Modelling the coefficient of thermal expansion in Ni-based superalloys and bond coatings

The coefficient of thermal expansion (CTE) of nickel-based superalloys and bond coat layers was modelled by considering contributions from their constituent phases. The equilibrium phase composition of the examined materials was determined using thermodynamic equilibrium software with an appropriate database for Ni-based alloys, whereas the CTE and elastic properties of the principal phases were modelled using published data. The CTEs of individual phases were combined using a number of approaches to determine the CTE of the phase aggregate. As part of this work, the expansion coefficients of the superalloy IN-738LC and bond coat Amdry-995 were measured as a function of temperature and compared with the model predictions. The predicted values were also validated with the published data for the single-crystal superalloy CMSX-4 and a number of other Ni-based alloy compositions at 1000 K. A very good agreement between experiment and model output was found, especially up to 800  $$^\circ$$ � C. The modelling approaches discussed in this paper have the potential to be an extremely useful tool for the industry and for the designers of new coating systems

Modelling of microstructural evolution in multi-layered overlay coatings

Functionally graded, multi-layered coatings are designed to provide corrosion protection over a range of operating conditions typically found in industrial gas turbines. A model incorporating diffusion, equilibrium thermodynamics and oxidation has been developed to simulate the microstructural evolution within a multi-layered coating system. The phase and concentration profiles predicted by the model have been compared with an experimental multi-layered system containing an Al-rich outer layer, a Cr-enriched middle layer and an MCrAlY-type inner layer deposited on a superalloy substrate. The concentration distribution and many microstructural features observed experimentally can be predicted by the model. The model is expected to be useful for assessing the microstructural evolution of multilayer coated systems which can be potentially used on industrial gas turbine aerofoils

Eco-Friendly Alternatives for Storage Pest Management:Leaves of Ruta Graveolens (Aruda) as a Repellent Against the Rice Weevil, Sitophilus Oryzae L.

In view of worldwide interest and greater public awareness in finding plant products as the most promising and ecologically safer alternatives for synthetic insecticides in post-harvest protection of stored rice, present study was undertaken to explore the potential of leaves of Ruta graveolens (Aruda) as a repellent against S.oryzae infestations. Leaf powder and solvent extracts of R. graveolens were evaluated for their contact and fumigant repellent properties against seven day old S. oryzae adults. In contact repellency test, weevils (20 each) were exposed to 1.0 g, 3.0 g, 5.0 g, and 7.0 g of leaf powder mixed with white raw rice grains in a modified cup bioassay apparatus. Fumigation repellency of leaf powder was tested using same dosages and the number of weevils in a fumigation-repellency chamber. Number of weevils that moved from the bioassay chamber was recorded one hour after weevil introduction. Leaves of R. graveolens were extracted in hexane, ethyl acetate, methanol, distilled water and different concentrations 10, 50, 100% (v/v) were assessed separately to evaluate repellent activity by means of an area preference bioassay. In all experiments, ten weevils for each were tested and the number repelled was recorded 30 minutes after weevil introduction. Highest contact and fumigant repellent effects were elicited by 7.0 g of leaf powder resulting 96% and 95% respectively, whilst lowest dose also produced more than 50% repellency indicating extremely strong repellent action of the plant powder. In comparison, aqueous extract exhibited the most potent repellent activity (91%) while other extracts were producing over 70% repellent effects on weevils at the concentration of 100% (v/v). Overall findings of the study suggest that both powder and extracts of R. graveolens leaves could be used as eco-friendly agents for post-harvest rice protection. KEYWORDS: Ruta graveolens, Sitophilus oryzae, stored rice, leaf powder, repellen

Applications of Computation-In-Memory Architectures based on Memristive Devices

Today's computing architectures and device technologies are unable to meet the increasingly stringent demands on energy and performance posed by emerging applications. Therefore, alternative computing architectures are being explored that leverage novel post-CMOS device technologies. One of these is a Computation-in-Memory architecture based on memristive devices. This paper describes the concept of such an architecture and shows different applications that could significantly benefit from it. For each application, the algorithm, the architecture, the primitive operations, and the potential benefits are presented. The applications cover the domains of data analytics, signal processing, and machine learning

Pathological Characteristics of Primary Bladder Carcinoma Treated at a Tertiary Care Hospital and Changing Demographics of Bladder Cancer in Sri Lanka

Objectives. The aim was to compare demographics and pathological features of bladder carcinoma treated in a urology unit with findings of previous studies done in Sri Lanka. Materials and Methods. Data of newly diagnosed patients with bladder cancer in a tertiary referral centre from 2011 to 2014 were analysed. Data on bladder cancers diagnosed from 1993 to 2014 were obtained from previous publications and Sri Lanka Cancer Registry. Results. There were 148 patients and mean age was 65 years. Male to female ratio was 4.1 : 1. Urothelial carcinoma (UC) was found in 89.2% of patients. Muscle invasion was noted in 35% of patients compared to 48.4% two decades ago. In patients with UC, 16.5% were found to have pT1 high grade tumour. It was 5.3% from 1993 to 2000. Pure squamous cell carcinoma was found in 8.1% of patients while primary or de novo carcinoma in situ (not associated with high grade pT1 tumours) was seen in one patient only. Conclusions. The percentage of squamous carcinoma is higher among Sri Lankan patients while primary carcinoma in situ is a rarity. The percentage of muscle invasive disease has decreased while the percentage of pT1 high grade tumours has increased during the last two decades in Sri Lanka

Urea-Hydroxyapatite Nanohybrids for Slow Release of Nitrogen

While slow release of chemicals has been widely applied for drug delivery, little work has been done on using this general nanotechnology-based principle for delivering nutrients to crops. In developing countries, the cost of fertilizers can be significant and is often the limiting factor for food supply. Thus, it is important to develop technologies that minimize the cost of fertilizers through efficient and targeted delivery. Urea is a rich source of nitrogen and therefore a commonly used fertilizer. We focus our work on the synthesis of environmentally benign nanoparticles carrying urea as the crop nutrient that can be released in a programmed manner for use as a nanofertilizer. In this study, the high solubility of urea molecules has been reduced by incorporating it into a matrix of hydroxyapatite nanoparticles. Hydroxyapatite nanoparticles have been selected due to their excellent biocompatibility while acting as a rich phosphorus source. In addition, the high surface area offered by nanoparticles allows binding of a large amount of urea molecules. The method reported here is simple and scalable, allowing the synthesis of a urea-modified hydroxyapatite nanohybrid as fertilizer having a ratio of urea to hydroxyapatite of 6:1 by weight. Specifically, a nanohybrid suspension was synthesized by $\textit{in situ}$ coating of hydroxyapatite with urea at the nanoscale. In addition to the stabilization imparted due to the high surface area to volume ratio of the nanoparticles, supplementary stabilization leading to high loading of urea was provided by flash drying the suspension to obtain a solid nanohybrid. This nanohybrid with a nitrogen weight of 40% provides a platform for its slow release. Its potential application in agriculture to maintain yield and reduce the amount of urea used is demonstrated.Authors thank Hayleys Agro Ltd., Sri Lanka for initiating this research programme at SLINTEC and Nagarjuna Fertilizer and Chemical Ltd (NFCL), India for providing further support. Authors acknowledge Mr Sunanda Gunesekara of SLINTEC for assistance with scaling up the production process to enable the field trials. ARK acknowledges the financial support received from ICTPELETTRA Users Program, Trieste, Italy to conduct photoemission experiments at Materials Science beam line (MSB) and ELETTRA SRS on HA and urea coated HA samples. ARK further acknowledges Dr. R.G. Acres of MSB beam line for his extensive support to conduct photoemission experiments. We acknowledge the Department of Agriculture and Rice Research and Development Institute of Sri Lanka, in particular Dr Priyantha Weerasinghe, Mr D Sirisena and Dr Amitha Benthota for the assistance in carrying out pot and farmers filed trials. NFCL and Central Salt & Marine Chemicals Research Institute, Gujarat, India for TEM and BET analysis

Graphene-based Wireless Agile Interconnects for Massive Heterogeneous Multi-chip Processors

The main design principles in computer architecture have recently shifted from a monolithic scaling-driven approach to the development of heterogeneous architectures that tightly co-integrate multiple specialized processor and memory chiplets. In such data-hungry multi-chip architectures, current Networksin- Package (NiPs) may not be enough to cater to their heterogeneous and fast-changing communication demands. This position paper makes the case for wireless in-package networking as the enabler of efficient and versatile wired-wireless interconnect fabrics for massive heterogeneous processors. To that end, the use of graphene-based antennas and transceivers with unique frequency-beam reconfigurability in the terahertz band is proposed. The feasibility of such a wireless vision and the main research challenges towards its realization are analyzed from the technological, communications, and computer architecture perspectives

Buzzing Wild Bee Visits Enhance Seed Set in Eggplant, Solanum melongena

Sixty percent of the angiosperms with poricidal anthers are buzz-pollinated by bees (Hymenoptera: Apoidea: Apiformes). Plant taxa with Solanum-type flowers have larger anthers and shorter filaments. Solanum melongena (Solanaceae) is more commonly and efficiently pollinated by buzz pollinators. The present study documented bees and their diurnal pattern of visitation to flowers, relationship between their handling time and flower age, and the effect of bee visits on fruit and seed set in S. melongena in two sites in Kandy District. Efficiency of buzz pollination over pollination in the absence of bees was determined using open buds and buds covered with pollinator exclusion bags. On average, 150 days were taken to complete the life cycle of Solanum melongena. Three buzzing bees and two nonbuzzing bees in site I and five buzzing bees and two nonbuzzing bees in site II were recorded. Handling time of Pachynomia sp. and Hoplonomia westwoodi indicates that bees spend more time at new flowers than at old flowers. Handling time is higher in the smaller bee, Pachynomia sp., than in the larger bee, H. westwoodi. Statistical data on pollinator exclusion experiment revealed that the fruit set and seed set of S. melongena are enhanced by buzz-pollinating bees