The Oxford-Kew ozone sonde

An ozone sonde capable of measuring and transmitting the local ozone concentration has been developed for the I. G. Y. and is described in some detail. A continuous electrochemical detector measures the ozone concentration, providing a d. c. electric current of 0 to 5 μ A according to the amount of ozone in the air passed through it. This output current is telemetered by a current-controlled variable inductance which is interchangeable with a standard inductance coil in a Kew radiosonde. The element is of low cost, weighs about 600 g and requires very limited auxiliary equipment for its use. Sixty-five successful ascents have been made and the results of the European ascents are given.

1956 ◽  
Vol 11 (1) ◽  
pp. 71-75
Author(s):  
E. Haeffner ◽  
Th. Sjöborg ◽  
S. Lindhe

The isotope separation effect of a direct electric current in a liquid metal is demonstrated by passing a current through mercury, which is enclosed in a capillary tube. The second part of the paper deals with an attempt of establishing an isotope effect when a direct current is passed through an uranium wire.


2012 ◽  
Vol 95 (3) ◽  
pp. 773-777 ◽  
Author(s):  
Leonardo Luiz Okumura ◽  
Luis Octávio Regasini Regasini ◽  
Daniara Cristina Fernandes ◽  
Dulce Helena Siqueira da Silva ◽  
Maria Valnice Boldrin Zanoni ◽  
...  

Abstract A fast, low-cost, convenient, and especially sensitive voltammetric screening approach for the study of the antioxidant properties of isoquercitrin and pedalitin from Pterogyne nitens is suggested in this work. These flavonoids were investigated for their redox properties using cyclic voltammetry in nonaqueous media using N,N-dimethylformamide and tetrabutylammonium tetrafluorborate as the supporting electrolyte, a glassy carbon working electrode, Ag|AgCl reference electrode, and Pt bare wire counter electrode. The comparative analysis of the activity of rutin has also been carried out. Moreover, combining HPLC with an electrochemical detector allowed qualitative and quantitative detection of micromolecules (e.g., isoquercitrin and pedalitin) that showed antioxidant activities. These results were then correlated to the inhibition of β-carotene bleaching determined by TLC autographic assay and to structural features of the flavonoids.


Author(s):  
AP Pandit ◽  
Neha Bhagatkar ◽  
Mallika Ramachandran

ABSTRACT The potential size of India's dental market is vast and is expected to become one of the largest single country markets for overseas dental products and materials. The total market for the dental equipment and materials is estimated to be around US$ 90 million annually. There are more than 1, 80,000 dental professionals in India, 297 dental institutes and over 5,000 dental laboratories. Thus, there is a huge potential for the market of personal protective equipment (PPE) used for infection control in dentistry. India's market for dental products is extremely dynamic, with a current estimated growth rate of between 25 and 30%. Overall, the dental market is expected to grow by 20%.1 The personal protective equipment used in the practice of dentistry in India. Since dentistry is predominantly a surgical discipline, it leads to exposure to the pathogenic microorganisms harbored in blood, body fluids and other potentially infectious material. Thus, the use of adequate and good quality PPE is imperative for infection control in dental practice. With the growing potential of India's dental market, the growth of the market for PPE is inevitable. But, it is equally important to raise the awareness among dental community about good quality products adhering to required standards to prevent the usage of low-cost, uncertified and sub-standard products that decrease the safety levels of personnel. The present study is conducted with a view to observe the personal protective equipment used for infection control in dental practices. How to cite this article Pandit AP, Bhagatkar N, Ramachandran M. Personal Protective Equipment used for Infection Control in Dental Practices. Int J Res Foundation Hosp Healthc Adm 2015;3(1):10-12.


2019 ◽  
Vol 10 ◽  
pp. 281-293 ◽  
Author(s):  
Donghui Zheng ◽  
Man Li ◽  
Yongyan Li ◽  
Chunling Qin ◽  
Yichao Wang ◽  
...  

Developing a facile and environmentally friendly approach to the synthesis of nanostructured Ni(OH)2 electrodes for high-performance supercapacitor applications is a great challenge. In this work, we report an extremely simple route to prepare a Ni(OH)2 nanopetals network by immersing Ni nanofoam in water. A binder-free composite electrode, consisting of Ni(OH)2 nanopetals network, Ni nanofoam interlayer and Ni-based metallic glass matrix (Ni(OH)2/Ni-NF/MG) with sandwich structure and good flexibility, was designed and finally achieved. Microstructure and morphology of the Ni(OH)2 nanopetals were characterized. It is found that the Ni(OH)2 nanopetals interweave with each other and grow vertically on the surface of Ni nanofoam to form an “ion reservoir”, which facilitates the ion diffusion in the electrode reaction. Electrochemical measurements show that the Ni(OH)2/Ni-NF/MG electrode, after immersion in water for seven days, reveals a high volumetric capacitance of 966.4 F/cm3 at a current density of 0.5 A/cm3. The electrode immersed for five days exhibits an excellent cycling stability (83.7% of the initial capacity after 3000 cycles at a current density of 1 A/cm3). Furthermore, symmetric supercapacitor (SC) devices were assembled using ribbons immersed for seven days and showed a maximum volumetric energy density of ca. 32.7 mWh/cm3 at a power density of 0.8 W/cm3, and of 13.7 mWh/cm3 when the power density was increased to 2 W/cm3. The fully charged SC devices could light up a red LED. The work provides a new idea for the synthesis of nanostructured Ni(OH)2 by a simple approach and ultra-low cost, which largely extends the prospect of commercial application in flexible or wearable devices.


2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Tay Ching En Marcus ◽  
Michael David ◽  
Maslina Yaacob ◽  
Mohd Rashidi Salim ◽  
Mohd Haniff Ibrahim ◽  
...  

Ultraviolet absorption spectroscopy is reliable for ozone concentration measurement. Concentration range and optical path length are inversely related based on theoretical calculation and observation of previous work. However, gas cells for ozone application are typically not expandable. In addition, they incur cost for custom fabrication. Here we design a reconfigurable brass gas cell that may interchange optical path length between 5.6 cm and 10.8 cm. Components are available at low cost, easy to joint and ready to use. Theoretical background and gas cell structure are discussed. Practical transmittance values between e-0.65 and e-0.05 are proposed for theoretical calculation of concentration via Beer-Lambert law. The concentration values are used in SpectralCalc.com gas cell simulation to obtain transmittance. Both approaches yield comparable result. Simulation result shows concentration range of 5.6 cm optical path length gas cell (31.82 ppm to 413.67 ppm) is wider than concentration range of 10.8 cm optical path length gas cell (16.50 ppm to 214.49 ppm). Simulation condition is at transmittance from 0.5291 to 0.9522, sampling wavelength 253.65 nm, temperature 300 K and pressure 1 atm. Thus, we strongly recommend short optical path length gas cell (5.6 cm) for wide range of concentration measurement (31.82 ppm to 413.67 ppm).


2003 ◽  
Vol 769 ◽  
Author(s):  
YongWoo Choi ◽  
Ioannis Kymissis ◽  
Annie Wang ◽  
Akintunde I. Akinwande

AbstractTextiles are a suitable substrate for large area, flexible and wearable electronics because of their excellent flexibility, mechanical properties and low cost manufacturability. The ability to fabricate active devices on fiber is a key step for achieving large area and flexible electronic structures. We fabricated transistors and inverters with a-Si film and pentacene film on Kapton film and cut them into fibers. The a-Si TFT showed a threshold voltage of 8.5 V and on/off ratio of 103 at a drain voltage of 10 V. These are similar to the characteristics of a TFT fabricated on a glass substrate at the same time. The maximum gain of the inverter with an enhancement n-type load was 6.45 at a drain voltage of 10 V. The pentacene OTFT showed a threshold voltage of -8 V and on/off ratio of 103 at a drain voltage of -30 V. The inverter with a depletion p-type load showed a voltage inversion but the inversion occurred at the wrong voltage. The antifuse was successfully programmed with a voltage pulse and also a current pulse. The resistance decreased from 10 GΩ to 2 kΩ after the programming.


2019 ◽  
Vol 19 (19) ◽  
pp. 8597-8604 ◽  
Author(s):  
Kessararat Ugsornrat ◽  
Patiya Pasakon ◽  
Chanpen Karuwan ◽  
Chakrit Sriprachuabwong ◽  
Thitima Maturos ◽  
...  

Author(s):  
Vadym Avrutov

The wire-electric gyroscope (WEG) is a new type of the angular rate sensor. The basic principle of the WEG is based on the hypothesis of invariance of the electric current speed for the same wire (coil). It is similar to the Sagnac effect for the speed of light. The method of angular rate determination is described. The voltage difference between two wire coils with different line coupling can be expressed in applied rotation (angular) rate and velocity of electric current. The scale factor depends on the magnitude of the current, number of the coil turns, the coil’s radius, the cross-section area of the wire and specific (unit) resistance of the wire. WEG can be produced cost-effectively and can be a good choice for low-cost applications.


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