59 research outputs found

    Comparing the environmental impacts of using bio-renewable and fossil-derived solvent in polymer membrane fabrications

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    Sustainable production methods for polymer membrane fabrication are gaining attention due to concerns about the toxicity of conventional fossil-derived solvents in the production process. In addition, the promotion of using chemicals from renewable source for synthesis processes among industries and researches has increased to decelerate resource depletion. As such, more benign and bio-renewable solvents, dihydrolevoglucosenone (Cyrene™) and 2-methyltetrahydrofuran (2-MeTHF), have been proposed as replacements for traditional fossil-derived solvents, n-hexane and dimethylformamide (DMF). In this work, a life cycle assessment (LCA) was employed to quantitatively evaluate the environmental impacts of using the aforementioned bio-renewable solvents versus fossil-derived solvents for fabricating 1 g of polymer membrane. The analysis adopted a cradle-to-gate perspective and assessed three endpoint impact categories: Human health, Ecosystems and Resources. Despite lower environmental impacts for producing bio-renewable solvents, using such solvents to fabricate membranes displayed a higher environmental impact score in all endpoint categories. This discrepancy was attributed to the lower yield of the membrane fabrication process when using bio-based solvents. This indicated that further work is needed to optimise membrane fabrication so that the benefits of using bio-based solvents can be maximised

    The effect of fluidity of palm kernel oil with pour point depressant on coefficient of friction using fourball tribotester

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    The growing awareness worldwide of the need to promote the use of renewable materials such as vegetable oils is due to increasing concerns about the damage to the environment that is being caused by the use of non-biodegradable mineral oils. Vegetable oils have the potential to replace mineral oils as a lubricant because of their specific properties, namely that they are non-toxic and biodegradable. The main problem with the use of vegetable oils is that they perform poorly at low temperatures. In this research, palm kernel oil (PKO), which behaves as a semi-solid, was used as a bio-lubricant by mixing it with different weight percentages of a pour point depressant (PPD) to investigate the performance of the pour point depressant and also to determine the effect on the lubricity of the bio-lubricant when it is blended with different percentages of PPD (5 wt.%, 10 wt.%, 20 wt.% and 30 wt.%). The experiment was conducted according to ASTM D4172 and ASTM D2783. The results of the experiment showed that at low temperatures the PKO samples with 20 wt.% PPD and 30 wt.% PPD performed well, where they were able to remain in a liquid form at a temperature of 15°C. From all antiwear test result, the coefficient of friction for the PPD sample shows poor tribological performance when adding PPD into the palm kernel oil

    Intraoperative hypothermia in patients undergoing Total knee arthroplasty: A cross-sectional study from a developing country

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    Background: Intraoperative hypothermia is associated with various risk factors, morbidity, and mortality in patients undergoing total knee arthroplasty (TKA), increasing the emotional and financial burden on patients. This study aimed to identify risk factors of intraoperative hypothermia in patients undergoing TKA.Materials and methods: All adult patients (⩾18 years) who underwent TKA from January 2016 to December 2017 at a tertiary-care hospital in Pakistan were included in this retrospective, cross-sectional study. Temperature \u3c 36 °C was defined as hypothermia.Results: The study included 286 patients (77.6% female) with a mean age of 61.4 ± 10.4 years. The overall proportion of intraoperative hypothermia was 26.6%. Of the total patients, 66.1% underwent bilateral TKA whereas 33.9% underwent unilateral TKA. 73.8% of the patients were ASA Level 2. Only 13.3% of patients had postoperative hypothermia.Conclusion: Intraoperative hypothermia was significantly associated with age, bilateral procedure, ASA level and postoperative hypothermia in patients undergoing TKA. The surgeon and the operative team should be aware of the risk factors and the adverse outcomes associated with intraoperative hypothermia, especially in resource constrained settings to plan preventive strategies.Trial registration: This study was retrospectively registered on ClinicalTrials.gov on 3rd October 2020. The registration ID is NCT04575246

    A Potentially Disastrous Life -Threatening Complication of Emergency Tube Thoracostomy in A Simple Case of Spontaneous Pneumothorax

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    Emergency tube thoracostomy carries risks of infective and technical complications. The aseptic technique is essential to prevent infections, while blunt dissection method can minimise the associated technical complications. Preparation and adherence to protocols as well as appropriate knowledge and skills, however, are of utmost importance to reduce risks of complications. Physicians must have adequate knowledge of anatomy and the procedure to ensure for accurate site tube placement without any complication. This case illustrates how a failure to appropriately use the instrument resulted in a displaced scalpel blade inside the thoracic cavity. It caused an unnecessary thoracotomy for blade retrieval. The mishap escalated a simple procedure to the potentially disastrous life-threatening event

    The tribological performance of modified RBD palm kernel oil under extreme pressure load test

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    Lubrication is one of the most used components globally in various types of applications. The hiking in demand of lubrication oil annually rise several issues such as environmental wastage and oil supply. This paper discussed the alternate option of lubricant oil performance from renewable resources that helps to preserve the environment and support the current mineral oil supply. Refined Bleach and Deodorised Palm Kernel Oil was used in this research as tested lubricant undergone normal load test (ASTM D4712) and extreme pressure (ASTM D2783) according to the ASTM test standards. The Refined Bleach and Deodorised Palm Kernel Oil was tested at two conditions of semi-solid form and liquid form. A liquid form of Refined Bleach and Deodorised Palm Kernel Oil was synthesized with transesterification process to convert the semi-solid form into liquid at room temperature. Results shows that Refined Bleach and Deodorised Palm Kernel Oil performance was comparable to the fully synthetic oil in terms of COF, WSD, and surface roughness while in the extreme pressure test shows that ISL of palm-based oil are slightly lower than fully synthetic oil by 127N