Balancing irrigation and hydropower: Case study from Southern Sri Lanka

Reservoirs / Dams / Hydroelectric schemes / Economic analysis / Canals / Irrigation scheduling / Cropping systems / Case studies

Frustration of square cupola in Sr(TiO)Cu4_{4}(PO4_{4})4_{4}

The structural and magnetic properties of the square-cupola antiferromagnet Sr(TiO)Cu$_{4}$(PO$_{4}$)$_{4}$ are investigated via x-ray diffraction, magnetization, heat capacity, and $^{31}$P nuclear magnetic resonance experiments on polycrystalline samples, as well as density-functional band-structure calculations. The temperature-dependent unit cell volume could be described well using the Debye approximation with the Debye temperature of $\theta_{\rm D} \simeq$ 550~K. Magnetic response reveals a pronounced two-dimensionality with a magnetic long-range-order below $T_{\rm N} \simeq 6.2$~K. High-field magnetization exhibits a kink at $1/3$ of the saturation magnetization. Asymmetric $^{31}$P NMR spectra clearly suggest strong in-plane anisotropy in the magnetic susceptibility, as anticipated from the crystal structure. From the $^{31}$P NMR shift vs bulk susceptibility plot, the isotropic and axial parts of the hyperfine coupling between $^{31}$P nuclei and the Cu$^{2+}$ spins are calculated to be $A_{\rm hf}^{\rm iso} \simeq 6539$ and $A_{\rm hf}^{\rm ax} \simeq 952$~Oe/$\mu_{\rm B}$, respectively. The low-temperature and low-field $^{31}$P NMR spectra indicate a commensurate antiferromagnetic ordering. Frustrated nature of the compound is inferred from the temperature-dependent $^{31}$P NMR spin-lattice relaxation rate and confirmed by our microscopic analysis that reveals strong frustration of the square cupola by next-nearest-neighbor exchange couplings.Comment: 11 pages, 13 figures, 1 table, Phys. Rev. B (Accepted, 2018

Soft White Tissue Detection From Pressure Ulcer Images Using Anisotropic Diffused Total Variation Fuzzy C Means

The goal of image segmentation is to cluster pixels into salient image regions. It can identify the regions of interest in an image or annotate the data. In medical imaging, these segments often correspond to different tissue classes, pathologies, or other biologically relevant structures. Medical image segmentation is made difficult by low contrast, noise, and other imaging ambiguities. The goal of segmentation of pressure ulcer images is to find out the level of tissue wound and soft white tissue present. Soft white tissue protein level changes are mostly found in elderly people. Soft white tissue present may be dark red or light yellow gel based on the different imaging modes of severity of pressure ulcer. This helps in diagnosing the disease and to plan for the treatment. The soft white tissue detection is made difficult for the segmentation because of the noise present in the image. Clustering techniques are best suited to segment the input images with noise. Clustering is usually performed when no information is available concerning to the membership of data items to predefined classes. For this reason clustering is traditionally seen as a part of unsupervised learning

Physical and nutritional factors affecting the production of amylase from species of bacillus isolated from spoiled food waste

Amylase producing Bacillus sp. was isolated from spoiled food waste, which yielded 30 U ml-1 of amylase in medium containing 4% starch and 2% yeast extract at 37°C, pH 7.0 after 20 h of incubation. Maximum amylase activity was at pH 7.0 and 37°C. The enzyme retained 70% activity at pH 9.0. It exhibited 77% activity at 42°C and decreased to a low value of 25% at 52°C proving it as sensitive for temperature. In addition, the identified enzyme showed a maximum activity (32 U/ml) with sodiumdodecyl sulphate compared to other additives. Wheat was found to be a suitable natural source for maximum production of amylase activity. These properties indicated possible use of this amylase in starch saccharification and detergent formulation

Topology and Size Optimization of Composite Ply Cargo Door

Structural optimization has seen accelerated deployment throughout all industries in the past decade, largely due to the recognition that tremendous efficiency gain can be achieved at concept design stage through topology optimization. For composite laminate design a three-phase optimization process is used. The target of the first phase is the material distribution in terms of orientation and thickness. This is achieved through topology optimization where thickness of each 'super-ply' of a unique fiber direction is allowed to change freely throughout the structure. As a result thickness contour of each fiber orientation is obtained. A discrete interpretation of the thickness contour results in concept design of ply layout and thickness. Then in Phase-II the interpreted ply-based structural model is further optimized under all design constraints with discrete design variables representing the number of plies of each ply patch. During Phase-III, ply stacking optimization is performed to refine the design according to detailed manufacturing constraints. All manufacturing constraints are considered throughout all three optimization phases. Such requirement would translate into percentage requirement during Phase-I and II so that a balanced distribution of fiber orientation is achieved to allow feasible stacking during Phase-III. The three-phase optimization process is illustrated in this paper. A unique modeling technique developed in conjunction with the optimization process is the ply-based finite element analysis model where ply entities are defined as sets of elements. Then ply layup is specified by a stack definition. In the following sections the procedure is demonstrated for one of the preliminary configurations developed for the composite cargo door

Institutions, impact synergies and food security: a methodology with results from the Kala Oya Basin, Sri Lanka

Institutional development / Development plans / Development policy / Impact assessment / River basins / Food security / Models