818 research outputs found
Coherent and semiclassical states in magnetic field in the presence of the Aharonov-Bohm solenoid
A new approach to constructing coherent states (CS) and semiclassical states
(SS) in magnetic-solenoid field is proposed. The main idea is based on the fact
that the AB solenoid breaks the translational symmetry in the xy-plane, this
has a topological effect such that there appear two types of trajectories which
embrace and do not embrace the solenoid. Due to this fact, one has to construct
two different kinds of CS/SS, which correspond to such trajectories in the
semiclassical limit. Following this idea, we construct CS in two steps, first
the instantaneous CS (ICS) and the time dependent CS/SS as an evolution of the
ICS. The construction is realized for nonrelativistic and relativistic spinning
particles both in (2+1)- and (3+1)- dimensions and gives a non-trivial example
of SS/CS for systems with a nonquadratic Hamiltonian. It is stressed that CS
depending on their parameters (quantum numbers) describe both pure quantum and
semiclassical states. An analysis is represented that classifies parameters of
the CS in such respect. Such a classification is used for the semiclassical
decompositions of various physical quantities.Comment: 35 pages, 2 figures. Some typos in (77), (101), and (135) corrected
with respect to the published version. Results unchange
Dummy Cb sebagai Alat Simulator Kubikel untuk Pemeliharaan Preventif dan Korektif Guna Mengurangi Frekuensi Padam Penyulang 20 Kv (Aplikasi pada Sistem Scada 20 Kv Pt.pln (Persero) Apd Jateng & DIY)
Meira Dwi Primanto, Priyo Sasmoko, in paper dummy CB as cubicle simulator for preventive and corrective maintenance to reduce off frequency 20 KV feeders (20 KV scada system at APD Central Java and Yogyakarta) explain that in 2013, the APD PT.PLN Central Java and Yogyakarta are conducting integration to SCADA at 20 KV feeders in distribution substation. For the next stage has been installed SCADA maintenance should be done periodically. Maintenance can be planned or due to interference with the SCADA system. Maintenance is usually done by the team must perform SCADA Distribution feeder outages and transfer of the load. In the installation of equipment, SCADA team should get a working permit to shut down the feeder, and to transfer the load to another feeder, so that the work has to get permission. SCADA systems are already installed requires maintenance to keep the system reliability. When maintenance SCADA, feeders should be extinguished, whereas for medium voltage customers such as factories, hospitals, and airports should always be channeled electrical energy. Feeder outages and load Delegation KWH lost causes. To the authors attempt to provide solutions that can overcome the missing KWH with a tool innovations made. The author makes a tool such as a dummy circuit breaker simulator 20 KV cubicles. This tool serves Especially when employees perform maintenance or investigation SCADA Disorders, which aims for 20 KV feeders should not be extinguished when performing preventive and corrective maintenance. So the number of frequency of feeder outages can be reduced
Organização estratégica de plataforma para caracterização espacial de riscos no setor agropecuário e agroflorestal.
bitstream/CNPDIA-2009-09/11041/1/DOC28_2007.pd
Paraquat Intoxication – experience of an Internal Medicine ward for 18 years
Introduction: Paraquat is a contact herbicide commercially available
since 1962. Paraquat intoxication (PI) is usually voluntary
and highly lethal, since there is no effective antidote. Toxicity
occurs through cyclic redox reactions, damaging mainly the
kidneys and lungs.
Aim, material and methods: featuring the clinical presentation,
management and outcome of patients with PI over an 18 years
period (from the 01st January 1993 to the 31st December 2010)
through the retrospective analysis of clinical files and comparing
the survivors and the deceased.
Results: Thirty-one cases of Paraquat intoxication were included,
with a male: female ratio 1:1. Age range from 13 to 80 years,
mean age 42.4years (±18.7).All intoxications were voluntary and
by oral route. There was statistical difference in the amount ingested
(22.1 mL vs. 72.7 mL, p<0.0005). A non-significant trend
to a longer delay until getting medical attention in the deceased
group (1.6 h vs. 3.2 h, p=0.091). Statistical significance was found
between mortality and leukocytosis, hypocapnea, hypoxemia, LDH,
alkaline phosphatase and AST. There was no difference between
groups according to treatment options, although hemocarboperfusion
was used more often in the deceased group (53.9%
vs. 66.7%, p=0.471) and corticosteroids in the survivor group
(61.5% vs. 44.4%, p=0.350). Mortality rate was 58.1% (66.7%
in the first 72 hours), due to respiratory insufficiency and multiple
organ failure. Variable levels of pulmonary fibrosis occurred in
38.5% of the survivors.
Discussion & Conclusion: Paraquat intoxication has a poor
prognosis with limited efficiency of treatment approaches. The
relation between Paraquat in the urine and the time elapsed after
ingestion is the main determinant factor in the prognosis. In this
study the presence of dyspnea, hypocapnea and hypoxemia was
linked to a bad prognosis. There was no statistical difference
between the available treatment options
Behaviour of cementitious matrices subjected to the combined action of chloride ions and carbonation
Carbonation and chloride action are the two leading causes of degradation in reinforced concrete structures. Despite the combined action of these two mechanisms being a reality, there is little research on the effect of this combination in cementitious matrices. Furthermore, the incorporation of fly ash in cementitious matrices has been frequently used in order to make the matrix more resistant to the action of chlorides. On the other hand, it is known that Ca(OH)2 existing in the matrix is consumed by the pozzolanic reactions, which makes easier the carbonation front advance. Therefore, this paper presents a study of the behavior of cementitious matrices, with and without fly ash, subjected to the combined action of chlorides and carbonation. Two different kinds of mortars were produced: reference (only cement CEM I 42.5R) and fly ash mortar (40% replacement of cement). After curing, the specimens were subjected to three different wetting-drying cycles, considering NaCl solutions and CO2 atmospheres. Afterwards, chloride profiles and carbonation front were measured. Results show that carbonation has a direct influence on chloride penetration, decreasing it for cement mortars with 0% fly ash and increasing it for mortars with 40% cement replacement by fly ash. Moreover, the evolution of carbonation is also influenced by chloride presence, which decreases under the combined action.The authors thank the Foundation for Science and Technology (FCT) for supporting this research. The authors also thank the SECIL for making available cement used in this research and the CIMENTEIRA DO LOURO for providing the aggregates used. This work is co-financed by FEDER funds through the Competitively Factors Operational Programme - COMPETE and by national funds through FCT within the scope of the project POCI-01-0145-FEDER007136.info:eu-repo/semantics/publishedVersio
Coherent states of non-relativistic electron in magnetic-solenoid field
We construct coherent states of a nonrelativistic electron in the
magnetic-solenoid field, which is a superposition of the Aharonov-Bohm field
and a collinear uniform magnetic field. In the problem under consideration
there are two kind of coherent states, the first kind corresponds to classical
trajectories which embrace the solenoid and the second one to trajectories
which do not. Mean coordinates in the constructed coherent states are moving
along classical trajectories, the coherent states maintain their form under the
time evolution, and represent a complete set of functions, which can be useful
in semi classical calculations. In the absence of the Aharonov-Bohm filed these
states are reduced to the well-known in the case of uniform magnetic field
Malkin-Man'ko coherent states.Comment: 11 pages, version accepted for publication in J. Phys. A, 3 figures
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