condition are found for the SE so as to obtain the same DC as that of the small one. Among the different alternatives used (change of the die l/d ratio or adjusting moisture level or the change of rpm), the decrease in the die l/d ratio seems to be the best, because the higher cooking capacity of the SE allows to increase the output by reducing the die flow restriction ( l/d).

A force identification method for slider/disk contact force measurement

Slider/disk contacts existing during operation in almost all current disk drives significantly affect drive reliability and performance. We propose a force identification method to measure the contact force from a single impact. Laser Doppler Vibrometers (LDV) are used to measure the slider's response. A procedure, which combines experiment and FE analysis, is proposed to model the system, and it is claimed to have many advantages over other methods. The proposed method is successfully applied to measure the contact forces of two nano sliders when they make contact with a bump on a disk. A smaller contact force was noted with the negative pressure slider. Also, the contact force is smaller at higher rpm for these two sliders.

Thermal processing of suspended food particles in cans with end-over-end agitation

Heating rate index ( f h ), heating lag factor ( j h ) and accumulated lethality ( F o ) were determined in the plastic, 307 diameter retortable bowls during tests at 7 rotation speeds (0–30 rpm), and 3 radial positions ( R 1=0 mm, R 2=115 mm, R3=175 mm). End-over-end (EOE) rotation from 0 to 30 rpm significantly influenced all parameters, however, the effect of rotation speed was non-linear, such that higher rpm did not always improve heating rates. Substantial improvements in heating of the particle portion were seen at relatively low rpm. Although less important than rpm, even small (115 mm) radial position differences significantly altered F o in some cases ( p≤0.05). The effect of immobilization of food particles on the end of a thermocouple, investigated with Bacillus stearothermophilus ATCC 7953 spores sealed in differential scanning calorimetry (DSC) pans, revealed significantly lower lethality delivered to freely moving particles than to particles immobilized in the can center. A Hydrophobic Grid Membrane (HGM) technique allowed rapid and convenient enumeration of surviving spores. The bio-indicator approach provided a more conservative estimate of minimum lethality than rigid thermocouples positioned in the center of particles within cans. ©

Sterilization of canned products by placing cans in autoclave and two-stage heating at specified pressure, at each stage : Astrakhan Fishing Ind. Tech. Inst. SU-1741753; 23 June 1992

Heating rate index (fh), heating lag factor (jh) and accumulated lethality (Fo) were determined in the plastic, 307 diameter retortable bowls during tests at 7 rotation speeds (0–30 rpm), and 3 radial positions (R1=0 mm, R2=115 mm, R3=175 mm). End-over-end (EOE) rotation from 0 to 30 rpm significantly influenced all parameters, however, the effect of rotation speed was non-linear, such that higher rpm did not always improve heating rates. Substantial improvements in heating of the particle portion were seen at relatively low rpm. Although less important than rpm, even small (115 mm) radial position differences significantly altered Fo in some cases (p≤0.05). The effect of immobilization of food particles on the end of a thermocouple, investigated with Bacillus stearothermophilus ATCC 7953 spores sealed in differential scanning calorimetry (DSC) pans, revealed significantly lower lethality delivered to freely moving particles than to particles immobilized in the can center. A Hydrophobic Grid Membrane (HGM) technique allowed rapid and convenient enumeration of surviving spores. The bio-indicator approach provided a more conservative estimate of minimum lethality than rigid thermocouples positioned in the center of particles within cans. ©

An appraisal of the value of vitamin B 12 in the prevention of motion sickness

Unpublished reports have suggested that hydroxycobalamin (B 12, i.m.) prevents motion sickness. Some biomedical evidence supports this contention in that B 12 influences the metabolism of histidine and choline; dietary precursors to neurotransmitters with established roles in motion sickness. Susceptibility to motion sickness was evaluated after B 12 (1000 μg, i.m.). Subjects initially completed vestibular function and motion sickness susceptibility tests to establish normal vestibular function. The experimental motion stressor was a modified coriolis sickness susceptibility test. Subjects executed standardized head movements at successively higher RPM until a malaise III endpoint was reached. Following two baseline tests with this motion stressor, subjects received a B 12 injection, a second injection two weeks later, and a final motion sickness test three weeks later. No significant differences in susceptibility were noted after B 12. Hematological parameters revealed no B 12 deficiency before injection. The possibility that patients with B 12 deficiencies are more susceptible to motion sickness cannot be ruled out.

Rate of dissolution of solid iron in a carbon-saturated liquid iron alloy with evolution of CO.

Studies have been made on the rates of dissolution of stationary or rotated cylindrical iron specimens containing various amounts of oxygen into molten carbon-saturated iron alloys. The explored temperature range was from 1200°C to 1 450°C. The highest oxygen concentration of the specimen was 1.14%. The dissolution rate was determined from the rate of decrease in diameter of the cylinder.In the case of stationary dissolution, oxygen in the iron specimen, that is, the evolution of CO was found to have a marked effect on the dissolution rate. This phenomenon is shown to be analogous to the mass transfer at a gas evolving electrode. At high oxygen contents of the specimen, a phenomenon analogous to nucleate-film boiling of liquid over a hot solid surface was observed. The highest dissolution rate which was observed at 1 400°C for iron containing 0.96% oxygen is 590 times as large as the lowest rate observed at 1200°C for aluminum-killed iron.In the case of rotational dissolution of iron specimens containing oxygen, at lower rpm the rate is controlled mainly by the extent of CO evolution. At higher rpm, the effect of rotation becomes predominant.

Forensic Analysis of Disintegrated Grinding Wheels using the Sem and X-Ray Microanalysis

Grinding is a microscopic chipping process for removing material from metal or other hard surfaces. This is commonly accomplished by a rotating wheel consisting of abrasive grains bonded into place with a resin or ceramic material. Aluminum oxide and silicon carbide are the usual abrasives. The most frequently used bond is a vitrified composition of feldspars and clays fired in a ceramic process along with a desired mixture of abrasives. This type of wheel is very hard and easily subject to damage and is normally used in a stationary grinding position. For portable hand-held grinding a resin bonded wheel is used. Resinoid wheels have a more porous structure than vitreous wheels and can be used at high speeds for cool cutting. Frequently fabric reinforcement is used within the structure of the wheel, and it may be operated at higher RPM than other types of wheels.

Measurement of the acoustic impedance of an internal combustion engine

The specific acoustic impedance ζ of an internal combustion engine has been studied experimentally to promote the computer-aided muffler design to a higher level of sophistication. Measurements were performed with a specially prepared impedance tube facility capable of accommodating the hot and moving exhaust gases. At low engine speeds (RPM) the ζ trace on the complex ζ plane follows an irregular path that cannot be readily modeled in terms of simpler acoustic components. At higher RPM, however, the trace becomes a spiral, centered at and slowly converging towards ζ = 1, indicating a resemblance to an open-ended pipe segment. The measured ζ has been used in designing a muffler for this internal combustion engine with favorable results.

Perceived exertion during exercise with concentric and eccentric muscle contractions.

The perception of exertion was studied with special reference to oxygen consumption anil heart rate under two exercise conditions, namely with concentric (shortening) and eccentric (lengthening) muscle contractions. Exercise was performed on a Krogh cycle ergomoter adapted for the two types of exercise. Oxygen consumption was determined by Douglas bag-Haldane toehniquo, heart rate by ECG, and perceived exertion by a rating scale. Eccentric exercise was perceived as requiring less exertion compared to concentric exercise at similar intensities. When compared on the basis of equal oxygen consumption and heart rate, eccentric exercise was perceived as requiring greater exertion. Exercise at lower rpm was perceived as requiring greater exertion in both forms of exercise as opposed to exercise at higher rpm. It is suggested that exertion during various forms of exercise and under different conditions is perceived or assessed from differonfc combinations of information obtained from afferent and efferent signals.

A Circulating Pump for Ultrapure or Toxic Gases

A small, stainless steel, Roots-type pump for gases is described. The pump employs helium leak tight rotary seals which render it suitable for use in ultrahigh vacuum gas handling systems. A throughput (at atmospheric pressure) of 100 liters/min has been measured at 1800 rpm. At higher rpm's, the throughput is correspondingly larger.

Frictional Adhesion of Metal to Glass, Quartz, and Ceramic Surfaces

In 1947 W. A. Wooster and G. L. McDonald reported that titanium would adhere by frictional contact to glass, certain mineral, and ceramic surfaces. In order to explore this property further small disks of a number of different metals, mounted separately on one-eighth-inch shafts driven by a high-speed hand-grinder, were applied to glass, quartz, and ceramic surfaces. By suitably varying the rpm of the motor and the pressure of application, the metal of the disks could be made to adhere securely to such surfaces. At higher rpm erosion of the glass surfaces usually occurred. Variations of the technique of application allowed either the metallic coating or the cutting of glass. Some of the metals tested were titanium, zirconium, aluminum, magnesium, gold, silver, copper, iron, nickel, cobalt, cadmium, zinc, and lead.

The Elastic-Fluid Centripetal Turbine for High Specific Outputs

Abstract The radial inward-flow (or centripetal) turbine for elastic fluids has been the subject of theoretical and experimental investigation by the author for the past 25 years, during which time a number of applications were made by his Company to steam and gas turbines—applications for which the centripetal turbine was found to be distinctly superior to the axial-flow type. In so far as is known, no other manufacturer used this type of turbine until recently, when several companies applied it to the construction of small gas turbines, and coincidental therewith several technical papers were written expounding its virtues. Judging from these applications and the published material, it would appear that the greatest merit of the centripetal turbine—which lies in the fact that it can be designed for specific outputs far exceeding those of the axial-flow wheel—still remains unrecognized. In this paper it will be shown, by the presentation of drawings, photographs, test results, and numerical examples, that the centripetal turbine can be designed to handle larger flows and higher enthalpy drops at higher rpm with better efficiency and lower stresses than the axial-flow turbine, and that because very high specific outputs are thus made possible, it permits the solution of design problems which cannot be solved by the axial-flow wheel.

Elementary theory of the gyroscope

Amongst, the floating systems catering to the offshore wind energy, barge floater is the simplest structure but its limitation of application is constrained by its large motion. Mitigating these motions can help in efficient and economical production of energy. The present work focuses on the experiments conducted on a 1:50 scaled model of a barge without and with static Offshore Wind Turbine (OWT) with active gyrostabilizer ‘off’ and ‘on’ condition for regular and irregular waves for three different rpms. The roll responses were recorded for a range of regular wave heights from 2 cm to 5.5 cm and time periods varying from 0.8 to 1.3 s and irregular waves with significant wave height from 3 cm to 5 cm with peak period ranging from 0.8 to 1.25 s. For barge, the maximum motion reduction observed was 60% and for barge fitted with static OWT the maximum reduction observed was 55% at higher rpm in regular waves. In case of irregular waves, significant response heights were compared. For barge, the maximum response reduction observed was 50% and for barge fitted with static OWT the maximum response reduction observed was 54% in irregular waves.