16,582 research outputs found

    Water Quality Monitoring and Constituent Load Estimation in the Upper Illinois River Watershed, 2009

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    The Arkansas Water Resources Center (AWRC) monitored water quality at eight sites in the Upper Illinois River Watershed (UIRW) during base flow conditions and storm events from July 1, 2009 through June 30, 2010. Water samples were collected manually with an alpha or Kemmerer style sampler and analyzed for nitrate-nitrogen (NO₃-N), sulfate (SO₄), chloride (Cl), soluble reactive phosphorus (SRP), total phosphorus (TP), dissolved ammonia (NH₃-N), total N (TN), total suspended solids (TSS), and turbidity. Physico-chemical parameters were measured in the field including pH, conductivity, water temperature, and dissolved oxygen concentration. The selected sites were at established discharge monitoring stations maintained by the US Geological Survey or AWRC, and constituent loads were determined using regression models between constituent concentrations, discharge, and seasonal factors to estimate daily loads, which were then summed to produce monthly and annual load estimates. The constituent loads and annual flow-weighted concentrations for the 2009 calendar year are summarized in the tables below, using the data collected in this study. The regression models were applied throughout the discharge record of the entire calendar year to estimate loads. Summary of calculate

    Illinois River Volunteer Monitoring

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    Understanding how water quality conditions change along a land use gradient and over time is important for sustainable watershed management. Therefore, a volunteer monitoring program was created to measure water chemistry at 37 established sites within the Upper Illinois River Watershed and to evaluate changes in water chemistry over the past 15 years. The Illinois River Watershed Partnership (IRWP), a non‐profit organization subcontracted with the Arkansas Water Resources Center at the University of Arkansas, to manage the volunteer monitoring project, train volunteers to collect samples following EPA approved methods, and to analyze the collected samples. The AWRC trained 27 volunteers to collect water samples at 37 sites that were previously sampled in 1993 and 1994. Samples were collected during baseflow conditions during September and December 2008 and February and May 2009 and analyzed for soluble reactive phosphorus, nitrate‐nitrogen, sulfate, chloride, fluoride, total phosphorus, total nitrogen, total suspended solids, and turbidity. Geomean concentrations were calculated and compared to the concentrations observed during the 1993‐1994 study. Overall, total phosphorus and soluble reactive phosphorus concentrations significantly increased at 14% and 11% of the sampled sites, respectively, between the previous and current studies, while respective concentrations significantly decreased at 8% and 16% of sampled sites. The greatest reductions in phosphorus concentrations occurred at sites downstream of effluent discharges, and both total phosphorus and soluble reactive phoshporus concentrations were positevely correlated to pasture and urban land use within the catchment (R²= 0.11, P=0.045; R²= 0.16, P=0.015, respectively). Similarly,both total nitrogen and nitrate‐nitrogen concentrations were positvely correlated to urban and pasture land use (R²= 0.38, P \u3c 0.0001; R²=0.29, P=0.0006, respectively), and 5% and 14% of the sampled sites significantly increased in total nitrogen and nitrate nitrogen concentrations, respectively, between the two study periods. Overall, very few significant changes in water quality (i.e., water chemistry) were observed over the last 15 years; those changes that were most noticeable resulted from either improvements in the phosphorus mangement of waterwater treatment facilities or the introdiction of effluent discharge into a new receiving stream. Volunteer monitoring programs are an excellent way to promote environmental education and stewardship, and these programs can be useful in documenting changes in watershed conditions over time

    Computation using Noise-based Logic: Efficient String Verification over a Slow Communication Channel

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    Utilizing the hyperspace of noise-based logic, we show two string verification methods with low communication complexity. One of them is based on continuum noise-based logic. The other one utilizes noise-based logic with random telegraph signals where a mathematical analysis of the error probability is also given. The last operation can also be interpreted as computing universal hash functions with noise-based logic and using them for string comparison. To find out with 10^-25 error probability that two strings with arbitrary length are different (this value is similar to the error probability of an idealistic gate in today's computer) Alice and Bob need to compare only 83 bits of the noise-based hyperspace.Comment: Accepted for publication in European Journal of Physics B (November 10, 2010

    The thinning of lamellae in surfactant-free foams with non-Newtonian liquid phase

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    Thinning rates of liquid lamellae in surfactant-free non-Newtonian gas–liquid foams, appropriate for ceramic or polymer melts and also in metals near the melting point, are derived in two dimensions by matched asymptotic analysis valid at small capillary number. The liquid viscosity is modelled (i) as a power-law function of the shear rate and (ii) by the Ellis law. Equations governing gas–liquid interface dynamics and variations in liquid viscosity are derived within the lamellar, transition and plateau border regions of a corner of the liquid surrounding a gas bubble. The results show that the viscosity varies primarily in the very short transition region lying between the lamellar and the Plateau border regions where the shear rates can become very large. In contrast to a foam with Newtonian liquid, the matching condition which determines the rate of lamellar thinning is non-local. In all cases considered, calculated lamellar thinning rates exhibit an initial transient thinning regime, followed by a t−2 power-law thinning regime, similar to the behaviour seen in foams with Newtonian liquid phase. In semi-arid foam, in which the liquid fraction is O(1) in the small capillary number, results explicitly show that for both the power-law and Ellis-law model of viscosity, the thinning of lamella in non-Newtonian and Newtonian foams is governed by the same equation, from which scaling laws can be deduced. This result is consistent with recently published experimental results on forced foam drainage. However, in an arid foam, which has much smaller volume fraction of liquid resulting in an increase in the Plateau border radius of curvature as lamellar thinning progresses, the scaling law depends on the material and the thinning rate is not independent of the liquid viscosity model parameters. Calculations of thinning rates, viscosities, pressures, interface shapes and shear rates in the transition region are presented using data for real liquids from the literature. Although for shear-thinning fluids the power-law viscosity becomes infinite at the boundaries of the internal transition region where the shear rate is zero, the interface shape, the pressure and the internal shear rates calculated by both rheological models are indistinguishable

    Value Addition to Organically Produced Naturally-Coloured Cotton under Contract Farming

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    The Agricultural Research Station of the University of Agricultural Sciences, Dharwad, Karnataka, has released a naturally-coloured cotton variety, DDCC–1. To popularize this variety, its large scale cultivation in Uppinabetageri village of the Dharwad district was arranged under contract farming system in collaboration with Khadi Nekar Sahakari Utpadak Sangha, Niyamita, which buys back cotton of the contract farmers and processes it into garments for marketing. This study has analysed the value addition to naturally-coloured cotton at different stages of processing. It has been found that during ginning one quintal of colour cotton yielded 35 kg lint, 64 kg seed and 1 kg of waste. This lint underwent spinning process and yielded 29.69 kg yarn and 5.31 kg waste. The yarn underwent the weaving process and yielded 28.96 kg cloth and 0.98 kg. waste. The 29.96 kg cloth has been found equivalent to 106.28 metres of cloth. While preparing (cuttings) shirts, 1.28 m of waste material was obtained. Finally, 42 shirts were made from 105 m of cloth. The study has found that an additional value of Rs 5,875 was generated through processing kapas into cotton garments (shirts). Its break-up at different levels of processing has been recorded as follows: ginning, Rs 327 (5.57%); spinning, Rs 781 (13.30%); weaving, Rs 1626 (27.68%); and garments manufacturing, Rs 3140 (53.45%).Crop Production/Industries,

    Water Quality Sampling, Analysis and Annual Load Determinations for Nutrients and Solids on the Ballard Creek, 2008

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    The Arkansas Water Resources Center monitored water quality at Ballard Creek at the Washington County Road 76 Bridge in northwest Arkansas during base flow and storm events from July 1, 2008 through June 30, 2009. Water samples were collected manually or with an auto-sampler and analyzed for nitrate-nitrogen, ammonia-nitrogen, total nitrogen, total phosphorus, soluble reactive phosphorus, sulfate, chloride and total suspended solids. Instantaneous stage and discharge were recorded at the site; total annual discharge was 55,800,000 m³ , with 27% attributed to base flow and 73% attributed to storm flow. Loads were estimated using the mid-interval integration approach using continuous discharge (i.e., 30 min intervals) and measured concentrations as applied to sampling intervals; the incremental loads were then summed to get annual loads for the 2008 calendar year. The constituent loads and annual flow-weighted concentrations are summarized in the table below, using data collected through this study (July through December 2008) plus data from the prior study (January through June 2008)

    Water Quality Sampling, Analysis and Annual Load Determinations for the Illinois River at Arkansas Highway 59 Bridge, 2008

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    The Arkansas Water Resources Center monitored water quality at the Illinois River at the Arkansas Highway 59 Bridge, just upstream from the Arkansas-Oklahoma state border during base flow and storm events from July 1, 2008 through June 30, 2009. Water samples were collected manually or with an auto-sampler and analyzed for nitrate-nitrogen, ammonia-nitrogen, total nitrogen, total phosphorus, soluble reactive phosphorus, sulfate, chloride and total suspended solids. The U.S. Geological Survey recorded instantaneous stage and discharge at the site, total annual discharge was 1,010,000,000 m³ , with 37% attributed to base flow and 63% attributed to storm flow. Loads were estimated using the mid-interval integration approach using continuous discharge (i.e., 30 min intervals) and measured concentration as applied to sampling intervals; the incremental loads were then summed to get annual loads for the 2008 calendar year. The constituent loads and annual flow-weighted concentrations for the 2008 calendar year are summarized in the table below, using data collected through this study (July through December 2008) plus data from the prior study year (January through June 2008)

    Palaeopathology and horse domestication: the case of some Iron Age horses horn the Altai Mountains, Siberia

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    We discuss the use of palaeopathological indicators in horse skeletons as potential sources I of evidence about the use of horses for riding and traction. We suggest that this type of information can provide an important and perhaps more reliable complement to other indicators of domestication such as morphological changes, kill-off patterns and bit wear, which suffer from various ambiguities of interpretation. We emphasise the importance of studying the skeletons of modern control samples of horses of known life histories as a constraint on the interpretation of palaeopathological evidence and demonstrate the viability of the technique through a comparison of free-living Exmoor ponies with Iron Age Scythian horse remains from Siberia. We demonstrate that stresses caused by riding produce characteristic lesions on the vertebrae which can be distinguished from age-related damage in free-living animals, and in addition that these stresses could have been moderated by changes of saddle design in the Medieval period. These results also throw new light on customs associated with horse burial

    Osteochondrosis lesions of the lateral trochlear ridge of the distal femur in four ponies

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    Lesions of the lateral trochlear ridge (LTR) of the distal femur were investigated in four pony or pony cross horses. The animals were all geldings and were six to 15 months of age. Lesions were bilateral in three ponies and unilateral in one. Femoropatellar joint effusion and lameness were present in two ponies; clinical signs were absent in the others. The proximal LTR was affected in all four animals. The radiographic appearance of the lesions was a subchondral defect containing mineralised bodies. Arthroscopic and postmortem examination findings included an osteochondral flap, a fissured or irregular articular surface and a smooth surface overlying focally thickened cartilage that extended into subchondral bone. Thickened articular cartilage was a histological feature of all the lesions. Among the other histological features, the most common were chondronecrosis, chondrocyte clusters, phenotypically abnormal chondrocytes, horizontal fissures at the osteochondral junction and retained blood vessels. The signalment of the four ponies, their clinical signs and the pathological features of their lesions were consistent with osteochondrosis of the LTR in horses. The use of multiple criteria was considered to be important in making a specific diagnosis
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