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In this study, we simulate the irrigation of tomato plants with arsenic (As)-contaminated water (from 0 to 3.2 mg L −1 ) and investigate the effect of the application of silicon nanoparticle (Si NPs) in the form of silicon dioxide (0, 250, and 1000 mg L −1 ) on As uptake and stress. Arsenic concentrations were determined in substrate and plant tissue at three different stratums. Phytotoxicity, As accumulation and translocation, photosynthetic pigments, and antioxidant activity of enzymatic and non-enzymatic compounds were also determined. Our results show that irrigation of tomato plants with As-contaminated water caused As substrate enrichment and As bioaccumulation (roots > leaves > steam), showing that the higher the concentration in irrigation water, the farther As translocated through the different tomato stratums. Additionally, phytotoxicity was observed at low concentrations of As, while tomato yield increased at high concentrations of As. We found that application of Si NPs decreased As translocation, tomato yield, and root biomass. Increased production of photosynthetic pigments and improved enzymatic activity (CAT and APX) suggested tomato plant adaptation at high As concentrations in the presence of Si NPs. Our results reveal likely impacts of As and nanoparticles on tomato production in places where As in groundwater is common and might represent a risk.

Sequential batch reactor is widely used for industrial wastewater treatment. To consider sequential batch reactor for biological treatment of wastewater at a specific site, it is essential to ensure economy and sustainability. An approach for scrutiny of economic aspects may be based upon use of cost functions to compare sequential batch reactor and other technologies. Such approach will enable to conduct prudent analysis and select the most economic treatment scheme for a particular project. In most of published studies, the cost functions for conventional wastewater treatment systems are described with historic or some other data available to the investigators. No detailed engineering exercise related to cost functions for sequential batch reactor is cited in earlier research studies. In this document the novel and appropriate methodology has been presented to develop cost functions based on engineering, estimation and statistical approach to forecast cost for sequential batch reactor based wastewater treatment system.

Water is essential to all lifeforms including various ecological, geological, hydrological, and climatic processes/activities. With the changing climate, associated El Niño/Southern Oscillation (ENSO) events appear to stimulate highly uncertain patterns of precipitation (P) and evapotranspiration (EV) processes across the globe. Changes in P and EV patterns are highly sensitive to temperature (T) variation and thus also affect natural streamflow processes. This paper presents a novel suite of stochastic modelling approaches for associating streamflow sequences with climatic trends. The present work is built upon a stochastic modelling framework (HMM_GP) that integrates a hidden Markov model (HMM) with a generalised Pareto (GP) distribution for simulating synthetic flow sequences. The GP distribution within the HMM_GP model aims to improve the model’s efficiency in effectively simulating extreme events. This paper further investigated the potential of generalised extreme value distribution (GEV) coupled with an HMM model within a regression-based scheme for associating the impacts of precipitation and evapotranspiration processes on streamflow. The statistical characteristic of the pioneering modelling schematic was thoroughly assessed for its suitability to generate and predict synthetic river flow sequences for a set of future climatic projections, specifically during ENSO events. The new modelling schematic can be adapted for a range of applications in hydrology, agriculture, and climate change.

This paper presents the methodology for the determination of integrated cost functions to estimate the forecast level cost for biological treatment of wastewater by use of Moving Bed Biofilm Reactor–one of the space-saving wastewater treatment options for improvement of local infrastructure. The cost functions developed are useful for inflows over a broad range and have been derived based on process design and cost estimation but not on collection of historic cost data. The same have been validated by the determination of mean absolute percentage error. Cost function equations for small and large capacities are noted to be best expressed by polynomial equations. Cost function equation for medium capacities is best expressed by linear equation. The values of determination coefficient R 2 of the cost functions for small, medium and large capacities are 0.9968, 0.9988 and 0.9988, respectively. The respective values of mean absolute percentage errors with reference to cost functions for small, medium and large capacities are 1.35%, 1.12% and 0.91%, respectively, which are well below the benchmark 10%. It is established from the study that accurate cost forecasts can be made by cost functions developed for small, medium and large capacities of biological treatment of wastewater by use of Moving Bed Biofilm Reactor.

Adaptation, a complex bilingual and bicultural process, is further problematised in a colonial scenario inflected by burgeoning nationalism and imperialist counter-oppression. Nagendranath Bose’s Karnabir (1884/85), the second extant Bengali translation of Macbeth was written after the First War of Indian Independence in 1857 and its aftermath - the formation of predominantly upper and middle class nationalist organisations that spearheaded the freedom movement. To curb anti-colonial activities in the cultural sphere, the British introduced repressive measures like the Theatre Censorship Act and the Vernacular Press Act. Bengal experienced a revival of Hinduism paradoxically augmented by the nationalist ethos and the divisive tactics of British rule that fostered communalism. This article investigates the contingencies and implications of domesticating and othering Macbeth at this juncture and the collaborative/oppositional strategies of the vernacular text vis-à-vis colonial discourse. The generic problems of negotiating tragedy in a literary tradition marked by its absence are compounded by the socio-linguistic limitations of a Sanskritised adaptation. The conflicted nature of the cultural indigenisation evidenced in Karnabir is explored with special focus on the nature of generic, linguistic and religious acculturation, issues of nomenclature and epistemology, as well as the political and ideological negotiations that the target text engages in with the source text and the intended audience.

Large attenuation of arsenic is observed in a shallow aquifer in central Mexico, where the concentration decreases from 91.5 to 11.3 mg/L, over 1.3 km horizontal distance. To investigate possible mechanisms of attenuation of this pollutant, we dug a pit between the surface and the saturated zone. We then described the soil profile and determined arsenic and iron concentrations in soil samples as a function of depth. Next, we determined particle size distribution, bulk density, particle density, soil moisture and porosity of the soil material. We also analyzed arsenic concentration in the groundwater. The 2.2 m deep profile intersected 4 soil horizons (A, AB, B1 and B2). We found arsenic accumulation in the B2 horizon, directly overlying the saturated zone. These accumulations coincide with the thickness of the capillary fringe, revealing that arsenic is drawn up in the soil profile by capillary rise of arsenic-contaminated groundwater. Furthermore, arsenic accumulation showed a direct relationship with iron, likely due to arsenic adsorption on iron oxides. Results from this study contribute to understanding a capillary-driven natural attenuation mechanism that removes contaminants from groundwater by sinking them in the capillary fringe.

This paper considers a single server queue that operates in a random environment defined by an alternating renewal process with states 1 and 2. When the random environment is in state i ( i = 1, 2), the arrivals occur at a mean rate of i and the distribution of service-time for these arrivals is B i ( t ). The server is working when the random environment is in state 1 and not working when the state is 2. This model is applicable to situations in manufacturing, computer and telecommunications problems when the server is subject to random breakdown. It is also useful in modeling some priority and cyclic server queues. We analyze the problem by first examining the steady-state distribution of work in the system. We show that the work in the system is closely related to the waiting time in a special GI / G /1 queue. For the special case when the off-period is exponentially distributed, exact closed-form expressions are obtained for the performance measures of interest. For other cases, we propose an approximation and show that it works well when compared with simulations.

In this note, we show that for a stationary FCFS G/G/ 1 queue, the virtual waiting time and the time spent in the system by the customer in service have the same distribution. We assume that the latter is zero if the queue is empty.

In this note, we show that for a stationary FCFS G/G/1 queue, the virtual waiting time and the time spent in the system by the customer in service have the same distribution. We assume that the latter is zero if the queue is empty.

We have two aims in this paper. First, we generalize the well-known theory of matrix-geometric methods of Neuts to more complicated Markov chains. Second, we use the theory to solve a last-come-first-served queue with a generalized preemptive resume (LCFS-GPR) discipline. The structure of the Markov chain considered in this paper is one in which one of the variables can take values in a countable set, which is arranged in the form of a tree. The other variable takes values from a finite set. Each node of the tree can branch out into d other nodes. The steady-state solution of this Markov chain has a matrix product-form, which can be expressed as a function of d matrices Rl,· ··, Rd. We then use this theory to solve a multiclass LCFS-GPR queue, in which the service times have PH-distributions and arrivals are according to the Markov modulated Poisson process. In this discipline, when a customer's service is preempted in phase j (due to a new arrival), the resumption of service at a later time could take place in a phase which depends on j. We also obtain a closed form solution for the stationary distribution of an LCFS-GPR queue when the arrivals are Poisson. This result generalizes the known result on a LCFS preemptive resume queue, which can be obtained from Kelly's symmetric queue.