Current blockage in sheared flow: Experiments and numerical modelling of regular waves and strongly sheared current through a space-frame structure

Space-frame structures supporting marine renewable energy devices such as offshore wind turbines are exposed to complex hydrodynamic forces resulting from the coexistence of waves and currents. Previous investigations on the interaction of such structure acting as an obstacle array with regular waves and in-line uniform current reported a reduced fluid loading due to current blockage. This paper documents laboratory-scale experimental evidence for reduced fluid loading on a truss structure exposed to regular waves with in-line sheared current in shallow water. Strongly sheared current of different speeds is generated and profiled using purposely-built wire resistance arrays in a wave-current flume, and a range of regular waves are created using a piston-type wavemaker. The global hydrodynamic force time history on a truss structure is measured for a range of sheared current speeds and regular wave heights. For all test cases, two loading configurations are considered, with the truss positioned end-on and diagonal to the incident flow direction. Comparisons are made with the analytical current blockage model for steady uniform current by Taylor (1991) and Taylor et al. (2013), and with the numerical simulations conducted in OpenFOAM using a porous tower model following the approach by Santo et al. (2015). Under the same input condition, the diagonal loading configuration is observed to attract higher forces and therefore it should not be ignored when assessing the survivability of such structures. Overall, good agreement in terms of the peak forces and the shapes of force time history is achieved, all with a single and consistent value for each of Cd and Cm. On the other hand, predictions using standard Morison with no blockage and the present API recommendation with the same Cd and Cm result in force overpredictions for all cases of regular waves with in-line current. For steady sheared current flow through a porous tower, apart from the dominant lateral flow divergence, numerical flow visualisation reveals an existence of vertical flow interaction in the porous tower. This is attributed to the non-uniform loading with water depth and was not observed previously for uniform current flow. This study provides the first experimental validation and justification on the use of a simple porous block in representing a complex geometry of real space-frame structures when exposed to combined large regular waves and in-line current

Searching for supergiant fast X-ray transients with Swift

Supergiant fast X-ray transients (SFXTs) are high mass X-ray binaries (HMXBs) hosting a neutron star and an OB supergiant companion. We examine the available Swift data, as well as other new or archival/serendipitous data, on three sources: IGR J17407-2808, 2XMM J185114.3-000004, and IGR J18175-2419, whose X-ray characteristics qualify them as candidate SFXT, in order to explore their properties and test whether they are consistent with an SFXT nature. As IGR J17407-2808 and 2XMM J185114.3-000004 triggered the Burst Alert Telescope on board Swift, the Swift data allow us to provide their first arcsecond localisations, leading to an unequivocal identification of the source CXOU J174042.0-280724 as the soft X-ray counterpart of IGR J17407-2808, as well as their first broadband spectra, which can be fit with models generally describing accreting neutron stars in HMXBs. While still lacking optical spectroscopy to assess the spectral type of the companion, we propose 2XMM J185114.3-000004 as a very strong SFXT candidate. The nature of IGR J17407-2808 remains, instead, more uncertain. Its broad band properties cannot exclude that the emission originates from either a HMXB (and in that case, a SFXT) or, more likely, a low mass X-ray binary. Finally, based on the deep non-detection in our XRT monitoring campaign and a careful reanalysis of the original Integral data in which the discovery of the source was first reported, we show that IGR J18175-2419 is likely a spurious detection.Comment: Accepted for publication in Astronomy and Astrophysics. 12 pages, 11 figures, 6 table

Perkembangan Oosit Induk Osteochilus Hasselti C.v. yang Diberi Hormon Estradiol-17β dan Pakan dengan Kadar Protein Berbeda

The availability of fish seed is very important in fish propagation. Good quality of fish seeds were produced by a good brooder which characterized a large number of egg production at spawning. The aims of this research were to evaluate the oocytes development in the hard-lipped Barb (Osteochilus hasselti C.V.) given 17β-estradiol, different percentage of protein in the diet, and their combination. This research was conducted experimentally applying Factorial Completely Randomized Design. The first factor was percentage of protein in the diet consisted of 4 levels namely 25% (P1), 30% (P2), 35% (P3), and 40% (P4), the second factor was dose of 17β-estradiol benzoate (EB) consisted of 3 levels namely 0 µg/kg of body weight (D0), 126 µg/kg of body weight (D1), and 210 µg/kg of body weight (D2), thus there were 12 combinations of treatment with 3 replicates. The results showed that neither of protein proportion or 17β-estradiol affected the proportion of oocytes of any developmental stage (p>0,05) within the first two weeks post spawning. The treatments, however, significantly increased the proportion of oocytes at V3-V5, V6-V7, and post-vitellogenic stages (p 0.05). In conclusion, the percentage of protein in the diet and different doses of 17β-estradiol improved oocyte development of Hard-Lipped Barb (Osteochilus hasselti C.V.)

Subjective Assessment of Sleep Quality Across the Menstrual Cycle in Women with Premenstrual Dysphoric Disorder

Existing evidence demonstrates that sleep structure varies across the menstrual cycle in healthy women (1). These variations could be more severe in women suffering from premenstrual dysphoric disorder (PMDD) (2). In a previous study of healthy women, subjective sleep quality was shown to be constant across both phases of the menstrual cycle (3). The current study aims to test whether there exists a variation in subjective sleep quality of PMDD sufferers across the follicular and luteal phases of the menstrual cycle

Development of a bilayered system for periodontal regeneration using tissue engineering approaches

Periodontitis is a prevalent gram negative infection disease that causes the destruction of the tooth supportive tissues. Effective treatment of periodontal disease is important, since periodontal disease is correlated with several systemic diseases. However, adult periodontal tissues have a low potential of self-renewing and regeneration. Concerted efforts have been made to accelerate periodontal tissue regeneration, using a plethora of techniques including grafting materials, signalling molecules and cell-based tissue engineering. Nevertheless, a strategy for predictable reconstruction of normal structure and functionality of periodontal damaged tissue is still missing. In this work, we propose the development of a bilayered system for the regeneration of alveolar bone and periodontal ligament. This system consists of a bilayered composite made of calcium phosphate (CaP) cement incorporating hyaluronic acid microspheres loaded with Platelet Lysates (PL) and a hydrogel layer based on PL, harbouring mesenchymal stem cells (MSCs). The advantage of this strategy lies in the ability to develop a system that can be easily injected and which provides adequate mechanical support, both initially and during new tissue ingrowth. After the degradation of the HA microspheres incorporated in the CaP cement, a fully interconnected network can be created, which leads to rapid penetration of bone-forming cells into the CaP cement. Additionally, the distinct degradation rates of the components of the bilayered system allow a controlled release of the entrapped growth factors and further accelerate the periodontal tissues remodelling process, mimicking the physiologic wound healing process. The data collected suggests that it is possible to fabricate the cement composite layer incorporating PL from which a number of growth factors are released in a controlled manner. Moreover, the cement composites incorporating HA microspheres loaded with PL show low cytotoxic values and induce the expression of early markers of osteogenic differentiation in human adipose-derived stem cells (hACS)

3-200 keV spectral states and variability of the INTEGRAL Black Hole binary IGR J17464-3213

On March 2003, IBIS, the gamma-ray imager on board the INTEGRAL satellite, detected an outburst from a new source, IGR J17464-3213, that turned out to be a HEAO-1 transient, H1743-322. In this paper we report on the high energy behaviour of this BHC studied with the three main instruments onboard INTEGRAL. The data, collected with unprecedented sensitivity in the hard X-Ray range, show a quite hard Comptonised emission from 3 keV up to 150 keV during the rising part of the source outburst, with no thermal emission detectable. A few days later, a prominent soft disk multicolour component appears, with the hard tail luminosity almost unchanged: 10-9 erg*cm-2*s-1. Two months later, during a second monitoring campaign near the end of the outburst, the observed disk component was unchanged. Conversely, the Comptonised emission from the central-hot part of the disk reduced by a factor of 10. We present here its long term behaviour in different energy ranges and the combined JEM-X, SPI and IBIS wide band spectral evolution of this source.Comment: 12 pages, 4 figures, accepted for pubblication in AP

Mechanistic insights into the release of doxorubicin from graphene oxide in cancer cells

Liposomal doxorubicin (L-DOX) is a popular drug formulation for the treatment of several cancer types (e.g., recurrent ovarian cancer, metastatic breast cancer, multiple myeloma, etc.), but poor nuclear internalization has hampered its clinical applicability so far. Therefore, novel drug-delivery nanosystems are actively researched in cancer chemotherapy. Here we demonstrate that DOX-loaded graphene oxide (GO), GO-DOX, exhibits much higher anticancer efficacy as compared to its L-DOX counterpart if administered to cellular models of breast cancer. Then, by a combination of live-cell confocal imaging and fluorescence lifetime imaging microscopy (FLIM), we suggest that GO-DOX may realize its superior performances by inducing massive intracellular DOX release (and its subsequent nuclear accumulation) upon binding to the cell plasma membrane. Reported results lay the foundation for future exploitation of these new adducts as high-performance nanochemotherapeutic agents