Coupled heat and water transport in frozen soils

The effect of freezing on soil temperature and water redistribution was examined in four Mesocosms maintained at different initial water content profiles. An innovative experimental setup involving use of a frozen base layer acting as a proxy to permafrost beneath an active layer made up of packed and undisturbed peat cores was used. The experimental setup was successfully validated for its ability to maintain one dimensional change in temperature and soil water content in frozen soil. There was a substantial amount of water redistribution towards the freezing front, enough to create an impermeable frozen, saturated zone within 15 cm of the soil surface. The water movement was likely due to the potential head gradients between colder and warmer regions created by temperature effects on matric potential of frozen soil. In addition, there is enough evidence that water migration in form of vapour contributed to moisture movement towards the freezing front. Initial moisture profiles appeared to have a significant effect on the freezing induced soil water redistribution likely through differences in moisture dependant hydraulic conductivity. Initial soil moisture profiles also affected the rate of freezing front movement. Frost propagation was controlled by latent heat for long periods, while soil thermal conductivity and heat capacity appeared to control the rate of frost migration once the majority of water was frozen. Using the observations of this study, a conceptual model was proposed to explain freezing of an active layer on a permafrost plateau assuming a variable moisture landscape at onset of winter. Further, a one-dimensional model based on coupled cellular automata approach was developed. The model is based on first order conservation laws to simulate heat and water flow in variably-saturated soil. Inside the model, Buckingham-Darcy’s -and Fourier’s heat laws are used to define the local interactions for water and heat movement respectively. Phase change is brought about by the residual energy after sensible heat removal has dropped the temperature of the system below freezing point. Knowing the amount of water that can freeze, the change in soil temperature is then modeled by integrating along the soil freezing curve. This approach obviates the use of apparent heat capacity term. The 1D model is successfully tested by comparing with analytical and experimental solutions

Effects of Freezing on Soil Temperature, Freezing Front Propagation and Moisture Redistribution in Peat: Laboratory Investigations

There are not many studies that report water movement in freezing peat. Soil column studies under controlled laboratory settings can help isolate and understand the effects of different factors controlling freezing of the active layer in organic covered permafrost terrain. In this study, four peat Mesocosms were subjected to temperature gradients by bringing the Mesocosm tops in contact with subzero air temperature while maintaining a continuously frozen layer at the bottom (proxy permafrost). Soil water movement towards the freezing front (from warmer to colder regions) was inferred from soil freezing curves, liquid water content time series and from the total water content of frozen core samples collected at the end of freezing cycle. A substantial amount of water, enough to raise the upper surface of frozen saturated soil within 15 cm of the soil surface at the end of freezing period appeared to have moved upwards during freezing. Diffusion under moisture gradients and effects of temperature on soil matric potential, at least in the initial period, appear to drive such movement as seen from analysis of freezing curves. Freezing front (separation front between soil zones containing and free of ice) propagation is controlled by latent heat for a long time during freezing. A simple conceptual model describing freezing of an organic active layer initially resembling a variable moisture landscape is proposed based upon the results of this study. The results of this study will help in understanding, and ultimately forecasting, the hydrologic response of wetland-dominated terrain underlain by discontinuous permafrost

Failure Analysis of Rolling Contact Bearing for Cold Drawing Machine Using Vibration Signal Processing

In rotating machineries, rolling contact bearings are commonly used. Their failure mostly causes down time in plant. In current work ball bearing chrome steel and phosphors bronze material is carried out defects are identified using FFT analyzer in frequency domain. Signal processing is done to simulate the vibration signal obtained from ball bearing. The simulation results are validated with experimental results

Aquatic flora and fauna associated with the freshwater snail Lymnaea acuminata in Kham river at Aurangabad (M.S.)

The present study includes considerable variations in aquatic flora and fauna recorded in Kham River during the period of Jun. 2009 – Sept. 2009. Lymnaea work as vector for various trematode pathogens and it is common in the bitant of the Kham River.Hence the present investigation was undertaken to study other associate flora and fauna in the vicinity of the snail Lymnaea acuminata with their relationship. Density of the molluscan species carried out with the study

A Study of Different Segmentation Techniques to Detect Tumor from Brain MR Images

The brain is the frontal part of the central nervous system. Brain tumor is an irregular growth caused by cells reproducing themselves in an uncontrolled manner. Brain tumor is may be serious and critical because of space formed inside the skull. So detection of the tumor is very important in earlier stages. Brain tumor detection helps in finding the exact size and location of tumor. This paper is the review of different segmentation techniques used in detection of brain tumor. These segmentation techniques use the MRI Scanned Images to detect the tumor in the brain. DOI: 10.17762/ijritcc2321-8169.150314

Cercarial development of Fasciola within the intermediate snail host Lymnaea acuminata from river waters of Aurangabad (M.S.) India

Collection of snail specimens of Lymnaea acuminata was done from river water around the city Aurangabad. Naturally infected snails were identified and dissected in order to study the cercarial development within the snail body. Infected gonads were collected and got processed for general histological study in order to investigate cercarial development. Light microscopic observations of the gonadal sections show various stages of cercarial development within redia of liver fluke, Fasciola. Redia are formed after completion of the sporocyst development. Fully developed rediae are polymorphic shaped sacks having mouth opening at the anterior end. Just behind the collar region at one site there is presence of birthpore which acts as an exit for developing cercaria. From the germinal layer proliferation of germ balls take place vegetatively. At the initial stages of germball development, it is simple ball of cells. On further development it becomes elongated with mesenchyme tissue.Advancement in further development, there starts the formation of digestive system with distinct intestinal lobes or caecae. During post developmental stages there is appearance of pharynx, suckers and tail of cercaria. It seems that cercaria move towards anterior region with progress in their development. Fully developed cercaria having distinct tail gets birth through birthpore

INTEGRATION OF CAD AND CAE IN SME’S FOR PRODUCT DEVELOPMENT

Small manufacturing enterprises face a number of challenges when integrating computer aided design (CAD) tools and computer-aided engineering (CAE) tools into their design processes. One of the most significant challenges is interoperability across the wide range of commercial CAD and CAE tools. Although many of these tools support industry data standards and claim to be interoperable, the connection between them is not seamless. This paper summarizes studies of tool integration activities at one small manufacturer. The paper shows the enhancement of the product development process resulting from replacement of a two dimensional CAD system with a three-dimensional CAD system and creation of an inhouse capability to perform finite element analysis (FEA), replacing analysis that had previously been outsourced. As a result of these experiences, the manufacturer learned that improved productivity and superior designs could be obtained by integrating analysis into the design process at the earlier stages of conceptual and preliminary design