11,673 research outputs found
Underlying Fermi surface of SrCaCuO in two-dimensional momentum space observed by angle-resolved photoemission spectroscopy
We have performed an angle-resolved photoemission study of the two-leg ladder
system SrCaCuO with = 0 and 11. "Underlying Fermi
surfaces" determined from low energy spectral weight mapping indicates the
quasi-one dimensional nature of the electronic structure. Energy gap caused by
the charge density wave has been observed for =0 and the gap tends to close
with Ca substitution. The absence of a quasi-particle peak even in =11 is in
contrast to the two-dimensional high- cuprates, implying strong carrier
localization related to the hole crystalization.Comment: 5 pages, 3 figure
ARPES studies of cuprate Fermiology: superconductivity, pseudogap, and quasiparticle dynamics
We present angle-resolved photoemission spectroscopy (ARPES) studies of the
cuprate high-temperature superconductors which elucidate the relation between
superconductivity and the pseudogap and highlight low-energy quasiparticle
dynamics in the superconducting state. Our experiments suggest that the
pseudogap and superconducting gap represent distinct states, which coexist
below T. Studies on Bi-2212 demonstrate that the near-nodal and
near-antinodal regions behave differently as a function of temperature and
doping, implying that different orders dominate in different momentum-space
regions. However, the ubiquity of sharp quasiparticles all around the Fermi
surface in Bi-2212 indicates that superconductivity extends into the
momentum-space region dominated by the pseudogap, revealing subtlety in this
dichotomy. In Bi-2201, the temperature dependence of antinodal spectra reveals
particle-hole asymmetry and anomalous spectral broadening, which may constrain
the explanation for the pseudogap. Recognizing that electron-boson coupling is
an important aspect of cuprate physics, we close with a discussion of the
multiple 'kinks' in the nodal dispersion. Understanding these may be important
to establishing which excitations are important to superconductivity.Comment: To appear in a focus issue on 'Fermiology of Cuprates' in New Journal
of Physic
Level-crossing rate and average duration of fades for mobile radio channel with hyperbolically distributed scatterers
In this paper we study the geometrical and time-variant wireless vector channel model with hyperbolically distributed scatterers for a macrocell mobile environment. In this study we investigate the level-crossing rate (LCR), the average duration of fades (ADF), the probability density function (PDF), the cumulative distribution function (CDF) and the autocorrelation functions (ACF) of this recently-proposed model. The simulated results are verified against the analytical Clarke's channel model. In this paper we study the geometrical and time-variant wireless vector channel model with hyperbolically distributed scatterers for a macrocell mobile environment. In this study we investigate the level-crossing rate (LCR), the average duration of fades (ADF), the probability density function (PDF), the cumulative distribution function (CDF) and the autocorrelation functions (ACF) of this recently-proposed model. The simulated results are verified against the analytical Clarke's channel model
Adherence to Gluten Free Diet in Pakistan-Role of Dietitian
Celiac disease (CD) is a common multi-system autoimmune disease, affecting approximately 1% of people worldwide 1. Predisposed individuals develop an immune response to gluten, a protein found in the cereal grains: wheat, barley and rye. Autoimmune intestinal damage is the cardinal feature of celiac disease, and typically involves villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes 2. Symptoms may be subclinical, varying from gastrointestinal upset to severe malabsorption 3,4. Skin, nervous system, and multisystem involvement is also recognized. Strict avoidance of gluten-containing foods can reverse both enteric and extra-intestinal manifestations of the disease
A novel approach in development of dynamic muscle model for paraplegic with functional electrical stimulation
This paper presents the development of paraplegic muscle model with Adaptive Neuro-Fuzzy Inference System (ANFIS). A series of experiments using Functional Electrical Stimulation (FES) with different stimulation frequencies, pulse width and pulse duration to investigate the impact on muscle output torque are conducted. The data that is obtained is used to develop the paraplegic muscle model. 500 training data and 300 testing data set are used in the development of muscle model. The muscle model thus developed is validated with clinical data from one paraplegic subject and in comparison with two other muscle models from previous researchers. The ANFIS muscle model is found to be the most accurate muscle model representing paraplegic muscle model. The established model is then used to predict the behaviour of the underlying system and will be used in the future for the design and evaluation of various control strategies
Recommended from our members
Exploring the interplay between passive following on Facebook, fear of missing out, self-esteem, social comparison, age, and life satisfaction in a community-based sample
Facebook is amongst the most frequently used Social Networking Sites (SNSs) worldwide. Previous research reported SNS use such as Facebook use may have both positive and negative psychological impact on users, particularly with regards to users' psychological wellbeing and life satisfaction. To fully acknowledge the extent to which SNS use may affect psychological wellbeing and life satisfaction, different forms of SNS use and experiences need to be taken into account by researchers. There is currently a lack of research investigating how Passive Facebook Use may impact on users' well being. The present study sought to investigate how passive following on Facebook, fear of missing out, self-esteem, social comparison, and age may affect life satisfaction. A sample of 196 Facebook users (Mean age = 31.16, SD = 8.75) completed an online survey consisting of several psychometric tools. Overall, the results obtained suggest that life satisfaction may be differentially affected by a wide range of SNS-related experiences such as social comparison and fear of missing out. The implications of these findings for the use of SNSs are discussed
Hyperforin: A lead for antidepressants
Depression is a complex but treatable disorder if diagnosed appropriately. However, despite the advances in the understanding of the molecular basis of this disorder and the vast range of medication, psychotherapy and electroconvulsive therapy, very safe and effective drug to treat this disease is still being sought. Several studies suggest that St.John’s wort (Hypericum perforatum L.) has phloroglucinol derivative, hyperforin, exhibiting antidepressant activity. This bioactive component can be exploited to create a major shift in the safer treatment of
depression.
Keywords: Hypericum perforatum L., St. John's wort, Antidepressant, Hyperfori
Water management reforms in the Yellow River Basin: implications for water savings, farm incomes and poverty
River basins / Water management / Governance / Water use / Crop production / Models / Farm income / Poverty / Water users’ associations / China / Yellow River Basin
Estimation of volatile organic compounds in farmed and wild rohu, Labeo rohita
Volatile organic compounds in farmed and wild rohu, Labeo rohita, were extracted by Likens-Nickerson concurrent distillation apparatus. The farmed raised rohu of two weight categories designated as FW1 (1001-1200g) and FW2 (501-700g) were procured from the Fish Seed Hatchery, Faisalabad. Concurrently, wild rohu of two weight categories designated as WW1 (1001-1200g) and WW2 (501-700g) were captured with gillnet from the Trimu Head. Quantitative and qualitative estimation was made by gas chromatography. In farmed and wild L. rohita of the weight group FW1 and WW1, 14 and 6 volatile compounds were extracted, respectively. In weight group FW1, six compounds were identified as 3-methyl-1-butanol, 3-hexene-1-ol, heptanal, 3-octanol, decanal and 2-undecanone. In weight group WW1, out of six compounds three were identified as heptanal, 1-octen-3-ol, 2-nonanone. In weight categories FW2 and WW2, 14 and 13 volatile compounds were detected, respectively. In weight category FW2, out of 14 compounds, 3-hexene-1-ol, heptanal, 3-octanol, 2-undecanone and decanal were identified. In weight category WW2, out of 13 compounds, 7 were identified as 3-methyl-1-butanol, 2-heptanone, heptanal, 3-octanol, 2-nonanone, decanal and 2-undecanone. The analysis of variance for retention time and concentration of volatile compounds showed no significant difference (p>0.05). The correlation coefficient between retention time and concentration was significant (p< 0.05)
- …