Invention of the split-anode magnetron.

Magnetron production and use far exceed that of other microwave tubes due to their high operational efficiency, power efficiency, and cost-effectiveness in production. The magnetron was named by A. W. Hull; however, the device invented by Hull differs from the magnetron utilized as a microwave tube. The magnetron widely used today is based on the split-anode magnetron invented by K. Okabe. This overview introduces two papers published by Okabe in the Proceedings of the Imperial Academy and discusses the events that led to the discovery of the split-anode magnetron. In addition, the operation mechanisms of magnetrons are explained.

Numerical Simulation and Analysis of Turbulent Characteristics near Wake Area of Vacuum Tube EMU.

Due to aerodynamic resistance, aerodynamic noise, and other problems, the further development of traditional high-speed electric multiple units (EMUs) on the open line has been seriously restricted, and the construction of a vacuum pipeline high-speed train system has become a new solution. In this paper, the Improved Detached Eddy Simulation (IDDES) is used to analyze the turbulent characteristics of the near wake region of EMU in vacuum pipes, so as to establish the important relationship between the turbulent boundary layer, wake, and aerodynamic drag energy consumption. The results show that there is a strong vortex in the wake near the tail, which is concentrated at the lower end of the nose near the ground and falls off from the tail. In the process of downstream propagation, it shows symmetrical distribution and develops laterally on both sides. The vortex structure far from the tail car is increasing gradually, but the strength of the vortex is decreasing gradually from the speed characterization. This study can provide guidance for the aerodynamic shape optimization design of the rear of the vacuum EMU train in the future and provide certain reference significance for improving the comfort of passengers and saving the energy consumption caused by the speed increase and length of the train.

High Performance Broadcast Receiver Based on Obsolete Technology.

Since its inception, the electronics industry has mass-produced equipment. The fast evolution of electronic technologies made obsolete the entire generation of products and even technologies. Until the government issued regulations and guidelines on how to address the issue of reuse of obsolete electronic equipment, with special regard to the ones still operating (e.g., give it to family/friends, donate to charity, or sell to individuals or recycling companies), most of it was thrown out with usual rubbish, with a destructive effect on the environment. This paper presents the design techniques and methods for revaluation of obsolete vacuum tube analog receivers, with a focus on the manufacturing steps of a high-performance receiver. The choice of receiver type is not accidental at all, since tube technology is still a real success among audiophiles many providers offer vacuum tube amplifiers at considerably high prices. The redesign implied the original FM unit replacement with a DSP-based AM/FM tuner while the AM RF vacuum tube section has been preserved with the original architecture to allow the reception of the broadcast stations for the long-wave band and the alternative operation with the silicon tuner for the medium-wave and short-wave bands. The electrical performances of the modified receiver in terms of reliability, sensitivity, selectivity, and distortions on the reception chain are clearly superior to the original one, while the power consumption of the RF section is reduced more than 10 times from 11.5 W-15.5 W to 1 W. Last, but not least important, the proposed solution implied the use of few additional parts and resources and extended significantly the lifetime of the original vacuum tubes receiver. The work has been developed to serve as an example of how obsolete electronic equipment can be redesigned and reused avoiding its complete recycling or even worse, its disposal with usual rubbish. It has been imagined and performed as the initial step in launching a professional student contest on the reuse/redesign of obsolete equipment aimed at raising awareness regarding the issue of pollution with e-waste amongst students from the electronic departments of Romanian technical universities.

Vacuum Tunneling Transistor with Nano Vacuum Chamber for Harsh Environments.

A nano vacuum tube which consists of a vacuum transistor and a nano vacuum chamber was demonstrated. For the device, a vacuum region is an electron transport channel, and a vacuum is a tunneling barrier. Tilted angle evaporation was studied for the formation of the nano level vacuum chamber structure. This vacuum tube was ultraminiaturized with several tens of 10-18 L scale volume and 10-6 Torr of pressure. The device structure made it possible to achieve a high integration density and to sustain the vacuum state in various real operations. In particular, the vacuum transistor performed stably in extreme external environments because the tunneling mechanism showed a wide range of working stability. The vacuum was sustained well by the sealing layer and provided a defect-free tunneling junction. In tests, the high vacuum level was maintained for more than 15 months with high reliability. The Al sealing layer and tube structure can effectively block exposed light such as visible light and UV, enabling the stable operation of the tunneling transistor. In addition, it is estimated that the structure blocks approximately 5 keV of X-ray. The device showed stable operating characteristics in a wide temperature range of 100-390 K. Therefore, the vacuum tube can be used in a wide range of applications involving integrated circuits while resolving the disadvantages of a large volume in old vacuum tubes. Additionally, it can be an important solution for next-generation devices in various fields such as aerospace, artificial intelligence, and THz applications.

Claims of priority - The scientific path to the discovery of X-rays.

Shortly after Röntgen's publication about a new kind of rays, a dispute about priority claims began. Röntgen was not the first researcher to produce X-rays nor the first to take X-ray images. An analysis of the history of cathode ray research in the 19th century reveals ample evidence that researchers before Röntgen had already produced X-rays, albeit without knowing this. Most of them, for their part, did not claim any priority, some did so rather casually. The German-Hungarian physicist Philipp Lenard, a co-founder of German Physics, considered himself a "true discoverer". It remains to be said, however, that he, like many others before him, failed to recognize the character of the new radiation. It was Wilhelm Conrad Röntgen, with his three scientific publications on X-rays, who laid the foundations for their physical clarification and paved the way for the success story of their application in a variety of fields that continues to this day.

Parameter Evaluation and Application Demonstration of a New Type of Blood Vacuum Tube Cap Opening and Closing Machine.

BACKGROUND: We aimed to evaluate the basic performance and basic parameters of a new type of blood vacuum tube cap opening and closing machine for further application. METHODS: From July 2013 to March 2018, 110, 000 cases involved in the clinical trials in Third People's Hospital of Dongguan City were selected as the instrument group, and 10,000 cases were selected as the manual operation group. The application demonstration and instrument performance assessment were performed by five units. Unified evaluation indicatory system and the standard of assessment were set up. The instrument assessments and demonstration tests were carried out by these 5 units. Finally, the basic parameters of the instrument were analyzed and compared. RESULTS: The new instrument had excellent performance, and thirty parameters were excellent. Five patents had been granted already. There were no differences between the instrument groups in different units, and among different units. However, there were some differences in the manual operation group between different units. The average cap opening time was 21 "04 in the instrument group, and 152" 48 in the manual operation group (P<0.05); the cap closing time was 18 "56 in the instrument group, and 104"24 in the manual operation group (P<0.05). The instrument group outperformed the manual operation group in cap closing time, pollution rate, spill rate and failure rate (P<0.01). The design of the instrument was original. CONCLUSION: This blood vacuum tube cap opening and closing machine can perform a wide variety of functions, and it is stable, intelligent and superior to manual operation. More efforts need to be made for the industrialization of this instrument.

Payback times and multiple midpoint/endpoint impact categories about Building-Integrated Solar Thermal (BIST) collectors.

The purpose of the present article is the evaluation, by means of life cycle assessment, of a system which consists of vacuum-tube solar thermal collectors. The system is appropriate for building integration and it has been developed in France. The methods ReCiPe and USEtox have been adopted. Regarding life-cycle results, according to the scenario "without recycling" and for 30-year system lifespan, ReCiPe payback time was calculated to be 18.14 years based on France's electricity mix whereas by using Spain's electricity mix (hypothetical scenario) it was found to be 4.03 years. Recycling offers a ReCiPe-payback time reduction of 2.66 years based on France's electricity mix and 0.59 years based on Spain's electricity mix. All the studied cases show ReCiPe payback times much lower than an assumed system-lifespan of 30 years. On the basis of ReCiPe midpoint and by considering material manufacturing of the 16 collectors and the additional elements of the system (scenario "without recycling"), among glass-, aluminium-, copper- and steel-based components, the copper-based ones present the highest impact in 15 of the 18 impact categories. For instance, for Freshwater eutrophication, the copper-based elements have a score that is around 30 times higher comparing to that of the aluminium-based ones. The USEtox findings, for the material manufacturing of the 16 collectors and the supplementary elements of the system and for the scenario "without recycling", reveal that the material with the highest total score in terms of: i) human toxicity/cancer is copper (6.7E-09 CTUh), ii) human toxicity non-cancer is propylene glycol (4.0E-08 CTUh), iii) ecotoxicity is copper (2.06 CTUe). Recycling of the metals, according to USEtox, offers an impact reduction of 20-95%. A discussion about factors that influence the environmental profile of building-integrated solar systems is also provided.

Some physics from 550 BC to AD 1948.

This chapter outlines terminology and its origins. It traces the development of physics ideas from Thales of Miletus, via Isaac Newton, to the nuclear physics investigations at the beginning of the twentieth century. It also outlines the evolving technology required to make the discoveries that would form the basis of radiosurgery. Up to the 1920s, all experiments on atomic structure and radioactivity had involved the use of vacuum tubes and naturally occurring radioactive substances. There was a need to make useable subatomic particles to obtain better understanding of the interior structure of atoms. Because of this, machines that could make atoms move at high speed were invented, known as particle accelerators. A new era had dawned. There is a brief mention of the effect of radiation on living tissue and of the units used to measure it.

Alexander Forbes, Walter Cannon, and science-based literature.

The Harvard physiologists Alexander Forbes (1882-1965) and Walter Bradford Cannon (1871-1945) had an enormous impact on the physiology and neuroscience of the twentieth century. In addition to their voluminous scientific output, they also used literature to reflect on the nature of science itself and its social significance. Forbes wrote a novel, The Radio Gunner, a literary memoir, Quest for a Northern Air Route, and several short stories. Cannon, in addition to several books of popular science, wrote a literary memoir in the last year of his life, The Way of an Investigator. The following will provide a brief overview of the life and work of Forbes and Cannon. It will then discuss the way that Forbes used literature to express his views about the changing role of communications technology in the military, and his evolving view of the nervous system itself as a kind of information-processing device. It will go on to discuss the way that Cannon used literature to articulate the horrors he witnessed on the battlefield, as well as to contribute to the philosophy of science, and in particular, to the logic of scientific discovery. Finally, it will consider the historical and philosophical value of deeper investigation of the literary productions of scientists.

Low vacuum and discard tubes reduce hemolysis in samples drawn from intravenous catheters.

OBJECTIVES: In-vitro hemolysis is a great challenge to emergency departments where blood is drawn from intravenous catheters (IVCs). Although high quality samples can be obtained by straight needle venipuncture, IVCs are preferred for various reasons. The aim of this study was to identify blood collection practices that reduce hemolysis while using IVC. DESIGN AND METHODS: The study was conducted at an emergency department where blood is drawn in ≥ 90% of patients from IVC. Hemolysis, measured spectrophotometrically, was compared between syringe and vacuum tubes. The following practices were tested in combination with vacuum collection; a Luer-slip adapter, a Luer-lock adapter, discard tubes and low vacuum tubes. Each intervention lasted 1 week and retrieved 154 to 297 samples. As reference, hemolysis was also measured in vacuum tubes retrieved from departments where only straight needle venipuncture is performed. RESULTS: Vacuum collection led to more hemolytic samples compared with syringe tubes (24% versus 16% respectively, p=0.008). No difference in hemolysis was observed between the Luer-slip and the Luer-lock adapter. The use of discard (17% hemolytic, p=0.045) and low vacuum tubes (12% hemolytic, p<0.001) substantially decreased hemolysis. None of the interventions reduced the hemolysis rate to the level observed when drawing blood by straight needle venipuncture (3%, p<0.02). CONCLUSIONS: In summary, both discard and low vacuum tubes reduce hemolysis while drawing blood from IVC. Of these practices the use of a low vacuum tube is preferred considering the less volume of blood and the amount of tubes drawn.