Electrical transport properties of 0.5Li2O-0.5M2O-2B2O3 (M=Li, Na and K) glasses

Transparent glasses in the system 0.5Li2O-0.5M2O-2B2O3 (M=Li, Na and K) were fabricated via the conventional melt quenching technique. Amorphous and glassy nature of the samples were confirmed via the X-ray powder diffraction and the differential scanning calorimetry, respectively. The frequency and temperature dependent characteristics of the dielectric relaxation and the electrical conductivity were investigated in the 100 Hz - 10 MHz frequency range. The imaginary part of the electric modulus spectra was modeled using an approximate solution of Kohrausch-Williams-Watts relation. The stretching exponent, {\beta}, was found to be temperature independent for 0.5Li2O-0.5Na2O-2B2O3 (LNBO) glasses. The activation energy associated with DC conductivity was found to be higher (1.25eV) for 0.5Li2O-0.5K2O-2B2O3 (LKBO) glasses than that of the other glass systems under study. This could be attributed to the mixed cationic effect.Comment: 22 page

Integrated nutrient management for improving crop yields, soil properties, and reducing greenhouse gas emissions

Recently, most agrarian countries have witnessed either declining or stagnant crop yields. Inadequate soil organic matter (SOM) due to the poor physical, chemical, and biological properties of the soil leads to an overall decline in the productivity of farmlands. Therefore, the adoption of integrated nutrient management (INM) practices is vital to revive sustainable soil health without compromising yield potential. Integrated nutrient management is a modified nutrient management technique with multifarious benefits, wherein a combination of all possible sources of plant nutrients is used in a crop nutrition package. Several studies conducted in various parts of the world have demonstrated the benefits of INM in terms of steep gain in soil health and crop yields and at the same time, reducing greenhouse gas emissions and other related problems. The INM practice in the cropped fields showed a 1,355% reduction in methane over conventional nutrient management. The increase in crop yields due to the adoption of INM over conventional nutrient management was as high as 1.3% to 66.5% across the major cropping systems. Owing to the integration of organic manure and residue retention in INM, there is a possibility of significant improvement in soil aggregates and microbiota. Furthermore, most studies conducted to determine the impact of INM on soil health indicated a significant increase in overall soil health, with lower bulk density, higher porosity, and water-holding capacity. Overall, practicing INM would enhance soil health and crop productivity, in addition to decreasing environmental pollution, greenhouse gas emissions, and production costs

Failure of A Novel, Rapid Antigen and Antibody Combination Test to Detect Antigen-Positive HIV Infection in African Adults with Early HIV Infection

BACKGROUND: Acute HIV infection (prior to antibody seroconversion) represents a high-risk window for HIV transmission. Development of a test to detect acute infection at the point-of-care is urgent. METHODS: Volunteers enrolled in a prospective study of HIV incidence in four African cities, Kigali in Rwanda and Ndola, Kitwe and Lusaka in Zambia, were tested regularly for HIV by rapid antibody test and p24 antigen ELISA. Five subgroups of samples were also tested by the Determine Ag/Ab Combo test 1) Antigen positive, antibody negative (acute infection); 2) Antigen positive, antibody positive; 3) Antigen negative, antibody positive; 4) Antigen negative, antibody negative; and 5) Antigen false positive, antibody negative (HIV uninfected). A sixth group included serial dilutions from a p24 antigen-positive control sample. Combo test results were reported as antigen positive, antibody positive, or both. RESULTS: Of 34 group 1 samples with VL between 5x105 and >1.5x107 copies/mL (median 3.5x106), 1 (2.9%) was detected by the Combo antigen component, 7 (20.6%) others were positive by the Combo antibody component. No group 2 samples were antigen positive by the Combo test (0/18). Sensitivity of the Combo antigen test was therefore 1.9% (1/52, 95% CI 0.0, 9.9). One false positive Combo antibody result (1/30, 3.3%) was observed in group 4. No false-positive Combo antigen results were observed. The Combo antigen test was positive in group 6 at concentrations of 80 pg/mL, faintly positive at 40 and 20 pg/mL, and negative thereafter. The p24 ELISA antigen test remained positive at 5 pg/mL. CONCLUSIONS: Although the antibody component of the Combo test detected antibodies to HIV earlier than the comparison antibody tests used, less than 2% of the cases of antigen-positive HIV infection were detected by the Combo antigen component. The development of a rapid point-of-care test to diagnose acute HIV infection remains an urgent goal

Real-time task attributes and temporal constraints

Real-time tasks need attributes for monitoring their execution and performing recovery actions in case of failures. Temporal constraints are a class of real-time task attributes where the constraints relate the status of the task to temporal entities. Violating temporal constraints can produce consequences of unknown severity. This paper is part of our on-going research on real-time multi agent systems constraints. We discuss the importance of temporal constraints and present a task model that explicitly represents temporal constraints. We also present our preliminary results from our initial implementation in the domain of Meeting Schedules Management involving multiple users assisted by agents

Origin of giant dielectric constant and conductivity behavior in Zn1-xMgxO (0 ≤ x ≤ 0.1) ceramics

Zn1−xMgxO ( ≤ x ≤ 0.1) ceramics were fabricated by conventional solid-state reaction of co-precipitated zinc oxide and magnesium hydroxide nanoparticles. Structural and morphological properties of the fabricated ceramics were studied using X-ray diffraction and scanning electron microscopic analysis. The dielectric measurements of the ceramics were carried out as a function of frequency and temperature respectively. Interestingly, Mg doped ZnO (MZO) samples exhibited colossal dielectric response (∼1 × 104 at 1 kHz) with Debye like relaxation. The detailed dielectric studies and thermal analyses showed that the unusual dielectric response of the samples were originated from the defected grain and grain boundary (GB) conductivity relaxations due to the absorbed atmospheric water vapor (moisture). Impedance spectroscopy was employed to determine the defected grain and GB resistances, capacitances and which supported Maxwell–Wagner type relaxation phenomena

Assessment of stress distribution with 3 taper design preparation of root canal using finite element analysis

Aim: Present research was done to assess stress distribution in three different taper design preparation of root canal with the help of finite element analysis. Materials and Methods: Lower incisors teeth having single canals that were cleaned and shaped with the help of NeoEndo Flex Titanium (NiTi) rotary file and later three designs were created such as 4%, 6%, and 8% canal preparation taper. Cone beam computed tomography (CBCT) was done for all teeth and subjected to finite element analysis for stresses. The collected data were statistically analyzed. Results: Highest stress was found in the coronal followed by the middle and least in the apical part in all three designs. The highest stress value was found in enamel than dentin (MPa). The highest stress value was found with design 3 (8% taper) followed by designs 2 (6% taper) and 1 (4% taper) for enamel and dentin with either oblique or vertical stress loading. Conclusion: All canals preparation exhibited maximum enamel stress at the coronal load points compared to apical and middle portions. The stress increases with increase in canal tapering

Dielectric and Impedance Studies on 0.5Li(2)O-0.5K(2)O-2B(2)O(3) Glasses

Transparent glasses in the system 0.5Li(2)O-0.5K(2)O-2B(2)O(3) (LKBO) were fabricated via the conventional melt quenching technique. Amorphous and glassy nature of the samples was confirmed by X-ray diffraction and differential scanning calorimetry (DSC) respectively. Complex dielectric and impedance studies were conducted on the samples at different temperatures in the 100 Hz-10 MHz frequency range. ac conductivity was calculated from the dielectric data and the conductivity relaxation was found to obey the Jonscher's law. The Nyquist's plots (Z `'(omega) vs. Z'(omega)) showed single suppressed semicircles at all the temperatures under study indicating the non ideal Debye type relaxation process to be active. Activation energies for conduction and relaxation process were calculated using the Arrhenius relation. The UV-visible optical transmission spectra was shown a wide transmission window and calculated optical band gap was found to be 5.67 eV

Low-cost novel synthesis route to prepare cobalt ferrite based nanocrystals

Magnetic nanoparticles of cobalt ferrite are synthesized via a simple reduction route. These synthesized nanoparticles were characterized using x-ray diffraction (XRD), Scanning Electron Microscopy, Raman Spectroscopy, Fourier Transform Infrared studies and their magnetic properties were measured using Vibrating-sample magnetometer. The XRD analysis confirms the formation of single phase CoFe2O4 nanoparticles, with cubic spinel structure, having crystalline size of 5-10 nm, depending on the annealing temperature. Raman spectra analysis confirmed that all the synthesized powders are phase pure. The maximum magnetic saturation of 268 A m(-1) has been observed for the sample calcined at 600 degrees C and correspondingly the magnetic anisotropic constant values are reported. The proposed hydrazine reduction synthesis route is simple in execution and cost effective, which makes it economically adaptable for large scale production of CoFe2O4 nanoparticles