Evolution of the fishtail-effect in pure and Ag-doped MG-YBCO

We report on magnetic measurements carried out in a textured YBa$_2$Cu$_3$O$_{7-\delta}$ and YBa$_2$(Cu$_{1-x}$Ag$_x$)$_3$O$_{7-\delta}$ (at $x \approx$ 0.02) crystals. The so-called fishtail-effect (FE) or second magnetization peak has been observed in a wide temperature range 0.4~$<T/T_c<$~0.8 for $\textbf{H}\parallel c$. The origin of the FE arises for the competition between surface barrier and bulk pinning. This is confirmed in a non-monotonically behavior of the relaxation rate $R$. The value $H_{max}$ for Ag-doped crystals is larger than for the pure one due to the presence of additional pinning centers, above all on silver atoms.Comment: 6 pages, 6 figure

Effect of alendronate on post-traumatic osteoarthritis induced by anterior cruciate ligament rupture in mice.

IntroductionPrevious studies in animal models of osteoarthritis suggest that alendronate (ALN) has antiresorptive and chondroprotective effects, and can reduce osteophyte formation. However, these studies used non-physiologic injury methods, and did not investigate early time points during which bone is rapidly remodeled prior to cartilage degeneration. The current study utilized a non-invasive model of knee injury in mice to investigate the effect of ALN treatment on subchondral bone changes, articular cartilage degeneration, and osteophyte formation following injury.MethodsNon-invasive knee injury via tibial compression overload or sham injury was performed on a total of 90 mice. Mice were treated with twice weekly subcutaneous injections of low-dose ALN (40&nbsp;μg/kg/dose), high-dose ALN (1,000&nbsp;μg/kg/dose), or vehicle, starting immediately after injury until sacrifice at 7, 14 or 56&nbsp;days. Trabecular bone of the femoral epiphysis, subchondral cortical bone, and osteophyte volume were quantified using micro-computed tomography (μCT). Whole-joint histology was performed at all time points to analyze articular cartilage and joint degeneration. Blood was collected at sacrifice, and serum was analyzed for biomarkers of bone formation and resorption.ResultsμCT analysis revealed significant loss of trabecular bone from the femoral epiphysis 7 and 14&nbsp;days post-injury, which was effectively prevented by high-dose ALN treatment. High-dose ALN treatment was also able to reduce subchondral bone thickening 56&nbsp;days post-injury, and was able to partially preserve articular cartilage 14&nbsp;days post-injury. However, ALN treatment was not able to reduce osteophyte formation at 56&nbsp;days post-injury, nor was it able to prevent articular cartilage and joint degeneration at this time point. Analysis of serum biomarkers revealed an increase in bone resorption at 7 and 14&nbsp;days post-injury, with no change in bone formation at any time points.ConclusionsHigh-dose ALN treatment was able to prevent early trabecular bone loss and cartilage degeneration following non-invasive knee injury, but was not able to mitigate long-term joint degeneration. These data contribute to understanding the effect of bisphosphonates on the development of osteoarthritis, and may support the use of anti-resorptive drugs to prevent joint degeneration following injury, although further investigation is warranted

Perencanaan Pembangkit Listrik Tenaga Mini Hidro Pada Daerah Non-cat Di DAS Bekasi

Mini Hydro Power Plant (MHPP) is a Hydro Power Plant that generates electrical energy within 100 KWH to1 MWH. MHPP on non-ground water in Bekasi watershed located on 6º28'16,66'' S - 106º53'48,75'' E for Bekasi Upstream Weir and 6º27'57,06'' S - 106º53'39,75'' E for the power house. Bekasi Upstream Weir is located on Cileungsi River stream and the power house is on Bantarjati Village, Kelapa Nunggal Sub-District, Bogor District, West Java Province. The MHPP planning first starts by analyzing the hydrology to get the flood discharge plan and dependable discharge. Structure planning for MHPP includes weir planning, intake building, settling basin, penstock, and power house. With 205 km2 total area of non-ground water in Bekasi watershed, Cileungsi River has a 962.30 m3/second flood discharge plan with 50 years repeating period and 2,5 m3/second dependable discharge. Power plant has a weir to elevate water level with 43.2 m effective width and 10 m crest height. This MHPP has 10 m head fall height and generates electricity 154.22 kwH with one turbine

Inter- and intragrain currents in bulk melt-grown YBaCuO rings

A simple contactless method suitable to discern between the intergrain (circular) current, which flows in the thin superconducting ring, and the intragrain current, which does not cross the weakest link, has been proposed. At first, we show that the intergrain current may directly be estimated from the magnetic flux density $B(\pm z_0)$ measured by the Hall sensor positioned in the special points $\pm z_0$ above/below the ring center. The experimental and the numerical techniques to determine the value $z_0$ are discussed. Being very promising for characterization of a current flowing across the joints in welded YBaCuO rings (its dependencies on the temperature and the external magnetic field as well as the time dissipation), the approach has been applied to study corresponding properties of the intra- and intergrain currents flowing across the $a$-twisted grain boundaries which are frequent in bulk melt-textured YBaCuO samples. We present experimental data related to the flux penetration inside a bore of MT YBaCuO rings both in the non-magnetized, virgin state and during the field reversal. The shielding properties and their dependence on external magnetic fields are also studied. Besides, we consider the flux creep effects and their influence on the current re-distribution during a dwell.Comment: 13 pages, 16 figures (EPS), RevTeX4. In the revised version, corrections to perturbing effects near the weak links are introduced, one more figure is added. lin

A Novel Magnetoscan Setup

Due to a modification in the original magnetoscan setup, a significant improvement in resolution was obtained. The paper focuses on experimental results which should support the idea of the new setup using two magnets with opposite direction of magnetization. This contribution to the characterization techniques of melt-grown bulk superconductors should promote the easy installation of this technique in industry. The improved magnetoscan technique may further help to investigate growth-induced inhomogeneities of the top-seeded-melt-growth process in the submillimeter range, and it offers new possibilities to the characterization of smaller structures such as superconducting films or coated conductors.Comment: 7 pages, 7 figure

From their own perspective - constraints in the Polio Eradication Initiative: perceptions of health workers and managers in a district of Pakistan's Punjab province

<p>Abstract</p> <p>Background</p> <p>The success of the Global Polio Eradication Initiative was remarkable, but four countries - Afghanistan, Pakistan, India and Nigeria - never interrupted polio transmission. Pakistan reportedly achieved all milestones except interrupting virus transmission. This paper describes the perceptions of health workers and managers regarding constraints in the Polio Eradication Initiative (PEI) to ultimately provide evidence for designing future interventions.</p> <p>Methods</p> <p>A qualitative cross-sectional study using focus group discussions and in-depth interviews was conducted in the Nankana Sahib District of Pakistan's Punjab province. Study subjects included staff at all levels in the PEI at district headquarters, in all 4 tehsils (sub-districts) and at 20 randomly selected primary health centers. In total, 4 FGD and 7 interview sessions were conducted and individual session summary notes were prepared and later synthesized, consolidated and subjected to conceptual analysis.</p> <p>Results</p> <p>The main constraints identified in the study were the poor condition of the cold chain in all aspects, poor skills and a lack of authority in resource allocation and human resource management, limited advocacy and communication resources, a lack of skills and training among staff at all levels in the PEI/EPI in almost all aspects of the program, a deficiency of public health professionals, poor health services structure, administrative issues (including ineffective means of performance evaluation, bureaucratic and political influences, problems in vaccination areas and field programs, no birth records at health facilities, and poor linkage between different preventive programs), unreliable reporting and poor monitoring and supervision systems, limited use of local data for interventions, and unclear roles and responsibilities after decentralization.</p> <p>Conclusion</p> <p>The study highlights various shortcomings and bottlenecks in the PEI, and the barriers identified should be considered in prioritizing future strategies.</p

Fostering coastal resilience to climate change vulnerability in Bangladesh, Brazil, Cameroon and Uruguay: a cross-country comparison

© 2017, Springer Science+Business Media B.V. This paper describes a comparative study of four different cases on vulnerability, hazards and adaptive capacity to climate threats in coastal areas and communities in four developing countries: Bangladesh, Brazil, Cameroon and Uruguay. Coastal areas are vulnerable to sea-level rise (SLR), storm surges and flooding due to their (i) exposure, (ii) concentration of settlements, many of which occupied by less advantaged groups and (iii) the concentration of assets and services seen in these areas. The objective of the paper is twofold: (i) to evaluate current evidence of coastal vulnerability and adaptive capacity and (ii) to compare adaptation strategies being implemented in a sample of developing countries, focusing on successful ones. The followed approach for the case evaluation is based on (i) documenting observed threats and damages, (ii) using indicators of physical and socioeconomic vulnerability and adaptive capacity status and (iii) selecting examples of successful responses. Major conclusions based on cross-case comparison are (a) the studied countries show different vulnerability, adaptive capacity and implementation of responses, (b) innovative community-based (CBA) and ecosystem-based adaptation (EbA) and (c) early warning systems are key approaches and tools to foster climate resilience. A recommendation to foster the resilience of coastal communities and services is that efforts in innovative adaptation strategies to sea-level rise should be intensified and integrated with climate risk management within the national adaption plans (NAPAs) in order to reduce the impacts of hazards

Investigation of DyBa2CU3O7-d superconducting domains grown by the infiltration technique starting with small size Dy-211 particles

An infiltration and growth process is here used as an alternative to the classical top-seeded melt-textured growth process for the production of Dy-123 single-domains with finely dispersed small size Dy-211 particles. The starting materials are the 211-particles and a barium and copper rich liquid phase precursor. The infiltration and growth process allows for controlling both the spatial and size distribution of the 211-particles in the final superconducting 123-single-domain. The main parameters (set-ups, maximum processing temperature with respect to the peritectic temperature, nature of reactant, porosity of the 211-preform) of the infiltration and growth process are discussed. Moreover, different processes of chimie douce are shown in order to produce Dy-211 particles with controlled shape and size, particles that can be used as precursors for the infiltration and growth process