Sensor based corrosion condition monitoring of coating substrate system informed by fracture mechanics, electrochemistry and heat transfer concepts

This research investigates delamination and blistering as coating failure mechanisms due to corrosive diffusing species, residual and thermal stresses. Several mathematical models to include environmental variables as temperature, humidity ratio and atmospheric constituents have been developed and reported. During this study various coating failures have been analysed through a combination of electrochemistry, fracture mechanics and heat transfer concepts. This approach enabled the development of comprehensive mathematical models for the prediction and prognoses of coating failures applied to high value assets. The formation of blister and its propagation due to diffusion of corrosive species was investigated. Fracture mechanics concepts were utilised to study the initiation and propagation of a circular blister as an interfacial crack under the coupling affects of compressive and diffusion induced stresses along with heat transfer due to pressure gradient at the interface of coating substrate system. The direction of blister propagation was defined through a mathematical model with blister radius r and radial angle θ as initial defining parameters. Experimental work was conducted to assess the influence of varying temperatures, humidity ratios and environmental pollutants as SO2 and salt particles to investigate corrosion failures. Live condition monitoring techniques were developed to assess corrosion rate with respect to large vehicles operation frequencies to study the effects of changing environments. Three years of real time data consisted of 150K data points was acquired for investigating corrosion failures with or without coatings. Both experimental and simulation data was compared to predictive and prognostics models. There is excellent agreement between experimental and simulation results to be applied for live corrosion condition monitoring of large high value assets. A sensor based corrosion condition monitoring methodology, informed by experimental and simulation results has been developed and is presented

Diverse trends witnessed in assessing laryngeal lesions while comparing transcutaneous laryngeal ultrasound & videolaryngoscopy

Objective: To determine the accuracy of Transcutaneous Laryngeal Ultrasound (TLUS) and Video Laryngoscopy (VL) taking Direct Laryngoscopy (DL) as Gold Standard for assessment of  laryngeal pathologies.Methodology: This Cross Sectional Comparative clinical study recruited a sample of 24 cases of either gender, requiring laryngeal examination prospectively using convenience sampling from otolaryngology outpatients of Capital Hospital, Islamabad, Pakistan over a period of six months from 1st March, 2018 to 31st August, 2018. Patients fulfilling the selection criteria were subjected to Video Laryngoscopy under local anesthesia, Transcutaneous Laryngeal Ultrasound followed by Direct Laryngoscopy under general anesthesia and findings recorded.  Data was analyzed using SPSS 23. Variables specially studied included Diagnostic values of both VDL and TLUS versus DL and presented with frequency, percentage, sensitivity, specificity, PPV and NPV and Accuracy Rate.Results: Study sample revealed 54.2% males and 45.8% females with mean age of 46.79 + 25.34 years. Hoarseness was commonest presentation (58.3%) and Laryngeal Polypi was the more frequent pathology noted (25%). VL had a sensitivity of 87.50%, specificity of 37.50%, PPV of 73.7%, NPV of 60% and Accuracy rate of 70.83%. While TLUS revealed a sensitivity of 43.80%, specificity of 70.80%, PPV of 100%, NPV of 47.15% and Accuracy rate of 62.50%.Conclusion: Video Laryngoscopy with a higher Accuracy and sensitivity compared to Transcutaneous Laryngeal Ultrasound, is more accurate examination for assessment of Laryngeal lesions

Sustainable and Resilient Smart Water Grids: A Solution for Developing Countries

According to a United Nations report, the world population will increase from 7 billion to 9 billion by 2050. Further, the water stress level is more than 70% in 22 countries while in another 31 countries it is between 25% and 70%. More than 2 billion people live in these 53 countries which are all underdeveloped. Water use has increased by 1% per year since the 1980s, so global demand is expected to rise by 30% by 2050. Thus, efficient water grid management is imperative to ensure there is sufficient water for the future. Information and Communication Technology (ICT) can be used to create smart water grids to optimize water distribution, reduce waste and leakage, and resolve quality and overuse issues. In this work, a low cost, real-time, reliable and sustainable IoT based solution called SmartTubewell is proposed for smart water grid management. It is composed of two components, a sensor node installed at tube wells and an application layer on Amazon Web Services (AWS) for data analysis, storage and processing. The sensor node is based on a Raspberry Pi with integrated current and voltage sensors and a local database. The sensor data is transmitted to AWS using a cellular (GPRS) network. A comparison between the proposed system and SCADA is presented which shows that SmartTubewell has a much lower cost. A field test with multiple tube wells in Peshawar, Pakistan indicates that this is a suitable solution for developing countries

Structural Monitoring System for proactive detection of corrosion and coating failure

The performance and availability of high priority structures can be greatly affected by corrosion damage. The application of protective coatings, frequent inspections and scheduled based maintenance activities result in huge direct and indirect financial loss to organisations. The expeditious detection of coating failure and corrosion damage can result in precise and cost-effective condition-based maintenance. Coating failure and corrosion phenomena are driven by complex multi-disciplinary parameters according to extensive research findings in the literature. State-of-the-art prognostic models proposed in recent years incorporate complex multi-disciplinary parameters, therefore a real-time prognostic monitoring system must acquire these complex parameters to allow accurate prediction. The work reported here covers the development of a real-time monitoring system using micro-sensors and includes the validation of the system through accelerated corrosion and coating failure testing. The system contains a remote terminal unit that includes a linear polarisation method for corrosion detection under the coating and a micro-strain gauge method for monitoring stress behaviour over the coating. The software at base station includes a graphical user interface and database to store parameters for further processing and failure prediction. The real-time monitoring system can be applied to remote, stationary and mobile assets to monitor the mechanical and chemical changes within coating-substrate systems

An optimal condition based maintenance scheduling for metal structures based on a multidisciplinary research approach

Latest research findings show that the deterioration of metal coatings results due to complex combination of material and meteorological parameters. The classical maintenance scheduling do not consider complex interface of materials and meteorological parameters to determine optimal maintenance framework. The cost of recoating can be optimised through appropriate selection of coating specifications and maintenance strategy. This research provides a multidisciplinary algorithmic approach to determine cost-effective solutions for recoating. The specifications of red oxide primer coating and structural steel substrate system are considered for simulation analysis. The results show that the appropriate selection of 10% increase in coating thickness based on coating-substrate system specifications resulted in 20-25% reduction in annual patch failures which reduces 5-6 % cost of recoating. Furthermore, the proposed model also simulated to compare Patch recoating and Part recoating strategy and algorithm show that the Part recoating is cost-effective as compared to Patch recoating if number of annual patch failure is greater than ‘2’ and area of the part is ‘2x’times larger than the area of the patch. Contrary, the Patch recoating results in low cost if the part area is ‘10x’ times larger than patch area and number of annual patch failures are less than ‘7’

Recent advances in the synthesis of triazole derivatives

Triazole ring system has attracted a continuously growing interest of synthetic organic chemists and those dealing with the medicinal compounds due to its versatile potential to interact with biological systems. The triazole compounds possess a wide range of biological activities and are especially focused for antifungal behavior. In thisreview article, we have summarized the recent developmentsin the synthetic methodologies of this ring system. The main focus was on the methodologies which deal with the facile and convenient synthesis

ROLE OF PARENTAL SUSPICION OF HEARING IMPAIRMENT ON AGE OF DIAGNOSIS & INTERVENTION: A PAKISTANI PERSPECTIVE

OBJECTIVE: To determine the role of parental suspicion of hearing impairment (HI) on age of identification and intervention. METHODS: This Retrospective chart review, reviewed medical records of hearing-impaired children of both genders, aging 6 months to 12 years, who attended Cochlear Implant Centre, Department of Otolaryngology, Capital Hospital, Islamabad, Pakistan from 1st July 2015 to 31st June 2016.  Data extracted from medical records included basic demographic information and facts like when hearing loss was suspected, who suspected hearing loss, which professional conducted the first assessment, when was final diagnosis established and when did child receive intervention. RESULTS: Out of 81 hearing impaired children, Majority (n=55; 67.9%) were males. Most (n=62; 76.5%) of the patients were suspected to have HI by parents and 56 (69.2%) were suspected to have HI in first year of life. In 67 (82.7%) cases, diagnosis was made within the first two years of life. Forty two (42.9%) patients received intervention in the first two years of life. There was significant association of age of suspicion of hearing impairment by parents with the age at diagnosis (p<0.001) and age at intervention (p<0.001) with those in whom HI was suspected earlier were able to be diagnosed and received intervention at an earlier age. No significant association was found for age of suspicion, age of diagnosis and age of intervention with persons who suspected HI and gender of the patients. CONCLUSION: Parental suspicion of hearing impairment has significant role to play in the early diagnosis as well as intervention

New subgenera and a new species of the genus Raphignathus Dugès (Prostigmata, Raphignathidae), with taxonomic notes on the genus Neoraphignathus Smiley &amp;amp; Moser

Four new subgenera in the genus Raphignathus Dugès are hereby proposed: Raphignathus (Raphignathus), subgen. nov., Raphignathus (Monoraphignathus), subgen. nov., Raphignathus (Diraphignathus), subgen. nov., and Raphignathus (Triraphignathus), subgen. nov. These subgenera are diagnosed by the number of setae on the interscutal membrane of females. A new species, R. (D.) neohecmatanaensis sp. nov., is described and illustrated based on females collected from Ziziphus spina-christi Mill. (Rhamnaceae). The taxonomic status of the monotypic genus Neoraphignathus Smiley &amp;amp; Moser and three species (R. evidus, R. hsiufui, and R. johnstoni) are discussed. A key to world species of the family Raphignathidae is given

Drug overdose: a wake up call! Experience at a tertiary care centre in Karachi, Pakistan

OBJECTIVE: To study the characteristics of patients admitted with drug overdose caused either by accidental overdose of the prescribed medications or as an act of deliberate self harm (DSH) at a tertiary care hospital in Karachi, Pakistan.METHODS: A retrospective case series review was conducted at the Aga Khan University Hospital from January 2002 to October 2006. Three hundred and twenty four adult patients admitted with drug overdose were included in the study.RESULTS: Our sample group revealed mean age of 36.2 +/- 17.0 years, more females (59%), housewives (34%), and students (20%). Fifty six percent of patients committing DSH were married (p = 0.001), 81% needed in-patient psychiatric services (p = 0.016) of whom a significantly high number (38%) refused it. Domestic and social issues were rated highest among DSH group (p = 0.003), depression among females was common (p = 0.028) and Benzodiazepines (41%) was the most frequently used drug (p = 0.021). Sub-group analysis of accidental overdoses revealed mean age of 45.6 +/- 19.6 years, single (75.4%) and males (54.1%). Drugs used were mainly Benzodiazepines (18%) followed by Opioids (11%), Antiepileptics (10%) and Warfarin (10%).CONCLUSION: Our study showed that depressed housewives are at greater risk for DSH. Domestic and social issues were rated highest and Benzodiazepines were the most commonly used agents. Most of our patients refused inpatient psychiatric treatment leading us to believe that general awareness of psychiatric illnesses is imperative in our community. High number of accidental overdoses is alarming in older, single males convincing us to believe that existing pharmacy system needs further evaluation and modification