2,021 research outputs found
A model for deformable roll coating with negative gaps and incompressible compliant layers
A soft elastohydrodynamic lubrication model is formulated for deformable roll coating involving two contra-rotating rolls, one rigid and the other covered with a compliant layer. Included is a finite-strip model (FSM) for the deformation of the layer and a lubrication model with suitable boundary conditions for the motion of the fluid. The scope of the analysis is restricted to Newtonian fluids, linear elasticity/viscoelasticity and equal roll speeds, with application to the industrially relevant highly loaded or 'negative gap' regime. Predictions are presented for coated film thickness, interroll thickness, meniscus location, pressure and layer deformation as the control parameters - load (gap), elasticity, layer thickness and capillary number, Ca - are varied. There are four main results:
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(i) Hookean spring models are shown to be unable to model effectively the deformation of a compliant layer when Poisson's ratio nu --> 0.5. In particular, they fall to predict the swelling of the layer at the edge of the contact region which increases as v - 0.5; they also fail to locate accurately the position of the meniscus, X-M, and to identify the presence, close to the meniscus, of a 'nib' (constriction in gap thickness) and associated magnification of the sub-ambient pressure loop.
(ii) Scaling arguments suggest that layer thickness and elasticity may have similar effects on the field variables. It is shown that for positive gaps this is true, whereas for negative gaps they have similar effects on the pressure profile and flow rate yet quite different effects on layer swelling (deformation at the edge of the contact region) and different effects on X-M.
(iii) For negative gaps and Ca similar to O(1), the effect of varying either viscosity or speed and hence Ca is to significantly alter both the coating thickness and X-M. This is contrary to the case of fixed-gap rigid roll coating.
(iv) Comparison between theoretical predictions and experimental data shows quantitive agreement in the case of X-M and qualitive agreement for flow rate. It is shown that this difference in the latter case may be due to viscoelastic effects in the compliant layer
The Neuroleptic Treatment of Schizophrenia: Dosing Strategies, Depot Preparations and Novel Medications
Significant progress has been made over the past decade in the use of antipsychotic medication. An improved understanding of neuroleptic side effects has led to the development of new clinical strategies for dosing traditional medications. Traditional medications have become widely used in depot preparations. Risperidone, a new medication with an improved side effect profile, has recently become available. Clozapine, a novel medication, has entered widespread use. The use of these new clinical technologies is briefly discussed, along with the implications they have for the role of the psychiatrist in community mental health settings
Psychiatric Comorbidity in Transformed Migraine: Presentation, Treatment, Impact and Outcome
Transformed migraine is one of the subtypes of chronic daily headache (CDH), and is similar to chronic migraine, described in the new International Headache Society (IHS) classification 2004. The term CDH refers to the Headache disorders experienced 15 or more days a month and includes headaches associated with medication overuse. CDH can be divided into primary and secondary varieties. Primary CDH is not related to a structural or systemic illness. It includes diseases such as Transformed migraine (TM). Chronic tension-type headache (CTTH), new daily persistent headache (NDPH), and hemicrania continua (HC). Secondary CDH has an identifiable underlying cause, including post-traumatic headache, cervical spine disorders, vascular disorders, nonvascular intracranial disorders and headaches associated with temporomandibular joint disorders, sinus infections, chronic meningitis, low and high intracranial pressure. In this study we have adopted the 1996 definition of TM proposed by Silberstein and Lipton in preference to the new discredited 2004 IHS criteria for chronic migraine.
The association between migraine and psychiatric disorders has long been established. Several clinic-based and population-based studies have discussed the relationship. However psychiatric comorbidity in transformed migraine has seldom been discussed, and the effect on overall outcome has not been examined . Population based studies have shown that 4% to 5% of the general population has primary CDH. Transformed migraine is the major cause of CDH and is associated with poor quality of life and greater medical and social expenses compared to episodic migraine. CDH is most commonly transformed Migraine and is accompanied by high anxiety levels in most patients and with hysterical traits in some. These patients frequently have a coexisting depressive disorder. The purpose of this study is to characterize psychiatric disorders accompanying TM in a tertiary headache center and to examine their impact on outcome
Globular cluster systems of spiral and S0 galaxies: Results from WIYN imaging of NGC1023, NGC1055, NGC7332, and NGC7339
We present results from a study of the globular cluster (GC) systems of four spiral and S0 galaxies imaged as part of an ongoing wide-field survey of the GC systems of giant galaxies. The target galaxies - the SB0 galaxy NGC1023, the SBb galaxy NGC1055, and an isolated pair comprised of the Sbc galaxy NGC7339 and the S0 galaxy NGC7332 - were observed in BVR filters with the WIYN 3.5m telescope and Minimosaic camera. For two of the galaxies, we combined the WIYN imaging with previously published data from the and the Keck Observatory to help characterize the GC distribution in the central few kiloparsecs. We determine the radial distribution (surface density of GCs versus projected radius) of each galaxy's GC system and use it to calculate the total number of GCs (). We find = 490 ± 30, 210 ± 40, 175 ± 15, and 75 ± 10 for NGC1023, NGC1055, NGC7332, and NGC7339, respectively. We also calculate the GC specific frequency (N GC normalized by host galaxy luminosity or mass) and find values typical of those of the other spiral and E/S0 galaxies in the survey. The two lenticular galaxies have sufficient numbers of GC candidates for us to perform statistical tests for bimodality in the GC color distributions. We find evidence at a high confidence level (>95%) for two populations in the distribution of the GC system of NGC1023. We find weaker evidence for bimodality (>81% confidence) in the GC color distribution of NGC7332. Finally, we identify eight GC candidates that may be associated with the Magellanic dwarf galaxy NGC1023A, which is a satellite of NGC1023
Structure and dynamics of the interface between a binary hard-sphere crystal of NaCl type and its coexisting binary fluid
Molecular dynamics simulations are performed to study the [100] and [111]
orientations of the crystal-melt interface between an ordered two-component
hard sphere with a NaCl structure and its coexisting binary hard-sphere fluid.
The diameter ratio of the two types of hard spheres making up the mixture is
taken to be 0.414. This work complements our earlier interface simulations [J.
Chem. Phys.116, 3410] for the same diameter ratio at lower pressures where the
smaller component is immiscible in the solid and the fluid mixture coexists
with a pure FCC crystal of large particles. Density profiles and diffusion
coefficient profiles are presented for the AB interfacial system. We find that
for this system, the transition from crystal-like to fluid-like behavior of
both the density and diffusion constant profiles occurs over a narrower region
than that seen in our previous studies [J. Chem. Phys. 116, 3410] of the
FCC/binary fluid system. But similar to what was found in the FCC/binary fluid
interface the transition region for the large particle diffusion constant is
shifted about the size of the large particles toward the fluid phase relative
to that for the small particles.Comment: 8 page
Effects of 12 weeks nutrition education on nutritional status in hemodialysis patients
Protein-energy malnutrition is present in a large proportion of patients with end stage renal disease and, is a strong risk factor for mortality in these patients. This study was aimed to evaluate the effectiveness of 12-weeks nutrition education during the hemodialysis session for the improvement of nutritional status. From the June 2011 to the September 2011, patients who were on regular hemodialysis in Pusan National University Hospital were enrolled in this study. In education group, intensive nutrition education was performed by the hemodialysis nurse, for fifty to sixty minutes during the hemodialysis session, once a week. Curriculum for renal nutrition includes regular taking of their medication, intake of moderate amount of protein and sufficient calories, reduction of water, salt, potassium and phosphate intake. Otherwise, any education program was not performed in patients of control group. Nutrition status was assessed by the subjective global assessment (SGA),body mass index (BMI), triceps skinfold thickness (TSF), arm muscle area(AMC) and laboratory markers such as serum albumin, serum blood urea nitrogen(BUN) and hemoglobin(Hb) level before and after the education. Effect of nutrition education was analyzed using ANCOVA test. A total of 49 patients were enrolled in this study and nutrition education was provided to 25 hemodialysis patients. Their mean age was 57.20±15.49 in education group and 55.13±14.42 in control groupand male was 56.0% in education group and 50.0% in control group and, other baseline characteristics were not significantly different between two groups. After the 12-week education, significant improvement was found in SGA, serum albumin, BUN and Hb level. SGA score was improved from 6.36±0.99 to 6.72±0.61 in education group, compared to control group(6.38±0.88 to 6.42±0.88, p=0.029 ). Improvement of serum albumin level, BUN and Hb was as follows: serum albumin(4.23±0.28 to 4.30±0.25 in education group, 4.28±0.39 to 4.13±0.34 in control group, p=0.040), serum Hb(10.45±1.49 to 11.13±1.74 in education group, 10.51±1.12 to 10.04±1.02 in control group, P=0.004), serum BUN(66.52±18.76 to 70.94±17.26 in education group, 59.50±13.61 to 58.68±13.88 in control group, p=0.032). 12 week nutrition education during the hemodialysis session by hemodialysis nurse was effectiv
The Incidence of Gastro-Esophageal Disease for the Patients with Typical Chest Pain and a Normal Coronary Angiogram
Background : Although patients may present with typical chest pain and exhibit ischemic changes on the cardiac stress test, they are frequently found to have a normal coronary angiogram. Thus, we wanted to determine which procedures should be performed in order to make an adequate diagnosis of the cause of chest pain. Methods : 121 patients (males: 42, 34.7%) who had a normal coronary angiogram with typical chest pain were included in this study. All the patients underwent upper endoscopy, Bernstein's test and esophageal manometry. Results : Among the 121 patients, clinically stable angina was noted in 107 (88.4%). Stress testing was done in 82 (67.8%); it was positive in 52 (63.4%). Endoscopic findings were erosive gastritis in 18 (14.8%), gastric ulcer in 4 (3.3%), duodenal ulcer in 5 (4.1%), and reflux esophagitis in 16 (13.2%). Positive results were observed on Berstein's test for 68 patients (56.2%); 59 (86.8%) of them had non-erosive reflux disease. On the esophageal manometry, 35 (28.9%) of these patients had motility disorders. Nutcracker esophagus was observed in 27 patients (22.3%), nonspecific esophageal motility disorder was observed in 5 (4.1%), and hypertensive lower esophageal sphincter was observed in 3 (2.5%). Among the 52 patients with positive cardiac stress testing and a negative coronary angiogram (this clinically corresponded to microvascular angina), 46 patients (85.1%) showed abnormal findings on the gastro-esophageal studies. Conclusions : In our study, 85.1% of the patients with microvascular angina revealed positive results of gastric or esophageal disease. In spite of any existing evidence of microvascular angina or cardiac syndrome X, it would be more advisable to perform gastro-esophageal studies to adequately manage chest pain
Cognitive Effects of Low-dose Topiramate Compared with Oxcarbazepine in Epilepsy Patients
Background and Purpose: Low-dose topiramate (TPM) monotherapy has recently been found effective for seizure control in newly diagnosed epilepsy. In higher dosages, TPM has been associated with relatively high rates of adverse cognitive effects; similar side effects have been seen after rapid titration or polytherapy. However, its cognitive effects during low-dose monotherapy have not been established. We evaluated the cognitive effects of low-dose TPM compared with oxcarbazepine (OXC), a drug that does not appear to affect cognitive function. Methods: Cognitive tests and subjective complaints of 30 patients with low-dose TPM monotherapy (50-200 mg/day) were retrospectively compared with those of 30 patients with OXC monotherapy at 1 year of medication. The two groups did not differ with respect to epilepsy-relevant variables, nor on baseline neuropsychological tests. Results: The TPM group showed a significant difference in the performance of delayed word recall (P<0.05), backward digit span (P<0.01), and verbal fluency (P<0.05) compared with the OXC group. The TPM group showed worse performances of digit span and verbal fluency. The OXC group showed better performances of delayed word recall. The incidence of cognitive complaints was higher in the TPM group (50%) than in the OXC group (20%) (P< 0.05). These cognitive effects shown in the TPM group were dose-related. The cognitive dysfunction was trivial with patients taking 50 mg/day TPM. Conclusions: Even at low-dose, TPM has a negative effect on working memory and verbal fluency compared with OXC. It can be demonstrated at 1 year of treatment
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