Large Amount Of Debris Research Articles

Land Use Change and Sinkhole Flooding in Cookeville, Tennessee

In karst regions, urban flooding is exacerbated by the presence of sinkholes that flood adjacent areas when surface runoff rates exceed sinkhole drainage rates. Repeated sinkhole flooding has occurred in Cookeville, Tennessee, causing damage to both residential and commercial areas of the city. This paper documents land use change in Cookeville between 1955 and 1997 and employs the TR-55 rainfall-runoff model to estimate the effect of these changes on sinkhole flooding. Between 1955 and 1997, the percentage of commercial land in Cookeville increased five-fold, while the percentage of residential land doubled. Over the same period land area in pasture decreased by onethird. Approximately two-thirds of the natural stream channels in the city were converted to concrete-lined channels beginning in the 1980s, further increasing runoff rates to sinkholes. In addition to increasing runoff, paving and filling of many sinkhole swallets in Cookeville has probably increased the flooding threat by decreasing sinkhole drainage rates. Results from the rainfallrunoff model suggest that urbanization has caused a tripling of flood magnitudes for some sinkhole watersheds. A 1998 storm caused floodwaters in one sinkhole to rise within 3 m of a drainage divide that separates the sinkhole from a major shopping center. Greater flood heights within this sinkhole are likely to occur in the future given that the 1998 event was estimated to be only a 1-hr, 10-yr storm, and because large amounts of debris that are regularly swept into the swallet threaten to reduce sinkhole drainage rates. Results from this study highlight the need for flood mitigation strategies that regulate urban development within sinkhole watersheds, as well as limit activities that interfere with the drainage function of sinkholes.

Development of a novel catheter preventing the outflow of debris and thrombus on percutaneous transluminal angioplasty for hemodialysis access fistulas

If a large amount of debris or thrombus dislodges from a lesion because of dilation of the stenotic or occluded lesion in the hemodialysis access fistula when angioplasty is performed, it may move into the pulmonary artery via the central vein, resulting in pulmonary embolism. A novel sheath has been developed to prevent the outflow of debris or thrombus to the central vein. The catheter consists of a 5 F sheath introducer and a silicone balloon attached at the tip of the sheath. The silicon balloon is inflated via small inflation lumen on the shaft wall of the sheath. In the case of percutaneous transluminal angioplasty (PTA), the silicone balloon is inflated to block the blood flow by a mixture of contrast medium and physiological saline, and then dilate a stenotic or occluded lesion by PTA balloon. Next, the debris and thrombus are aspirated using the flush-lumen of this device. Finally, the silicone balloon is deflated and the dilation of the lesion is confirmed. A case of hemodialysis access fistula graft with massive thrombotic occlusion was presented. This device enabled Fogarty procedure using PTA balloon and the blood flow of the graft was completely improved and a large amount of thrombus was removed. This novel device is useful to prevent the embolic complication of the intervention for hemodialysis access fistula.

A method to separate plant roots from soil and analyze root surface area

Analysis of the effects of soil management practices on crop production requires knowledge of these effects on plant roots. Much time is required to wash plant roots from soil and separate the living plant roots from organic debris and previous years’ roots. We developed a root washer that can accommodate relatively large soil samples for washing. The root washer has a rotary design and will accommodate up to 24 samples (100 mm diam. by 240 mm long) at one time. We used a flat-bed scanner to digitize an image of the roots from each sample and used a grid system with commercially-available image analysis software to analyze each sample for root surface area. Sensitivity analysis and subsequent comparisons of ‘dirty’ samples containing the roots and all the organic debris contained in the sample and ‘clean’ samples where the organic debris was manually removed from each sample showed that up to 15% of the projected image could be coveredwith debris without affecting accuracy and precision of root surface area measurements. Samples containing a large amount of debris may need to be partitioned into more than one scanning tray to allow accurate measurements of the root surface area. Sample processing time was reduced from 20 h, when hand separation of roots from debris was used, to about 0.5 h, when analyzing the image from an uncleaned sample. The method minimizes the need for preprocessing steps such as dying the roots to get better image contrast for image analysis. Some information, such as root length, root diameter classes and root weights, is not obtained when using this technique. Root length measurements, if needed, could be made by hand on the digital images. Root weight measurement would require sample cleaning and the advantage of less processing time per sample with this method would be lost. The significance of the tradeoff between information not obtained using this technique and the ability to process a greater number of samples with the time and personnel resources available must be determined by the individual researcher and research objectives.

DNA ploidy, S-phase fraction and associations with 2-18F-fluoro-deoxy-2-D-glucose positron emission tomography findings before and during therapy of head and neck squamous cell carcinoma

ObjectivesThe main purpose of this study was to investigate the feasibility of fine needle aspiration (FNA) of neck node metastases in head and neck squamous cell carcinoma (HNSCC) for evaluating changes in DNA ploidy and S-phase fraction (SPF) during cytotoxic treatment. The results of flow cytometric (FCM) and image cytometric (ICM) analyses of ploidy were compared. Secondly, the association of SPF and ploidy with the metabolic rate (MR) of 2-18F-fluoro-deoxy-2-D-glucose (FDG) in positron emission tomography (PET) was studied.Material and MethodsBetween 1993 and 1999, 47 patients with locally advanced, non-resectable HNSCC underwent FDG PET prior to (PET1) and early during (PET2) cytotoxic radical treatment. The MR of FDG was calculated separately in primary tumours and lymph node metastases. Immediately after both PET scans, FNA of node metastases was done in 29 patients at PET1 and in 27 at PET2. DNA ploidy was evaluated using FCM and manually using ICM. The SPF was evaluated using FCM only.ResultsAt PET1 it was possible to evaluate the SPF using FCM in only 13/29 aspirations due to a poor cell yield or large amounts of debris. Ploidy was obtained in 23/29 aspirates using FCM and in 27/29 using ICM. A discordance in ploidy findings was apparent, with more non-diploid clones being detected by ICM than FCM. Eradication of non-diploid clones during therapy was observed in six cases using FCM, of which only one was confirmed by ICM. Neither SPF nor ploidy status showed any strong correlation with the MR of FDG.ConclusionFNA of HNSCC metastases demands a high and qualitatively good cell yield for FCM examinations. ICM is laborious but feasible and offers more accurate detection of non-diploid cell clones. Ploidy and SPF were not strongly associated with FDG metabolism.

Effects of catchment characteristics and disturbances on storage and export of dissolved organic carbon in a boreal headwater stream

The transportation of large amounts of dissolved organic carbon (DOC) down a stream within a 15.51-km2 catchment in Alberta, Canada, related directly to events, such as high rainfall and beaver (Castor canadensis) dam failures, that created major disturbances. A 2.3-km section of the stream was drastically altered in June 1994 when a flood wave resulting from a breached beaver dam deposited large amounts of debris and sediment within the section. Results from stream DOC-storage analyses, in which a difference method was used, suggest that the organic-debris dams created by the failed dam event served as both sources and sinks for DOC. Discharge and DOC measurements at hydrometric stations located at intervals along the stream indicated that storage of DOC on the catchment was strongly influenced by the presence of wetlands and beaver. In 1994 and 1995, disturbances occurring during periods totalling 17 days and 28 days accounted for 94% (1374 kg·km–2) and 84% (204 kg·km–2), respectively, of the amount of DOC exported from the catchment. DOC concentrations in the stream were greatest (77.0 mg·L–1) near the top of the catchment and decreased progressively downstream to the catchment outlet, where the mean concentration was 23.3 mg·L–1.

Glomerular calcification induced by bolus injection with dibasic sodium phosphate solution in Sprague-Dawley rats.

To elucidate the nephrotoxicity of phosphate, dibasic sodium phosphate solution was given to Sprague-Dawley rats by daily bolus intravenous administration at concentrations of 0, 1, 25, 250, or 360 mM (0, 1, 28, 284, or 408 mg/kg Na2HPO4) for 14 days, and the kidneys were pathologically examined. There were no remarkable changes in blood chemistry values; however, urinalysis revealed mild to moderate proteinuria in the 250 and 360 mM groups. The kidneys from the 360 mM group were macroscopically pale. Histopathology revealed panglomerular deposition of basophilic dense granules, which were positive for von Kossa's staining, accompanied by dose-dependent degeneration of the glomerular epithelium and parietal epithelium in the 250 and 360 mM groups. Electron microscopic examination showed fusion of podocytes and increased microvilli, with large amounts of debris in the Bowman's space. Low-density lamellar structures were present not only in the glomerular epithelium, basement membrane, mesangial matrix and parietal epithelium but also within the Bowman's space depending on the severity of the glomerular lesion. Phosphorus and calcium were detected by X-ray microanalysis as fine particles admixed with lamellar structures. These results suggest that high-dose phosphate used in this study transiently overloads the glomerular epithelium during filtration through glomerular capillaries and produces insoluble calcium salt and glomerular lesions, resulting in proteinuria.

Dry Sliding Wear of TiNx PVD Coating on 7075-T6 Aluminium Alloy

The present paper studies the dry sliding wear behaviour of a 7075-T6 aluminium alloy coated with a substoichiometric TiNx film. The coating was deposited industrially (Teer Coatings Ltd) using the closed field unbalanced magnetron sputtering ion plating (CFUBMSIP) deposition technique. Coating characteristics such as morphology, thickness, compositional variation with thickness, residual stress, composite hardness and absolute hardness are also presented. The wear tests were conducted in a ball on disc tribometer, where a constant sliding velocity of 0.1 m s–1 and normal loads of 1, 2 and 5 N were used. The static counterparts employed during the test were 6 mm diameter balls made of AISI type 52100 steel. For comparison, the wear behaviour of the uncoated alloy is also reported. Both the maximum Herztian pressure and the von Mises stress values in the TiN coated aluminium alloy for each normal load used during the wear test were calculated, employing a commercially available software package Elastica 2.0.5, and the results were related to the wear performance. It was shown that the coated alloy presented an improved wear resistance only when the wear tests were performed at normal loads as low as 1 and 2 N, when the material from the static counterpart was transferred to the surface of the coated discs, and the TiN coating was able to protect the aluminium alloy from plastic deformation. However, when the wear test was carried out at a load of 5 N, the coating presented low wear resistance with a wear coefficient as low as 10–4 mm3 (N m)–1. This behaviour could be attributed to the fact that, in these conditions, the coating could not protect the substrate from plastic flow and fracture, producing a large amount of debris, which contributed to the abrasive wear of the system. SE/S277

Motion--pancreatic endoscopy is useful for the pain of chronic pancreatitis: arguments for the motion.

Pain is the dominant clinical problem in patients with chronic pancreatitis. It can be due to pseudocysts, as well as strictures and stones in the pancreatic ducts. Most experts agree that obstruction could cause increased pressure within the main pancreatic duct or its branches, resulting in pain. Endoscopic therapy aims to alleviate pain by reducing the pressure within the ductal system and draining pseudocysts. Approaches vary according to the specific nature of the problem, and include transgastric, transduodenal and transpapillary stenting and drainage. Additional techniques for the removal of stones from the pancreatic duct include extracorporeal shockwave lithotripsy. Success rates for stone extraction and stenting of strictures are high in specialized centres that employ experienced endoscopists, but pain often recurs during long term follow-up. Complications include pancreatitis, bleeding, infection and perforation. In the case of pancreatic pseudocysts, percutaneous or even surgical drainage should be considered if septae or large amounts of debris are present within the lesion. This article describes the techniques, indications and results of endoscopic therapy of pancreatic lesions.

Measurement and origin of tape edge damage in a linear tape drive

Integrity of the magnetic tape edge is the key to maintaining high performance of modern tape drives. Damage to the tape edge under normal drive operation results in the change in tape dimensions and debris generation, both leading to degradation in the reproduction of the recorded signal. The objective of the present study is to develop a methodology for evaluation of tape edge quality and to apply the methodology to monitor tape edge degradation under normal drive operation. Optical microscopy, atomic force microscopy and scanning electron microscopy are employed to study and quantify the quality of the tape edge. AFM measure-ments were made on both individual tape layers and the tape reel. An edge quality measurement technique is used to quantify the damage to tape edge. A technique for the tape lateral motion measurement is used to study the effect of continuous sliding on tape guiding. A lateral force measurement technique is developed to measure the force exerted by the tape edge on the guide flange. The effect of normal drive operation on tape edge quality and on tape guiding in a linear tape drive is studied. It is shown that two edges of a factory-slit tape are imperfect and different, with cracking of the magnetic coating occurring at one edge. Under normal drive operation, one edge experiences more wear with larger amount of debris produced. This larger debris generation occurs on the edge with cracks developed during manufacturing. A possible mechanism of tape edge wear under normal drive operation is proposed.

Modeling for Evaluation of Debris Coolability in Lower Plenum of Reactor Pressure Vessel

Effectiveness of debris cooling by water that fills a gap between the debris and the lower head wall was estimated through steady calculations in reactor scale. In those calculations, the maximum coolable debris depth was assessed as a function of gap width with combination of correlations for critical heat flux and turbulent natural convection of a volumetrically heated pool. The results indicated that the gap with a width of 1 to 2 mm was capable of cooling the debris under the conditions of the TMI-2 accident, and that a significantly larger gap width was needed to retain a larger amount of debris within the lower plenum. Transient models on gap growth and water penetration into the gap were developed and incorporated into CAMP code along with turbulent natural convection model developed by Yin, Nagano and Tsuji, categorized in low Reynolds number type two-equation model. The validation of the turbulent model was made with the UCLA experiment on natural convection of a volumetrically heated pool. It was confirmed that CAMP code predicted well the distribution of local heat transfer coefficients along the vessel inner surface. The gap cooling model was validated by analyzing the in-vessel debris coolability experiments at JAERI, where molten Al2O3 was poured into a water-filled hemispherical vessel. The temperature history measured on the vessel outer surface was satisfactorily reproduced by CAMP code.

Development of a new and efficient laboratory method for processing testicular sperm.

Testicular biopsy specimens contain large amounts of debris that makes sperm pick-up for ICSI more difficult than with epididymal aspirates. We sought to develop improved processing techniques for testicular sperm extraction (TESE). Retrievals were with azoospermic male partner scheduled to undergo percutaneous epididymal sperm aspiration (PESA) and TESE. The study group consisted of 9 retrievals with a new TESE technique (TESE-N). The control group was 21 retrievals with PESA and 3 retrievals with a previous TESE technique (TESE-P). TESE-N eliminated almost all debris, which made ICSI sperm pick-up more rapid. TESE-N, PESA, and TESE-P fertilization (77, 75, and 72%) and ongoing/delivered pregnancy rates per retrieval (67, 76, and 67%) were similar. Our new technique provides for easy removal of debris from TESE specimens and fertilization and pregnancy rates equal to epididymal sperm's. Eliminating debris from TESE specimens allows for rapid sperm pick-up for ICSI, making the procedure more efficient for embryology staff.

Efficacy of irrigation for removal of particulate debris after cemented total knee arthroplasty

We studied the amount of particulate debris removed with pulsatile lavage irrigation before and after component implantation in 13 consecutive patients undergoing primary cemented total knee arthroplasty (TKA) done by a single surgeon. Before component implantation, the knees were copiously lavaged with 3 L of pressurized irrigant; all fluid was collected in 1 aliquot using standard wall suction canisters. After cementing the components in place, another 3 L of pressurized irrigant was used; this fluid was collected in 3 sequentially labeled 1-L aliquots. Collected fluids were centrifuged, and the residue was washed, recentrifuged, and dried. Residual particulate debris was quantitated by weight. An average of 537 mg/L (range, 16–1,406 mg/L) of debris were removed before implantation with 3 L of irrigation. An average of 217 mg/L (range, 31–999 mg/L), 52 mg/L (range, 0–189 mg/L), and 49 mg/L (range, 1–185 mg/L) of debris was removed after implantation with each of the additional liters. Using analysis of variance testing, there was a statistically significant difference between the amount of debris removed with 3 L and after 4 L ( P = .02) and 5 L ( P = .03) of irrigant. There was no statistical difference between irrigation with 5 L and 6 L of irrigation ( P = .92). The residua particulate debris was also analyzed to determine the relative amounts of bone-soluable organics and polymethyl methacrylate (PMMA). Before implantation, the residual debris, by weight, consisted of 79% bone and 21% soluable organics. We found on average that after implantation of components the specimens contained 53% bone and 47% PMMA and soluable organics by weight. We believe that despite careful implantation and meticulous cement technique, large amounts of debris, including bone and PMMA, remain after TKA, which require at least several liters of pulsatile lavage to removed. Removal of this particulate debris may decrease third-body polyethylene wear.

Influence of kerosene and distilled water as dielectrics on the electric discharge machining characteristics of Ti–6A1–4V

Abstract In electrical discharge machining (EDM), a process utilizing the removal phenomenon of electrical discharge in dielectric, the working fluid plays an important role affecting the material removal rate and the properties of the machined surface. In this paper the machining characteristics of Ti–6A1–4V were investigated with kerosene and distilled water as the dielectrics. The results show that the material removal rate is greater and the relative electrode wear ratio is lower, when machining in distilled water rather than in kerosene. By using X-ray diffraction, it is confirmed that carbide (TiC) and oxide (TiO) are formed on the workpiece surface when using kerosene and distilled water, respectively. The lower removal rate when machining Ti–6A1–4V alloy in kerosene can be explained by both the formation of TiC, which has a higher melting temperature and therefore requires a larger discharge energy, and carbon deposition on the electrode, causing further retardation of the discharge process. A larger amount of debris and more micro cracks are also found when using distilled water as the dielectric.

Interaction between water pressure in the basal drainage system and discharge from an Alpine glacier before and during a rainfall-induced subglacial hydrological event

Combined measurements of meltwater discharge from the portal and of water level in a borehole drilled to the bed of Findelengletscher, Switzerland, were obtained during the later part of the 1993 ablation season. A severe storm, lasting from 22 through 24 September, produced at least 130 mm of precipitation over the glacier, largely as rain. The combined hydrological records indicate periods during which the basal drainage system became constricted and water storage in the glacier increased, as well as phases of channel growth. During the storm, water pressure generally increased as water backed up in the drainage network. Abrupt, temporary falls in borehole water level were accompanied by pulses in portal discharge. On 24 September, whilst borehole water level continued to rise, water started to escape under pressure with a resultant increase in discharge. As the drainage network expanded, a large amount of debris was flushed from a wide area of the bed. Progressive growth in channel capacity as discharge increased enabled stored water to drain and borehole water level to fall rapidly. Possible relationships between observed borehole water levels and water pressures in subglacial channels are influenced by hydraulic conditions at the base of the hole, distance between the hole and a channel, and the nature of the substrate.

Interaction between water pressure in the basal drainage system and discharge from an Alpine glacier before and during a rainfall-induced subglacial hydrological event

Combined measurements of meltwater discharge from the portal and of water level in a borehole drilled to the bed of Findelengletscher, Switzerland, were obtained during the later part of the 1993 ablation season. A severe storm, lasting from 22 through 24 September, produced at least 130 mm of precipitation over the glacier, largely as rain. The combined hydrological records indicate periods during which the basal drainage system became constricted and water storage in the glacier increased, as well as phases of channel growth. During the storm, water pressure generally increased as water backed up in the drainage network. Abrupt, temporary falls in borehole water level were accompanied by pulses in portal discharge. On 24 September, whilst borehole water level continued to rise, water started to escape under pressure with a resultant increase in discharge. As the drainage network expanded, a large amount of debris was flushed from a wide area of the bed. Progressive growth in channel capacity as discharge increased enabled stored water to drain and borehole water level to fall rapidly. Possible relationships between observed borehole water levels and water pressures in subglacial channels are influenced by hydraulic conditions at the base of the hole, distance between the hole and a channel, and the nature of the substrate.

Lectins and heparin-binding features of human spermatozoa as analyzed by flow cytometry

Sperm cell surface characteristics may serve as a useful diagnostic feature for the evaluation of seminal samples, but to date no useful analytical method(s) is available for their routine quantitative analysis. Fluorescein isothiocyanate-conjugated lectins, proteins with unique and specific saccharide-binding characteristics, and heparin are potentially useful markers for such an analytical procedure. A protocol is outlined whereby frozen semen is thawed and treated with either fluorescein isothiocyanate-conjugated soybean agglutinin SBA (Glycine max), peanut agglutinin PNA (Arachis hypogaea), and garden pea agglutinin PSA (Pisum sativum) lectins or fluorescein isothiocyanate-heparin to assess differences in spermatozoa-bound fluorochrome by flow cytometry. Use of propidium iodide to identify nuclei containing sperm cells within the ejaculate is essential to the method because of the large amount of debris associated with the samples. The precision of the assay is high, with the coefficient of variation for the individual probes being less than 20%. Analysis of a patient pool of 22 revealed that a range in binding properties is observed and a mode of grouping these samples into classes for later analysis is outlined. Semen parameters and fluorescein isothiocyanate-ligand binding values were different in a population of unproven fertility as compared with a comparable population of known fertility. A positive correlation (p less than 0.001) for garden pea agglutinin PSA binding and concentration of motile cells, percentage of motility, and number of motile cells was found. These data suggest the possible utility of flow cytometry for the assessment of human seminal samples.

Contaminación por desechos sólidos llevados por corrientes marinas a la costa caribeña de Honduras

Large amounts of debris of international origen were found along the inhabited artas of the Mosquitia Coast of Honduras, with ao estimaliao of 123.4 Kg. pcr Km of beach: 91.5 % polymer origen. 7.4% glass botl.Ies and 0.94% aluminium can.s. Plastic pellets in densities of 50 to 200/m2 and petroleum tan in densities of Sn.5 m2, with a estimatcd weight of la la 50 gr/m2. We conclude that this material is carried by tbe Caribbean currents from the Antillas and beyond.

A rapid flow cytometric method for bivariate bromodeoxyuridine/DNA analysis using simultaneous proteolytic enzyme digestion and acid denaturation

This report describes an immunocytochemical procedure for the simultaneous quantification of bromodeoxyuridine (BrdUrd) incorporated into cellular DNA and total DNA content in individual cells in suspension. Improvement of existing methods was achieved by combining acid denaturation and proteolytic enzyme digestion (0.2 mg/ml pepsin in 2N HCl for 30 min at room temperature). Acid denaturation preceded by enzyme digestion resulted in a large amount of debris and the occurrence of naked nuclei. In contrast, the simultaneous denaturation/protein digestion procedure did not damage the cellular structure, is rapid and reproducible, and has cell recoveries of more than 85%. Although experimental conditions were tested on human cultured keratinocytes, this method also appeared applicable to bone marrow cells and cells obtained from solid tissues.

Dynamics of large woody debris in streams in old-growth Douglas-fir forests

Transfer of large woody debris (>10 cm diameter) from old-growth Douglas-fir (Pseudotsugamenziesii (Mirbel) Franco) forests into five first-to fifth-order stream reaches (drainage areas of 0.1 to 60.5 km2) has ranged from 2.0 to 8.8 Mg•ha−1•year−1 in 7- to 9-year study periods. Amounts of large debris in these streams range from 230 to 750 Mg•ha−1 with generally lower values in larger channels. The addition of woody debris is widely scattered in time and space and comes mainly from single trees rooted away from the streambank. We infer that wind is a major agent for entry of wood into these streams. Downstream movement of debris is strongly related to length of individual pieces; most pieces that moved were shorter than bankfull width.

A MAJOR OIL BARGE POLLUTION INCIDENT ON THE ARKANSAS RIVER

ABSTRACT When the towboat Girard Lewis lost power on the Arkansas River Navigation System, it drifted into a railroad bridge near Pine Bluff, Arkansas. Upon impact, it lost the two oil barges it was pushing; one barge floated downstream and was impaled by icebreakers on U.S. Army Corps of Engineers Lock and Dam No. 4. The resulting damage to the barge caused a major discharge (8,000 barrels) of No. 6 fuel oil, which affected industrial and recreational uses of the river and threatened sensitive environmental areas, including the White River National Wildlife Refuge. The discharger accepted responsibility for salvage of the damaged barge but not for containment and cleanup of the spilled oil. Consequently, the U.S. Environmental Protection Agency initiated a federal removal project using the oil pollution response fund authorized under the Clean Water Act. A coordinated effort among at least seven federal and state agency representatives on site was carried out over 25 days. Special problems were encountered and resolved involving unusually high river flow, large amounts of debris, use and effectiveness of various oil recovery devices, barge salvage operations, closure of the navigation system to traffic, protection of environmentally sensitive areas, and levels of cleanup of shorelines and locks and dams. The project was effectively carried out over 60 miles of affected river at a cost of $372,000, with a minimum of environmental and real property damages. It was the worst pollution incident that has occurred on the Arkansas River Navigation System.