Shields

About: Shields is a research topic. Over the lifetime, 1456 publications have been published within this topic receiving 10896 citations.

Multilayer film shields for the protection of PMT from constant magnetic field.

Abstract: Photomultiplier tubes (PMTs) are widely used in physical experiments as well as in applied devices. PMTs are sensitive to magnetic field, so creation of effective magnetic shields for their protection is very important. In this paper, the results of measurements of shielding effectiveness of multilayer film magnetic shields on PMT-85 are presented. Shields were formed by alternating layers of a material with high magnetic permeability (Ni-Fe) and high electric conductivity—Cu. The maximum number of bilayers reached 45. It is shown that in weak magnetic fields up to 0.5 mT, the output signal amplitude from PMT-85 does not change for all used multilayer shields. In strong magnetic field of 2–4 mT, the output signal amplitude decrease with 10%–40% depending from the number of layers in the shield. The Pulse distribution of PMT-85 in magnetic field 0.2–4 mT slightly changed in the range 1.1%–1.3% for the case when the number of layers do not exceed 10 and practically did not change for a shield with 45 double layers.

Variations in the Number of Costal Shields in Caretta

Abstract: occurs, but were perfectly normal radial canals. The individual was otherwise perfectly normal. The other and more striking variation was an individual with two radial canals and two manubria. The only variations in manubria noted by Dr. Hargitt were slight variations in size and a spike-like projection from the side of the manubrium of a single individual. The individual with two radial canals and two manubria is a female of approximately one centimeter in diameter. There are forty-two tentacles (which falls within the normal range of twenty-ninle to seventy-two), and in the aquarium the individual acted quite normally in respect to food and tactile stimulation. Both inanubria were functional and an attempt was made by the animal to engulf a small fish with both manubria at the same time. The gonads were rather full of eggs, although one of the gonads (and the adjacent radial canal) was somewhat shortened. One manubriumn was located as close to the center of the subumbrella surface as is common in Gonionemus and the other was located immediately adjacent to it. The musculature of each manubrium was apparently normal and there seemed to be no reduction in size of either. The gonad extending from the extra mnanubrium had lost that portion of its proximal folds which was displaced by the presence of the extra manubrium. This is true except for the slight increase in folding of this gonad under the velumn, at its distal end. Variations in themselves hav-e little real significance, but when they have physiological or genetical involvements they are of genuine interest to biologists. There is room for further study on these variations, especially in light of their physiological effects and inheritance.

Lithography equipment, method of manufacturing device, and device manufactured thereby

Abstract: PROBLEM TO BE SOLVED: To provide lithography equipment which makes temperature stability of a projection system surer by active heat transport, while minimizing impact of mechanical vibration by the heat transport. SOLUTION: In the lithography projection equipment, the projection system comprises one or more optical operating mirrors, and a heat shield which shields heat emission to the mirrors and/or a supporting structure of the mirrors or from the mirrors and/or the supporting structure of the mirrors. Although the heat shield is cooled compulsorily, as the mirrors and the heat shield are supported separately by a supporting frame, vibration of the mirrors by forced cooling is reduced. Preferably, the heat shield includes a heat shield which shields heat emission to the mirrors or from the mirrors, and shields heat emission to heat shields and/or supporting structures for individual mirrors or from the heat shields and/or the supporting structures. COPYRIGHT: (C)2005,JPO&NCIPI

Evaluation of Face Shields, Goggles, and Safety Glasses as a Virus Transmission Control Measure to Protect the Wearer Against Cough Droplets

Abstract: Abstract Face shields (also referred to as visors), goggles and safety glasses have been worn during the COVID-19 pandemic as one measure to control transmission of the virus. However, their effectiveness in controlling facial exposure to cough droplets is not well established and standard tests for evaluating eye protection for this application are limited. A method was developed to evaluate face shields, goggles, and safety glasses as a control measure to protect the wearer against cough droplets. The method uses a semi-quantitative assessment of facial droplet deposition. A cough simulator was developed to generate droplets comparable to those from a human cough. The droplets consisted of a UV fluorescent marker (fluorescein) in water. Fourteen face shields, four pairs of goggles and one pair of safety glasses were evaluated by mounting them on two different sizes of breathing manikin head and challenging them with the simulated cough. The manikin head was positioned in seven orientations relative to the cough simulator to represent various potential occupational exposure scenarios, for example, a nurse standing over a patient. Droplet deposition in the eyes, nose and mouth regions were visualised following three ‘coughs’. Face shields, goggles, and safety glasses reduced, but did not eliminate exposure to the wearer from droplets such as those produced by a human cough. The level of protection differed based on the design of the personal protective equipment and the relative orientation of the wearer to the cough. For example, face shields, and goggles offered the greatest protection when a cough challenge was face on or from above and the least protection when a cough challenge was from below. Face shields were also evaluated as source control to protect others from the wearer. Results suggested that if a coughing person wears a face shield, it can provide some protection from cough droplets to those standing directly in front of the wearer.