Modeling Groundwater Flow and Seawater Intrusion in the Coastal Aquifer of Wadi Ham,UAE

Groundwater pumping from Kalbha and Fujairah coastal aquifer of the United Arab Emirates (UAE) has increased significantly during the last two decades to meet the agriculture water demands. Due to the lack of natural replenishment from rainfall and the excessive pumping, groundwater levels have declined significantly causing an intrusion of seawater in the coastal aquifer of Wadi Ham. As a result, many pumping wells in the coastal zone have been terminated and a number of farms have been abandoned. In this paper, MODFLOW was used to simulate the groundwater flow and assess the seawater intrusion in the coastal aquifer of Wadi Ham. The model was calibrated against a five-year dataset of historical groundwater levels and validated against another eleven-year dataset. The effects of pumping on groundwater levels and seawater intrusion were investigated. Results showed that reducing the pumping from Khalbha well field will help to reduce the seawater intrusion into the southeastern part of the aquifer. Under the current groundwater pumping rates, the seawater will continue to migrate inland.     

Use of a thiamine antagonist to evaluate the effects of thiamine deficiency on lake trout embryonic development

To more fully understand the secondary effects of thiamine deficiency on embryo development of lake trout Salvelinus namaycush, we used an immersion protocol to administer graded doses of the thiamine antagonist oxythiamine (OXY) (e.g., 0, 12.5, 25, 50, 100, 200, and 400 mg/L). OXY was administered to eggs of six families at water hardening (fertilization) with the intent that early mortality syndrome (EMS), an acute thiamine deficiency mortality, would only occur at the highest OXY concentration. We assessed the effect of OXY and family on the occurrence of EMS and other embryonic mortality, and alevin growth dynamics up until 2 weeks post emergence. EMS reached only 4% at the highest OXY concentration (400 mg/L) where there was a significant decline in alevin length and yolkless alevin dry weight but not the dry weight of alevins whose yolk-sac was still attached. The dry weight of the yolk-sac as a percentage of total alevin dry weight was lower than controls at low concentrations of OXY (12.5, 25 mg/L), but higher than controls at the highest concentration of OXY (400 mg/L). OXY appeared to exert its effect on growth through reduced yolk-sac utilization although the mechanism(s) involved is unknown. Reduced growth and yolk-sac utilization of alevins resulting from thiamine deficiency may contribute to mortality through decreased ability of affected alevins to secure food and avoid predation. We conclude that even for very low EMS, alevin growth effects resulting from thiamine deficiency may pose a significant impediment to lake trout reproduction.     

Electroless Ni-B supported on carbon for direct alcohol fuel cell applications

Ni-B coatings were deposited by electroless technique onto the surface of commercial carbon electrodes for direct alcohol fuel cell applications. An acidic bath having nickel chloride as a source of nickel and dimethyleamine borane (DMAB) as a reducing agent was used to prepare the electroless Ni-B coatings. The boron content of the Ni-B/C deposits was determined by inductively coupled plasma-mass spectrometer (ICP-MS) and its value was 5 wt%. The influence of deposition time of the Ni-B coatings on the electrooxidation of methanol and ethanol was studied. The structural and textural properties of Ni-B/C coatings were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The fabricated Ni-B/C electrodes exhibited enhanced electrocatalytic activity towards electrooxidation of methanol and ethanol in 1.0 M NaOH. The Ni-B/C catalyst that was prepared after 60 min displayed a higher electrocatalytic activity compared to the other Ni-B/C prepared electrodes or the electroless Ni-P/C electrode. The stability of Ni-B/C electrodes towards the electrooxidation process improves as the time of Ni-B deposition increases; additionally, it is superior to that of Ni-P/C electrode prepared at the same deposition time. The surface coverage of the redox species, the number of monolayer of Ni-B and the transfer coefficient α has been determined.     

EM‐based yield optimization exploiting trust‐region optimization and space mapping technology

Design centering is a design problem which looks for nominal values of circuit parameters that maximize the probability of satisfying the design specification (yield function). Direct yield optimization of electromagnetic (EM)‐based circuits is obstructed by the high expense of EM simulations required in the yield estimation process. Also, the absence of any gradient information represents an obstacle against the optimization process. In this article, a new approach for design centering and yield optimization of EM‐based circuits is introduced. In the proposed approach, the generalized space mapping (SM) technique is incorporated with a derivative‐free trust region optimization method (NEWUOA). Moreover, a variance reduction sampling technique is implemented in the yield estimation process. Two techniques suitable for the microwave circuit design centering process are introduced. The first technique exploits the surrogate developed using any circuit optimizer, for example, minimax optimizer, in the yield maximization process. While the second technique iteratively constructs and updates an SM surrogate during the yield optimization process. Our novel approach is illustrated by practical examples showing its efficiency. One of the examples is entirely designed within the sonnet em environment. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:474–484, 2015.     

Finite iterative Hermitian R-conjugate solutions of the generalized coupled Sylvester-conjugate matrix equations

In this paper, an iterative algorithm for solving a generalized coupled Sylvester-conjugate matrix equations over Hermitian $R$-conjugate matrices given by $A_{1}V{B}_1+C_{1}W{D}_1=E_1\overline{V}{F}_1+G_1$ and $A_{2}V{B}_2+C_{2}W{D}_2=E_2\overline{V}{F}_2+G_2$ is presented. When these two matrix equations are consistent, the convergence theorem shows that a solution can be obtained within finite iterative steps in the absence of round-off error for any initial arbitrary Hermitian $R$-conjugate solution matrices $V_1$, $W_1$. Some lemmas and theorems are stated and proved where the iterative solutions are obtained. A numerical example is given to demonstrate the behavior of the proposed method and to support the theoretical results.     

Heat and mass transfer from a laminar humid air stream to a plate at subfreezing temperatureTransfert de chaleur et de masse entre un écoulement laminaire d'air humide et une plaque à une température inférieure au point de congélation

Processes involving the transfer of heat from a humid air stream in laminar flow to a horizontal plate with the simultaneous deposition of frost is of importance in a variety of refrigeration equipment. The accumulating frost layer impedes the heat flow to the cooling surface. The present study is carried out to determine both theoretically and experimentally the factors that influence, frost formation on a cold surface and to correlate the Nusselt and Sherwood numbers with these factors.Experiments were conducted on a 600 mm long, flat horizontal plate, the Reynolds number and the relative humidity of the impinging air stream were varied from 30 000 to 140 000 and from 40% to 60% respectively, while the average surface temperature was near - 18°C. Empirical correlations of the Nusselt number and Sherwood number are presented.     

Generating Arabic text in multilingual speech-to-speech machine translation framework

The interlingual approach to machine translation (MT) is used successfully in multilingual translation. It aims to achieve the translation task in two independent steps. First, meanings of the source-language sentences are represented in an intermediate language-independent (Interlingua) representation. Then, sentences of the target language are generated from those meaning representations. Arabic natural language processing in general is still underdeveloped and Arabic natural language generation (NLG) is even less developed. In particular, Arabic NLG from Interlinguas was only investigated using template-based approaches. Moreover, tools used for other languages are not easily adaptable to Arabic due to the language complexity at both the morphological and syntactic levels. In this paper, we describe a rule-based generation approach for task-oriented Interlingua-based spoken dialogue that transforms a relatively shallow semantic interlingual representation, called interchange format (IF), into Arabic text that corresponds to the intentions underlying the speaker’s utterances. This approach addresses the handling of the problems of Arabic syntactic structure determination, and Arabic morphological and syntactic generation within the Interlingual MT approach. The generation approach is developed primarily within the framework of the NESPOLE! (NEgotiating through SPOken Language in E-commerce) multilingual speech-to-speech MT project. The IF-to-Arabic generator is implemented in SICStus Prolog. We conducted evaluation experiments using the input and output from the English analyzer that was developed by the NESPOLE! team at Carnegie Mellon University. The results of these experiments were promising and confirmed the ability of the rule-based approach in generating Arabic translation from the Interlingua taken from the travel and tourism domain.     

Genetic Programming to Predict Bridge Pier Scour

Bridge-pier scour is a significant problem for the safety of bridges. Extensive laboratory and field studies have been conducted examining the effect of relevant variables. This note presents an alternative to the conventional regression-based equations (HEC-18 and regression equation developed by the writers), in the form of artificial neural networks (ANNs) and genetic programming (GP). There had been 398 data sets of field measurements that were collected from published literature and were used to train the network or evolve the program. The developed network and evolved programs were validated by using the observations that were not involved in the training. The performance of GP was found more effective when compared to regression equations and ANNs in predicting the scour depth at bridge piers.     

Triangle Routing Problem in Mobile IP

Mobile Internet Protocol is a recommended Internet protocol designed to support the mobility of a user （host）. Host mobility is becoming important because of the recent blossoming of laptop computers and the high desire to have continuous network connectivity anywhere the host happens to be. The development of Mobile IP makes this possible. The traditional Mobile IP specification forces all packets forwarded to the MN （mobile node）, to be routed via HA （home agent）, which often leads to Triangular routing, which in turn causes data transmission delay and wastes network resources. This paper discusses means of resolving the triangle routing problem, it introduces some of the recent route optimization schemes that have been used to solve that problem.     

Phase error analysis of the effect of feed movement on bandwidth performance of a broadband X‐Ku band reflectarray

A new cell element is introduced for broadband reflectarray applications. The presented unit cell exhibits linear phase response which makes it a suitable candidate for broadband X‐Ku band applications. This cell element consists of three concentric rectangular loops etched on a two‐layer grounded substrate. The dimensions of the cell element have been optimized to achieve linear phase response in the operation band. A square offset‐fed reflectarray of 40 cm × 40 cm was designed and fabricated based on this unit cell with wideband performance at X‐Ku band. Considering three different feed positions, the whole reflectarray was simulated in CST and good agreement between simulated and measured results was observed. A maximum gain of 32 dBi was obtained which is equivalent to 58% aperture efficiency. Also, a remarkable value of 36%, 1.5‐dB gain bandwidth was measured which is higher compared to previously reported designs in the literature. Another investigation that is carried out in this development through theory and simulation is determination of the effect of feed movement along the focal axis on the operating band of the reflectarray. It is shown for the first time that changing the feed location leads to a considerable shift in the operation bandwidth and maximum gain of the designed broadband reflectarray. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.