4,649 research outputs found
A 4-unit-cell superstructure in optimally doped YBa2Cu3O6.92 superconductor
Using high-energy diffraction we show that a 4-unit-cell superstructure,
q0=(1/4,0,0), along the shorter Cu-Cu bonds coexists with superconductivity in
optimally doped YBCO. A complex set of anisotropic atomic displacements on
neighboring CuO chain planes, BaO planes, and CuO2 planes, respectively,
correlated over ~3-6 unit cells gives rise to diffuse superlattice peaks. Our
observations are consistent with the presence of Ortho-IV nanodomains
containing these displacements.Comment: Corrected typo in abstrac
Physical-vapor-deposited metal oxide thin films for pH sensing applications: Last decade of research progress
In the last several decades, metal oxide thin films have attracted significant attention for the development of various existing and emerging technological applications, including pH sensors. The mandate for consistent and precise pH sensing techniques has been increasing across various fields, including environmental monitoring, biotechnology, food and agricultural industries, and medical diagnostics. Metal oxide thin films grown using physical vapor deposition (PVD) with precise control over film thickness, composition, and morphology are beneficial for pH sensing applications such as enhancing pH sensitivity and stability, quicker response, repeatability, and compatibility with miniaturization. Various PVD techniques, including sputtering, evaporation, and ion beam deposition, used to fabricate thin films for tailoring materials’ properties for the advanced design and development of high-performing pH sensors, have been explored worldwide by many research groups. In addition, various thin film materials have also been investigated, including metal oxides, nitrides, and nanostructured films, to make very robust pH sensing electrodes with higher pH sensing performance. The development of novel materials and structures has enabled higher sensitivity, improved selectivity, and enhanced durability in harsh pH environments. The last decade has witnessed significant advancements in PVD thin films for pH sensing applications. The combination of precise film deposition techniques, novel materials, and surface functionalization strategies has led to improved pH sensing performance, making PVD thin films a promising choice for future pH sensing technologies
Different behaviour of the spin structure functions and at
We consider low- behaviour of the spin structure functions and
in the unitarized chiral quark model which combines ideas on the
constituent quark structure of hadrons with a geometrical scattering picture
and unitarity. A nondiffractive singular low- dependence of and
indicated by the recent SMC experimental data is described. A
diffractive type smooth behaviour of is predicted at small . The
expectations for the double-spin asymmetries in the low-mass Drell-Yan
production at RHIC in the central region are discussed alongside.Comment: LaTeX, 10 pages, 2 figure
Spatial prediction of malaria prevalence in an endemic area of Bangladesh
<p>Abstract</p> <p>Background</p> <p>Malaria is a major public health burden in Southeastern Bangladesh, particularly in the Chittagong Hill Tracts region. Malaria is endemic in 13 districts of Bangladesh and the highest prevalence occurs in Khagrachari (15.47%).</p> <p>Methods</p> <p>A risk map was developed and geographic risk factors identified using a Bayesian approach. The Bayesian geostatistical model was developed from previously identified individual and environmental covariates (p < 0.2; age, different forest types, elevation and economic status) for malaria prevalence using WinBUGS 1.4. Spatial correlation was estimated within a Bayesian framework based on a geostatistical model. The infection status (positives and negatives) was modeled using a Bernoulli distribution. Maps of the posterior distributions of predicted prevalence were developed in geographic information system (GIS).</p> <p>Results</p> <p>Predicted high prevalence areas were located along the north-eastern areas, and central part of the study area. Low to moderate prevalence areas were predicted in the southwestern, southeastern and central regions. Individual age and nearness to fragmented forest were associated with malaria prevalence after adjusting the spatial auto-correlation.</p> <p>Conclusion</p> <p>A Bayesian analytical approach using multiple enabling technologies (geographic information systems, global positioning systems, and remote sensing) provide a strategy to characterize spatial heterogeneity in malaria risk at a fine scale. Even in the most hyper endemic region of Bangladesh there is substantial spatial heterogeneity in risk. Areas that are predicted to be at high risk, based on the environment but that have not been reached by surveys are identified.</p
in interacting quintessence model
A model consisting of quintessence scalar field interacting with cold dark
matter is considered. Conditions required to reach are discussed. It
is shown that depending on the potential considered for the quintessence,
reaching the phantom divide line puts some constraints on the interaction
between dark energy and dark matter. This also may determine the ratio of dark
matter to dark energy density at .Comment: 10 pages, references updated, some notes added, minor changes
applied, accepted for publication in Eur. Phys. J.
An Approach to Utilize Crust Leather Scrapes, Dumped into the Land, for the Production of Environmental Friendly Leather Composite
Among all the natural fiber, leather fiber is one of the animal fibers which is bearing hydrophilic and hydrophobic functional group. Leather is tanned with different types of chemicals and scraped crust leather containing chemical are coming from the leather industry after preparing footwear and leather products. In this was varied from 100 ml to 40 ml and benzoyl peroxide was used as a radical initiator. Tensile strength (TS), Young modulus and elongation at break (Eb) were measured. Tensile strength found to increase from 9.80 Mpa to 10.85 MPa. Young's modulus was found highest in 70:5 ratios and it was 158.16 Mpa research an attempt was taken to prepare composite with waste scrape crust leather. Leather fiber reinforced polyester resin based composites were prepared by wet layup method. Polyester content in the composite.Scraped crust reinforced composite will reduce the environmental pollution. So it can be concluded that scraped crust leather reinforced composite found to have better result than matrix and reinforced material
Simulation of Quantum Magnetism in Mixed Spin Systems with Impurity Doped Ion Crystal
We propose the realization of linear crystals of cold ions which contain
different atomic species for investigating quantum phase transitions and
frustration effects in spin system beyond the commonly discussed case of
. Mutual spin-spin interactions between ions can be tailored via the
Zeeman effect by applying oscillating magnetic fields with strong gradients.
Further, collective vibrational modes in the mixed ion crystal can be used to
enhance and to vary the strength of spin-spin interactions and even to switch
those forces from a ferro- to an antiferromagnetic character. We consider the
behavior of the effective spin-spin couplings in an ion crystal of spin-1/2
ions doped with high magnetic moment ions with spin S=3. We analyze the ground
state phase diagram and find regions with different spin orders including
ferrimagnetic states. In the most simple non-trivial example we deal with a
linear Ca, Mn, Ca crystal with spins of \{1/2,3,1/2}. To
show the feasibility with current state-of-the-art experiments, we discuss how
quantum phases might be detected using a collective Stern-Gerlach effect of the
ion crystal and high resolution spectroscopy. Here, the state-dependent
laser-induced fluorescence of the indicator spin-1/2 ion, of species
Ca, reveals also the spin state of the simulator spin-3 ions,
Mn as this does not possess suitable levels for optical excitation
and detection.Comment: 15 pages, 5 figure
Hyperon Polarization in the Constituent Quark Model
We consider mechanism for hyperon polarization in inclusive production. The
main role belongs to the orbital angular momentum and polarization of the
strange quark-antiquark pairs in the internal structure of the constituent
quarks. We consider a nucleon as a core consisting of the constituent quarks
embedded into quark condensate. The nonperturbative hadron structure is based
on the results of chiral quark models.Comment: 14 pages, LaTeX, 2 Figures, References adde
Role of proline, K/Na ratio and chlorophyll content in salt tolerance of wheat (Triticum aestivum
Abstract Studies to determine the role of proline, K/Na ratio and chlorophyll contents in salt tolerance of wheat genotypes were conducted in lysimeters using hydroponics technique. Seeds were allowed to germinate under normal condition (1.5 dS m -1 ) and salinity treatment of 12 dS m -1 was imposed after one week of germination. Crop was irrigated at the interval of two weeks or whenever required with 1/4 th Hoagland nutrient solution of respective concentrations. Results clearly indicated that wheat genotypes with higher proline, K/Na ratio and chlorophyll contents had higher grain yield. On the basis of yield reduction, three genotypes viz. Lu-26s, Sarsabz and KTDH were found tolerant. These genotypes also maintained the higher concentration of proline, K/Na ratio and chlorophyll contents under saline conditions
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