1,697 research outputs found
Log-Domain Current-mode Quadrature Sinusoidal Oscillator
A log-domain current-mode quadrature sinusoidal oscillator based on lossless integrators is presented. The circuit is a direct realization of a first-order differential equation for obtaining the lossy and lossless integrators. Each of the log-domain lossless integrators is realized by using only NPN transistors and a grounded capacitor for achieving low-power and fast response. The proposed oscillator uses two-lossless integrator loop which can be electronically tuned through bias currents. A validated BJT model which is used in SPICE simulation operated from a single power supply as low as 2.5V. The oscillation frequency is controlled over four decades of frequency. The total harmonic distortions for two-phases QSO (12MHz) is obtained around 0.93% which enables fully integrated in telecommunication systems. The proposed circuit is also suitable for high-frequency applications. Nonideality studies are included and PSpice simulation results confirm the theoretical results
MulPSSM: a database of multiple position-specific scoring matrices of protein domain families
Representation of multiple sequence alignments of protein families in terms of position-specific scoring matrices (PSSMs) is commonly used in the detection of remote homologues. A PSSM is generated with respect to one of the sequences involved in the multiple sequence alignment as a reference. We have shown recently that the use of multiple PSSMs corresponding to an alignment, with several sequences in the family used as reference, improves the sensitivity of the remote homology detection dramatically. MulPSSM contains PSSMs for a large number of sequence and structural families of protein domains with multiple PSSMs for every family. The approach involves use of a clustering algorithm to identify most distinct sequences corresponding to a family. With each one of the distinct sequences as reference, multiple PSSMs have been generated. The current release of MulPSSM contains ∼33 000 and ∼38 000 PSSMs corresponding to 7868 sequence and 2625 structural families. A RPS_BLAST interface allows sequence search against PSSMs of sequence or structural families or both. An analysis interface allows display and convenient navigation of alignments and domain hits. MulPSSM can be accessed at
ROLE OF PANCHAKARMA IN RESTLESS LEG SYNDROME - A CASE STUDY
Restless leg syndrome (RLS) is common medical condition, which is characterized by unpleasant leg sensation that is eased by movement (Motor restlessness). It has a strong familial tendency and can present with day time somnolence due to poor sleep. A need to move the legs usually accompanied or caused by uncomfortable, unpleasant sensation in legs, which worsens during period of rest or being inactivity such as lying or sitting. It generally worsens only during evening or night and relieves partially by movement such as walking or stretching, which are the diagnostic criteria of RLS. As it is a syndrome, it cannot be co-related to a single disease in Ayurveda. In RLS both Sensory and Motor changes takes place which is governed by Vatadosha, where sensation can be considered as Sensory thing (Gandana) and Movement is a Motor thing (Gati) which comes in responses to Sensory thing. When there is imbalance between the same, it can causes disturbances related both Sensory and Motor responses. Vrudha Vayu due to Nidana causes different types of Shula. Pain that aggravates during nights and Sheetha kala shows its predominancy. Pindikodweshtana appreciated in the case can also be considered under Nanatmaja Vatavyadhi. Thus by considering all these, it can be included under the broad heading of Vata vyadhi. Amapachana followed by Samanya Vatavyadhi Chikitsa in the form of Rukshana karma followed Snehana and Swedana were the treatment modalities adopted in the case, which showed significant improvements in all the symptoms patients had
Spectral Efficiency Maximization of a Single Cell Massive MU-MIMO Down-Link TDD System by Appropriate Resource Allocation
This paper deals with the problem of maximizing the spectral efficiency in a massive multi-user MIMO downlink system, where a base station is equipped with a very large number of antennas and serves single-antenna users simultaneously in the same frequency band, and the beamforming training scheme is employed in the time-division duplex mode. An optimal resource allocation that jointly selects the training duration on uplink transmission, the training signal power on downlink transmission, the training signal power on uplink transmission, and the data signal power on downlink transmission is proposed in such a way that the spectral efficiency is maximized given the total energy budget. Since the spectral efficiency is the main concern of this work, and its calculation using the lower bound on the achievable rate is computationally very intensive, in this paper, we also derive approximate expressions for the lower bound of achievable downlink rate for the maximum ratio transmission (MRT) and zero-forcing (ZF) precoders. The computational simplicity and accuracy of the approximate expressions for the lower bound of achievable downlink rate are validated through simulations. By employing these approximate expressions, experiments are conducted to obtain the spectral efficiency of the massive MIMO downlink time-division duplexing system with the optimal resource allocation and that of the beamforming training scheme. It is shown that the spectral efficiency of the former system using the optimal resource allocation is superior to that yielded by the latter scheme in the cases of both MRT and ZF precoders
No Eigenvalue in Finite Quantum Electrodynamics
We re-examine Quantum Electrodynamics (QED) with massless electron as a
finite quantum field theory as advocated by Gell-Mann-Low, Baker-Johnson,
Adler, Jackiw and others. We analyze the Dyson-Schwinger equation satisfied by
the massless electron in finite QED and conclude that the theory admits no
nontrivial eigenvalue for the fine structure constant.Comment: 13 pages, Late
Influence of mastication and its relationship with Body Mass Index before and after prosthetic rehabilitation in partially edentulous patients
BACKGROUND: The main purpose of prosthetic rehabilitation is to enhance the masticatory function by replacing the missing teeth with an artificial substitute, which improves nutrient-rich food intake. There are recent studies which indicate the influence of chewing behavior and energy intake, but little is known about the relationship between chewing on nutritional status. OBJECTIVE: This study intended to assess the changes in masticatory efficiency before and after prosthetic rehabilitation and its influence on nutritional status and body weight. METHODS: A total of 40 partially edentulous subjects aged between 45- 65 years were recruited. Body Mass Index was determined by measuring body weight using a medical grade weighing scale. Height was measured using wall mounted stature meter and Waist circumference was measured with an anthropometric measure tape. Masticatory efficiency was determined using the sieve method with peanuts as test food at baseline, at 3 and 6 months of prosthetic rehabilitation with a removable partial denture. RESULTS: Sieve test performed for evaluating masticatory efficiency showed an increase in the percentage of smaller particles by 28.3% in non-obese and 32.15% in the obese group. The obese/overweight group showed a decrease in BMI values and non-obese subjects showed no significant change in BMI.
CONCLUSION: The study concluded that improving masticatory efficiency by prosthodontic rehabilitation can aid in normalizing the nutritional status in certain partially edentulous non-obese and obese individuals
Performance Improvement of a Centrifugal Compressor by Passive Means
The present experimental investigation deals with performance improvement of a low-speed centrifugal compressor by inexpensive passive means such as turbulence generator placed at different positions and partial shroud near the rotor blade tip. The experiments are carried out at three values of tip clearance, namely 2.2%, 5.1%, and 7.9% of rotor blade height at the exit. Performance tests are carried out for a total of 13 configurations. From these measurements, partial shroud is found to give the best performance. The improvement in the compressor performance may be due to the reduction of tip leakage flows by the small extension of partial shroud (2 mm on the pressure surface side). Although there is nominal change in performance due to turbulence generator (TG), TG has beneficial effect of increased operating range
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