Search results for " coi"

The phase diagram of a single polymer chain: New insights from a new simulation method

2006

We present simulation results for the phase behavior of a single chain for a flexible lattice polymer model using the Wang-Landau sampling idea. Applying this new algorithm to the problem of the homopolymer collapse allows us to investigate not only the high temperature coil–globule transition but also an ensuing crystallization at lower temperature. Performing a finite size scaling analysis on the two transitions, we show that they coincide for our model in the thermodynamic limit corresponding to a direct collapse of the random coil into the crystal without intermediate coil–globule transition. As a consequence, also the many chain phase diagram of this model can be predicted to consist o…

Gd-DTPA in blood-ocular barrier damage: a new diagnostic tool for future application in MRI?

1995

The blood-brain barrier is not the only neuroepithelial blood filter in the body: the eye too is supported by a highly specialised microvascular filter, the so-called blood-ocular barrier (BOB). The BOB is actually divided into a blood-aqueous (BAB) and a blood-retinal (BRB) barrier, filtering the aqueous fluid and biological supplies, respectively, to the retina. The authors’ purpose was to study the possibility of imaging BAB or BRB damage by contrast-enhanced MRI: they examined 21 patients with a 0.5 T system and surface coil. Despite the normal findings in the damaged eyes immediately after a Gd-DTPA bolus, delayed contrast-enhanced MRI was able to show focal or diffuse barrier damage.

Dramme, didrammi e tetradrammi di Panormos e a legenda ṣyṣ nel V secolo a.C.: aggiornamenti e riflessioni intorno alle sequenze dei conî

2019

The main objective of this essay is to comment upon the modes of production and the datings of the 5th century BC non-fractional silver coinage bearing the Greek legend ΠΑΝΟΡΜΟΣ (and variants) and the Punic legend ṣyṣ. The reconstruction of the die sequences published by G. Kenneth Jenkins in 1971 and its recent updates will be discussed in detail. As far as the identification of the issuing authority and of the minting place of the coins with legend ṣyṣ is concerned, for a long time to the center of the scientific research interests, only the inferences made from an analysis of the die sequence have been taken into consideration.

Possibili livelli di intervento nella scuola in una prospettiva organizzativa.

2012

DNA-Barcoding to solve the tricky case of co-occuring Sabellaria (ANNELIDA) species in the Mediterranean Sea

2015

Intraspecific morphological variation of key taxonomic features is probably responsible for frequent misidentification of Sabellaria (Lamarck, 1818) species. This is the case of Sabellaria alcocki Gravier, 1906 whose Mediterranean records probably refer to juveniles of S. spinulosa (Leuckart, 1849). We hereby provide molecular tools (DNA barcoding) to improve correct delimitation of the Mediterranean species of this genus.

Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound with a 1.5 Tesla Scanner: A Prospective Intraindividual Comparison Study of Intraop…

2021

Background: High-quality intraoperative imaging is needed for optimal monitoring of patients undergoing transcranial MR-guided Focused Ultrasound (tcMRgFUS) thalamotomy. In this paper, we compare the intraoperative imaging obtained with dedicated FUS-Head coil and standard body radiofrequency coil in tcMRgFUS thalamotomy using 1.5-T MR scanner. Methods: This prospective study included adult patients undergoing tcMRgFUS for treatment of essential tremor. Intraoperative T2-weighted FRFSE sequences were acquired after the last high-energy sonication using a dedicated two-channel FUS-Head (2ch-FUS) coil and body radiofrequency (body-RF) coil. Postoperative follow-ups were performed at 48 h usin…

Electrical Safety of Resonant Grounding

2019

The resonant grounding is one of the possible methods of system neutral grounding for the medium-voltage distribution. IEEE standards do define this grounding configuration, but important advantages and drawbacks of the resonant grounding might not be fully known, due to its rather uncommon application in North America. On the other hand, resonant grounding in Europe is imposed by the increased requirements for power quality, especially for medium-voltage industrial users, and imposed to electric utilities by Regulatory Authorities, with the purpose to protect the interests of users and consumers. Level of the continuity of the service, magnitude and phase of ground-fault currents, magnitud…

Coil homogeneity and the effect of rotor filling on the spectral resolution

2009

Spectral resolution depends upon the length (N) of the transform interval: N=F/ f, where f is the smallest frequency difference which can be distinguished at a given sampling frequency F. f depends on the signal width, which, in turn, is influenced by the relaxation time of the sampled signal. Relaxation time is affected by the external magnetic field and the applied pulse sent to the sample through the transmitter/receiver coil. The pulse length homogeneity throughout this coil is a major factor affecting NMR resolution and also the sensitivity of the measurement. So far, this fact is only considered when small sample amounts are used, where care should be taken to place the sample in the …

Performance maps for an air-cooled air conditioning system as a preliminary instrument for the diagnosis of evaporator fouling

2018

During the past few decades, there has been increased interest in the development of automated approaches for detecting and diagnosing faults in air conditioning systems. One diagnostic approach involves the use of exergy analysis. As a first step towards understanding the application of exergy analysis to diagnostics, this work is focused on the thermodynamic and exergy analysis of a direct expansion air conditioning system used in small commercial building applications. The analysis was carried out by means of experimental activities on a 17.5 kW rooftop unit installed at the Herrick Laboratories, Purdue University, Indiana (USA). The system under investigation was equipped with a variabl…

On the reliability of thermoeconomic diagnosis of fouled evaporators: assessing the influence of geometries, operating conditions and reference state

2015

Thermoeconomic diagnosis of refrigeration systems is a pioneeristic approach, which has been proven to achieve good performances (under favorable conditions) for the detection of specific faults such as condenser and evaporator fouling and compressor valve leakage. In this paper the sensitivity of performance in detecting fouled Direct Expansion (DX) coils is investigated; the examined parameters are the temperature and relative humidity of coil inlet air and the sensible/latent heat ratio of the coil (varied by considering different numbers of rows). As the thermoeconomic model requires splitting the specific exergy of cooling air into “mechanical”, “thermal” and “chemical” fractions, and …