scholarly journals Impacts of Desalinated and Recycled Water in the Abu Dhabi Surficial Aquifer

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2853
Author(s):  
Sadhasivam Sathish ◽  
Claudia Cherubini ◽  
Nicola Pastore ◽  
Concetta I. Giasi ◽  
Dimitra Rapti
Keyword(s):  
Management Practices ◽  
Transport Model ◽  
Three Dimensional ◽  
Radial Distance ◽  
Abu Dhabi ◽  
Recycled Water ◽  
Desalinated Water ◽  
Long Term Storage ◽  
Density Dependent Flow

In Abu Dhabi, one of the most arid regions in the world, in recent decades, desalinated water has been identified as a prime solution in solving the water demand issues. In this study, a three-dimensional coupled density-dependent flow and solute transport model was set up in order to study the effect of the artificial recharge using desalinated water and the influence of nonconventional water with a salt concentration in the range 0.1–2 g/L The results confirm that this region demands the adoption of a more rational use of irrigation water or additional usage of desalinated water and recycled water together with optimizing groundwater pumping at locations that are vulnerable to further quality degradation and depletion. The long-term storage of desalinated freshwater with a maximum radial distance of 653 m in the dune surface is ensured with the formation of the transition zone, and change in the groundwater head up to 5 km. The maximum recovery obtained by immediate recovery is 70%. The study expresses the long-term feasibility of desalinated freshwater storage and the need for further management practices in quantifying the contribution of desalinated and recycled water for agriculture activities which might have improved groundwater quality and increased hydraulic head at some locations.

scholarly journals Long term storage and the compensatory growth of white shrimp Litopenaeus vannamei in aquaculture ponds

2017 ◽  
Vol 44 (3) ◽  
pp. 588-594
Author(s):  
Geraldo Fóes ◽  
Dariano Krummenauer ◽  
Gabriele Lara ◽  
Luis Poersch ◽  
Wilson Wasielesky Jr.
Keyword(s):  
Compensatory Growth ◽  
Management Practices ◽  
Specific Growth ◽  
Survival Rates ◽  
White Shrimp ◽  
Growth And Survival ◽  
Conventional Management ◽  
Long Term Storage ◽  
Term Storage

Effects of shrimp confinement in a situation of high density stocking in a long term nursery on their growth performance in grow out ponds. Were analized two nurseries with a density of 2000 shrimp m-2 were stocked at two different times. The first nursery (LTN) lasted 144 days, and the SGR of the animals was 3.0% day-1. The second nursery (STN) lasted 18 days and the specific growth rate (SGR) was 19.9% day-1. On the same day, shrimps were transferred to six lined ponds at a density of 20 shrimp m2 where they remained for 101 days. In the first biometry, the SGR in the LTN treatment, increased to 6.7% day-1 and in the STN it decreased to 5.0% day-1. At the end, shrimps of the LTN and STN treatments reached weights of 8.46 and 6.72 g and had productivities of 1287 and 1015 kg ha-1, respectively. Shrimps reared in nurseries for long periods showed growth and survival rates similar to those obtained using conventional management practices in grow out structures.

scholarly journals Mid-latitude ozone changes: studies with a 3-D CTM forced by ERA-40 analyses

2007 ◽  
Vol 7 (9) ◽  
pp. 2357-2369 ◽  
Author(s):  
W. Feng ◽  
M. P. Chipperfield ◽  
M. Dorf ◽  
K. Pfeilsticker ◽  
P. Ricaud
Keyword(s):  
Transport Model ◽  
Three Dimensional ◽  
Chemical Transport ◽  
Positive Anomaly ◽  
Small Decrease ◽  
Chemical Transport Model ◽  
Abrupt Changes ◽  
Column Ozone ◽  
The Impact

Abstract. We have used an off-line three-dimensional (3-D) chemical transport model (CTM) to study long-term changes in stratospheric O3. The model was run from 1977–2004 and forced by ECMWF ERA-40 and operational analyses. Model runs were performed to examine the impact of increasing halogens and additional stratospheric bromine from short-lived source gases. The analyses capture much of the observed interannual variability in column ozone, but there are also unrealistic features. In particular the ERA-40 analyses cause a large positive anomaly in northern hemisphere (NH) column O3 in the late 1980s. Also, the change from ERA-40 to operational winds at the start of 2002 introduces abrupt changes in some model fields (e.g. temperature, ozone) which affect analysis of trends. The model reproduces the observed column increase in NH mid-latitudes from the mid 1990s. Analysis of a run with fixed halogens shows that this increase is not due to a significant decrease in halogen-induced loss, i.e. is not an indication of recovery. The model predicts only a small decrease in halogen-induced loss after 1999. In the upper stratosphere, despite the modelled turnover of chlorine around 1999, O3 does not increase because of the effects of increasing ECMWF temperatures, decreasing modelled CH4 at this altitude, and abrupt changes in the SH temperatures at the end of the ERA-40 period. The impact of an additional 5 pptv stratospheric bromine from short-lived species decreases mid-latitude column O3 by about 10 DU. However, the impact on the modelled relative O3 anomaly is generally small except during periods of large volcanic loading.

3D modelling of transport, deposition and resuspension of highway deposited sediments in wet detention ponds

2010 ◽  
Vol 62 (3) ◽  
pp. 736-742 ◽  
Author(s):  
T. R. Bentzen
Keyword(s):  
Transport Model ◽  
Numerical Study ◽  
Wind Waves ◽  
Three Dimensional ◽  
Flume Experiments ◽  
Detention Ponds ◽  
Advection Dispersion ◽  
Simulation Based ◽  
Physical Phenomena

The paper presents results from an experimental and numerical study of flows and transport of primarily particle bound pollutants in highway wet detention ponds. The study presented here is part of a general investigation on road runoff and pollution in respect to wet detention ponds. The objective is to evaluate the quality of long term simulation based on historical rains series of the pollutant discharges from roads and highways. A three-dimensional hydrodynamic and mud transport model is used for the investigation. The transport model has been calibrated and validated on e.g. experiments in a 30 m long concrete channel with width of 0.8 m and a water depth of approximately 0.8 m and in circular flume experiments in order to reproduce near-bed specific processes such as resuspension and consolidation. With a fairly good agreement with measurements, modelling of hydrodynamics, transport of dissolved pollutants and particles in wet detention ponds is possible with application of a three dimensional RANS model and the advection/dispersion equation taken physical phenomena like wind, waves, deposition, erosion and consolidation of the bottom sediment into account.

scholarly journals Localization and Dynamics of the Methionine Sulfoxide Reductases MsrB1 and MsrB2 in Beech Seeds

2021 ◽  
Vol 22 (1) ◽  
pp. 402
Author(s):  
Natalia Wojciechowska ◽  
Agnieszka Bagniewska-Zadworna ◽  
Julia Minicka ◽  
Kornel M. Michalak ◽  
Ewa M. Kalemba
Keyword(s):  
Stress Responses ◽  
Management Practices ◽  
Seed Viability ◽  
Methionine Sulfoxide ◽  
Embryonic Axes ◽  
Long Term Storage ◽  
Protein Storage Vacuoles ◽  
Methionine Sulfoxide Reductases ◽  
Term Storage

Beech seeds are produced irregularly, and there is a need for long-term storage of these seeds for forest management practices. Accumulated reactive oxygen species broadly oxidize molecules, including amino acids, such as methionine, thereby contributing to decreased seed viability. Methionine oxidation can be reversed by the activity of methionine sulfoxide reductases (Msrs), which are enzymes involved in the regulation of many developmental processes and stress responses. Two types of Msrs, MsrB1 and MsrB2, were investigated in beech seeds to determine their abundance and localization. MsrB1 and MsrB2 were detected in the cortical cells and the outer area of the vascular cylinder of the embryonic axes as well as in the epidermis and parenchyma cells of cotyledons. The abundances of MsrB1 and MsrB2 decreased during long-term storage. Ultrastructural analyses have demonstrated the accumulation of these proteins in protein storage vacuoles and in the cytoplasm, especially in close proximity to the cell membrane. In silico predictions of possible Msr interactions supported our findings. In this study, we investigate the contribution of MsrB1 and MsrB2 locations in the regulation of seed viability and suggest that MsrB2 is linked with the longevity of beech seeds via association with proper utilization of storage material.

Modelling of the impact of future climate changes on salt accumulation in paddocks of different soil types due to recycled water irrigation

2015 ◽  
Vol 16 (3) ◽  
pp. 653-666 ◽  
Author(s):  
Muhammad Muhitur Rahman ◽  
Dharma Hagare ◽  
Basant Maheshwari ◽  
Peter Dillon ◽  
Golam Kibria
Keyword(s):  
Transport Model ◽  
Root Zone ◽  
Global Climate Model ◽  
Salt Transport ◽  
Loamy Sand ◽  
Recycled Water ◽  
Salt Accumulation ◽  
Loam Soil ◽  
The Impact

Recycled water contains elevated amounts of salt compared with irrigation water originating from surface water sources. As such, recycled water, if used for irrigation over a long period of time may increase the root zone salinity. However, the phenomenon depends on variability of climatic condition and soil characteristics. In this study, a salt transport model, HYDRUS 1D, was used to predict long-term salt accumulation in two paddocks containing loamy sand and loam soil. The paddocks are located within Western Sydney University, Hawkesbury campus. Impact of rainfall on salt accumulation was studied with the data from the Global Climate Model for the years 2021–2040. The long-term (20 years) salt accumulation showed a cyclical pattern because of variation in rainfall and evapotranspiration. It was found that soil water electrical conductivity (ECSW) was 24% higher in loam soil paddock compared with that of loamy sand. Amount of leachate in the loamy sand paddock was 27% more than the amount leached from that of loam, which may pose a salinity risk to the groundwater if there is a perched aquifer in the field at a depth <1 m. Results from this study indicate that salt accumulation depends on soil type which seems to be more pronounced under low rainfall condition.

scholarly journals Mid-latitude ozone changes: studies with a 3-D CTM forced by ERA-40 analyses

2006 ◽  
Vol 6 (4) ◽  
pp. 6695-6722
Author(s):  
W. Feng ◽  
M. P. Chipperfield ◽  
M. Dorf ◽  
K. Pfeilsticker
Keyword(s):  
Transport Model ◽  
Three Dimensional ◽  
Chemical Transport ◽  
Positive Anomaly ◽  
Small Decrease ◽  
Chemical Transport Model ◽  
Abrupt Changes ◽  
Column Ozone ◽  
The Impact

Abstract. We have used an off-line three-dimensional (3-D) chemical transport model (CTM) to study long-term changes in stratospheric O3. The model was run from 1977–2004 and forced by ECMWF ERA-40 and operational analyses. Model runs were performed to examine the impact of increasing halogens and additional stratospheric bromine from short-lived source gases. The analyses capture much of the observed interannual variability in column ozone, but there are also unrealistic features. In particular the ERA-40 analyses cause a large positive anomaly in northern hemisphere (NH) column O3 in the late 1980s. Also, the change from ERA-40 to operational winds at the start of 2002 introduces abrupt changes in some model fields which affect analysis of trends. The model reproduces the observed column increase in NH mid-latitudes from the mid 1990s. Analysis of a run with fixed halogens shows that this increase is not due to a significant decrease in halogen-induced loss, i.e. is not an indication of recovery. The model predicts only a small decrease in halogen-induced loss after 1999. In the upper stratosphere, despite the modelled turnover of chlorine around 1999, O3 does not increase to the effects of increasing ECMWF temperatures, decreasing modelled CH4 at this altitude, and abrupt changes to the SH temperatures at the end of the ERA-40 period. The impact of an additional 5 pptv stratospheric bromine from short-lived species decreases mid-latitude column O3 by about 10 DU. However, the impact on the modelled relative O3 anomaly is generally small except during periods of large volcanic loading.

scholarly journals Impact of meteorological analyses and chemical data assimilation on modelled long-term changes in stratospheric NO<sub>2</sub>

2012 ◽  
Vol 12 (5) ◽  
pp. 12023-12050
Author(s):  
L. N. Gunn ◽  
M. P. Chipperfield ◽  
W. Feng ◽  
M. Van Roozendael ◽  
M. Gil ◽  
...  
Keyword(s):  
Transport Model ◽  
Three Dimensional ◽  
Tracer Transport ◽  
Chemical Transport Model ◽  
Wind Fields ◽  
Basic Model ◽  
Long Term Changes ◽  
Ozone Trends ◽  
The Mean

Abstract. We have used a three-dimensional (3-D) off-line chemical transport model (CTM) to investigate long-term changes in stratospheric NO2. The basic model was integrated from 1977 to 2001 using ECMWF (European Centre for Medium-Range Weather Forcasts) ERA-40 reanalyses. Additional model runs were performed which assimilated HALOE observations of long-lived tracers to constrain the model trace gas distributions. Assimilation of a single long-lived species (CH4) improves not only the distribution of all other long-lived species, via tracer-tracer correlations, but also shorter lived radical and reservoir species. Assimilation of the long-lived species corrects for errors in the model, due to horizontal transport from the ERA-40 reanalyses, and allows a more direct test of the model's chemistry. The basic model significantly underestimates the observed column NO2 from mid-latitude ground-based sites in the mid-late 1990s. The mean underestimate is ~ 26% for summertime values between 1992 and 1998. Moreover, as the model agreement is better in the early 1990s, it underestimates the increasing trend throughout the decade. However, when the model assimilates HALOE CH4 data both comparisons are greatly improved. The mean model-observation difference reduces to 8% for summertime values and the trend improves. This indicates that given realistic wind fields to constrain the tracer transport, the model chemistry and aerosol schemes are able to reproduce the observed trends in NO2. Implications of this for using analysed wind fields to determine dynamical ozone trends are discussed. Ozone trends derived directly from transport models forced by analysed winds are likely subject to similar errors.

Impacts of Desalinated Irrigation Water in the Abu Dhabi surficial aquifer

2021 ◽  
Author(s):  
Claudia Cherubini ◽  
Sathish Sadhasivam ◽  
Nicola Pastore ◽  
Monica Ghirotti
Keyword(s):  
Management Practices ◽  
Groundwater Resources ◽  
Abu Dhabi ◽  
Aquifer Recharge ◽  
Aquifer System ◽  
Desalinated Water ◽  
Wide Range ◽  
The Arid Regions ◽  
Rainfall Recharge ◽  
Rate Of Evaporation

&lt;p&gt;Abu Dhabi is one of the arid regions in the world having less than 100 mm of rainfall per annum. The renewability of freshwater occurs only in the eastern part. The groundwater resources under desirable quality are very concise due to limited dilution/rainfall and higher rate of evaporation. Hence, in recent decades, desalinated water has been introduced for agriculture activities and surplus desalinated water is injected into the aquifer as artificial recharge. This study is conducted to understand the impacts in the aquifer system caused by the introduction of desalinated water for agriculture activities and for aquifer recharge structures. The simulation was carried out from 2000 to 2050 using reported rate of groundwater pumping and of desalinated water with 0.1 g/l, 0.5 g/l, 1 g/l, 1.5 g/l and 2 g/l degrees of salinity. A wide range of decline in the groundwater table is noticed in the western part of the aquifer due to less rainfall recharge. The results confirm that this region demands either reduction in agricultural activities or additional usage of desalinated water by which the pumping of groundwater can be reduced further. The improvement in the groundwater quality is noticed in the aquifer due to the addition of less saline desalinated water into the aquifer. This study confirms the long term suitability of existing aquifer recharge structure. Also, it expresses the need of further management practices in quantifying the desalinated water contribution for agriculture activities.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

Practical electron tomography

1995 ◽  
Vol 53 ◽  
pp. 742-743
Author(s):  
C.L. Woodcock
Keyword(s):  
Electron Tomography ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3D Shape ◽  
Computational Resources ◽  
Shape Of Particles

Despite the potential of the technique, electron tomography has yet to be widely used by biologists. This is in part related to the rather daunting list of equipment and expertise that are required. Thanks to continuing advances in theory and instrumentation, tomography is now more feasible for the non-specialist. One barrier that has essentially disappeared is the expense of computational resources. In view of this progress, it is time to give more attention to practical issues that need to be considered when embarking on a tomographic project. The following recommendations and comments are derived from experience gained during two long-term collaborative projects.Tomographic reconstruction results in a three dimensional description of an individual EM specimen, most commonly a section, and is therefore applicable to problems in which ultrastructural details within the thickness of the specimen are obscured in single micrographs. Information that can be recovered using tomography includes the 3D shape of particles, and the arrangement and dispostion of overlapping fibrous and membranous structures.

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