7,222 research outputs found
Autoionization in time-dependent density-functional theory
We compute the exact exchange-correlation potential of the time-dependent density-functional theory (TDDFT) for the correlated process of autoionization. The potential develops barriers which regulate the autoionization rate. TDDFT employing known and practicable exchange-correlation potentials does not capture any autoionization dynamics. Approximate exchange-correlation potentials capturing such dynamics would necessarily require memory effects and are unlikely to be developed, as will be illustrated
Location and welfare in cities: impacts of policy interventions on the urban poor
Informal settlements are an integral part of the urban landscape in developing countries. These settlements are widely distributed within cities, including central business centers and peripheral areas with environment hazards. In most cases, residents of these settlements do not have access to basic public services and amenities. In this paper, the authors examine the impact of interventions, such as upgrading basic services and resettlement policies, on the welfare of residents of these informal settlements, who are typically the urban poor. To examine these interventions, they estimate models of residential location choice and allow households to be sensitive to commuting costs to work, demand for public services, and preferences for community composition. The authors'empirical analysis is based on recently collected survey data from Pune, India, and shows that poor households prefer to live close to work and in communities that consist of people sharing common socio-demographic characteristics. From the perspective of households living in informal settlements, upgrading settlements in the original place is welfare enhancing. If a household must be relocated, it greatly prefers to be moved to a community that resembles its current community.Municipal Financial Management,Public Health Promotion,Decentralization,Housing&Human Habitats,Urban Services to the Poor,Municipal Financial Management,Housing&Human Habitats,VN-Acb Mis -- IFC-00535908,Urban Housing,City Development Strategies
Determination and Correlation of Anticardiolipin Antibody with High Sensitivity C- reactive Proteins and its Role in Predicting Short Term Outcome in Patients with Acute Coronary Syndrome
Anticardiolipin antibody (aCL) is considered to be an independent risk factor while high sensitivity C reactive protein (hsCRP) is an established marker for coronary artery disease. This study was conducted to determine levels of aCL antibodies and hsCRP, their correlation and role in predicting recurrence of events in patients presenting with Acute Coronary Syndrome (ACS). Sixty patients admitted with Acute Coronary Syndrome were followed up for 7 days or until discharge. Patients were classified into two groups as those having experienced an ischemic event needing intervention within 7 days (Group I) and other having an event free recovery (Group II). aCL antibody and hsCRP levels were estimated and compared in these two groups. Twenty age and sex matched disease free persons served as controls. The levels of aCL were significantly higher in patients with ACS as compared to the controls (p=0.020). However the levels of aCL in Group I (13.39±9.46 GPL-U/ml) and Group II (13.51±9.93 GPL-U/ml) were not significantly different (p =0.838). The mean hsCRP levels were higher in cases with an event (23.30±10.68 mg/dl) than in cases without an event (20.60±11.45mg/dl) though it was not significant statistically (p=0.389). aCL and CRP were not found to be significantly correlated in causing the recurrence of events(p=0.178). Therefore anticardiolipin antibody is an independent risk factor which could be implicated in the pathogenesis of ACS. However it is not significantly associated with recurrence of short-term events in patients with ACS. Also, aCL antibody does not have significant correlation with hSCRP in causing recurrence of events in the patients of acute coronary syndrome
The Band Gap in Silicon Nanocrystallites
The gap in semiconductor nanocrystallites has been extensively studied both
theoretically and experimentally over the last two decades. We have compared a
recent ``state-of-the-art'' theoretical calculation with a recent
``state-of-the-art'' experimental observation of the gap in Si nanocrystallite.
We find that the two are in substantial disagreement, with the disagreement
being more pronounced at smaller sizes. Theoretical calculations appear to
over-estimate the gap. Recognizing that the experimental observations are for a
distribution of crystallite sizes, we proffer a phenomenological model to
reconcile the theory with the experiment. We suggest that similar
considerations must dictate comparisons between the theory and experiment
vis-a-vis other properties such as radiative rate, decay constant, absorption
coefficient, etc.Comment: 5 pages, latex, 2 figures. (Submitted Physical Review B
C-band superconductor/semiconductor hybrid field-effect transistor amplifier on a LaAlO3 substrate
A single-stage C-band superconductor/semiconductor hybrid field-effect transistor amplifier was designed, fabricated, and tested at 77 K. The large area (1 inch x 0.5 inches) high temperature superconducting Tl-Ba-Ca-Cu-O (TBCCO) thin film was rf magnetron sputtered onto a LaAlO3 substrate. The film had a transition temperature of about 92 K after it was patterned and etched. The amplifier showed a gain of 6 dB and a 3 dB bandwidth of 100 MHz centered at 7.9 GHz. An identical gold amplifier circuit was tested at 77 K, and these results are compared with those from the hybrid amplifier
Prospective Randomized Trial Comparing Endoscopic Sphincterotomy Followed by Surgery with Surgery Alone in Good Risk Patients with Choledocholithiasis
Background: Role of endoscopic sphincterotomy (ES) in high risk patients with choledocholithiasis is established but its role in good risk patients is unclear
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