Directed transport of active particles over asymmetric energy barriers

We theoretically and numerically investigate the transport of active colloids to target regions, delimited by asymmetric energy barriers. We show that it is possible to introduce a generalized effective temperature that is related to the local variance of particle velocities. The stationary probability distributions can be derived from a simple diffusion equation in the presence of an inhomogeneous effective temperature resulting from the action of external force fields. In particular, transitions rates over asymmetric energy barriers can be unbalanced by having different effective temperatures over the two slopes of the barrier. By varying the type of active noise, we find that equal values of diffusivity and persistence time may produce strongly varied effective temperatures and thus stationary distributions

Aksesibilitas Ruang Terbuka Publik Bagi Kelompok Masyarakat Tertentu Studi Fasilitas Publik Bagi Kaum Difabel di Kawasan Taman Suropati Menteng-Jakarta Pusat

Taman merupakan fasilitas umum yang memiliki fungsi ruang yang sangat penting dan merupakan salah satu ruang terbuka publik kota yang di mana berlaku universal bagi setiap orang dan berhak untuk menikmati dan menggunakannya. Bukan hanya milik orang yang normal saja namun juga kaum difabel terutama para tuna daksa (penyandang cacat fisik) yang memiliki hak yang sama untuk dapat hidup layak dan bermasyarakat seperti orang-orang lainnya yang normal, sangat jarang terlihat menggunakan ruang terbuka publik kota seperti di kawasan Taman Suropati Menteng yaitu melakukan berbagai macam kegiatan aktivitas seperti masyarakat lainnya. Hal tersebut diakibatkan karena tidak tersedianya fasilitas kemudahan yang membantu pergerakan mereka atau aksesibilitas. Tujuan dari studi identifikasi ini adalah merumuskan upaya untuk mengefektifkan pelaksanaan penyediaan aksesibilitas bagi kaum difabel. Sasaran yang ditetapkan untuk mencapai tujuan tersebut adalah Perumusan prinsip perancangan ruang terbuka publik yang dapat juga digunakan oleh difabel terutama tuna daksa yang dilakukan dengan studi pustaka, peniliaian kelangkapan peraturan yang berlaku dengan mengacu pada hasil Perumusan prinsip perancangan, penilaian pelaksanaan penyediaan aksesibilitas di ruang terbuka publik Kawasan Taman Suropati Menteng Jakarta Pusat dengan mengunankan prinsip perancangan serta peraturan yang berlaku sebagai dasar penilaian, serta identifikasi persoalan yang dihadapi dalam penyediaan aksesibilitas bagi kaum difabel terutama tuna daksa yang didapat melalui wawancara. Upaya agar penyediaan aksesibilitas bagi kaum difabel dapat dilaksanakan dengan efektif dan untuk mewujudkan kesamaan kesempatan hidup bagi kaum difabel adalah dengan menyusun dan melengkapi suatu peraturan dan standar di tingkat daerah dan usulan perancangan teknis yang dilengkapi oleh ilustrasi berupa gambar dan foto dengan jelas, membentuk badan khusus yang bertugas untuk melakukan sosialisasi perda yang proses didalamnya melibatkan secara langsung para kaum difabelnya sendiri serta koordinasi dengan dinas terkait, pemberian insentif bagi pengembang dan masyarakat serta menyediaakan dana untuk penyediaan aksesibilitas

G51.04+0.07 and its environment: Identification of a new Galactic supernova remnant at low radio frequencies

We have identified a new supernova remnant (SNR), G51.04+0.07, using observations at 74 MHz from the Very Large Array Low-Frequency Sky Survey Redux (VLSSr). Earlier, higher frequency radio continuum, recombination line, and infrared data had correctly inferred the presence of nonthermal radio emission within a larger, complex environment including ionised nebulae and active star formation. However, our observations have allowed us to redefine at least one SNR as a relatively small source (7.05 × 30in size) located at the southern periphery of the originally defined SNR candidate G51.21+0.11. The integrated flux density of G51.04+0.07 at 74 MHz is 6.1 ± 0.8 Jy, while its radio continuum spectrum has a slope α = −0.52 ± 0.05 (Sν ∝ να), typical of a shell-type remnant. We also measured spatial variations in the spectral index between 74 and 1400 MHz across the source, ranging from a steeper spectrum (α = −0.50 ± 0.04) coincident with the brightest emission to a flatter component (α = −0.30 ± 0.07) in the surrounding fainter region. To probe the interstellar medium into which the redefined SNR is likely evolving, we have analysed the surrounding atomic and molecular gas using the 21 cm neutral hydrogen (HI) and 13CO(J = 1 − 0) emissions. We found that G51.04+0.07 is confined within an elongated HI cavity and that its radio emission is consistent with the remains of a stellar explosion that occurred ∼6300 yr ago at a distance of 7.7 ± 2.3 kpc. Kinematic data suggest that the newly discovered SNR lies in front of HII regions in the complex, consistent with the lack of a turnover in the low frequency continuum spectrum. The CO observations revealed molecular material that traces the central and northern parts of G51.04+0.07. The interaction between the cloud and the radio source is not conclusive and motivates further study. The relatively low flux density (∼1.5 Jy at 1400 MHz) of G51.04+0.07 is consistent with this and many similar SNRs lying hidden along complex lines of sight towards inner Galactic emission complexes. It would also not be surprising if the larger complex studied here hosted additional SNRs.Fil: Supán, Jorge Leonardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Castelletti, Gabriela Marta. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Peters, W. M.. Spece Sciences División. Naval Research Laboratory; Estados UnidosFil: Kassim, N. E.. Spece Sciences División. Naval Research Laboratory; Estados Unido

Grants and debt forgiveness in Africa : a descriptive analysis

The authors analyze the effects of bilateral debt forgiveness on 32 low-income countries in Africa (1984-93). Asking whether it makes a difference for recipient countries to receive pure grants rather that official development assistance (ODA) debt relief, they focus on how one form of aid or the other affects the countries'import capacity. They conclude that: a) grants allowed recipient countries to significantly expand their import capacity for 1984-93 as grants and import capacity have been increasing since 1984. But the increasing share of concessional lending and debt relief in recent years has not allowed these countries to reduce total indebtedness nor solve debt overhang. b) the biggest recipients of debt relief also received the lion's share of the pure grants increase. Debt forgiveness and pure grants were allocated not entirely consistent with standard economic hierarchies. c) bilateral ODA debt forgiveness appears to be neutral in the sense of not having any significant impact on import capacity. During 1989-93, multilateral lending replaced the bilateral lending decrease caused by an increase in grants. d) private creditors have typically withdrawn money as grants increased. And debt relief has had a crowding-out effect on new lending. Bilateral donors are switching their development finance to Africa from concessional and non-concessional lending to a combination of pure grants and ODA relief.Payment Systems&Infrastructure,Banks&Banking Reform,Public Sector Economics&Finance,Municipal Financial Management,Public&Municipal Finance,Urban Economics,Municipal Financial Management,Banks&Banking Reform,Public Sector Economics&Finance,Public&Municipal Finance