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This article is devoted to study the following quasilinear Schrödinger system with super-quadratic condition: { − Δ u + V 1 (x) u − Δ (u 2) u = h (u , v) , x ∈ R N , − Δ v + V 2 (x) v − Δ (v 2) v = g (u , v) , x ∈ R N , where N ≥ 3 , V 1 (x) , V 2 (x) are variable potentials and h , g satisfy some conditions. By establishing a suitable Nehari-Pohožaev type constraint set and considering related minimization problem, we prove the existence of ground states. [ABSTRACT FROM AUTHOR]

The conventional z-test statistic, which is one of the most popular statistics, is based on the mean of a sample and the standard error of the mean. Consequently, in case of a violation of the normality of the data, the traditional z-test may lead to incorrect test conclusions. The main aim of this article is to present two robust parametric modifications of the traditional z-test statistic. In order to minimize the effect of non-normality due to the presence of the outliers and some potential contaminated observations in a sample we use either the center or the C_2 statistic and their standard errors, respectively, instead of the mean and the standard error of the mean. The statistical power of one-sample z-tests based on the mean, center and C_2 statistics were compared by generating of random number samples with different sizes and known expectations. These samples were derived from some popular distributions. The comparison shows that the z-tests based on the center and the C_2 statistics are more powerful and efficient than the traditional one. In addition, real-data illustrations by implementing both one-sample z-test and two-sample z-test are also provided. [ABSTRACT FROM AUTHOR]

Abstract: De Laet (2015) claimed that minimization of ad hoc hypotheses of homoplasy does not lead to a preference for trivial optimizations when analysing unaligned sequence data, as claimed by Wheeler (2012; see also Kluge and Grant, 2006). In addition, De Laet asserted that Kluge and Grant's (2006) parsimony rationale is internally inconsistent in terms of Baker's (2003) theoretical framework. We argue that De Laet used extraneous presuppositions to critique Wheeler's position and, as such, his criticism should be considered cautiously in terms of its scope. Finally, we demonstrate that considering Kluge and Grant's parsimony rationale as inconsistent rests on De Laet's misunderstanding of the ideographic character concept and the consequences of relating it to Baker's rationale. [ABSTRACT FROM AUTHOR]

Power electronic converters for medium- and high-power/voltage applications employ low-frequency fundamental switching frequencies and, therefore, minimize switching losses. There are two main control techniques of switching angle estimation; total harmonic distortion (THD) minimization and selective harmonic elimination (SHE). In case of the first control technique, the switching angles are found based on THD minimization without being specifically focused on eliminating some exact harmonics. For the SHE control technique, all degrees of freedom, due to available number of switching angles, is used for the elimination of certain low-order harmonics. The basic idea of combining those two control techniques consists of using some degrees of freedom for eliminating certain harmonics and using the others for minimizing the remaining THD content. This generalized problem formulation includes classic minimal THD and SHE problems as special cases. Theoretical developments are verified by the set of experimental cases for the voltage and current THDs selecting characteristic working points over the modulation index range. [ABSTRACT FROM AUTHOR]

In this paper, the waste collection problem (WCP) of a city in the south of Spain is addressed as a multiobjective routing problem that considers three objectives. From the company's perspective, the minimization of the travel cost is desired as well as that of the total number of vehicles. Additionally, from the employee's point of view, a set of balanced routes is also sought. Four variants of a multiobjective hybrid algorithm are proposed. Specifically, a GRASP (greedy randomized adaptive search procedure) with a VND (variable neighborhood descent) is combined. The best GRASP-VND algorithm found is applied in order to solve the real-world WCP of a city in the south of Spain. [ABSTRACT FROM AUTHOR]

Due to continuous increases in water demand, the need for seasonal forecasts of available groundwater resources becomes inevitable. Hydrogeological models might provide a valuable tool for this kind of resource management. Because predictions over short time horizons are foreseen, the reliability of model outputs depends on accurate estimates of the initial conditions (ICs), as well as the estimated parameter values, boundary conditions and forcing terms (e.g., recharge, as well as sinks and sources). Here, we provide an inverse procedure for estimating these ICs. The procedure is based on an adaptive parameterization of the ICs that limits over-parameterization and involves the minimization of an ad hoc objective function. The quasi-Newton algorithm is used for the minimization, and the gradients are computed with an adjoint-state method. Two test cases based on a real aquifer that are designed to evaluate the capability of the method were addressed. It is assumed that the boundary conditions, hydraulic parameters and forcing terms are known from an existing hydrogeological model. In both test cases, the proposed method was quite successful in estimating the ICs and predicting head values that were not used in the calibration. 50 calibrations for each test case have been performed to quantify the reliability of the predictions. [ABSTRACT FROM AUTHOR]

The non-biodegradable wastes have been increasing widely day by day. These wastes not only cause harm to the environment and its resources, but also they have an adverse impact on the human health causing a number of health problems. In order to control this issue, a number of approaches have been done and carried out by the hosts. In the present article, we are discussing this issue taking into consideration certain factors and strategies. The factors of waste disposal were identified to be human health, waste reduction, sustainability, cost effective and environmental benefits using the disposing strategies such as landfills, incineration, energy transform, reuse and recycling. The nonbiodegradable wastes include plastics, construction wastes, metal scraps, rubber tyres, man-made nylons, polyesters, glass, cable wires, cellophane, CDs, DVDs, processed wood, styrofoam, aluminium cans and bottles. The survey was carried out using the Fussy Topsis Method, which is a multi-criteria decision making optimization tool. It helps us in making the best choice out of the available options. The results obtained revealed that recycling is the most efficient method, whereas the landfill is an unpleasant option of solid waste management. [ABSTRACT FROM AUTHOR]

• Zn is directly separated from ZnS in choline chloride-urea-malonic acid (ChCl-urea-MA) deep eutectic solvent. • This process achieves the current efficiency of 86.5 % with the energy consumption of 2621.8 kW·h·t−1. • MA causes 0.13 mol·L-1 ZnS being dissolved to form stable MA-based ligands. • This study initiatively simplifies Zn separation from ZnS in green solution with hazardous waste minimization. Zinc sulfide (ZnS), one of the main ingredients of zinc ore and emerging materials, partly processes environmental risk. Deep eutectic solvents (DESs) are green solvents to efficiently separate metals with less emission. In this study, a novel route for direct electroseparation of Zn from ZnS in eco-friendly choline chloride-urea DES with the addition of malonic acid (MA) is studied for the first time. The role of MA and the reduction behavior of Zn(II) are systematically analyzed by cyclic voltammetry. The reduction of Zn(II) is quasi-reversible and follows one-step two-electron transfer process. Pure Zn with nanostructure is obtained with the current efficiency of 86.5 % and energy consumption of 2621.8 kW·h·t−1 at the optimized parameters of 10 mA·cm−2, 353 K and 100 mM·L-1 ZnS. Mechanisms analyses indicate that in the presence of 60 mM·L-1 MA, besides [ZnCl− 3 ]- and [ZnCl− 5 ]3-, some ZnS are dissolved to form stable [Zn(MA)2-Cl− 2 ]4-, [Zn(MA)2-Cl-]3- and other MA based ligands, which causes a higher Zn ion solubility of 0.13 mol·L-1 and may promote the subsequent electroseparation of ZnS. Results from this study are expected to propose a simplified route to directly separate Zn from ZnS without oxidation pretreatment to achieve hazardous waste minimization. [ABSTRACT FROM AUTHOR]

The ability of an electrical drive to continue operation without tripping in spite of short-duration voltage sags or power supply interruptions is known as power failure ride-through capability. Critical production processes in industries require the drives to smoothly ride-through during momentary power interruptions. The reliability of the drive is dependent on the maximum duration for which a total power supply failure can be tolerated without process interruption. This paper presents a method to extend the duration of the ride-through in voltage-source-inverter-fed vector-controlled induction motor drives with a front-end diode bridge rectifier. The proposed method minimizes the losses in the system during the ride-through, thereby enabling a longer ride-through duration. The method only requires a modification of the control software and hence is easy to implement. This paper also briefly describes two conventional methods used for ride-through and compares the proposed method with the conventional methods to clearly bring out its advantage. Simulation study using MATLAB/PLECS verifies the effectiveness of the proposed method. Hardware implementation of the method on a 30-kW induction machine indicates an extension of up to 34% in the ride-through duration with the proposed method, as compared with the conventional method. [ABSTRACT FROM AUTHOR]

Recent research indicates that many convex optimization problems with random constraints exhibit a phase transition as the number of constraints increases. For example, this phenomenon emerges in the ℓ1 minimization method for identifying a sparse vector from random linear measurements. Indeed, the ℓ1 approach succeeds with high probability when the number of measurements exceeds a threshold that depends on the sparsity level; otherwise, it fails with high probability. This paper provides the first rigorous analysis that explains why phase transitions are ubiquitous in random convex optimization problems. It also describes tools for making reliable predictions about the quantitative aspects of the transition, including the location and the width of the transition region. These techniques apply to regularized linear inverse problems with random measurements, to demixing problems under a random incoherence model, and also to cone programs with random affine constraints. The applied results depend on foundational research in conic geometry. This paper introduces a summary parameter, called the statistical dimension, that canonically extends the dimension of a linear subspace to the class of convex cones. The main technical result demonstrates that the sequence of intrinsic volumes of a convex cone concentrates sharply around the statistical dimension. This fact leads to accurate bounds on the probability that a randomly rotated cone shares a ray with a fixed cone. [ABSTRACT FROM AUTHOR]

Chemical surplus sharing (CSS) programs exist at many universities. These programs have the potential to minimize hazardous waste and reduce costs associated with waste disposal to the university by reducing the amount of chemicals purchased and later disposed of as hazardous waste. In this study, information was collected from EHS personnel at institutions of higher education where CSS programs have been tried. Respondents at many of these institutions considered their CSS programs successful. This investigation derived criteria for evaluating the success of a CSS program and identified elements critical for program success. [Copyright &y& Elsevier]

In this paper, various metal ions were utilized for the demulsification of spent metalworking fluids discharged from an automobile parts workshop. Five types of metal ions, i.e., Fe3+, Al3+, Fe2+, Ca2+ and Mg2+, combined with coagulant were systematically evaluated, and the synergistic effect as well as the optimum operating conditions were studied. The results indicated that the Ca2+ as well Mg2+ possessed hardly efficiency for the demulsification, on the contrary, Fe2+ reduced the yield of the by-product sludge and lowered the SV30 ratio, and Al3+ boosted the CODCr removal. Furthermore, Fe3+ and Al3+ had a significant synergistic effect to achieve a better transmittance and a higher CODCr/SV30 ratio which revealed that more CODCr was removed, as well as less by-product sludge was generated. For a better demulsification of spent metalworking fluids, the optimum operating conditions were gathered as follows: the dosage of metal ions was 0.08 mol/L with Al3+:Fe3+ ratio was 1.5:1, the reaction pH was 6.00, the reaction time was 18.00 min and the temperature was 323.00 K. Based on this, the CODCr removal, the SV30 ratio and the transmittance and CODCr/SV30 ratio of the spent metalworking fluids were 80.21%, 40.00%, 95.20% and 128.33 mg/mL, respectively. This combined metal ion demulsification method possessed an advantageous minimization of spent metalworking fluids, which greatly benefited the automobile parts workshops in cutting down the operating cost in environmental protection. [ABSTRACT FROM AUTHOR]

Identification work of solid wastes' risks is a kind of improvement and amendment for environmental impact assessment document of constructed projectss. In the research, waste identification is classified as per entrustment source and the characteristics of pollution accidents are analyzed, with major problems of National Catalogue of Hazardous Wastes and countermeasures proposed. [ABSTRACT FROM AUTHOR]

The main goal of the vitrification process for environmental research is the destruction of hazardous waste. This study proposes the use of a thermal plasma treatment process to transform fly ash and chromium-rich sewage sludge into glassy products called vitrificates that can be stored on the land without harmful environmental effects. This is achieved by: (i) decreasing the temperature and energy used to adjust process cost minimization; and (ii) stabilization of vitrificates for different compositions of waste mixture. The chemical stabilization of final products was examined by heavy metals leachability tests. Hardness tests were done to verify the physical stabilization of vitrificates. The most stable vitrificates were obtained from a sample consisting of 90 wt% fly ash and 10 wt% chromium sludge. The thermal plasma treatment is an effective method which can be used to convert hazardous waste mixtures into less toxic or inert glassy products. The chemical composition of raw materials influenced the chemical and physical properties of the vitrificates and determined their internal structures. Mixtures of two different hazardous wastes reduces the process cost without negative environmental impact, which is an innovation in thermal plasma treatment technology. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Waste pyrolysis technology as a new method of waste treatment induces more and more attention. Waste pyrolysis technology is not only good for garbage reduction, but also can restrain the generation of dioxin, reaching the target for harmless decrement. We introduced technique process, development situations at home and abroad, existing problems and improvement measures of waste pyrolytic technology. [ABSTRACT FROM AUTHOR]