12 research outputs found

    A New Method for Searching for Free Fractional Charge Particles in Bulk Matter

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    We present a new experimental method for searching for free fractional charge in bulk matter; this new method derives from the traditional Millikan liquid drop method, but allows the use of much larger drops, 20 to 100 mm in diameter, compared to the traditional method that uses drops less than 15 mm in diameter. These larger drops provide the substantial advantage that it is then much easier to consistently generate drops containing liquid suspensions of powdered meteorites and other special minerals. These materials are of great importance in bulk searches for fractional charge particles that may have been produced in the early universe.Comment: 17 pages, 5 figures in a singl PDF file (created from WORD Doc.). Submitted to Review of Scientific Instrument

    The Search for Stable, Massive, Elementary Particles

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    In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches - what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review.Comment: 34 pages, 8 eps figure

    Dark sectors 2016 Workshop: community report

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    This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    Salivary levels of Streptococcus mutans and Streptococcus sanguinis in early childhood caries: An in vivo study

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    Background: The oral microflora primarily involved in early childhood caries (ECC) is Streptococcus mutans while Streptococcus sanguinis is related to healthy caries-free mouth. The antagonism between the two at biological level is well recognized. Aim: This study aims to compare the pre- and posttreatment salivary levels of S. mutans and S. sanguinis in ECC. Methods: This cross-sectional study was performed on 40 eligible participants. Clinical examination was done, and decayed teeth were recorded. Pre- and Posttreatment saliva sample was taken, processed and bacterial counts were compared. Results: A statistically significant posttreatment reduction was found in S. mutans counts; however, a significant posttreatment elevation was seen in S. sanguinis counts (P < 0.001) using Wilcoxon signed-rank test. A significant weak positive correlation was found between S. mutans and decayed teeth in the mouth (r = 0.366 and P = 0.028) using Spearman's correlation. No significant gender association was found between pre- and posttreatment S. mutans and S. sanguinis counts (P = 0.908) and also between decayed teeth (P = 0.321) using Mann–Whitney U-test. Conclusion: Complete dental treatment procedure showed significant reduction and elevation in S. mutans and S. sanguinis counts, respectively. A positive association was observed between S. mutans and ECC while S. sanguinis were positively associated with posttreatment oral environment
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