Transient analysis of a Markovian Single Vacation Feedback Queue with an Interrupted Closedown Time and Control of Admission During Vacation

This paper analyzes the transient behavior of an M/M/1 queueing model with single vacation, feedback, interrupted closedown time and control of admission during vacation. The time-dependent system size probabilities for the proposed model are obtained using generating function in the closed form. Further, the system performance measures like mean and variance of system size are also obtained for the time-dependent case. Finally, numerical illustrations are presented to understand the effect for various system parameters

Analysis of Batch Arrival Single and Bulk Service Queue with Multiple Vacation Closedown and Repair

In this paper, we analyze batch arrival single and bulk service queueing model with multiple vacation, closedown and repair. The single server provides single service if the queue size is ‘\u3c a’ and bulk service if the queue size is ‘ ≥ a’. After completing the service (single or bulk), the server may breakdown with probability ξ and then it will be sent for repair. When the system becomes empty or the server is ready to serve after the repair but no one is waiting, the server resumes closedown and then goes for a multiple vacation of random length. Using supplementary variable technique, the steady-state probability generating function (PGF) of the queue size at an arbitrary time is obtained. The performance measures and cost model are also derived. Numerical illustrations are presented to visualize the effect of system parameters

Performance Analysis of an M/M/1 Queue with N-policy Interrupted Closedown Preventive Maintenance Balking and Feedback

This paper investigates the transient and stationary behavior of a M/M/1 queueing model with N-policy, interrupted closedown, balking, feedback and preventive maintenance. The server stays dormant (off state) until N customers accumulate in the queue and then starts an exhaustive service (on state). After the service, each customer may either leave the system or get immediate feedback. When the system becomes empty, the server resumes closedown. If any arrival occurs before the completion of closedown time, the closedown work of the server is interrupted and starts the busy period in an exhaustive manner. If no arrival occurs during the closedown time, the server commences preventive maintenance work. When this period ends, the server moves to the idle state and waits N accumulate for service. When the Nth one enters the queue, the server starts the service. The customers may either join the queue or balk when the size of the system is less than N and the server is in off state. The transient and stationary system size probabilities of the proposed model are derived by the method of generating function. Some system performance indices are computed and the numerical simulations are also presented

Analysis of batch arrival bulk service queue with multiple vacation closedown essential and optional repair

The objective of this paper is to analyze an queueing model with multiple vacation, closedown, essential and optional repair. Whenever the queue size is less than , the server starts closedown and then goes to multiple vacation. This process continues until at least customer is waiting in the queue. Breakdown may occur with probability when the server is busy. After finishing a batch of service, if the server gets breakdown with a probability , the server will be sent for repair. After the completion of the first essential repair, the server is sent to the second optional repair with probability . After repair (first or second) or if there is no breakdown with probability , the server resumes closedown if less than ` \u27 customers are waiting. Otherwise, the server starts the service under the general bulk service rule. Using supplementary variable technique, the probability generating function of the queue size at an arbitrary time is obtained for the steady-state case. Also some performance measures and cost model are derived. Numerical illustrations are presented to visualize the effect of various system parameters

Isolation, purification, characterization and applications of serine protease from Bacillus megaterium

Bacillus megaterium isolated from poultry farm soil was identified by standard biochemical tests and screened for the production of serine protease. Production of serine protease was done using 5 different medias by varying the type of amino acid added. The purification was done by salt precipitation, dialysis and DEAEcellulose ion exchange chromatography. The proline containing media obtained the highest fold purification out of the five different medias (leucine, lysine, proline, tryptophan and methionine cotaining media). The enzyme showedan optimal activity at the temperature 37°C and the pH 6 which are known as its optimum temperature and pH respectively. The enzyme was proved as a Mn2+ dependent serine protease as it was activated by Mn2+ ions and inhibited by PMSF. The molecular weight of the enzyme was determined by SDS-PAGE technique as around 30kDa. It showed an excellent detergent activity on the blood stains and a very good stability in presence of locally available detrgents. The enzyme acted on the keratin protein of the chicken feather and showed a degrading capacity on the protein. So it was proved that the recently studied serine protease has a keratinase activity also. From these datas I conclude that the protease isolated from Bacillus megaterium is a Mn2+ dependent serine protease which has both keratinase and detergent activity

Growth, Laser Raman, Thermal, Edax and Photoluminescence Studies of Pure and Calcium Doped Zinc Hydrogen Phosphate Crystals Using Single Diffusion Technique

Growth aspects of pure and Calcium doped Zinc hydrogen phosphate single crystals from silica gel by the process of single diffusion technique are discussed. Crystals with different morphologies and effect on various parameters like gel pH, and gel ageing, gel density and concentration of reactants on the growth of pure and Calcium doped ZnHPO4 crystals were studied. Laser Raman spectra of the pure and Calcium doped ZnHPO4 crystals are recorded and the vibrational assignments have been made with possible explanations. Thermo gravimetrical analysis is undertaken to study the thermal stability of the grown crystals. The photoluminescence measurement shows that the material is suitable for photonic devices. The crystals grown were characterized by Laser Raman spectrum, TG/DTA, EDAX and Photoluminescence

Spectrally efficient multicarrier modulation system for visible light communication

Visible Light Communication (VLC) has become an accolade to its radio frequency counterpart. In VLC system, orthogonal frequency division multiplexing (OFDM) has drawn much attention, because of simple equalization, high spectral efficiency, high data rate and robustness to intersymbol interference (ISI). Besides, there are emerging applications that ought to be gotten with low latency and high reliability. To diminish power requirements with no transmission capacity extension, Trellis coded modulation (TCM) is utilized as a part of the framework in which the free distance of trellis diagram is equivalent to the minimum distance between the points of constellation focuses in partitioned subsets, which augments the coding gain up i.e. the performance parameter viably. TCM together with VLC-OFDM enhances the transmission execution in reasonable frameworks. In this paper, we propose OFDM which is based on TCM and is planned and exeuted for digitized OFDM frameworks by presenting delta sigma modulation (DSM) considering VLC channel. Simulation results show that the proposed TCM based VLC-OFDM offers incredible robustness against noises and nonlinear degradation

Superconductivity and Lattice Instability in Compressed Lithium from Fermi Surface Hot Spots

The highest superconducting temperature T$_c$ observed in any elemental metal (Li with T$_c$ ~ 20 K at pressure P ~ 40 GPa) is shown to arise from critical (formally divergent) electron-phonon coupling to the transverse T$_1$ phonon branch along intersections of Kohn anomaly surfaces with the Fermi surface. First principles linear response calculations of the phonon spectrum and spectral function $\alpha^2 F(\omega)$ reveal (harmonic) instability already at 25 GPa. Our results imply that the fcc phase is anharmonically stabilized in the 25-38 GPa range.Comment: 4 pages, 3 embedded figure

A Study on Role of Transdermal Nitroglycerine in Preterm Labour

BACKGROUND: The incidence of preterm labour in India is from 10-15% contributing to 40-45% of preterm births which could be managed by use of tocolytics. Goal of using tocolytics is to prolong the pregnancy to provide time to have the advantage of steroid therapy for improving fetal lung maturity and to transfer the fetus in utero from periphery to a tertiary care where NICU is available. Use of transdermal nitroglycerine can arrest preterm labour and thereby reduce neonatal morbidity and mortality. OBJECTIVES: The study aims to assess the role of “TransDermal Nitroglycerine Patch” (10 mg) in treatment of preterm labour. 1. To determine maternal outcome in terms of successful tocolysis thereby prolonging the duration of period of gestation required for fetal lung maturation. 2. To assess fetal outcome in terms of fetal distress, APGAR score < 7 at 5 minutes, resuscitation required, respiratory distress syndrome, NICU admission, mechanical ventilation required and neonatal death in the antenatal pregnant population with preterm labour pain at Government Coimbatore Medical College Hospital, Coimbatore, Tamilnadu. 3. To assess role, side effects, safety, tolerance and acceptance of the drug. METHODOLOGY: All patients with preterm labour being admitted at labour ward in Government Coimbatore Medical College Hospital based on inclusion and exclusion criteria will be enrolled in study. After application of patch, patients are monitored for contractions and fetal well being. Vitals are measured and the results were entered in data collection sheet. Maternal side effects and neonatal outcome with respect to APGAR scores and NICU admissions were measured. RESULTS: Out of the 100 patients studied 44 patients were Primi Gravita and 39 patients belonged to the age group of 26-30 years. Most of the patients (50%) presented at the gestational age of 31-33 weeks and there was a mean prolongation of pregnancy by 27.5 days. Neonatal outcome was better with greater APGAR scores and less NICU admissions. CONCLUSION: In this study conducted in Coimbatore Medical College Hospital by using Transdermal Nitroglycerine Patch as a Tocolytic in preterm labour it was found that success rate defined by Tocolysis achieved for 48 hours, providing time for action of Cortico steroids was found to be 94% with very minimal maternal side effects