2,690 research outputs found

    Design and Fabrication of Densified Biomass Briquette Maker Machine

    Full text link
    The project we designing & fabricating is to reduce the problems of Cutting Trees for fire logs. “Leaf Log Maker Machine” is designed to make dry leaves get compressed and made to logs as a fuel. Typically, dead leaves are dumped a lot in landfills and one of the problems with leaving wet leaves to decompose like this is that they give off methane 20 times more poisonous gas than carbon dioxide. In contrast, when leaves are burnt, they only give off the carbon they absorb while on the tree they add nothing extra to the environment. This machine is compact, easily accessible & eco-friendly. It can also able to compress wood wastes, papers & tin cans. This machine is to make fuels from the natural resources like dry leaves, instead of cutting them. This machine is easy to understand the operation to user. It had come over many changes and modifications within it

    Production of Biodiesel using waste temple oil from Shani Shingnapur temple (Dist. Ahmednagar), Maharashtra, India using chemical and biological methods

    Full text link
    In India, due to various mythological and religious reasons hundreds of devotees pour oil over the idols in Hanuman or Maruti and Shani temples. The oil once poured cannot be reutilized and was ultimately wasted. These waste temple oil from Shani Shingnapurwas used to produce biodiesel. Immobilized Pseudomonas aeruginosa was used to catalyze transesterification of waste temple oil. The cells of P.aeruginosa were immobilized within the sodium alginate. Biodiesel production and its applications were gaining popularity in recent years due to decreased petroleum based reserves. Biodiesel cost formed from waste temple oil was higher than that of fossil fuel, because of high raw material cost.To decrease the cost of biofuel, waste temple oil was used as alternative as feedstock. It has lower emission of pollutants; it is biodegradable and enhances engine lubricity. Waste temple oil contains triglycerides that were used for biodiesel production by chemical and biological method.Transesterification reaction of oil produces methyl esters that are substitutes for fatty acid alkyl biodiesel fuel. Characteristics of oil were studied such as specific gravity, viscosity, acid number, saponification number.Parameters such as temperature,oil: methanol ratio were studied and 88%, 96% of biodiesel yield was obtained with effect of temperature and oil: methanol ratio on transesterification reaction. Withaddition ofNaOH or KOH to fatty acids which formed salt known as soap,which is excellent emulsifying and cleaning agents

    A validation of the Oswestry Spinal Risk Index

    Get PDF
    Purpose The purpose of this study was to validate the Oswestry Spinal Risk Index (OSRI) in an external population. The OSRI predicts survival in patients with metastatic spinal cord compression (MSCC). Methods We analysed the data of 100 patients undergoing surgical intervention for MSCC at a tertiary spinal unit and recorded the primary tumour pathology and Karnofsky performance status to calculate the OSRI. Logistic regression models and survival plots were applied to the data in accordance with the original paper. Results Lower OSRI scores predicted longer survival. The OSRI score predicted survival accurately in 74% of cases (p = 0.004). Conclusions Our study has found that the OSRI is a significant predictor of survival at levels similar to those of the original authors and is a useful and simple tool in aiding complex decision making in patients presenting with MSC

    Coordination of Mobile Mules via Facility Location Strategies

    Full text link
    In this paper, we study the problem of wireless sensor network (WSN) maintenance using mobile entities called mules. The mules are deployed in the area of the WSN in such a way that would minimize the time it takes them to reach a failed sensor and fix it. The mules must constantly optimize their collective deployment to account for occupied mules. The objective is to define the optimal deployment and task allocation strategy for the mules, so that the sensors' downtime and the mules' traveling distance are minimized. Our solutions are inspired by research in the field of computational geometry and the design of our algorithms is based on state of the art approximation algorithms for the classical problem of facility location. Our empirical results demonstrate how cooperation enhances the team's performance, and indicate that a combination of k-Median based deployment with closest-available task allocation provides the best results in terms of minimizing the sensors' downtime but is inefficient in terms of the mules' travel distance. A k-Centroid based deployment produces good results in both criteria.Comment: 12 pages, 6 figures, conferenc

    Active wetting of epithelial tissues

    Full text link
    Development, regeneration and cancer involve drastic transitions in tissue morphology. In analogy with the behavior of inert fluids, some of these transitions have been interpreted as wetting transitions. The validity and scope of this analogy are unclear, however, because the active cellular forces that drive tissue wetting have been neither measured nor theoretically accounted for. Here we show that the transition between 2D epithelial monolayers and 3D spheroidal aggregates can be understood as an active wetting transition whose physics differs fundamentally from that of passive wetting phenomena. By combining an active polar fluid model with measurements of physical forces as a function of tissue size, contractility, cell-cell and cell-substrate adhesion, and substrate stiffness, we show that the wetting transition results from the competition between traction forces and contractile intercellular stresses. This competition defines a new intrinsic lengthscale that gives rise to a critical size for the wetting transition in tissues, a striking feature that has no counterpart in classical wetting. Finally, we show that active shape fluctuations are dynamically amplified during tissue dewetting. Overall, we conclude that tissue spreading constitutes a prominent example of active wetting --- a novel physical scenario that may explain morphological transitions during tissue morphogenesis and tumor progression

    Atomic-scale perspective on the origin of attractive step interactions on Si(113)

    Full text link
    Recent experiments have shown that steps on Si(113) surfaces self-organize into bunches due to a competition between long-range repulsive and short-range attractive interactions. Using empirical and tight-binding interatomic potentials, we investigate the physical origin of the short-range attraction, and report the formation and interaction energies of steps. We find that the short-range attraction between steps is due to the annihilation of force monopoles at their edges as they combine to form bunches. Our results for the strengths of the attractive interactions are consistent with the values determined from experimental studies on kinetics of faceting.Comment: 4 pages, 3 figures, to appear in Phys. Rev B, Rapid Communication

    Assessment of Physicochemical Parameters from Vermicompost of Eudrilus eugenae and Esienia foetida

    Get PDF
    In present investigation attempt has been made to investigate the physicochemical parameters like pH, temperature, moisture, salinity, nitrogen, electrical conductivity, nitrate, phosphate, chemical oxygen demand (COD) and biological oxygen demand (BOD) from vermicompost of Eudrilus eugenae and Esienia foetida species. The shade of size 10x10 meter and height 1.98 meter was constructed for rearing Eudrilus eugenae and Esienia foetida species. The production of vermicompost was found better in Eudrilus eugenae than Esienia foetida

    Dense active matter model of motion patterns in confluent cell monolayers

    Get PDF
    Epithelial cell monolayers show remarkable displacement and velocity correlations over distances of ten or more cell sizes that are reminiscent of supercooled liquids and active nematics. We show that many observed features can be described within the framework of dense active matter, and argue that persistent uncoordinated cell motility coupled to the collective elastic modes of the cell sheet is sufficient to produce swirl-like correlations. We obtain this result using both continuum active linear elasticity and a normal modes formalism, and validate analytical predictions with numerical simulations of two agent-based cell models, soft elastic particles and the self-propelled Voronoi model together with in-vitro experiments of confluent corneal epithelial cell sheets. Simulations and normal mode analysis perfectly match when tissue-level reorganisation occurs on times longer than the persistence time of cell motility. Our analytical model quantitatively matches measured velocity correlation functions over more than a decade with a single fitting parameter.Comment: updated version accepted for publication in Nat. Com

    Ballistic nanofriction

    Full text link
    Sliding parts in nanosystems such as Nano ElectroMechanical Systems (NEMS) and nanomotors, increasingly involve large speeds, and rotations as well as translations of the moving surfaces; yet, the physics of high speed nanoscale friction is so far unexplored. Here, by simulating the motion of drifting and of kicked Au clusters on graphite - a workhorse system of experimental relevance -- we demonstrate and characterize a novel "ballistic" friction regime at high speed, separate from drift at low speed. The temperature dependence of the cluster slip distance and time, measuring friction, is opposite in these two regimes, consistent with theory. Crucial to both regimes is the interplay of rotations and translations, shown to be correlated in slow drift but anticorrelated in fast sliding. Despite these differences, we find the velocity dependence of ballistic friction to be, like drift, viscous
    corecore