Simulating NO3-N Transport to Subsurface Drain Flows as Affected by Tillage Under Continuous Corn Using Modified RZWQM

The Root Zone Water Quality Model (RZWQM) was previously modified to simulate subsurface drain flows and evaluate the impact of different tillage systems on subsurface drain flows (Singh and Kanwar, 1994). This article discusses further modifications made in the RZWQM to simulate nitrate-nitrogen (NO3-N) concentrations and NO3-N losses with subsurface drain flows. Daily NO3-N concentrations were simulated in subsurface drain flows under four different tillage systems: chisel plow (CP), moldboard plow (MB), no-tillage (NT), and ridge-tillage (RT) by using the modified RZWQM. Simulations were conducted for the growing seasons of three years (1990 to 1992). Simulated NO3-N concentrations and losses with subsurface drain flows were compared with the measured data obtained from a water quality research site at Nashua, Iowa. Predicted NO3-N concentrations generally followed the same pattern as the observed concentrations. Simulated annual average NO3-N concentrations in subsurface drain flows were within 11% (averaged over all three years) of observed annual average NO3-N concentrations in subsurface drain flows. The model correctly predicted maximum concentrations under MB treatment and minimum under NT for all three years. Simulated annual NO3-N losses were within 14% (averaged over all three years) of observed annual NO3-N losses. Various NO3-N transformation processes need to be calibrated as a function of tillage system to improve model performance

Modification of RZWQM for Simulating Subsurface Drainage by Adding a Tile Flow Component

Fluctuating water table and subsurface drain flow components were incorporated in the Root Zone Water Quality Model (RZWQM) to enable the model to simulate subsurface drain flows. Parameters in a modified model were calibrated using observed subsurface drain flows for 1990. Model performance was evaluated by predicting subsurface drain flows for 1991 and 1992 by using the calibrated parameters and comparing the predicted drain flows with observed subsurface drain flows for the same years. The modified RZWQM model, in general, showed a good response to rainfall in terms of time of peak flows. However, the modified RZWQM model overpredicted total tile flows by an average of 13%, and the magnitudes of peak tile flows were generally underpredicted. Selected soil properties (bulk density, macroporosity, and residue content) in the surface horizon were changed to investigate tillage effects on tile flows using the modified RZWQM. Four different tillage systems, chisel plow (CP), moldboard plow (MB), no-tillage (NT), and ridge-tillage (RT), were considered. Predicted tillage effects on subsurface drain flows were consistent with the observed effects (i.e., maximum tile flow for NT and minimum tile flow for MB)

Benchmarking Scalability of NoSQL Databases for Geospatial Queries

NoSQL databases provide an edge when it comes to dealing with big unstructured data. Flexibility, agility, and scalability offered by NoSQL databases become increasingly essential when dealing with geospatial data. The proliferation of geospatial applications has tremendously increased the variety, velocity, and volume of data that the data stores must manage. Such characteristics of big spatial data surpassed the capability and anticipated use cases of relational databases. Because we can choose from an extensive collection of NoSQL databases these days, it becomes vital for organizations to make an informed decision. NoSQL Database benchmarks provide system architects, who shoulder a considerable burden of selecting the right technology for their data stores, with a vital start point and source of information. The major utility of these benchmarks is reproducing experiments on similar experimental data that can verify and optimize the process of selecting an optimum tool for data management needs in the early phases of the development. The goal of this research is to develop a benchmark that can compare the performance of NoSQL databases for querying complex geospatial data. We have analyzed throughputs, latencies, and runtime of MongoDB and Couchbase to identify the correct fit for our use case. This way we have also demonstrated a systematic process that can be followed to make an optimum choice of datastore. This benchmark can be extended easily to any NoSQL database that supports geospatial querying

Effect of Graphene Quantum Dots on Health and Environment: Implications for Everyday Life

Organic nanomaterials are carbon-based materials, which have dimensions in the range of 10-9 metres and are being utilised in a myriad of commercial applications. Quantum dots are unique particles with the size less than 10 nm. These particles have found to have excellent physicochemical properties as well as photolumincent abilities. However, the effect of continuous exposure to these particles has not been studies. Furthermore, more the production of these GQD from sources such as cigarette ash or fuel exhaust has not been reported. In this work we have attempted to understand the effect the of long-term effect of exposure to the GQD by estimating the in vitro cytotoxicity of the GQD by assays such as MTT, TBARS, ROS generation and the effect on protein misfloding over a period longer than hours. Further, we have tried to understand the effect that these particles have on the natural environment in terms of their effect on freezing point depression of water, the effect of the GQD on the biofilm formation as and health effects such as calcification of the arteries due to aggregation of calcium salts on the GQD particles

Immigration and Internal Security: Global Trends and Lessons for Andaman and Nicobar Islands

Migrations have been a universal phenomenon since the dawn of human civilization. The immigrations and emigrations have shaped the historical dynamics of almost all the major nations of the world and particularly those ones who owe their genesis and have thriven due   to the process of migration. In the contemporary times the issue of migration has elicited reactions from subtle to knee jerk from its sympathizers as well as detractors, the world over. The gravity of migration issue in the 21st century cannot be underestimated especially in the light of happenings in west Asia and north Africa with an unprecedented influx of masses from the war ravaged countries of the region to safer havens in Europe and to lesser extent, America. In the Indian context, the sub-continental drifts from the neighbouring countries particularly Bangladesh and Myanmar towards India have long created tensions in the border regions, both between the countries as well the communities. The violence based on ethnic nationalism has often been a logical corollary of such influx in India’s north eastern states.  Narrowing down to Andaman and Nicobar Islands, the strategic bio-diverse sentinel of India with window to the south east Asia, the unsolicited and unchecked immigrations have become serious security as well as socio-economic threat. The menace could attain an altogether different dimension because of the geographical remoteness of these Islands from the mainland India and their proximity to the nations of south east Asia.  A concrete immigration policy, hence, needs to be in place so as to differentiate between the infiltrators and the asylum seekers without jeopardizing the fragility of the Islands along with the humanitarian perspective. Keywords: Andaman and Nicobar Islands, immigration, migration, security, terrorism, refugees, policy

States, firms, and oil : British policy, 1939-54

New evidence from the records of the Anglo-Iranian Oil Company (now British Petroleum) and Shell for the period, 1939-45 supplements accounts of British oil relations based on state archives. This historical account demonstrates the continuity between the interwar industry cartel and the Allied wartime collaboration orchestrated through industry committees. The companies made use of their quasi-official position to manage crisis of prewar arrangements aggravated by the war which presaged the rapid expansion of postwar Middle East production. The companies then shaped the Anglo-American Oil Agreements of 1944 and 1945, establishing a basis for remaking their position in the Middle East, expanding the web of interfirm relations. The nationalisation of Anglo- Iranian in 1951 threatened the web and the companies were able to embargo nationalised Iranian oil and thus bankrupt the state. This society of oil majors was constituted by shared understandings and interests cultivated by the companies. Structures of private governance may be quite significant factors for states allied to them. The United Kingdom was more closely tied into the system of private governance that prevailed in international oil in the middle decades of the century than was the United States and consequently was able to call on more resources to resist United States initiatives during this period. British influence persisted in the oil issue-area, in spite of greater United States resources overall, because of this close working relationship between state and companies. Close examination of the relationship reveals the extent of penetration by the companies into both the decision-malting and implementation of foreign relations. The `national' interest was thus articulated through an interplay of Governmental and corporate agendas, and this supports a general argument that `national' power is not exercised solely by the state, but by the state in cooperation with other powerful social institutions. Non-state actors and their archives may enrich the study of foreign relations

Bama’s Sangati: A Traumatic Chain of Gender Discrimination

Sangati (1994), a novel in translation from Tamil to English, is the second work of Bama (b.1958) also known as Bama Faustina Soosairaj, a Dalit feminist. It is a unique novel without any marked plot or central character, and it seeks to explore the impact of a number of discriminations suffered by Dalit Christian women. This paper is a realistic investigation into the text of the novel to find out the events of gender discrimination resulting into subjugation and marginalization of women especially Dalit women, like Velliaiyamma, Mariamma, Thayi, Vasuki, Maikkani, Maikkani’s mother, Esakki and the narrator herself. All of them are exploited by the male members of their family as well as society and bear the traumatic behaviour at every step of their pathetic lives. In the broad light of day, they are entertained as the home servants and in darkness of night; they are treated as an object of sexual satisfaction.  Women have been declared as misbegotten and treated as animals, objects of sexual pleasure, and slaves of men who have their birthrights to exploit, to beat, to burn them alive and so on

Movement of NO3-N and atrazine through soil columns as affected by lime application

Lime (CaCO3) applied to the soil, to minimize or neutralize the soil pH, can influence the fate and transport of other chemicals in soil. This study was conducted to investigate the effect of lime application on the movement of NO3-N and atrazine through soil columns under saturated and unsaturated conditions

Calibration and Evaluation of Subsurface Drainage Component of RZWQM V.2.5

This study was designed to calibrate and evaluate the subsurface drain flow component of the Root Zone Water Quality Model (RZWQM; Version 2.5) for four tillage-systems: chisel plow (CP), moldboard plow (MB), no-tillage (NT), and ridge-tillage (RT). Measured subsurface drain flow data for 1990 was used for model calibration. Main parameters calibrated were lateral saturated hydraulic conductivity, and effective porosity. Subsurface drain flow predictions were made using calibrated parameters and compared with measured subsurface drain flows for 1991 and 1992. Measured subsurface drain flow data for all 3 yrs was obtained from the Nashua Water Quality Site in Iowa. The model, in general, showed a good agreement between measured and predicted subsurface drain flow values, although discrepancies existed for several days of a given year. Coefficients of determination calculated for predicted vs. measured daily subsurface drain flows ranged from 0.51 to 0.68 for 1990, 0.70 to 0.78 for 1991, and 0.54 to 0.69 for 1992. Simulated tillage effect on subsurface drain flows for 1991 and 1992 were consistent with those for calibrated year 1990 (maximum subsurface drain flow was observed under NT and minimum under MB). However, observed tillage effects varied from year to year, indicating a change in soil hydraulic properties, e.g., macroporosity. Other factors that could have caused the discrepancies between measured and simulated subsurface drain flows were: groundwater flux due to natural gradient, deep seepage, inaccuracies involved in the estimation of breakpoint rainfall data, and spatial variability in soil properties

Evaluation of the root zone water quality model for predicting water and NO3–N movement in an Iowa soil

Evaluation of computer models with field data is required before they can be effectively used for predicting agricultural management systems. A study was conducted to evaluate tillage effects on the movement of water and nitrate–nitrogen (NO3–N) in the root zone under continuous corn (Zea mays L.) production. Four tillage treatments considered were: chisel plow (CP), moldboard plow (MP), no-tillage (NT), and ridge-tillage (RT). The root zone water quality model (RZWQM: V.3.25) was used to conduct these simulations. Three years (1990–1992) of field observed data on soil water contents and NO3–N concentrations in the soil profile were used to evaluate the performance of the model. The RZWQM usually predicted higher soil water contents compared with the observed soil water contents. The model predicted higher NO3–N concentrations in the soil profile for MP and NT treatments in comparison with CP and RT treatments, but the magnitude of simulated NO3–N peak concentrations in the soil profile were substantially different from those of the observed peaks. The average NO3–N concentrations for the entire soil profile predicted by the model were close to the observed concentrations except for ridge tillage (percent difference for CP=+5.1%, MP=+12.8%, NT=+18.4%, RT=−44.8%). Discrepancies between the simulated and observed water contents and NO3–N concentrations in the soil profile indicated a need for the calibration of plant growth component of the model further for different soil and climatic conditions to improve the N-uptake predictions of the RZWQM