173 research outputs found

    Limits on monopole fluxes from KFG experiment

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    The nucleon decay experiment at KGF at a depth of 2.3 Km is eminently suited for the search of Grand Unified theory (GUT) monopoles, whose velocities at the present epoch are predicted to be around 0.001C. At this depth the cosmic ray background is at a level 2/day in the detector of size 4m x 6m x 3.7m and one can look for monopoles traversing the detector in all directions, using three methods, i.e., (1) dE/dx (ionization); (2) time of flight and (3) catalysis of nucleon decay. The detector is composed of 34 layers of proportional counters arranged in horizontal planes one above the other in an orthogonal maxtrix. Each of the 1594 counters are instrumented to measure ionization in the gas (90% Argon + 10% Methane) as well as the time of arrival of particles

    Results on nucleon life-time from the Kolar gold field experiment

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    The KGF nucleon decay experiment has been in operation since October 1980 with a 140 ton calorimetric detector at a depth of 2.3 Km underground. The detector comprises 34 layers of proportional counters arranged in an orthogonal geometry with 12 mm thick iron plates in between successive layers. The proportional counters are made up of square (10 x 10 square centimeters) iron plates of wall thickness 2.3 mm. Each of the 1600 counters is instrumented to provide data on ionization, DE/dx and arrival time. The visible energy of a particle is determined to an accuracy of approximately 20% from the ionization and range of its track. The end point ionization of a stopping track provides the direction of motion as well as the nature of the particle (mu/pi,k,p). Decay of mu is recorded with an overall efficiency of only 20% in view of the thickness of 13 g/square centimeters between successive layers

    Data acquisition system for phase-2 KGF proton decay experiment

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    Phase-2 of KGF proton decay experiment using 4000 proportional counters will start operating from middle of 1985. The detection systems, in addition to measuring the time information to an accuracy of 200 n see, also records ionization in the hit counters. It also monitors different characteristics of the counters like pulse height spectrum, pulse width spectrum and counting rate. The acquisition system is discussed

    Muon and neutrino results from KGF experiment at a depth of 7000 hg/square cm

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    The KGF nucleon decay experiment at a depth of 7000 hg/sq cm has provided valuable data on muons and neutrinos. The detector comprised of 34 crossed layers of proportional counters (cross section 10 x 10 sq cm; lengths 4m and 6m) sandwiched between 1.2 cm thick iron plates can record tracks of charged particles to an accuracy of 1 deg from tracks that traverse the whole of the detector. A special two-fold coincidence system enables the detector to record charged particles that enter at very large zenith angles. In a live time of 3.6 years about 2600 events have been recorded. These events include atmospheric muons, neutrino induced muons from rock, stopping muons, showers and events which have their production vertex inside the detectors. The results on atmospheric muons and neutrino events are presented

    Luffa operculata effects on the epithelium of frog palate: histological features

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    SummaryLuffa operculata is the botanical name of buchinha-do-norte or cabacinha, which is a medicinal plant widely used for the treatment of rhinitis and rhinosinusitis. In Europe and USA, it is available in homeopathic medicines. In Brazil, Luffa operculata dry fruit infusion is inhaled or instilled into the nose releasing profuse mucous secretion, thus relieving nasal symptoms. Nevertheless, this often may cause irritation, epistaxis or anosmia.Study designExperimental.Material and MethodThe effects of Luffa operculata were evaluated in different concentration infusions, in isolated frog palate preparation, testing 46 palates after immersion. Four groups (n = 10) were tested with the infusion prepared with frog Ringer (isotonic): control; 60 mg/L; 600 mg/L; and 1200 mg/L. An additional group was tested using the infusion with water (600 mg/L H2O, n = 6). Epithelial samples were harvested to be studied under light microscopy and electron transmission microscopy.ResultsIn treated palates, light microscopy findings were dose-dependent standard toxic changes. Electron transmission microscopy showed enlargement of intercellular spaces and tight junctions disruption, pointing to ion-fluid transport abnormalities. Conclusions: Luffa operculata infusion in currently used doses can promote significant structural and ultrastructural changes in the epithelium of this ex vivo model of respiratory mucosa

    Search for point sources of neutrinos with KGF underground muon detectors

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    The proton decay detectors operated underground in the Kolar Gold Fields in India during 1980-1993 have recorded a large number of muon events. Out of these, 243 large zenith angle events were selected as being due to muons arising from neutrino interactions in the surrounding rock. This selection was based on the different zenith angular distributions of the atmospheric and neutrino-induced muons. These selected events are analysed here to look for powerful point sources of neutrinos

    Postoperative otorhinolaryngologic complications in transnasal endoscopic surgery to access the skull base

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    AbstractIntroductionThe large increase in the number of transnasal endoscopic skull base surgeries is a consequence of greater knowledge of the anatomic region, the development of specific materials and instruments, and especially the use of the nasoseptal flap as a barrier between the sinus tract (contaminated cavity) and the subarachnoid space (sterile area), reducing the high risk of contamination.ObjectiveTo assess the otorhinolaryngologic complications in patients undergoing endoscopic surgery of the skull base, in which a nasoseptal flap was used.MethodsThis was a retrospective study that included patients who underwent endoscopic skull base surgery with creation of a nasoseptal flap, assessing for the presence of the following post-surgical complications: cerebrospinal fluid leak, meningitis, mucocele formation, nasal synechia, septal perforation (prior to posterior septectomy), internal nasal valve failure, epistaxis, and olfactory alterations.ResultsThe study assessed 41 patients undergoing surgery. Of these, 35 had pituitary adenomas (macro- or micro-adenomas; sellar and suprasellar extension), three had meningiomas (two tuberculum sellae and one olfactory groove), two had craniopharyngiomas, and one had an intracranial abscess. The complications were cerebrospinal fluid leak (three patients; 7.3%), meningitis (three patients; 7.3%), nasal fossa synechia (eight patients; 19.5%), internal nasal valve failure (six patients; 14.6%), and complaints of worsening of the sense of smell (16 patients; 39%). The olfactory test showed anosmia or hyposmia in ten patients (24.3%). No patient had mucocele, epistaxis, or septal perforation.ConclusionThe use of the nasoseptal flap has revolutionized endoscopic skull base surgery, making the procedures more effective and with lower morbidity compared to the traditional route. However, although mainly transient nasal morbidities were observed, in some cases, permanent hyposmia and anosmia resulted. An improvement in this technique is therefore necessary to provide a better quality of life for the patient, reducing potential complications

    Cosmic ray muons at a depth of 754 hg/cm<SUP>2</SUP> in the Kolar Gold Mines

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    A telescope of area 4 m2, consisting of horizontal layers of plastic scintillators, neon flash tubes and absorbers was operated at a depth of 754 hg/cm2 in the Kolar Gold Mines. New values for the vertical intensities of muons have been obtained from observations of the angular distribution over the slant depths ~750-2300 hg/cm2 and are compared with the existing measurements. From the angular distribution observed, we conclude that muons are produced wholly through the decay of pions and kaons up to energies of the order of 1 TeV. A value of 0.3&#177;0.2 is estimated for the K/&#960; ratio at production, for muon energies around 500 GeV. A decoherence distribution has been obtained for parallel muon events up to distances of the order of 10 m. From this we conclude that the average Pt of the parents of muons of energy ~250 GeV is of the order of 0.3 GeV/c. From an analysis of rock showers, we obtain the cross section for inelastic interaction of muons of mean energy 100 GeV as (3.8&#177;1.5)&#215;10-30 cm2/nucleon
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