146 research outputs found

    DETEKSI TURBIDITY FRONT MENGGUNAKAN CITRA SATELIT SENTINEL-2 HUBUNGANNYA DENGAN OSEANOGRAFI DI ESTUARI BENGAWAN SOLO

    Get PDF
    Estuari merupakan daerah percampuran antara massa air tawar dan air laut yang menyebabkan zat-zat di dasar perairan naik ke permukaan sehingga konsentrasi unsur hara menjadi tinggi. Penelitian mengenai pertemuan massa air estuari masih perlu dilakukan terutama terkait turbidity front estuary karena untuk mengetahui kemampuan citra Setinel-2 dalam mendeteksi turbidity front. Selama ini penelitian ini terbatas dari data in situ, oleh karena itu teknologi penginderaan jauh coba diterapkan untuk mendeteksi turbidity front estuary. Penelitian ini bertujuan untuk mengembangkan algoritma TSS lokal dan mendeteksi turbidity front berdasarkan citra satelit Sentinel-2. Metode penelitian ini menggunakan citra Sentinel-2 untuk mengetahui batas turbidity front berdasarkan TSS yang dibandingan dengan data in situ salinitas dan TSS sebagai validasi data. Hasil penelitian ini diketahui algoritma empiris yang diperoleh dari band ratio (merah/(biru+hijau+merah)) pada Sentinel-2 memiliki hasil yang terbaik dengan koefisien korelasi (r) = 0,86. Hasil citra satelit menunjukkan bahwa turbidity front estuary terjadi pada jarak 1,6 – 2,8 km, sedangkan pada data in situ terjadi pada jarak 2 – 4 km di muara Bengawan Solo. Terdapat perbedaan nilai TSS sebesar 1,9182 mg/L antara data in situ dengan citra satelit di daerah turbidity front estuary. Kondisi musim, curah hujan dan pasang surut memengaruhi konsentrasi dan jarak turbidity front dari muara sungai.The estuary is a mixing area between the mass of fresh water and seawater, which causes substances in the bottom waters to rise to the surface so that nutrient concentrations become high. Research on estuary water mass confluence still needs to be carried out, especially regarding the turbidity front estuary. So far, this research is limited to in situ data. Therefore remote sensing technology is trying to be applied to detect turbidity front estuary. This study aims to develop local TSS algorithms and detect turbidity fronts based on Sentinel-2 satellite imagery. This research method uses Sentinel-2 imagery to determine the turbidity front boundary based on TSS compared to in situ salinity data and TSS as data validation. The results of this study show that the empirical algorithm obtained from the band ratio (red/(blue+green+red)) on Sentinel-2 has the best results with a correlation coefficient (r) = 0.86. The results of satellite imagery show that the turbidity front estuary occurs at a distance of 1.6 – 2.8 km, while the in situ data occurs at a distance of 2 – 4 km at the Bengawan Solo estuary. There is a difference in the TSS value of 1.9182 mg/L between the in situ data and satellite imagery in the turbidity front estuary area. Seasonal conditions, rainfall and tides affect the concentration and distance of the turbidity front from the river mouth

    Cross sections for Coulomb and nuclear breakup of three-body halo nuclei

    Get PDF
    All possible dissociation cross sections for the loosely bound three-body halo nuclei 6^6He (n+n+α\alpha) and 11^{11}Li (n+n+9^{9}Li) are computed as functions of target and beam energy. Both Coulomb and nuclear interactions are included in the same theoretical framework. The measurements agree with the calculations for energies above 100 Mev/nucleon. The largest cross sections correspond to final states with zero or three particles for heavy and with two neutrons for light targets.Comment: 5 pages, 3 figures, revte

    XCDCC: Core Excitation in the Breakup of Exotic Nuclei

    Full text link
    The eXtended Continuum Discretized Coupled Channel (XCDCC) method is developed to treat reactions where core degrees of freedom play a role. The projectile is treated as a multi-configuration coupled channels system generated from a valence particle coupled to a deformed core which is allowed to excite. The coupled channels initial state breaks up into a coupled channels continuum which is discretized into bins, similarly to the original CDCC method. Core collective degrees of freedom are also included in the interaction of the core and the target, so that dynamical effects can occur during the reaction. We present results for the breakup of 17^{17}C=16^{16}C+n and 11^{11}Be=10^{10}Be+n on 9^{9}Be. Results show that the total cross section increases with core deformation. More importantly, the relative percentage of the various components of the initial state are modified during the reaction process through dynamical effects. This implies that comparing spectroscopic factors from structure calculations with experimental cross sections requires more detailed reaction models that go beyond the single particle model.Comment: 14 pages, revtex, submitted to Phys Rev

    Eikonal Reaction Theory for Neutron-Removal Reaction

    Full text link
    We present an accurate method of treating the one-neutron removal reaction at intermediate incident energies induced by both nuclear and Coulomb interactions. In the method, the nuclear and Coulomb breakup processes are consistently treated by the method of continuum discretized coupled channels without making the adiabatic approximation to the Coulomb interaction, so that the removal cross section calculated never diverges. This method is applied to recently measured one-neutron removal cross section for 31^{31}Ne+12^{12}C scattering at 230 MeV/nucleon and 31^{31}Ne+208^{208}Pb scattering at 234 MeV/nucleon. The spectroscopic factor and the asymptotic normalization coefficient of the last neutron in 31^{31}Ne are evaluated.Comment: 10 pages, 1 figur

    Comprehensive calculations of three--body breakup cross sections

    Get PDF
    We present in detail a theoretical model for fragmentation reactions of three--body halo nuclei. The different reaction mechanisms corresponding to the different processes are described and discussed. Coulomb and nuclear interactions are simultaneously included and the method is therefore applicable for any target, light, intermediate and heavy. Absolute values of many differential cross sections are then available as function of beam energy and target. We apply the method to fragmentation of 6^6He and 11^{11}Li on C, Cu and Pb. A large variety of observables, cross sections and momentum distributions, are computed. In almost all cases we obtain good agreement with the available experimental data.Comment: 41 pages, 10 figures, to be published in Nucl. Phys.

    Probing the 6He halo structure with elastic and inelastic proton scattering

    Full text link
    Proton elastic scattering and inelastic scattering to the first excited state of 6He have been measured over a wide angular range using a 40.9A MeV 6He beam. The data have been analyzed with a fully microscopic model of proton-nucleus scattering using 6He wave functions generated from large space shell model calculations. The inelastic scattering data show a remarkable sensitivity to the halo structure of 6He.Comment: 9 pages, 3 figures. RevTeX. Replaced figure 3 with updated figur

    The appropriateness of gatekeeping in the provision of reproductive health care for adolescents in Lithuania:the general practice perspective

    Get PDF
    BACKGROUND: Adolescents' consultation of primary health care services remains problematic despite their accessibility. The reproductive health service seeking behavior of adolescents is the object of much research but little is known about how this behavior is influenced by the gatekeeping system. This study aimed to explore general practitioners' perceptions of the appropriateness of gatekeeping in adolescent reproductive health care. METHODS: Twenty in-depth interviews regarding factors affecting adolescent reproductive health care were carried out on a diverse sample of general practitioners and analyzed using grounded theory. RESULTS: The analysis identified several factors that shaped GPs' negative attitude to gatekeeping in adolescent reproductive health care. Its appropriateness in this field was questionable due to a lack of willingness on the part of GPs to provide reproductive health services for teenagers, their insufficient training, inadequately equipped surgeries and low perceived support for reproductive health service provision. CONCLUSION: Since factors for improving adolescent reproductive health concern not only physicians but also the health system and policy levels, complex measures should be designed to overcome these barriers. Discussion of a flexible model of gatekeeping, encompassing both co-ordination of care provided by GPs and the possibility of patients' self-referral, should be included in the political agenda. Adolescents tend to under-use rather than over-use reproductive health services and every effort should be made to facilitate the accessibility of such services

    Systemic delivery of E6/7 siRNA using novel lipidic particles and its application with cisplatin in cervical cancer mouse models

    Get PDF
    Small interfering RNA (siRNA) shows great promise in cancer therapy, but its effectiveness in vivo still remains a crucial issue for its transition into the clinics. Although the successful use of polyethylene glycol (PEG)ylated lipidic delivery systems have already been reported, most of the formulation procedures used are labour intensive and also result in unstable end products. We have previously developed a simple yet efficient hydration-of-freeze-dried- matrix (HFDM) method to entrap siRNA within lipid particles, in which the products exhibited superior stability. Here, we show that these HFDM-formulated particles are stable in the presence of serum and can deliver siRNA efficiently to tumours after intravenous administration. Using these particles, around 50% knockdown of the target gene expression was observed in tumours. With the use of siRNA targeting the E6/7 oncogenes expressed in cervical cancer, we showed a 50% reduction in tumour size. This level of tumour growth suppression was comparable to that achieved from cisplatin at the clinically used dose. Overall, our results demonstrate the feasibility of using HFDM-formulated particles to systematically administer E6/7-targeted siRNA for cervical cancer treatment. The simplicity of preparation procedure along with superior product stability obtained from our method offers an innovative approach for the in vivo delivery of siRNA

    Inhibition of cervical cancer cell growth in vitro and in vivo with dual shRNAs

    Get PDF
    RNA interference (RNAi)-based gene silencing is widely used in laboratories for gene function studies and also holds a great promise for developing treatments for diseases. However, in vivo delivery of RNAi therapy remains a key issue. Lentiviral vectors have been employed for stable gene transfer and gene therapy and therefore are expected to deliver a stable and durable RNAi therapy. But this does not seem to be true in some disease models. Here, we showed that lentivirus delivered short-hairpin RNA (shRNA) against human papillomavirus (HPV) E6/E7 oncogenes were effective for only 2 weeks in a cervical cancer model. However, using this vector to carry two copies of the same shRNA or two shRNAs targeting at two different but closely related genes (HPV E6 and vascular endothelial growth factor) was more effective at silencing the gene targets and inhibiting cell or even tumor growth than their single shRNA counterparts. The cancer cells treated with dual shRNA were also more sensitive to chemotherapeutic drugs than single shRNA-treated cells. These results suggest that a multi-shRNA strategy may be a more attractive approach for developing an RNAi therapy for this cancer. Cancer Gene Therapy (2011) 18, 219-227; doi: 10.1038/cgt.2010.72; published online 19 November 201
    • …
    corecore