33 research outputs found

    Adaptive Backstepping Integral Sliding Mode Control for 5DOF Barge-Type OFWT under Output Constraint

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    This article presents a new control solution for a dynamical model of a translational oscillator with a rotational actuator (TORA) based on multi-body dynamics for a barge-type offshore floating wind turbine (OFWT). TORA has been employed as an active structural control strategy. The solution of bounding the output movements of platform pitch and tower bending angle to a certain limit, along with mitigating the OFWT vibrations due to environmental disturbances and uncertainties, is presented in this novel control framework. This new control algorithm consists of a high-gain observer (HGO)-based adaptive backstepping integral sliding mode control (ISMC) and a barrier Lyapunov function (BLF). This guarantees satisfying the constraints on the states and effectively resolves the problem of the unavailability of the system states. The proposed control law based on the BLF has been compared with an adaptive backstepping ISMC to show the efficiency of the output-constraint control scheme. Through MATLAB/SIMULINK numerical simulations and their numeric error table, the effectiveness of the proposed control scheme has been examined. The results confirm the validity and efficiency of the proposed control approaches

    GERM CELL TUMOURS OF THE OVARY IN CHILDREN AND ADOLESCENTS: A CLINICAL STUDY OF 109 PATIENTS IN A SPECIALIZED CANCER CENTRE

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    Objective: Paediatric ovarian germ cell tumours (GCTs) are rare tumours withmalignant tumours extremely rare.Methods: All the paediatric patients who received treatment for histology proven ovarian GCT at Shaukat Khanum Memorial Cancer Hospital from January 2006 to December 2014 were retrospectively reviewed. Patients over the age of 18 years were excluded from the study. A total of 109 patients were included in the study. A set of parameters were identified to record initial clinical presentation and examination, imaging and laboratory investigations including tumour marker levels. Decisions of multidisciplinary team meetings, surgical treatment, neo adjuvant, adjuvant chemotherapy and radiation data retrieved. Data analysiscarried out using SPSS 20.Results: In total 109 girls presented to our hospital during the study period, most of them above the age of 5 years, with dysgerminoma being the most common followed by yolk sac tumour. Most of the patients received treatment outside our hospital and were referred here for chemoradiotherapy. Fertility preserving surgery was the most commonly performed surgical procedure with a mean follow-up of 50.4 months and >75% overall 5-year survival.Conclusion: Regardless of histologic types, the outcomes of GCT can be improved with a multidisciplinary approach.Key words: Dysgerminomas, germ cell tumours, ovarian tumour

    An Ongoing Futuristic Career of Metal–Organic Frameworks and Ionic Liquids, A Magical Gateway to Capture CO<sub>2</sub>; A Critical Review

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    Carbon capture and storage (CCS) technologies are the “knight in shining armor” that can save humanity from burnout in the longer term, minimizing damage from CO2 emissions by keeping them out of the atmosphere. Metal–organic frameworks (MOFs) have received a promising career for CO2 capture due to their high porosity, surface area, excellent metal-to-ligand interaction, and good affinity to capture CO2 molecules. On the other hand, Ionic liquids (ILs) as emerging solvents have reported a significant influence on CO2 solubility due to their wide range of tunability in the selection of a variety of cations and anions along with the advantage of nonvolatility, high thermal stability, and nonflammability. The current Review highlights the recent progress and ongoing careers of employing MOFs and ILs in carbon capture technologies before their commercialization on a large scale. A brief overview of CO2 capturing using MOFs and ILs is given under the influence of their possible functionalization to enhance their CO2 separation. Information on the possible integration of MOFs-ILs as a composite system or membrane-based gas separation is also presented in detail. The integration has a high potential to capture CO2 while minimizing the unit operation costs for a stable, efficient, and smooth industrial gas separation operation. Present work attempts to link the chemistry of MOF and IL and their successful hybridization (MOF-IL composite) to process the economics for CO2 capture

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Abstracts from the 3rd International Genomic Medicine Conference (3rd IGMC 2015)

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    OPTIMISATION STUDIES ON RUBBER SEED OIL BASED METHYL ESTER SYNTHESIS VIA HYDRODYNAMIC CAVITATION TECHNOLOGY

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    Hydrodynamic cavitation (HC) technology is a viable way to produce sustainable biodiesel from high free fatty acid non-edible feedstock. This technology has affirmative environmental impacts with lower energy consumption and shorter reaction time, which offers a cleaner possibility. The limitation of conventional mechanical stirring (MS) process involved longer reaction time to obtain methyl ester content. Four newly designed orifice plates were studied as a cavitating device in HC reactor. HC reactor was connected to the diaphragm pump in a close loop reactor. The compressed air was supplied to operate the double diaphragm pump, which is the main device to dissipate the energy in a HC reacto

    OPTIMIZATION STUDIES ON POST BLENDING OF CRUDE PALM AND RUBBER SEED OIL FATTY ACID METHYL ESTERS

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    In avoiding the major issues of fossil fuel depletion and the environmental concerns, biodiesel is one of the most feasible sources of alternative energy. Rubber seeds, due to its non-edible characteristics have a potential to be converted to biodiesel. Its utilization will help to resolve food versus fuel controversy. Malaysia has a vast number of palm and rubber plantations that can supply sufficient seeds for biodiesel production. In present work, parametric studies and optimized conditions were determined via response surface methodology (RSM), using the central composite design (CCD) of the Design Expert 8.0 software. The parameters studied for solvent extraction of rubber seeds were solvent to seed ratio, temperature, extraction time and drying time of the seeds. A parametric study was also conducted to determine the effect of alcohol to oil (A:0) ratio, catalyst loading, reaction time and temperature on acid esterification and base transesterification process

    Diagnostic Accuracy of Serology Testing for Helicobacter Pylori in Perforated Peptic Ulcer

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    Background: To compare H. pylori serology testing with histopathological biopsy, in patients with perforated peptic ulcer.Methods: This cross sectional study was performed to document the diagnostic accuracy of H. pylori serology in patients with perforated duodenal ulcer. Perforated peptic ulcer was diagnosed on the basis of history, clinical findings and presence of free gas under the diaphragm on an x-ray. All individuals fulfilling inclusion criteria underwent laparotomy. Blood samples were sent for H Pylori serology by enzyme linked immunosorbent assay. At the same time, gastric antral biopsies were taken for histopathology for H. pylori.Results: Sstudy included 191 patients with diagnosed perforated peptic ulcer at laparotomy. Majority (70.2%) were males. The mean age was 41.72 years. In majority the perforation was seen along the first part of duodenum (76.4%). H. pylori serology was positive in 69.1% patients. One hundred and thirty nine (72.8%) patients had positive histopathology for H pylori. Out of these, 92.8% also had a positive H. pylori serology. Fifty two (27.2%) patients had negative histopathology for H. pylori. Out of these 5.8% had a positive serology test. One hundred and twenty nine were true positive i-e both had positive histopathology and serology and 52 were true negative i.e., they had both a negative serology and a negative histopathology. The results were therefore correct in 94.76%. The overall accuracy of serology in comparison to histopathology was 94.76%. The calculated sensitivity, specificity, positive predictive value and negative predictive value of serology in comparison to histopathology was 92.8%, 94.5%, 97.7% and 83.9% respectively.Conclusion: A high prevalence of H. pylori infection was found in patients with perforated peptic ulcers. Overall accuracy of serology in comparison to histopathology was 94.76%. Serological testing is a useful noninvasive method for the diagnosis of Helicobacter pylori infection
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