Cause Of Leakage Research Articles

RETRACTED: Mechanism of bio molecule stabilized selenium nanoparticles against oxidation process and Clostridium Botulinum

The bio molecules from plant leaf extract utilized in the preparation of selenium material at the nano scale. The selenium ion was reduced to selenium nanoparticles in the presence of molecule residue of the plant leaf extract. The bio molecule stabilized selenium nanoparticles were grown gradually in the reaction mixture. The selenium nanoparticles were characterized using atomic absorption spectroscopy, fourier transform inferred spectroscopy, X-ray diffraction, scanning electronic microscope and transmission electronic microscope. The selenium nanoparticles were synthesized successfully as the nano-crystalline pure hexagonal phase and the size range of 26-41 nm with spherical in shape. The activity and mechanism of nanoparticles suggested that the selenium nanoparticles are causes of leakage of reducing sugars and protein of pathogens membrane cell. The selenium nano are responsible for death and fully inhibited the microbial growth of pathogen. The bio molecule stabilized selenium nanoparticles were also investigated for the antioxidant agent. Selenium nanoparticles showed scavenging activity up to 94.48%. These results recommended that the advantages of using this method for synthesis of selenium nanoparticles with excellent antioxidant and antimicrobial mechanism and activity, which can be used as the antioxidant and antibiotic agent.

Leakage Analysis of Deriner Dam (Artvin-Turkey) Using 3D Modeling

Leakage in engineering structures is considered as one of the main issues. Analysis of the amount of water leakage can be useful in preventing such events. Deriner Dam consists of a concrete arch dam with ancillary structures including tunnels, and an underground powerhouse with an installed capacity of 670 MW. Leakage was observed on the powerhouse after the construction stage. For this purpose, a number of geotechnical data (including rheological and mechanical properties of the grout mixes) were re-assessed to examine the source of leaking. For determination of leakage source, graphics of grout curtain were prepared by using grouting charts with the RockWorks v.16 program. Leakage zones were obtained according to the prepared graphics and showed on 3D model. The results show that temperature variation of grouting mixes is the primary cause of leakage and its effect observed in the underground powerhouse wall of the Deriner Dam.

Use of fully covered self-expanding metal stents for benign biliary etiologies: a large multi-center experience.

Fully-covered self-expandable metal stents (FCSEMS) have been used in benign biliary diseases although reported data is limited. These devices are most commonly used to treat biliary leaks, strictures, or both. The aim of this study was to evaluate effectiveness of FCSEMS in treating benign biliary disease and recognize the associated complications. We performed a multicenter longitudinal retrospective cohort study of patients with benign biliary disease needing FCSEMS between 2011 and 2016. Descriptive statistics were performed using SPSS version 24 (SPSS Inc, Chicago, IL, USA) and continuous variables were presented as mean±standard deviation. 75, 57% M/43% F, with a mean age of 58.5±14.9 years, were included. 64 (85%) had benign strictures, 7 patients had leaks, and 4 patients had both a leak and a stricture. Chronic pancreatitis was the most common cause of BBS (47%) and cholecystectomy was the most common cause of leaks. FCSEMS placement was technically successful in all patients. Four patients died of unrelated causes. A recurrent stricture was observed in 24 (32%) of the patients. Recurrent strictures were most commonly seen in patients with chronic pancreatitis 12/35 (34%). Stent migration occurred in 8/75 patients (10.7%). Seven patients (9.3%) had adverse events, acute pancreatitis (N.=4) was most common. FCSEMS are safe and effective for treating biliary strictures and leaks. We report decreased rates of stent migration compared to previous studies. Prospective studies are needed to compare plastic stents with FCSEMS, determine optimal stent in-dwell times and cost effectiveness of FCSEMS.

Etiology of Leaks Following Sleeve Gastrectomy: Current Evidence.

The purpose of this paper is to study the causes of leaks following sleeve gastrectomy (SG). Pubmed was searched during January 2016 for publications reporting leak after SG. A total of 205 publications were identified, of which 17 papers were selected. In about 3018 patients, reinforcement was used compared with 4595 patients, in whom no reinforcement was applied; both groups were representing matched bariatric populations. The use of reinforcement/buttressing has resulted in different rates of leaks ranging from 0% to 3.9%; whereas with no reinforcement/buttressing, the leak rate was 0.16% to 3.5%. The use of reinforcement/buttressing did not result in reduction of leak to a statistical significance although the trend was suggesting so (P=0.06), whereas no reinforcement/buttressing did not statistically increase the leak rate (P=0.10). No statistical significant difference of leak with or without reinforcement. This mean case complexity and surgical technique and experience are the sole factors for leaks following SG.

Numerical interpretation of pressurized corroded cast iron pipe tests

Pitting/patch corrosion is a major and common cause of leaks and (or) bursts in cast iron (CI) pipes that consist of over 50% of global pipelines. The determination of the remaining life of a CI pipe is a major challenge facing water utilities requiring an estimate of the impact of pitting corrosion on the degradation of structural pipe capacity. This paper uses an efficient finite element analysis (FEA) to model the behaviour of large diameter CI pipes with natural or simulated corrosion pits and patches. The test results were obtained through laboratory pressure testing. Laser scanning was used to develop three dimensional geometric models of pipe specimens for direct use in the numerical modelling. The CI material was simulated by a non-linear hyperbolic elastic model (termed MHM-CI) recently developed by the authors for CI pipe modelling. The numerical results showed that the proposed FEAs with the MHM-CI model are reasonably capable to predict the measured responses with increasing water pressure, importantly at the critical pipe corrosion patches, such as hoop strains, initiation of leak and burst failures. The initiation of fracture was explained by material failure purely by tension, which can form a crack that could lead to water leakage. Final burst possibility was modelled by using a simplified fracture mechanics approach to determine the critical crack length for spontaneous fast fracture as in a burst. Our numerical findings suggest that the proposed simplified numerical approach may be used to determine whether a corroded cast iron pipe would leak before break provided that the corrosion condition of the pipe and the relevant material properties are available. However, the window of time for leak before break would require further testing since this would be governed by sub critical fracture growth subject to repetitive external and internal pipe loadings.

PD25-09 EMERGING MECHANICAL FAILURES AND COMPLICATIONS OF ECTOPICALLY PLACED CONCEAL RESERVOIRS

You have accessJournal of UrologySexual Function/Dysfunction: Surgical Therapy III1 Apr 2017PD25-09 EMERGING MECHANICAL FAILURES AND COMPLICATIONS OF ECTOPICALLY PLACED CONCEAL RESERVOIRS Yasmeen Jaber and Run Wang Yasmeen JaberYasmeen Jaber More articles by this author and Run WangRun Wang More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1204AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The AMS Conceal inflatable penile prosthesis (IPP) reservoir was introduced to the US market in February 2011. Unlike prior spherical models, the Conceal reservoir is known for its low profile and flat shape, which has rendered the Conceal the most common choice for ectopic placement. Consistent with its innovative shape, the reservoir allows for flexibility in filling volume, which ranges from 60 mL to 100 mL. This study seeks to identify any emerging mechanical failures and complications related to ectopic placement of the Conceal reservoir. METHODS Our single surgeon database of IPP implantation from February 2011 to December 2015 was reviewed and all reservoir-related mechanical failures and complications were identified. Only AMS inflatable penile prostheses with Conceal reservoirs were included in this study. Coloplast penile prostheses and malleable implants were excluded. The location of the reservoir, as well as the volume of saline used to fill the reservoir, were part of the data analyzed. RESULTS A total of 210 AMS IPP with Conceal reservoirs were included in this study. From this data set, there were four cases (1.9%) with reservoir-related mechanical failure or complication requiring revision surgeries. Of those four, two cases (0.95%) were mechanical failures resulting from the reservoir leaking. In both cases, the cause of leak was identified as an intrinsic point of weakness at the apex of the reservoir caused by inward folding of an unfilled segment. The inward folding of the reservoir was observed at volumes of 60 to 80 mL. In the remaining two cases (0.95%), the reservoir complication observed was refractory abdominal muscle pain related to ectopic location and intra-fascial placement. In both cases, revision surgery with reservoir repositioning resolved the pain. CONCLUSIONS While ectopic placement of the Conceal reservoir is mechanically reliable, it must be filled in excess of 80 mL to prevent inward reservoir folding and resultant reservoir leakage. Additionally, with surgical consent, it is prudent for the patient to be counseled on the possibility of abdominal muscle pain when the reservoir is placed ectopically, though they should be informed that such pain is a rare side effect. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e504-e505 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Yasmeen Jaber More articles by this author Run Wang More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

DETECTION OF DATA LEAKAGE

Sometimes sensitive data must be handed over to supposedly trust third parties. With the extensive application of database systems, the owners of the databases have urgent requirements to protect their copyright of databases. Some of the data is leaked and found in an unauthorized place the distributor must assess the likelihood that the leaked data came from one or more users. This paper contains concept of data leakage, its causes of leakage and different techniques to protect and detect the data leakage. In the field of IT huge database is being used. This database is shared with multiple people at a time. But during this sharing of the data, there are huge chances of data vulnerability, leakage or alteration. So, to prevent these problems, detection of data leakage system has been proposed. This paper includes brief idea about data leakage detection and a methodology to detect the data leakage persons. Data leakage is the main hindrance in data distribution. Traditionally this data leakage is handled by watermarking technique which requires modification of data.

EFFECTS OF NUMBER OF CONNECTIONS AND PIPE LENGTH TO THE WATER LOSSES IN MELAKA

One of the major challenges facing our water utilities is the high level of Non-Revenue Water (NRW) in the distribution networks. This paper assessed the performance of current management practices by Syarikat Air Melaka Berhad (SAMB) to deal with NRW. Information and NRW management data (from 2012 to 2013) were gathered and analysed. Statistical methods were used to evaluate the effects of pipe length and number of connections of the distribution network to the leakage level; and to determine the causes of leakage (water loss). In 2014, Melaka’s NRW percentage was 21.4% as compared to the national average of 35.6%, which is the second lowest rate among the states in Malaysia. Results of the study revealed significant positive relationships between average MNF (L/s) with number of connections and pipe length, with the prediction model of average MNF (L/s)=-4.42+1.088*10-2(NC)+1.07*10-4(PL), R2= 73.19%. The results also indicated that in a compact and urbanized city like Melaka, number of connections in the network appears to be most influential to the average MNF (water loss) (shown by a strong positive relationship, r = 0.847) as compared to the less compact zone (such as Perak) where pipe length appears to be more influential.

Method for reaching air-tightness of the joint between the casing of an impeller pump and its cover

A method is considered to reach the air-tightness of the flange joint of the casing of an impeller pump with its cover using an anaerobic sealant instead of a gasket made of a thermoplastic material. The possible causes of leakage of working fluids that are related to the errors of machining flange surfaces and the specific features of their assembly are shown. The properties of anaerobic sealants that ensure the air-tightness of the flange joints are presented.

Reduction of Oxide Inclusions in Aluminum Cylinder Heads Through Autonomous Designs of Experiments

Oxide inclusions, which are created during the pouring process of aluminum alloys, are the main cause of leaks in castings. This contribution shows how the integration of autonomous design of experiments (DOEs) into the casting process simulation tool MAGMASOFT® provides the basis for the evaluation and subsequent optimization of process parameters in the melt transport and pouring process, which are responsible for the creation and distribution of oxide inclusions. At the same time, quality criteria describing the creation of oxides during the casting process of cylinder heads were evaluated quantitatively. The utilization of autonomous DOEs creates variations of the gating system and process parameters autonomously. It will be shown that autonomous DOEs are leading to optimized gating designs and process parameters resulting in a significant reduction of oxides in castings. The experiments supported by simulation were accompanied and validated by high-speed video technology and the PREFIL-measurement technology.

Magnetic Resonance Imaging–Based Assessment of Gadolinium-Conjugated Diethylenetriamine Penta-Acetic Acid Test-Infusion in Detecting Dysfunction of Convection-Enhanced Delivery Catheters

In a phase 1 trial conducted at our institute, convection-enhanced delivery (CED) was used to administrate the Delta-24-RGD adenovirus in patients with a recurrent glioblastoma multiforme. Infusion of the virus was preceded by a gadolinium-conjugated diethylenetriamine penta-acetic acid (Gd-DTPA) test-infusion. In the present study, we analyzed the results of Gd-DTPA test infusion through 50 catheters. Thirteen adults with a recurrent glioblastoma multiforme were enrolled in a larger phase 1 multicenter, dose-finding study, in which a conditionally replication-competent adenovirus was administered by CED. Up to 4 infusion catheters per patient were placed intra- and/or peritumorally. Before infusion of the virus, a Gd-DTPA infusion was performed for 6 hours, directly followed by a MRI scan. The MRIs were evaluated for catheter position, Gd-DTPA distribution outcome, and contrast leakage. Leakage of Gd-DTPA into the cerebrospinal fluid was detected in 17 of the 50 catheters (34%). Sulcus crossing was the most frequent cause of leakage. In 8 cases, leakage could only be detected on the fluid-attenuated inversion recovery sequence. Nonleaking catheters showed a significantly larger Gd-DTPA distribution fraction (volume of distribution/volume of infusion) than leaking catheters (P= 0.009). A significantly lower volume of distribution/volume of infusion was observed in intratumoral catheters, compared with peritumoral catheters (P= 0.004). Gd-DTPA test infusion did not result in significant changes in Karnofsky Performance Score and Neurological Status. Pre-CED treatment infusion of Gd-DTPA is an adequate and safe method to identify dysfunctional catheters. The use of an optimized drug delivery catheter is necessary to reduce leakage and improve the efficacy of intracerebral drug infusion.

Observations of hydraulic fracturing in soils through field testing and numerical simulations

Hydraulic fracturing is a potential cause of leakage of earth dams or loss of fluid in drilling and field permeability testing. The effect of hydraulic fracturing on soil grouting is also a major concern. Although hydraulic fracturing has been adopted for decades by the petroleum industry for oil recovery in rock formations, studies on fracturing in soils are relatively few and inconclusive. The aim of this study is to provide further insight into the mechanism of hydrofracturing in soils through a field grouting trial and numerical simulation. We observe hydraulic fracturing in soils during this field trial as predicted by generally accepted groutability requirements. The hydraulic fractures are found vertically developed up to the ground surface. Numerical simulations show the hydraulic fracturing is easier to be initiated in anisotropic stress conditions, where the minor principal stress is the key factor. Numerical simulations also demonstrate significant compressions and shears during injection, suggesting the mechanism of fracturing in soils would be a shearing type. Based on this study, we propose a punching and splitting mode for the hydrofracturing in soils. The equation associated with estimating fracturing pressure is verified, and the results are found to be in good agreement with the cases examined.

Early Detection of Pipeline Leakage Using Ultrasonic Sensor

Pipelines leakage is the main problem faced by industries. The main causes of leakage on pipelines are corrosion, crack and disaster. This problem must be detected early to ensure that maintenance work can be done quickly to prevent pipe bursts, as well as to minimize operational costs. The objective of this research is to review a method for early detection of leakage on pipeline that affect by the changing water level in the pipeline. The method used in this research is ultrasonic sensor that is implanted on the outer surface pipeline.

A Case Study: Corrosion Failure of Tube Heat Exchanger

A failed heat exchanger was sent to CMRDI to investigate the possible causes of leaks occurred in the tubes of the heat exchanger. The heat exchanger tubes were made of stainless steel 316 straight type. The heat exchanger served to heat up water basin (desalinated water) during the cold winter time. The water contains a high chloride level. Corrosion testing indicated susceptibility towards pitting corrosion especially at high temperature. It was suggested that controlling chloride level and proper adjustment of pH are the optimum solutions to avoid corrosion of heat exchanger pipes.

A comparison of stresses in molar teeth restored with inlays and direct restorations, including polymerization shrinkage of composite resin and tooth loading during mastication

Polymerization shrinkage of composites is one of the main causes of leakage around dental restorations. Despite the large numbers of studies there is no consensus, what kind of teeth reconstruction—direct or indirect composite restorations are the most beneficial and the most durable. ObjectiveThe aim was to compare equivalent stresses and contact adhesive stresses in molar teeth with class II MOD cavities, which were restored with inlays and direct restorations (taking into account polymerization shrinkage of composite resin) during simulated mastication. MethodThe study was conducted using the finite elements method with the application of contact elements. Three 3D models of first molars were created: model A was an intact tooth; model B—a tooth with a composite inlay, and model C—a tooth with a direct composite restoration. Polymerization linear shrinkage 0.7% of a direct composite restoration and resin luting cement was simulated (load 1). A computer simulation of mastication was performed (load 2). In these 2 situations, equivalent stresses according to the modified von Mises criterion (mvM) in the materials of mandibular first molar models with different restorations were calculated and compared. Contact stresses in the luting cement–tooth tissue adhesive interface around the restorations were also assessed and analyzed. ResultsEquivalent stresses in a tooth with a direct composite restoration (the entire volume of which was affected by polymerization shrinkage) were many times higher than in the tooth restored with a composite inlay (where shrinkage was present only in a thin layer of the luting cement). In dentin and enamel the stress values were 8–14 times higher, and were 13 times higher in the direct restoration than in the inlay. Likewise, contact stresses in the adhesive bond around the direct restoration were 6.5–7.7 times higher compared to an extraorally cured restoration. In the masticatory simulation, shear contact stresses in the adhesive bond around the direct composite restoration reached the highest values 32.8MPa and significantly exceeded the shear strength of the connection between the resin luting cement and the tooth structure. SignificanceEquivalent stresses in the tooth structures restored with inlays and in the restoration material itself and contact stresses at the tooth–luting cement adhesive interface are many times lower compared to teeth with direct composite restorations. Teeth with indirect restorations are potentially less susceptible to damage compared to those with direct restorations. Composite inlays also ensure a better seal compared to direct restorations. Polymerization shrinkage determines stress levels in teeth with direct restorations, while its impact on adhesion in indirectly restored teeth is insignificant.

Effect of Baffle Openings to the Flow Distribution in a SERVCO Fume Cupboard

Recirculation region behind a fume cupboard sash is the potential contributor to the leakage of the contaminants due to its large size. This is found from the computational fluid dynamics (CFD) simulation of SERVCO fume cupboard using κ-ω turbulence model. For a good fume cupboard, the recirculation zone needs to be minimized while maintaining the flow distribution to all area in the fume cupboard. The opening on the baffle may reduce the recirculation zone which in turn may reduce back flow that is the cause of leakage. In this paper, the effect of shape of baffle openings on flow distributions of a SERVCO fume cupboard will be presented as a result of CFD. The results are presented in terms of velocity vectors Vy (in the direction towards the sash opening) at different cross sections for 4 opening shapes. The opening is found to improve the airflow distribution.

Investigation of Leakage on Water Wall Tube in a 660 MW Supercritical Boiler

The leakage of a supercritical boiler tube has been investigated. The leakage was observed during a working pressure hydrostatic test under 40.1 MPa. The internal geometry of the investigated leaking tube was multi-lead ribbed tube. Various methods for investigation namely radiography, microstructural analysis using optical and scanning electron microscopes, Vickers hardness testing and chemical analysis were conducted to investigate the main cause of leakage. The results revealed that the material tube met the standard for supercritical boiler tube (ASTM A 213 Grade T12). From the microstructural analysis, there was a crack, which initiated from the outer wall adjacent to the weld metal and propagated to the inner wall of the tube. The crack was due to a weld defect known as “excessive melt through” which is due to overheating during the welding process in joining the tubes. It is suggested that control of welding process parameters must be accomplished during fabrication to make a furnace wall, and placing strip of steel between the tubes to reduce the fit-up gap should be considered.

Effect of Baffle Opening Position to the Flow Distribution in a Servco Fume Cupboard

From the computational fluid dynamics (CFD) simulation of Servco fume cupboard using κ-ω turbulence model, it is found that recirculation region behind the sash is the potential contributor to the leakage of the contaminants due to its large size. To have a good fume cupboard, the recirculation zone needs to be minimised while maintaining the flow distributions to all area in the fume cupboard. The opening on the baffle may reduce the recirculation zone which in turn may reduce back flow that can be the cause of leakage. In this paper, the effect of baffle openings on flow distributions of a Servco fume cupboard will be presented as a result of computational fluid dynamics (CFD) simulation using κ-ω turbulence model. The results are presented in terms of magnitude of curl of velocity vectors Vxyz at different cross sections of the fume cupboard for 4 variations of location of baffles opening.

A Study on the Cause Analysis for the Wall Thinning and Leakage in Small Bore Piping Downstream of Orifice

A number of components installed in the secondary system of nuclear power plants are exposed to aging mechanisms such as FAC (Flow-Accelerated Corrosion), Cavitation, Flashing, and LDIE (Liquid Droplet Impingement Erosion). Those aging mechanisms can lead to thinning of the components. In April 2013, one inch small bore piping branched from the main steam line experienced leakage resulting from wall thinning in a 1000 MWe Korean PWR nuclear power plant. During the normal operation, extracted steam from the main steam line goes to condenser through the small bore piping. The leak occurred in the downstream of an orifice. A control valve with vertical flow path was placed in front of the orifice. This paper deals with UT thickness data, SEM images, and numerical simulation results in order to analyze the extent of damage and the cause of leakage in the small bore piping. As a result, it is concluded that the main cause of the small bore pipe wall thinning is liquid droplet impingement erosion. Moreover, it is observed that the leak occurred at the reattachment point of the vortex flow in the downstream side of the orifice.

주증기계통 오리피스 후단 소구경 배관의 감육 및 누설 발생

A number of components installed in the secondary system of nuclear power plants are exposed to aging mechanisms such as FAC (Flow-Accelerated Corrosion), Cavitation, Flashing, and LDIE (Liquid Droplet Impingement Erosion). Those aging mechanisms can lead to thinning of the components. In April 2013, one (1) inch small bore piping branched from the main steam line experienced leakage resulting from wall thinning in a 1,000 MWe Korean PWR nuclear power plant. During the normal operation, extracted steam from the main steam line goes to condenser through the small bore piping. The leak occurred in the downstream of an orifice. A control valve with vertical flow path was placed on in front of the orifice. This paper deals with UT (Ultrasonic Test) thickness data, SEM images, and numerical simulation results in order to analyze the extent of damage and the cause of leakage in the small bore piping. As a result, it is concluded that the main cause of the small bore pipe wall thinning is liquid droplet impingement erosion. Moreover, it is observed that the leak occurred at the reattachment point of the vortex flow in the downstream side of the orifice.