Unintentional Leakage Research Articles

Assessment of aquifer recharge and groundwater availability in a semiarid region of Brazil in the context of an interbasin water transfer scheme

Particularly in arid and semiarid areas, more and more populations rely almost entirely on imported water. However, the extent to which intentional discharge into transiting riversystems and unintentional leakage may be augmenting water resources for communities along and down gradient of the water transfer scheme has not previously been subject to research. The objective of this study was to assess both the potential of a large-scale watertransfer (WT) scheme to increase groundwater availability by channel transmission losses in a large dryland aquifer system (2,166 km²) in Brazil, and the capability of the receiving streams to transport water downstream under a prolonged drought. An integrated surface-water/groundwater model was developed to improve the estimation of the groundwater resources, considering the spatio-temporal variability of infiltrated rainfall for aquiferrecharge. Aquifer recharge from the WT scheme was simulated under prolonged drought conditions, applying an uncertainty analysis of the most influential fluxes and parameters. The annual recharge (66 mm/year) was approximately twice the amount of water abstracted(1990–2016); however, the annual recharge dropped to 13.9 mm/year from 2012 to 2016, a drought period. Under similar drought conditions, the additional recharge (6.89 × 106 m³/year) from the WT scheme did not compensate for the decrease in groundwater head in areas thatdo not surround the receiving streams. Actually, the additional recharge is counteracted by a decrease of 25% of natural groundwater recharge or an increase of 50% in pumping rate; therefore, WT transmission losses alone would not solve the issue of the unsustainable management of groundwater resources.

Responses of Bilevel Ventilators to Unintentional Leak: A Bench Study.

The impact of leaks has mainly been assessed in bench models using continuous leak patterns which did not reflect real-life leakage. We aimed to assess the impact of the pattern and intensity of unintentional leakage (UL) using several respiratory models. An active artificial lung (ASL 5000) was connected to three bilevel-ventilators set in pressure mode; the experiments were carried out with three lung mechanics (COPD, OHS and NMD) with and without upper airway obstruction. Triggering delay, work of breathing, pressure rise time, inspiratory pressure, tidal volume, cycling delay and the asynchrony index were measured at 0, 6, 24 and 36 L/min of UL. We generated continuous and inspiratory UL. Compared to 0 L/min of UL, triggering delays were significantly higher with 36 L/min of UL (+27 ms) and pressure rise times were longer (+71 ms). Cycling delays increased from -4 [-250-169] ms to 150 [-173-207] ms at, respectively 0 L/min and 36 L/min of UL and work of breathing increased from 0.15 [0.12-0.29] J/L to 0.19 [0.16-0.36] J/L. Inspiratory leakage pattern significantly increased triggering delays (+35 ms) and cycling delays (+263 ms) but decreased delivered pressure (-0.94 cmH2O) compared to continuous leakage pattern. Simulated upper airway obstruction significantly increased triggering delay (+199 ms), cycling delays (+371 ms), and decreased tidal volume (-407 mL) and pressure rise times (-56 ms). The pattern of leakage impacted more the device performances than the magnitude of the leakage per se. Flow limitation negatively reduced all ventilator performances.

Neurotoxicity of Chronic Co-Exposure of Lead and Ionic Liquid in Common Carp: Synergistic or Antagonistic?

Previous studies have indicated that the harmful heavy metal lead (Pb) contamination in aquatic systems has caused intelligence development disorders and nervous system function abnormalities in juveniles due to the increased permeability of the blood–brain barrier. Ionic liquids (ILs) are considered “green” organic solvents that can replace traditional organic solvents. Studies have found the presence of ILs in soil and water due to chemical applications or unintentional leakage. Therefore, what would happen if Pb interacted with ILs in a body of water? Could ILs enable Pb to more easily cross the blood–brain barrier? Therefore, we examined the combined exposure of Pb and ILs in common carp at low concentration (18.3 mg L−1 of Pb(CH3COO)2•3 H2O and 11 mg L−1 of the IL 1-methyl-3-octylimidazolium chloride, 5% of their LC50) for 28 days in the present study. The result of a neurobehavioral assay showed that chronic exposure of lead at lower concentrations significantly altered fish movement and neurobehaviors, indicating that lead exposure caused neurotoxicity in the carp. Increases in the neurotransmitter dopamine levels and injuries in the fish brain accounted for neurobehavioral abnormalities induced by lead exposure. Moreover, we also found that lead could easily cross the blood–brain barrier and caused significant bioaccumulation in the brain. Particularly, our study indicated that the ionic liquid could not synergistically promote blood–brain barrier permeability and hence failed to increase the absorption of lead in the fish brain, suggesting that the combined exposure of lead and ILs was not a synergistic effect but antagonism to the neurotoxicity. The results of this study suggested that ILs could recede the Pb induced neurotoxicity in fish.

Tighten up! Facial pressure sore after COVID-19 non-invasive ventilation

A 59-year old male patient with no past medical history presented to the emergency department with fever and impaired oxygenation after spending holidays in the Austrian Alps before the country was declared high-risk for COVID-19 infections. Due to clinical deterioration, admission to ICU was necessary for non-invasive ventilation (NIV), as shown in Figure 1. This therapy was sustained for five days while the attachment of the mask had to be tightened up repeatedly due to unintentional leakage compromising effective ventilation. As a result, the patient presented a circumscribed necrosis of about 20 X 15 mm at the dorsum of the nose (Figure 2). The zone of necrosis was clearly related to the tightly fastened bridge of the mask causing ischemia. However, this condition went unnoticed since the patient did not complain about pain on this site while ventilation therapy. As the presence of COVID-19 was confirmed by rRT-PCR and infectiousness was still highly suspected, surgical therapy (debridement and wound closure with a local flap) was postponed.

Custom-made 3D printed masks for children using non-invasive ventilation: a comparison of 3D scanning technologies and specifications for future clinical service use, guided by patient and professional experience

Non-invasive ventilation (NIV) is assisted mechanical ventilation delivered via a facemask for people with chronic conditions that affect breathing. Mass-produced masks are available for both the adult and paediatric markets but masks that fit well are difficult to find for children who are small or have asymmetrical facial features. A good fit between the mask and the patient's face to minimise unintentional air leakage is essential to deliver the treatment effectively. We present an innovative use of 3D assessment and manufacturing technologies to deliver novel custom-made facemasks for children for whom a well-fitting standard mask is not available. This paper aims to describe the processes undertaken to investigate and compare currently available technologies for 3D scanning children and to explore the design of a system for creating custom-made paediatric NIV masks within the NHS. The paper therefore considers not only the quality and accuracy of the data, but also other factors such as the time and ease of process. Searches for all currently available scanning technologies were made. Photogrammetry image stitch using a smartphone and a digital camera, and two structured light scanners were selected and compared in the laboratory, in discussion with user groups, and in adult volunteers. Using the processes described, it became apparent that the optimal 3D scanning system for this purpose was the handheld structured light scanner. This option offered both superior accuracy and convenience and was more cost effective.

Custom-made 3D printed masks for children using non-invasive ventilation: a feasibility study of production method and testing of outcomes in adult volunteers

Non-invasive ventilation (NIV) is assisted mechanical ventilation delivered via a facemask for people with chronic conditions that affect breathing. NIV is most commonly delivered via an interface (mask) covering the nose (nasal mask) or the nose and mouth (oronasal mask). The number of children in the UK requiring NIV is currently estimated to be around 5000. Mass-produced masks are available for both the adult and paediatric markets but masks that fit well are difficult to find for children who are small or have asymmetrical facial features. A good conforming fit between the mask and the patient’s face to minimise unintentional air leakage is essential to deliver the treatment effectively; most ventilators will trigger an alarm requiring action if such leakage is detected. We present an innovative use of 3D scanning and manufacturing technologies to deliver novel mask-face interfaces to optimise mask fit to the needs of individual patients. Ahead of planned user trials with paediatric patients, the project team trialled the feasibility of the process of creating and printing bespoke masks from 3D scan data and carried out testing of the masks in adult volunteers to select the strongest design concept for the paediatric trial. The evaluation of the process of designing a bespoke mask from scan data, arranging for its manufacture and carrying out user testing has been invaluable in gaining knowledge and discovering the pitfalls and timing bottlenecks in the processes. This allowed the team to iteratively refine the techniques and methods involved, informing user trials later on in the project. It has also provided indicative cost estimates for 3D printed mask prototype components which are useful in project decision making and trial planning. The value of the process extends to considerations for future implementation of the process within a clinical pathway.

Knowledge sharing, knowledge leaking in strategic alliances and firm innovation capacity: an empirical study

This study aims to examine the influence of firms’ alliance knowledge on their innovation capacity, under the contingencies of both intentional and unintentional leakage of business-critical knowledge. Based on a survey of 410 staff from 205 allied firms in Tunisia, this study applies the linear regression to investigate the research model. The results show that external knowledge sharing appears to have a positive effect on firms’ innovative capability while high levels of intentional and unintentional knowledge leakage by a focal firms’ employees, turns out to negatively moderate such a relationship. In this paper, actors of focal firm need to distinguish between the firms' critical knowledge, and the one which can be legally shared and exchanged with other partners. Sharing critical knowledge, intentionally or unintentionally, might hurt the focal firms’ innovative capacity. Although the issues of knowledge sharing and innovation have been exhaustively treated in the literature, very little are the research works which have undertaken to study the links between knowledge sharing, knowledge leakage and the firms’ innovation capacity. Thus, this study is designed to foster further enrichment to the literature, by proposing more clear differentiation between unintentional and intentional knowledge leakages and their impact on the firm’s innovation.

Knowledge sharing, knowledge leaking in strategic alliances and firm innovation capacity: an empirical study

This study aims to examine the influence of firms’ alliance knowledge on their innovation capacity, under the contingencies of both intentional and unintentional leakage of business-critical knowledge. Based on a survey of 410 staff from 205 allied firms in Tunisia, this study applies the linear regression to investigate the research model. The results show that external knowledge sharing appears to have a positive effect on firms’ innovative capability while high levels of intentional and unintentional knowledge leakage by a focal firms’ employees, turns out to negatively moderate such a relationship. In this paper, actors of focal firm need to distinguish between the firms' critical knowledge, and the one which can be legally shared and exchanged with other partners. Sharing critical knowledge, intentionally or unintentionally, might hurt the focal firms’ innovative capacity. Although the issues of knowledge sharing and innovation have been exhaustively treated in the literature, very little are the research works which have undertaken to study the links between knowledge sharing, knowledge leakage and the firms’ innovation capacity. Thus, this study is designed to foster further enrichment to the literature, by proposing more clear differentiation between unintentional and intentional knowledge leakages and their impact on the firm’s innovation.

Persistent organic pollutant emission via dust deposition throughout Pakistan: Spatial patterns, regional cycling and their implication for human health risks

In the current study, Persistent Organic Pollutants (POPs) in outdoor dustfall was monitored for the first time along the Indus river system of Pakistan. Among the studied OCPs (ng/g, dry weight), DDTs (0.16–62) were the predominant contaminants identified in deposited dust followed by HCHs (0.1–10.2), HCB (0.09–7.4) and chlordanes (0.1–2.8). The indicative diagnostic ratio for DDTs and HCHs suggested recent emission of DDTs as well as historical emission of both chemicals in regions where they were used for crop protection and malarial control. The levels of ∑31PCBs (ng/g, dry weight) in dust ranged from 0.95–125, and compositional profiles suggested arochlor-1248, -1254 commercial mixtures as source. A few exceptions were samples from urban areas that reflected the use of aroclor-1260, and-1262 and/or unintentional leakage from several industrial processes. The WHO05-TEQ values for dioxin-like PCBs (with major contributions of PCB-126) were found to be 0.07–34.5 (median; 1.87) pg TEQg−1dw for all the studied samples. Correlation analysis identified that DDTs, HCHs, HCB and PCBs were significantly associated (r=90; p<0.01) with dusts collected in proximity to urban centers with widespread anthropogenic activities in these areas. A few cases where high levels of POPs from remote mountain highlands were detected, point to the potential for long range transport of these chemicals. Human risk assessment analysis of contaminated dust showed that DDTs and PCBs are major constituent chemicals of concern with regard to the development of cancer in children, with ingestion being the main route of exposure of dust-borne DDTs (0.12–1.03×10−6) and PCBs (0.86–12.43×10−6).

Determinants of Unintentional Leaks During CPAP Treatment in OSA

Unintentional leakage from the mouth or around the mask may lead to cessation of CPAP treatment; however, the causes of unintentional leaks are poorly understood. The objectives of this study were (1) to identify determining factors of unintentional leakage and (2) to determine the effect of the type of mask (nasal/oronasal) used on unintentional leakage. Seventy-four polysomnograms from patients with OSA syndrome treated with auto-CPAP were analyzed (23 women; 56 ± 13 years; BMI, 32.9kg/m2 (range, 29.0-38.0kg/m2). Polysomnographic recordings were obtained under auto-CPAP, and mandibular behavior was measured with a magnetic sensor. After sleep and respiratory scoring, polysomnographic signals were computed as mean values over nonoverlapping 10-s intervals. The presence/absence of unintentional leakage was dichotomized for each 10-s interval (yes/no). Univariate and multivariate conditional regression models estimated the risk of unintentional leaks during an interval "T" based on the explanatory variables from the previous interval "T-1." A sensitivity analysis for the type of mask was then conducted. The univariate analysis showed that mandibular lowering (mouth opening), a high level of CPAP, body position (other than supine), and rapid eye movement (REM) sleep increased the risk of unintentional leaks and microarousal decreased it. In the multivariate analysis, the same variables remained independently associated with an increased risk of unintentional leakage. The sensitivity analysis showed that oronasal masks reduced the risk of unintentional leaks in cases of mouth opening and REM sleep. Mouth opening, CPAP level, sleep position, and REM sleep independently contribute to unintentional leakage. These results provide a strong rationale for the definition of phenotypes and the individual management of leaks during CPAP treatment.

Integrated strategy for mutagenicity prediction applied to food contact chemicals.

Food contamination due to unintentional leakage of chemicals from food contact materials (FCM) is a source of increasing concern. Since for many of these substances, only limited or no toxicological data are available, the development of alternative methodologies to establish rapidly and cost-efficiently level of safety concern is critical to ensure adequate consumer protection. Computational toxicology methods are considered the most promising solutions to cope with this data gap. In particular, mutagenicity assessment has a particular relevance and is a mandatory requirement for all substances released from plastic FCM, regardless how low migration and exposure are. In the present work, a strategy integrating a number of (Quantitative) Structure Activity Relationship ((Q)SAR) models for Ames mutagenicity predictions is proposed. A list of chemicals representing likely migrating moieties from FCM was selected to test the value of the newly defined strategy and the possibility to combine predictions given by the different algorithms was evaluated. In particular, a scheme to integrate mutagenicity estimations into a single final assessment was developed resulting in an increased domain of applicability. In most cases, a deeper analysis of experimental data, where available, allowed fixing misclassification errors, highlighting the importance of data curation in the development, validation and application of in silico methods. The high accuracy of the strategy provided the rationales for its application for toxicologically uncharacterized chemicals. Finally, the overall strategy of integration will be automated through its implementation into a freely available software application.

Unintentional and Involuntary Personal Information Leakage on Facebook from User Interactions

Online social networks (OSNs) have changed the way people communicate with each other. An OSN usually encourages the participants to provide personal information such as real names, birthdays and educational background to look for and establish friendships among them. Some users are unwilling to reveal personal information on their personal pages due to potential privacy concerns, but their friends may inadvertently reveal that. In this work, we investigate the possibility of leaking personal information on Facebook in an unintentional and involuntary manner. The revealed information may be useful to malicious users for social engineering and spear phishing. We design the inference methods to find birthdays and educational background of Facebook users based on the interactions among friends on Facebook pages and groups, and also leverage J-measure to find the inference rules. The inference improves the finding rate of birthdays from 71.2% to 87.0% with the accuracy of 92.0%, and that of educational background from 75.2% to 91.7% with the accuracy of 86.3%. We also suggest the sanitization strategies to avoid the private information leakage.

Data Lineage in Malicious Environments

Intentional or unintentional leakage of confidential data is undoubtedly one of the most severe security threats that organizations face in the digital era. The threat now extends to our personal lives: a plethora of personal information is available to social networks and smartphone providers and is indirectly transferred to untrustworthy third party and fourth party applications. In this work, we present a generic data lineage framework Lime for data flow across multiple entities that take two characteristic, principal roles (i.e., owner and consumer). We define the exact security guarantees required by such a data lineage mechanism toward identification of a guilty entity, and identify the simplifying non-repudiation and honesty assumptions. We then develop and analyze a novel accountable data transfer protocol between two entities within a malicious environment by building upon oblivious transfer, robust watermarking, and signature primitives. Finally, we perform an experimental evaluation to demonstrate the practicality of our protocol and apply our framework to the important data leakage scenarios of data outsourcing and social networks. In general, we consider Lime , our lineage framework for data transfer, to be an key step towards achieving accountability by design .

Macro/Nano-Gel Composite as an Injectable and Bioactive Bulking Material for the Treatment of Urinary Incontinence

Many women around the world are suffering from urinary incontinence, defined as the unintentional leakage of urine by external abnormal pressure. Although various kinds of materials have been utilized to treat this disease, therapies that are more effective are still needed for the treatment of urinary incontinence. Here, we present a macro/nanogel composed of in situ forming gelatin-based macrogels and self-assembled heparin-based nanogels, which can serve as an injectable and bioactive bulking material for the treatment of urinary incontinence. The hybrid hydrogels were prepared via enzymatic reaction in the presence of horseradish peroxidase and hydrogen peroxide. Incorporating a growth factor (GF)-loaded heparin nanogel into a gelatin gel matrix enabled the hybrid gel matrix to release GF continuously up to 28 days. Moreover, we demonstrated that the hydrogel composites stimulated the regeneration of the urethral muscle tissue surrounding the urethral wall and promoted the recovery of their biological function when injected in vivo. Thus, the macro/nanohydrogels may provide an advanced therapeutic technique for the treatment of urinary incontinence as well as an application for regenerative medicine.

Friction in ultra-thin conjunction of valve seals of pressurised metered dose inhalers

In many drug dispensing devices, such as syringes and inhalers, an elatomeric gasket is used to prevent the formulation from leaking from the chamber. During device actuation, the seal is subjected to friction, which in turn causes its deformation and can cause unintentional leakage, thus dose variability. Additionally, friction of seal is responsible for a host of potential problems such undue effort required for actuation and potential wear. The mechanism of friction generation in the seal conjunction is complex, arising from adhesion of rubber in contact with the moving interface, viscous action of a thin film of fluid and deformation of seal asperities. Therefore, the first step in understanding the conjunctional behaviour of rubber seals is a fundamental study of mechanisms of friction generation. A developed model can then be validated against measurements and used at a later stage to predict product performance, robustness and variability due to manufacturing tolerances. A friction model, based on the aforementioned mechanisms, for prediction of seal friction has been developed and validated against measured friction tests performed at both nano and component level scales. Pressure changes in the metered chamber have been taken into account in the model. Friction data are presented for nitrile rubber, using a silicon nitride AFM tip for nano-scale interactions and polybutylene terephthalate (PBT) for asperity interactions at a component level, where a traditional friction test apparatus is utilised. Reasonable agreement is found between measurements and model predictions for the nano-scale coefficient of friction of rubber against silicon nitride. Similarly, good agreement has been obtained for the mean coefficient of friction of rubber against PBT. It is found that dominant mechanism of friction is adhesion. For the typical asperity geometry of such seals and the usual low sliding speeds the other friction contributions, viscous shear and asperity deformation are negligible. However, this is not the case in many other seals or gaskets in other applications such as in hydraulic actuators.

SiGe Tunnel Field Effect Transistors

For conventional MOSFETs band-to-band tunnelling has to be avoided because it causes unintentional leakage currents. On the other hand the Tunnel FET, which basically consists of a gated pin-diode, takes advantage of tunnelling. The influence of technological parameters on device performance as well as scaling rules will be discussed. Finally it will be shown that band gap engineering with SiGe and the incorporation of high-k dielectrics strongly improve current slope and maximum ON current. A future device performance comparable or even better than the conventional MOSFET is predicted.