Stress and Strength Evaluation of Double Lap Adhesive Joint.

This paper summarizes the evaluation of stress and strength of double lap adhesive joint. Stress and deformation of the double lap adhesive joint is obtained by finite element analysis using ANSYS and strength is obtained by experimental method. Joint failure is one of the main causes of interruption of rotating or stationary machinery operation. This generally leads to unscheduled shut down thereby increasing the cost of operations. One of the major concerns in adhesive joint is the detection of the rupture initiation and strength of joint before it develops into a failure of material. The ability to achieve strength of adhesive joint is essential to the optimal maintenance of whole system with respect to cost and productivity. The effects of the length of adherend, width of adherend, the overlapping length of the joint, the thickness of the adhesive layer and the initial impact velocity of the impacted mass on the double lap adhesive joint are studied. Early detection of the stresses and rupture in the joint are crucial for the prevention of damage to the system

Geospatial assessment of groundwater quality in the Noyyal basin, Tamil Nadu, India using GIS and geostatistics

Water is crucial in agriculture, domestic use and industrial development. In recent years, the demand for groundwater has significantly risen due to industrialization, urbanization, population growth and increased agricultural activities. This study focuses on the groundwater quality spatial distribution and utilizes geostatistical analysis to predict groundwater chemical parameters within the Noyyal sub-basin, employing Geographic Information System (GIS) technology. Data transformation methods were applied to reduce skewness in several chemical parameters to improve the precision of the spatial representation of groundwater chemistry. Comparing the calculated concentrations to the established permissible limits showed that calcium, bicarbonate and sodium absorption ratio concentrations were within acceptable levels. In contrast, parameters such as magnesium, sodium, potassium, chlorine, sulfate, fluoride, pH, total hardness, electrical conductivity and total dissolved solids exceeded the permissible thresholds. The study also identified the most appropriate semi-variogram model for each water quality parameter based on the Root Mean Square Error (RMSE). The Exponential model with log-transformed data was the best fit for Ca, Na, K, HCO3, pH, HAR and EC, providing physically meaningful results. For TDS, Mg, SO4, F and SAR, the Spherical model with log-transformed data yielded the most reliable RMSE values. The Gaussian model produced satisfactory results for Cl and Na %

EVALUATION OF THRUST FORCE IN DRILLING OF BD-CFRP COMPOSITE USING TAGUCHI ANALYSIS, RESPONSE SURFACE METHODOLOGY AND NEURAL NETWORK

Drilling is the most frequently used machining operation in carbon fiber reinforced polymer (CFRP) composite materials. The quality of the drilled holes is significantly affected by the thrust force generated during drilling of CFRP composite materials. In the present work, an attempt has been made to study the effects of process parameters such as feed rate, spindle speed, drill diameter and point angle on thrust force in drilling of bi-directional carbon fiber reinforced polymer (BD-CFRP) composite laminate using Taguchi design of experiments (DOE), the response surface methodology (RSM) and the genetic algorithm optimized radial basis function neural network (GA-RBFNN). The analysis of variance (ANOVA) is also performed for investigating the influence of process parameters on machining process using high speed steel (HSS) drills. The results reveal that the drill diameter is the most significant design factor influencing the thrust force followed by the spindle speed. It is evident from the investigation that the experimental results of the thrust force in drilling of BD-CFRP composite laminate are in good agreement with the predicted results as per RSM and GA-RBFNN

Assessment of Irrigation Water Loss and Water Balance in the Thenpennaiyaru Basin of Tamil Nadu, India

This study employed a comprehensive technique for the systematic estimate of the water balance in Thenpennaiyaru river basin irrigation systems (TRB-IS) in Tamil Nadu, India. KRP reservoir and Sathanur reservoir in TRB are the primary water sources in the study area. We computed the actual water loss in open canals (e.g., leakage and evaporation). A water balance technique provides for the accounting of various system volume inputs (e.g., water abstraction, imported water, water volume owing to precipitation or surface runoff), authorized consumptions, and water losses in canals and intermediate reservoirs. The proposed methodology enables the evaluation of various water loss components (e.g., evaporation losses, unauthorized uses, metering errors, leakage, and discharges) and the calculation of water loss performance indicators that enable the identification of the most significant water loss problems and provide guidance for managing water losses. The approach is evaluated and implemented using a hybrid irrigation system. Results indicate that discharges in canal systems account for over half of the total volume of water loss, followed by leakage in canals and metering problems. These findings emphasize the need to enhance the everyday operation of these systems and restore their infrastructures

Handoffs in User-Centric Cell-Free MIMO Networks: A POMDP Framework

We study the problem of managing handoffs (HOs) in user-centric cell-free massive MIMO (UC-mMIMO) networks. Motivated by the importance of controlling the number of HOs and by the correlation between efficient HO decisions and the temporal evolution of the channel conditions, we formulate a partially observable Markov decision process (POMDP) with the state space representing the discrete versions of the large-scale fading and the action space representing the association decisions of the user with the access points (APs). We develop a novel algorithm that employs this model to derive a HO policy for a mobile user based on current and future rewards. To alleviate the high complexity of our POMDP, we follow a divide-and-conquer approach by breaking down the POMDP formulation into sub-problems, each solved separately. Then, the policy and the candidate pool of APs for the sub-problem that produced the best total expected reward are used to perform HOs within a specific time horizon. We then introduce modifications to our algorithm to decrease the number of HOs. The results show that half of the number of HOs in the UC-mMIMO networks can be eliminated. Namely, our novel solution can control the number of HOs while maintaining a rate guarantee, where a 47%-70% reduction of the cumulative number of HOs is observed in networks with a density of 125 APs per km2. Most importantly, our results show that a POMDP-based HO scheme is promising to control HOs.Comment: Accepted in IEEE Transactions on Wireless Communications (TWC

Surface runoff estimation using geographic information system and soil conservation service-curve number method for sub catchments of Karamadai, Tamil Nadu

Water conservation becomes essential as the resource becomes scarcer. The most important step in managing water resources is estimating watershed runoff generated from rainfall, as the runoff and rainfall are the key factors in determining water availability for surface storage and groundwater recharge. So, this study is mainly focused on estimating the surface runoff generated from the three sub-catchments of Karamadai, Tamil Nadu, India, using the heavy to extreme daily rainfall events received in the study area within the span of 20 years (2000–2019). The study was performed in the ArcGIS environment using remote sensing data. The SCSCN (Soil Conservation Service-Curve Number) method was used to estimate surface runoff. The changes in the land use in each sub-catchment were analysed in each decade and studied for their impact on the runoff depth. The land use and land cover classification map of the study area was prepared from LISS III satellite imagery for the years 2006 and 2016 by using supervised classification. The curve number was assigned based on land use as well as the hydrologic soil group. The weighted curve number was calculated from the area under each land use and then used to calculate storm runoff. The maximum runoff occurred in 2011 in all the catchments of the Karamadai block. It was found that more runoff occurred in the Mandrai Pallam catchment compared to Periya Pallam and Pare Pallam, as the Mandrai Pallam catchment had less soil moisture retention capacity than the other two catchments. So, more priority must be given to this catchment while planning to implement the soil and water conservation measures

Optimal signal timing for an oversaturated arterial intersection at road networks

Traffic congestion occurs frequently at downtown intersections during rush hours, at road construction zones as well as at accident sites. Under such circumstances, traffic flow exceeds intersection capacity causing queuing of automobiles that cannot be eliminated in one signal cycle. The objective of this work is to present a discrete minimal delay model to minimize the delay time of vehicles at each intersection by minimizing the total number of vehicles at each intersection at the signalized two intersections arterial. Discrete dynamic optimization models are developed and an algorithm to solve them is presented. The optimal cycle length and the optimal assigned green time for each approach are determined for the case of two-phase control. The initial number of vehicles at each lane at the intersections is counted by a camera which is the most exact method among other existing methods. The model is developed to minimize the number of waiting vehicles from cycle to cycle. The proposed model is solved by the method of sequential quadratic programming coded in MATLAB environment