Solution of Algebraic Lyapunov Equation on Positive-Definite Hermitian Matrices by Using Extended Hamiltonian Algorithm

This communique is opted to study the approximate solution of the Algebraic Lyapunov equation on the manifold of positive-definite Hermitian matrices. We choose the geodesic distance between -AHX - XA and P as the cost function, and put forward the Extended Hamiltonian algorithm (EHA) and Natural gradient algorithm (NGA) for the solution. Finally, several numerical experiments give you an idea about the effectiveness of the proposed algorithms. We also show the comparison between these two algorithms EHA and NGA. Obtained results are provided and analyzed graphically. We also conclude that the extended Hamiltonian algorithm has better convergence speed than the natural gradient algorithm, whereas the trajectory of the solution matrix is optimal in case of Natural gradient algorithm (NGA) as compared to Extended Hamiltonian Algorithm (EHA). The aim of this paper is to show that the Extended Hamiltonian algorithm (EHA) has superior convergence properties as compared to Natural gradient algorithm (NGA). Upto the best of author’s knowledge, no approximate solution of the Algebraic Lyapunov equation on the manifold of positive-definite Hermitian matrices is found so far in the literature.     

Novel tunable dynamic tweezers using dark-bright soliton collision control in an optical add/drop filter

We propose a novel system of the dynamic optical tweezers generated by a dark soliton in the fiber optic loop. A dark soliton known as an optical tweezer is amplified and tuned within the microring resonator system. The required tunable tweezers with different widths and powers can be controlled. The analysis of dark-bright soliton conversion using a dark soliton pulse propagating within a microring resonator system is analyzed. The dynamic behaviors of soliton conversion in add/drop filter is also analyzed. The control dark soliton is input into the system via the add port of the add/drop filter. The dynamic behavior of the dark-bright soliton conversion is observed. The required stable signal is obtained via a drop and throughput ports of the add/drop filter with some suitable parameters. In application, the trapped light/atom and transportation can be realized by using the proposed system.     

A comparative study on estimating the landfill gas potential: Modeling and analysis

The main objective of this study is to investigate the use of the landfill gas as potential energy and electricity obtained from the municipal solid waste (domestic, industrial, medical waste, and sewage sludge) stored regularly in the Harmandali solid waste landfill area, within the boundaries of the contiguous area of Izmir. The most important factor in making a decision about energy potential in the landfill is the amount of methane in the landfill gas. There are several approaches that have been used to determine the amount of the landfill gas. In this study, three different methods and one approach in the literature were used for this purpose. The methods used are the Multi-Phase, the LandGEM, and the IPCC 2006. The results of the landfill gas obtained using the three methods, namely the Multi-Phase, the LandGEM (k = 0.35, k = 0.1, and k = 0.05), and the IPCC 2006, were as follows, respectively: 291897215, 792073359, 769734749, 681685027, and 491752247 m³. It may be concluded that the Harmandali Landfill has high landfill gas potential based on the measurements and mathematical methods used in the Harmandali landfill.     

TEMPERATURE AND STRESS FIELDS IN SILVER DUE TO LASER PICOSECOND HEATING PULSE

Laser short-pulse heating of metallic surfaces is involved with nonequilibrium energy transport in the region irradiated by a laser beam. In this case, the Fourier heating model fails to predict correct temperature rise in this region. Moreover, for completeness of analysis, the thermomechanical coupling needs to be incorporated in the governing equations. In the present study, electron kinetic theory approach is introduced to model the heating process and thermomechanical coupling is formulated and accommodated in the energy transport equation. Temperature and stress fields are computed numerically for silver. It is found that electron temperature well in excess of lattice site temperature occurs in the surface vicinity of the substrate material. Although lattice site temperature rise is low (~170°C), stress levels as high 3 2 10 8 Pa are computed in the region heated by a laser beam. The thermal expansion of the surface at the irradiated spot center reaches 0.5 nm after 4 ns of the heating period.     

DNA Barcodes of Asian Houbara Bustard (Chlamydotis undulata macqueenii)

Populations of Houbara Bustards have dramatically declined in recent years. Captive breeding and reintroduction programs have had limited success in reviving population numbers and thus new technological solutions involving molecular methods are essential for the long term survival of this species. In this study, we sequenced the 694 bp segment of COI gene of the four specimens of Asian Houbara Bustard (Chlamydotis undulata macqueenii). We also compared these sequences with earlier published barcodes of 11 individuals comprising different families of the orders Gruiformes, Ciconiiformes, Podicipediformes and Crocodylia (out group). The pair-wise sequence comparison showed a total of 254 variable sites across all the 15 sequences from different taxa. Three of the four specimens of Houbara Bustard had an identical sequence of COI gene and one individual showed a single nucleotide difference (G > A transition at position 83). Within the bustard family (Otididae), comparison among the three species (Asian Houbara Bustard, Great Bustard (Otis tarda) and the Little Bustard (Tetrax tetrax)), representing three different genera, showed 116 variable sites. For another family (Rallidae), the intra-family variable sites among the individuals of four different genera were found to be 146. The COI genetic distances among the 15 individuals varied from 0.000 to 0.431. Phylogenetic analysis using 619 bp nucleotide segment of COI clearly discriminated all the species representing different genera, families and orders. All the four specimens of Houbara Bustard formed a single clade and are clearly separated from other two individuals of the same family (Otis tarda and Tetrax tetrax). The nucleotide sequence of partial segment of COI gene effectively discriminated the closely related species. This is the first study reporting the barcodes of Houbara Bustard and would be helpful in future molecular studies, particularly for the conservation of this threatened bird in Saudi Arabia.     

Prevalence and correlates of smoking on the roof of the world

OBJECTIVE—To determine the prevalence and correlates of cigarette smoking among adults in high mountain rural areas of northern Pakistan.
DESIGN—Cross sectional survey.
PARTICIPANTS—A sample of 4203 adults (aged 18 years and over) were selected by stratified random sampling from 16 villages.
MAIN OUTCOME MEASURE—Self reported smoking prevalence; age of smoking initiation; daily cigarette consumption and association between current smoking and sociodemographic variables, use of snuff, wine, body mass index, blood pressure, family history of stroke, and hypertension.
RESULTS—614/1406 men (43.7%) and 154/2797 (5.5%) women reported smoking cigarettes. The age standardised prevalence of smoking was 40.5% for men and 6.3% for women. Men were more likely (odds ratio (OR) 6.5, 95% confidence interval (CI) 4.75 to 8.79) to be smokers. Smokers were more likely to use snuff (OR 1.39, 95% CI 1.12 to 1.73), drink wine (OR 3.47, 95% CI 2.81 to 4.29), and were more likely to work as farmers (OR 1.55, 95% CI 1.05 to 2.29) or shopkeepers (OR 2.63, 95% CI 1.67 to 4.14). Individuals with college level education and with desirable body mass index were less likely to smoke (OR 0.55, 95% CI 0.35 to 0.87; OR 0.74, 95% CI 0.57 to 0.96).
CONCLUSION—Cigarette smoking is a major public health problem in this high mountain community of Pakistan, particularly among the male population, the majority of whom begin to smoke quite early in life. A comprehensive tobacco control effort incorporated into the existing community based health infrastructure is needed.


Keywords: Pakistan; prevalence of smoking     

A copper based metal-organic framework as single source for the synthesis of electrode materials for high-performance supercapacitors and glucose sensing applications

The article describes the conversion of MOF-199 to Cu–Cu₂O–CuO/C 700 (1) and Cu–Cu₂O–CuO/C 800 (2) nanostructures by simple pyrolysis at 700 and 800 °C under inert atmosphere. The X-ray photoelectron spectroscopy analysis reveals that the nanostructures Cu–Cu₂O–CuO/C consist of graphitic carbon functionalized with carboxylic, carbonyl and hydroxyl functional groups with copper/copper oxide particles on surfaces. The electrochemical properties of 1 and 2 are evaluated as electrode material for supercapacitors using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results for the capacitive performance from cyclic voltammetry and galvanostatic charge/discharge reveal that both the samples have gravimetric capacitance greater than 750 F g⁻¹ at a scan rate of 2 mV s⁻¹ and current density of 2 mA cm⁻². The samples retain about 43% of their initial capacitance even at high scan rate of 75 mV s⁻¹. The cycling performance of the nanostructures illustrate that there is 5.5% capacitance loss after 3000 cycles. The sample 1 and 2 are washed with 1 mol L⁻¹ HCl solution to obtain copper oxide free materials Cu/C 700 (3) and Cu/C 800 (4). Samples 3 and 4 are tested as electrocatalysts for glucose sensing and the cyclic voltammetry measurement shows enhanced current densities compared to the literature values.