Observational Constraints on Phantom Crossing DGP Gravity

We study the observational constraints on the Phantom Crossing DGP model. We demonstrate that the crossing of the phantom divide does not occur within the framework of the original Dvali-Gabadadze-Porrati (DGP) model or the DGP model developed by Dvali and Turner. By extending their model in the framework of an extra dimension scenario, we study a model that realizes crossing of the phantom divide. We investigate the cosmological constraints obtained from the recent observational data of Type Ia Supernovae, Cosmic Microwave Background anisotropies, and Baryon Acoustic Oscillations. The best fit values of the parameters with 1$\sigma$ (68%) errors for the Phantom Crossing DGP model are $\Omega_{m,0}=0.27^{+0.02}_{-0.02}$, $\beta=0.54^{+0.24}_{-0.30}$. We find that the Phantom Crossing DGP model is more compatible with the observations than the original DGP model or the DGP model developed by Dvali and Turner. Our model can realize late-time acceleration of the universe, similar to that of $\Lambda$CDM model, without dark energy due to the effect of DGP gravity. In our model, crossing of the phantom divide occurs at a redshift of $z \sim 0.2$.Comment: 17 pages, 9 figures, 1 table, Accepted for publication in International Journal of Modern Physics

Accelerating Universe as Window for Extra Dimensions

Homogeneous cosmological solutions are obtained in five dimensional space time assuming equations of state $p = k\rho$ and $p_{5}= \gamma\rho$ where p is the isotropic 3 - pressure and $p_{5}$, that for the fifth dimension. Using different values for the constants k and $\gamma$ many known solutions are rediscovered. Further the current acceleration of the universe has led us to investigate higher dimensional gravity theory, which is able to explain acceleration from a theoretical view point without the need of introducing dark energy by hand. We argue that the terms containing higher dimensional metric coefficients produce an extra negative pressure that apparently drives an acceleration of the 3D space, tempting us to suggest that the accelerating universe seems to act as a window to the existence of extra spatial dimensions. Interestingly the 5D matter field remains regular while the \emph{effective} negative pressure is responsible for the inflation. Relaxing the assumptions of two equations of state we also present a class of solutions which provide early deceleration followed by a late acceleration in a unified manner. Interesting to point out that in this case our cosmology apparently mimics the well known quintessence scenario fuelled by a generalised Chaplygin-type of fluid where a smooth transition from a dust dominated model to a de Sitter like one takes place.Comment: 20 pages,3 figure

Challenges in compression testing of 3D angle-interlocked woven-glass fabric-reinforced polymeric composites.

This paper describes the challenges in using testing standards such as D6641/D6641M-14, for determination of compressive strength of 3D angle interlocked glass fabric reinforced polymeric composites (3D-FRPC). It makes use of both experimental investigation and finite element analysis. The experimental investigation involved testing both 2D and 3D-FRPC using ASTM D6641/D6641M-14 and subsequent scanning electron microscopic imaging of failed specimens to reveal the stress state at failure. This was further evaluated using laminate level finite element (FE) analysis. The FE analysis required input of effective orthotropic elastic material properties of 3D-FRPC, which were determined by customizing a recently developed micro-mechanical model. The paper sheds new light on compressive failure of 3D angle interlocked glass fabric composites, as only scarce data is available in literature about this class of materials. It showed that although the tests produce acceptable strength values the internal failure mechanisms change significantly and the standard deviation (SD) and coefficient of variance (COV) of 3D-FRPC comes out to be much higher than that of 2D-FRPC. Moreover, while reporting and using the test data some additional information about the 3D-fabric architecture, such as the direction of angle interlocking fabric needs to be specified. This was because, for 3D angle interlocking of fabric along warp direction, the strength values obtained in the warp and weft direction were significantly different from each other. The study also highlights that due to complex weave architecture it is not possible to achieve comparable volume fractions with 2D and 3D fabric reinforced composites using similar manufacturing parameters for the vacuum assisted resin infusion process. Thus, the normalized compressive strength values (normalized with respect to volume fraction) are the highest for 3D-FRPC when measured along the warp direction, they are at an intermediate level for 2D-FRPC and the lowest for 3D-FRPC, when measured in the weft direction.DelPHE 780 Project grant (DFID UK

Compact and broadband polarization beam splitter based on a silicon nitride augmented low-index guiding structure

We propose a compact polarization beam splitter (PBS) based on a silicon nitride enhanced silicon-on-insulator platform using an augmented low-index guiding (ALIG) waveguide structure. In the ALIG structure, the TM mode is mostly confined in the low-index silicon nitride, while the TE mode is confined in the high-index silicon. Since the two modes are confined in two separate layers, their properties can be controlled independently. The PBS is formed using an asymmetric multimode interference (MMI) section. The TM mode is directed to an output port by the ALIG waveguide, while the TE mode is coupled to the other output port via the multimode interferometer. Such a PBS has a very small footprint, low insertion loss, high polarization extinction ratio, and broadband response

Reconstructing the potentials for the quintessence and tachyon dark energy, from the holographic principle

We propose an holographic quintessence and tachyon models of dark energy. The correspondence between the quintessence and tachyon energy densities with the holographic density, allows the reconstruction of the potentials and the dynamics for the quintessence and tachyon fields, in flat FRW background. The proposed infrared cut-off for the holographic energy density works for two cases of the constant $\alpha$: for $\alpha<1$ we reconstructed the holographic quintessence model in the region before the $\omega=-1$ crossing for the EoS parameter. The cosmological dynamics for $\alpha>1$ was also reconstructed for the holographic quintessence and tachyon models.Comment: 21 pages, 18 figures, 2 table

Analisis Kualitas Pelayanan Publik di Kabupaten Mamuju Utara

Absract: This study aims to provide an overview of the process of public service in the service of making the Family Card and Identity Card. As well as capabilities to tahui factors - factors that affect the public service performed by the Department of Population and Civil Registration Mamuju. The approach used in this study is a qualitative approach to the subject of research is the Department of Population and Civil Registration Mamuju

Peningkatan Mutu Tanaman Hias Anggrek Alam Phalaenopsis melalui Kegiatan Persilangan

Phalaenopsis celebencis dan Phalaenopsis venosamerupakan dua jenis anggrek di Sulawesi tengah yang berpotensi sebagai tetua untuk menghasilkan varietas baru anggrek bunga potong. Prospek tanaman anggrek untuk bunga potong dianggap masih sangat cerah untuk dikembangkan. Namun &nbsp;potensi &nbsp;ini &nbsp;belum &nbsp;dimanfaatkan secara proporsional. Rendahnya produksi anggrek disebabkan &nbsp;kurang &nbsp;tersedianya &nbsp;bibit &nbsp;bermutu, &nbsp;budidaya &nbsp;yang kurang efisien serta penanganan tanaman anggrek yang kurang baik. Untuk memenuhi permintaan pasar yang cenderung meningkat maka diperlukan ketersediaan bibit yang bermutu dan dalam jumlah banyak.&nbsp;Persilangan merupakan salah satu cara meningkatkan mutu tanaman anggrek. Persilangan pada tanaman anggrek tidak bisa terjadi secara alami kecuali pada jenis anggrek tertentu, sehingga diperlukan campur tangan manusia untuk melakukan penyerbukan dengan cara hibridisasi atau persilangan. . Persilangan ini dilakukan untuk memperkaya keaneka-ragaman genetik pada tanaman anggrek. Potensi USAha yang dikembangkan yaitu; USAha pembibitan (perbanyakan),&nbsp; pembesaran, dan perdagangan. Usaha pengembangan tanaman anggrek dilakukan melalui kegiatan persilangan atau hibridisasi. Hasil yang dicapai dari kegiatan pengabdianini adalah tersedianya indukan anggrek hasil persilangan yang digunakan sebagai sumber eksplan dalam kultur jaringan. Tersedianya anakan-anakan anggrek hybrid hasil persilangan dari hasil kultur jaringan. Dari rangkaian kegiatan ini dapat disimpulkan bahwa target kegiatan berupa tersedianya anakan anggrek dan pemasaran anggrek hasil kultur jaringan dapat tercapai dengan baik. Rangkaian kegiatan memberikan kontribusi besar baik terhadap institusi maupun bagi Masyarakat

Vertically integrated spot-size converter in AlGaAs-GaAs

We report on the demonstration of a spot size converter (SSC) for monolithic photonic integration at a wavelength of 850 nm on a GaAs substrate. We designed and fabricated a dual-waveguide AlGaAs chip. The design consists of a lower waveguide layer for efficient end-fire coupling to a single-mode fiber, an upper waveguide layer for high refractive index contrast waveguides, and a vertical SSC to connect the two waveguide layers. We measured a SSC conversion efficiency of 91% (or −0.4  dB) between the upper and lower waveguide layers for the TE mode at a wavelength of 850 nm

A Study on Screw Fastened Profile Steel Sheet Subjected to Simulated Uplift Load

Profiled steel sheets play an important role in light gauge metal building construction, particularly as roof claddings in houses, low-rise commercial and industrial buildings. Thin profiled steel sheets are commonly connected to the underlying purlins or steel trusses/frame by drilling or tapping of screws. Screw fastened light gauge steel profiled roofing sheets are mostly subjected to wind suction or wind uplift forces. Strong and fluctuating wind uplift force may fail locally in the vicinity of screw. Different types of ribbed have great significance on the structural strength and behaviour of profile steel sheet. The objective of this study is to investigate the structural strength and behaviour of different profiled steel sheet roofing elements under simulated wind uplift forces. A series of tests was performed on profiled steel sheet roofing subjected to wind uplift simulated pressure. Three different ribbed sheets namely; arc-tangent, tile type and trapezoidal profiled steel sheet are investigated in this research. Different diameter of screw and different span length of sheeting are considered in this research. The failure loads, failure modes the load- deformation behaviour of screwed fastened profile steel sheet under simulated wind load are presented. It was observed that during the increase of loading, the upward deflection of the unscrewed crest became larger than that of the screwed crest. It was found that the local diamond-shaped deformations may progressively develop around the screw fasteners at the support due to uplift load. It was found that structural behaviour of the roofing sheets under uplift loads was greatly dependent on different types of ribbed, diameter of the screw and span length of profiled steel sheet. Based on test results, tiles type profiled steel sheet provided better performance than others types. Finally, the finite element analysis (FEA) investigation is conducted to explore the investigation on structural strength and behaviour of different types profiled steel sheet roofing elements under simulated wind uplift. Good agreements are found between test and numerical result