Modelling groundwater flow in a variably-connected aquifer-stream system

University of Technology, Sydney. Faculty of Engineering and Information Technology.Catchments with variably-connected surface and subsurface flow systems are not uncommon in Australia or through various parts around the globe. Management of the available groundwater and surface water resources in such generic types of catchments is critical to ensure the sustainability of these valuable assets. This requires a decision making to be based on quantitative estimates of available volumes in the various interconnected water bodies, usually derived via suitable modelling. Fully coupled modelling of such systems still faces several complications such as: proper choice of spatial scale that better represents the interconnected system; availability and ease of access to the data required; availability of capable software to perform the simulation; and, occasionally certain jurisdictional conflicts- where these water bodies cross the trans-boundaries between neighbouring regions. Under these challenges, pseudo coupling- a less data-intensive but still rigorous modelling of aquifer-stream system- can provide estimates of acceptable accuracy for management decisions about the resource. Therefore, the primary objectives of the present research were to investigate the effect of variable model cell dimensions on the resulting simulated aquifer-stream water balance estimates; and to develop a pseudo-coupled groundwater-surface water model of a representative catchment with an unregulated intermittent stream. The first objective is to prove the effect of grid resolution on the calculated water balance components in modelling an interconnected aquifer-stream regime. Such analysis is of high importance for resolving double accounting and related issues in management of water allocations. This objective has been accomplished by pseudo coupling of MODFLOW with RIV and STR algorithms and MODFLOW-SURFACT with RIV applied to a synthetic aquifer-stream. Six cell resolutions (lOxlO, 25x25, 50x50, lOOxlOO, 150x150, and 250x250 m) were developed for pumping and nonpumping scenarios. It was found that as the cell dimension increases, the difference in the exchanged fluxes between the river and the aquifer also increases and could be more than 100% of the base case (i.e. the 1 Ox 10 m mesh, which has cell dimensions equal to the river width). The outcomes of the grid variation experiment were applied to a three-dimensional flow model with grid resolution of 250 x 255 m for the entire aquifer-stream system in Zone 2 of Cox's Creek Catchment. The MODFLOW-SURFACT and RIV algorithm has been utilised in the pseudo-coupled simulation of the groundwater and surface water regimes over 24 years. The qualitative assessments and the quantitative calibration measures illustrated that the model could reproduce the observed groundwater level variations. The hydrographs support the observational inference that the lower aquifers are probably used for irrigation more than the upper one. The contribution of Cox's Creek to the total inflow recharge is about 2852 ML/yr, which is nearly 13.4% of the total feed to the aquifers, and is around three times that from rainfall. The aquifers recharge the Cox's Creek by approximately 111 ML/yr (0.5% of the total groundwater outflow). The Creek receives the least amount of its flow from the underlying aquifers, a finding which supports the work of other researchers. The simulated monthly average leakage and baseflow of the Creek were 7.76 and 0.26 ML respectively throughout the simulation. These values provide further evidence that the Creek is generally a losing stream. While the simulation model has been designed for Zone 2 in the Cox's Creek region, it has potential for application to other catchments with unregulated intermittent streams. Such merits should prove helpful to decision makers in managing water resources in regions of similar character

SIMULTANEOUS DETERMINATION OF TARTRAZINE AND BRILLIANT BLUE IN FOODSTUFFS BY SPECTROPHOTOMETRIC METHOD

Objective: Objective of the study was to develop a simple spectrophotometric method for simultaneous determination of two colorants, Tartrazine (T) and Brilliant Blue (BB), in foodstuffs without any prior treatment.Methods: Derivative spectrophotometric (DS) and spectrophotometric methods were applied for the determination of (T) and (BB), respectively.Results: Tartrazine was determined by first derivative spectrophotometry at 454 nm (1D454); where Brilliant blue was determined by zero-order spectrum at 630 nm. Linearity ranges were 2-24 ðœ‡g/ml for (T) and 2-14 ðœ‡g/ml for (BB), regression analysis showed a good correlation co-efficient R2=0.9999 and R2=0.9998 for (T) and (BB), respectively. The limit of detection (LOD) and limit of quantification (LOQ) was to be 0.12 and 0.35 ðœ‡g/ml for (T), 0.17 and 0.52 ðœ‡g/ml for (BB), respectively.Conclusion: The proposed methods were successfully applied to analysis individual or mixture of Tartrazine and Brilliant Blue in foodstuffs. All studied samples showed dye levels conformity with Syrian legislation. Â

Simultaneous Determination Of Atenolol And Hydrocholrothiazide In Tablets Formulation By Derivative Spectrometry

The derivative spectrophotometric method was developed and applied for the simultaneous determination of Atenolol (ATE) and Hydrochlorothiazide (HCT) in Tablets formulations. The first derivative spectrophotometric (1DS) method was applied for the determination of (ATE) and (HCT), respectively. (ATE) was determined at 271.9 nm (1D 271.9) and (HCT) was determined at 279.3 nm (1D 279.3). Linearity showed a good correlation coefficients R2 = 0.9994 and R2 = 0.9989 for (ATE) and (HCT), respectively. Linearity ranges were (10 – 280

Determination of Glibenclamide By Analytical Spectrophotometry

Simple and rapid spectrophotometric method was developed and applied to determine Glibenclamide (GB) by zero spectrophotometric method and first derivative spectrophotometric method for determining of (GB) in the presence of Metformin hydrochloride (MET). Zero spectrophotometric (ZS) method was applied for the determination of (GB) at λmax = 300 nm. Linearity range was (4 – 360) μg/mL. Regression analysis showed a good correlation coefficients R2 = 0.99993. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.65 μg/mL and 2.31 μg/mL, respectively.  First derivative spectrophotometric (1DS) method was applied for the determination of (GB) in the presence (MET). (GB) was determined at 317 nm (1D317). Linearity ranges were (4 – 240) μg/mL for (GB). Regression analysis showed a good correlation coefficients R2 = 0.999914. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.60 μg/mL and 1.83 μg/mL for (GB). The proposed zero spectrophotometry method was applied to analysis individual (GB), and the derivative (1D317) method was applied to analysis (GB) individually or combined with (MET) in Syrian trademark drugs. The proposed method is simple, direct, sensitive and do not require any extraction process. Thus, this method could be readily applicable for the quality control and routine analysis

Attitudes Of Mathematics Teachers Toward Using Smart Board In Teaching Mathematics

This study aimed at investigating the attitudes of mathematics teachers toward using a smart board in teaching mathematics and also to determine the effect of gender, experience, and qualification of teachers on their attitudes. The sample of this study consisted of 74 mathematics teachers - 35 males and 39 females - from private schools in Amman city in Jordan. Means and standard deviations and T-test were used to analyze the results. The results of the study revealed that the mathematics teachers have positive attitudes toward using a smart board in teaching mathematics. Results showed that there is no statistically significant difference due to gender variable; however, there were statistically significant differences due to experience variable and due to qualification variable

Determination of Pitavastatin Calcium by Analytical Spectrophotometry

Simple and rapid spectrophotometric method for the quantitative analysis of Pitavastatin calcium (PTV) in raw material and tablets pharmaceutical formulation has been described. The method is based on the formation of yellow ion-pair complex between Pitavastatin calcium and Bromocresol purple (BCP) in chloroform medium. Different parameters affecting the reaction such as: effect of solvents, stability, reagent concentration, correlation ratio, etc. were optimized. The formed complex was quantified spectrophotometrically at absorption maximum 405 nm. Linearity range was 2.20 - 35.23 µg/mL, regression analysis showed a good correlation coefficient R2 = 0.9991. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.367 µg/mL and 1.112 µg/mL respectively. The average percent recovery was found to be (100.62 – 101.14) % for Pitavastatin Calcium. This study was applied on Syrian pharmaceutical trademark: (PAVACRIUM 4 & Londalop). The method was successfully applied for the determination of Pitavastatin calcium in tablets pharmaceutical formulation. The proposed method is simple, direct, sensitive and do not require any extraction process. Thus, this method could be readily applicable for the quality control and routine analysis

Estimating Willingness to Pay to Protect Acequia Irrigation and Culture: Lessons from San Miguel County, NM

[EN] Traditional gravity fed irrigation systems in Hispano communities in New Mexico, USA, are referred to as acequias. Water scarcity is currently motivating negotiations between acequias and municipalities over sharing agreements. Research on willingness to pay to protect and maintain acequias is still scarce. These valuation data could be helpful to improve the quality of water resources decision making and therefore rural development strategies in this region, which is relatively poor compared to the US average. Data from an open-ended CVM survey are used to examine WTP for a program designed to strengthen and perpetuate irrigation and culture on the acequias of El Río de las Gallinas, in rural northeastern New Mexico. Results indicate that the community supports the program in general, with higher levels of support among rural residents and Anglos.Raheem, N. (2015). Estimating Willingness to Pay to Protect Acequia Irrigation and Culture: Lessons from San Miguel County, NM. En Irrigation, Society and Landscape. Tribute to Tom F. Glick. Editorial Universitat Politècnica de València. 963-987. https://doi.org/10.4995/ISL2014.2014.205OCS96398

Enantioselective sensors and biosensors for clinical analysis

The enantioanalysis of compounds of biological importance with a chiral moiety is very important because each enantiomer is a marker for a different disease. Accordingly, very reliable methods of enantioanalysis should be employed for the correct diagnosis of the diseases. The utilization of amperometric biosensors and enantioselective, potentiometric membrane electrodes made the assay of a single enantiomer faster, easier and more reliable if one compare with the chromatographic techniques which are widely proposed for this kind of analyses. Monocrystalline diamond was proposed as matrix for amperometric electrodes and amperometric biosensors design. The advantages of using such material for electrode design are: (a) lower background currents and noise signals, which lead to improve S/B and S/N ratios, and lower detection limits; (b) good electrochemical activity (pre-treatment is not necessary); (c) wide electrochemical potential window in aqueous media; (d) very low capacitance; (e) extreme electrochemical stability; and (f) high reproducibility of analytical information. The design selected for the electrodes is simple, fast and reproducible. The carbon or diamond powders were mixed with paraffine oil to give the carbon or diamond paste which can act alone as electroactive material in the electrodes or it can be modified with a chiral selector (e.g., cyclodextrins, maltodextrins or antibiotics) or enzyme (e.g., L(D)-aminoacid oxidase, L-lysine oxidase). The results obtained by employing the amperometric electrodes and biosensors and the enantioselective, potentiometric membrane electrodes proved a high sensitivity, selectivity, accuracy and high reliability. These characteristics made them suitable to be used for the enantioanalysis of different compounds of biological importance (e.g., pipecolic acid, glyceric acid, 2-hydroxyglyceric acid, fucose, L-vesamicol and L-lysine) in serume and/or urine samples. The features of the proposed enantioselective, amperometric and potentiometric electrodes proposed in this thesis are their utilization for in vivo measurements and as detectors in flow systems (flow injection analysis or/and sequential injection analysis). This will simplify the enantioanalysis and will improve considerable the reliability of the analytical information favorazing a fast and accurate diagnosis of the diseases associated with the marker determined.Thesis (PhD (Chemistry))--University of Pretoria, 2006.Chemistryunrestricte

Resolution of five-component mixture using mean centering ratio and inverse least squares chemometrics

BACKGROUND: A comparative study of the use of mean centering of ratio spectra and inverse least squares for the resolution of paracetamol, methylparaben, propylparaben, chlorpheniramine maleate and pseudoephedrine hydrochloride has been achieved showing that the two chemometric methods provide a good example of the high resolving power of these techniques. Method (I) is the mean centering of ratio spectra which depends on using the mean centered ratio spectra in four successive steps that eliminates the derivative steps and therefore the signal to noise ratio is improved. The absorption spectra of prepared solutions were measured in the range of 220–280 nm. Method (II) is based on the inverse least squares that depend on updating developed multivariate calibration model. The absorption spectra of the prepared mixtures in the range 230–270 nm were recorded. RESULTS: The linear concentration ranges were 0–25.6, 0–15.0, 0–15.0, 0–45.0 and 0–100.0 μg mL(-1) for paracetamol, methylparaben, propylparaben, chlorpheniramine maleate and pseudoephedrine hydrochloride, respectively. The mean recoveries for simultaneous determination were between 99.9-101.3% for the two methods. The two developed methods have been successfully used for prediction of five-component mixture in Decamol Flu syrup with good selectivity, high sensitivity and extremely low detection limit. CONCLUSION: No published method has been reported for simultaneous determination of the five components of this mixture so that the results of the mean centering of ratio spectra method were compared with those of the proposed inverse least squares method. Statistical comparison was performed using t-test and F-ratio at P = 0.05. There was no significant difference between the results