Scaling behavior of a one-dimensional correlated disordered electronic System

A one-dimensional diagonal tight binding electronic system with correlated disorder is investigated. The correlation of the random potential is exponentially decaying with distance and its correlation length diverges as the concentration of "wrong sign" approaches to 1 or 0. The correlated random number sequence can be generated easily with a binary sequence similar to that of a one-dimensional spin glass system. The localization length (LL) and the integrated density of states (IDOS) for long chains are computed. A comparison with numerical results is made with the recently developed scaling technique results. The Coherent Potential Approximation (CPA) is also adopted to obtain scaling functions for both the LL and the IDOS. We confirmed that the scaling functions show a crossover near the band edge and establish their relation to the concentration. For concentrations near to 0 or 1 (longer correlation length case), the scaling behavior is followed only for a very limited range of the potential strengths.Comment: will appear in PR

Effects of petroleum ether, ethanol and aqueous extracts of indigofera capitata on oedema induced activity of naja nigricollis venom in envenomed rats

The growing demand for herbal products has led to high increase of plant material traded across the world. Indigofera species provide some of these plants’ materials. Indigofera capitata is a plant of the family Fabaceae. The acute toxicity and effects pet.ether, ethanol and aqueous extracts of the plant were carried out in albino rats. The results of acute toxicity studied revealed that pet.ether, ethanol and aqueous extracts had LD50 values of 774.6, 1131.4 and 3807.8mg/kg respectively. These helped to determine the safeness and dosage used for in vivo activity of each extract. The results of the effects of the extracts indicated all the plant extracts had significant (p<0.05) and dose-dependent Oedema forming activity against LD99 Naja nigricollis envenomed rats. Highest reduction in edema forming activity of the extract are shown at dose of 300mg/kg(ethanol) and 1000mg/kg (aqueous) with lowest edema forming activity of 108.00±1.90 and 102.00±1.90 (% mm) respectively compared with the positive control group. The finding revealed that the plant can be used for treatment of snake bite more especially Naja nigricollis bite

Use of an approximate similarity principle for the thermal scaling of a full-scale thrust augmenting ejector

Full temperature ejector model simulations are expensive, and difficult to implement experimentally. If an approximate similarity principle could be established, properly chosen performance parameters should be similar for both hot and cold flow tests if the initial Mach number and total pressures of the flow field are held constant. Existing ejector data is used to explore the utility of one particular similarity principle; the Munk and Prim similarity principle for isentropic flows. Static performance test data for a full-scale thrust augmenting ejector are analyzed for primary flow temperatures up to 1560 R. At different primary temperatures, exit pressure contours are compared for similarity. A nondimensional flow parameter is then used to eliminate primary nozzle temperature dependence and verify similarity between the hot and cold flow experiments

Peranan Kota Bogor, Depok, Tangerang, Bekasi, dan Cianjur (Bodetabekjur) dalam Menyokong Pembangunan Kota Jakarta

Kawasan Jakarta, Bogor, Depok, Tangerang, Bekasi, Puncak, Cianjur, yang selanjutnya disebut sebagai Kawasan Jabodetabekpunjur, adalah kawasan strategis nasional yang meliputi seluruh wilayah Provinsi Daerah Khusus Ibukota Jakarta, sebagian wilayah Provinsi Jawa Barat, dan sebagian wilayah Provinsi Banten (Perpres. No. 54 tahun 2008). Tujuan penelitian ini adalah (1) mengidentifikasi sektor unggulan perekonomian wilayah kabupaten/kota di Kawasan Jabodetabekjur serta; (2) mengidentifikasi peranan kabupaten/kota sekitar (Bogor, Depok, Tangerang, Bekasi, Puncak, Cianjur) terhadap pembangunan fisik infrastuktur Kota Jakarta. Penelitian ini menggunakan metode wawancara terhadap 3 responden yang merupakan penentu kebijakan pembangunan di Kota Jakarta. Teknik analisis yang digunakan adalah deskriptif kuantitatif dan kualitatif. Hasil penelitian menunjukkan bahwa setiap kota di Jabodetabekjur dan Kabupaten Cianjur memiliki sektor basis yang didominasi oleh sektor tersier. Kabupaten sisanya memiliki sektor unggulan pada sektor primer dan sektor sekunder. Peranan utama dari kabupaten/kota pada Bodetabekjur adalah pembangunan transportasi massal, peningkatan kapasitas jalan

Is Sustainable Development of Deserts Feasible?

Hot deserts that presently cover about one-fifth of the land area of our planet are rapidly devouring more and more arable lands mostly due to anthropogenic causes. We propose an interdisciplinary approach to revitalizing and commercializing hot deserts, which is based on systems thinking and Russian and NASA space technology experience in designing life-support systems for long-duration flights. We formulate ten principles for the design of sustainable life support systems in deserts, which can make the development of the deserts feasible. It is discussed how the principles can be employed to design and operate desert’s eco-industrial parks with greenhouses in which the transpired and evaporated moisture is collected and condensed. The potential benefits of setting up the eco-industrial parks in deserts include the slowdown and eventual reversal of the desertification trend, the migration of many industrial production facilities from mild-climate regions to deserts, the increased availability of potable water and food in deserts, the development of poor African countries, and the emergence of new investment markets

Febrile seizures: Factors affecting risk of recurrence in Pakistani children presenting at the Aga Khan University Hospital

Objectives: To (a) describe the effect of temperature rise on seizure recurrence in the ER (b) investigate the effect of age, gender, family and developmental history, type, duration and multiple seizures, past history and number of seizures and treatment given (either late or early) on seizure recurrence in the ER and (c) explore prognostic indicators for seizure recurrence.Methods: Data from 352 children [ages 3-84 months; 220 males (62.5%) 132 females (37.5%)] was taken using chart reviews for the years January 1998-August 2000 inclusive, from the Pediatric department of the Aga Khan University Hospital. Descriptive statistics, Chi-square, and Discriminant Analysis were used.Results: Of the 52 (16%) cases that had seizure recurrence in the ER, majority (36.5%) occurred in \u3e 38.5 degrees \u3c or = 39.5 degrees C temperature range. The percentage declined to 15% at higher temperatures. Bivariate tests showed that age, family and developmental history, type of seizure and treatment given did not affect seizure recurrence in the ER. Past history number of seizures (p = .006), duration of seizure (p \u3c 0.001), past history of seizures (p = 0.004) and multiple seizure (p = 0.024) were factors significantly associated with seizure recurrence in the ER at the bivariate level of analysis. Duration of seizure was the most important prognostic indicator for FS recurrence in the ER at the multivariate level with beta = .79.Conclusion: Duration of seizure (\u3e 5 minutes) was the most important prognostic factor for FS recurrence. Early treatment did not affect recurrence,suggesting timely anti-pyretic vs. anti-leptic medication use

Bott--Kitaev periodic table and index theory

We consider topological insulators and superconductors with discrete symmetries and clarify the relevant index theory behind the periodic table proposed by Kitaev. An effective Hamiltonian determines the analytical index, which can be computed by a topological index. We focus on the spatial dimensions one, two and three, and only consider the bulk theory. In two dimensions, the $\mathbb{Z}$-valued invariants are given by the first Chern number. Meanwhile, $\mathbb{Z}_2$-valued invariants can be computed by the odd topological index and its variations. The Bott-Kitaev periodic table is well-known in the physics literature, we organize the topological invariants in the framework of KR-theory.Comment: 37 page

Technical Efficiency and its Determinants in Water Melon Production in Borno State, Nigeria

This Study examined technical Efficiency of Watermelon in Borno State, Nigeria. Primary data collected through the use of structured questionnaire from 120 randomly selected watermelon farmers from six (6) villages in the two local government areas were used. Stochastic frontier production function was used to analyze the technical efficiencies of watermelon farmers. The results of the stochastic frontier function analyses revealed a mean technical efficiencies levels of 86%, implying that there was scope for increasing efficiencies by 14%. The main sources of technical inefficiencies were years of farming experience, extension contact, membership of cooperative societies, amount of credit obtained and educational level. The study recommends that extension contact, years of cooperative membership and access to credit were the sources of the inefficiencies and should be addressed through adequately trained and equipped extension workers, right use of credit facilities and the formation of cooperative societies and making membership a condition for microcredit benefit