Environmental impacts of utilization of ageing fixed offshore platform for ocean thermal energy conversion

Most Malaysian jacket platforms have outlived their design life. As these old platforms have outlived their design life, other alternatives must be considered. As several offshore oil and gas extraction installations approach the end of their operational life, many options such as decommissioning and the development of a new source of energy such as wind farms are introduced. The objective of this paper is to investigate the environmental impacts of utilising ageing fixed offshore platform as a source for Ocean Thermal Energy Conversion (OTEC). The environmental impact of utilising an ageing fixed offshore platform as an OTEC source is discussed. OTEC produces energy by taking advantage of temperature variations between the ocean surface water and the colder deep water through cold-water intake piping, which requires a seawater depth of 700 metres. The output of this study shows that OTEC is envisioned to preserve marine life, becoming a new and reliable source of energy, assist clean water production, and reduce the negative impact of climate change. OTEC platforms utilising ageing platforms may lead to 44 % of fish catch in the ocean, remove 13 GW of surface ocean heat for every GW of electricity production per year, generate 1.3105 tonnes of hydrogen per year for each GW of electricity generated. In addition, OTEC platforms can reduce approximately 5106 tonnes of carbon dioxide from the environment for 1 GW of electricity generated per year, and supply 2 million litres of water per day for a 1 MW platform. Since Malaysia's seawater profile allows for installing a fixed offshore platform as an OTEC power plant, Malaysia has many potentials to profit from the OTEC process

Offshore structural reliability assessment by probabilistic procedures—a review

Offshore installations must be built to resist fatigue as well as extreme forces caused by severe environmental conditions. The structural reliability analysis is the popular practise to assess a variety of natural waves determined by the long‐term probability distribution of wave heights and corresponding periods on the site. In truth, however, these structures are subjected to arbitrary wave‐induced forces in the open ocean. Hence, it is much more reasonable to account for the changed loading characteristics by determining the probabilistic characteristics of the random loads and outcomes responses. The key challenges are uncertainties and the non‐linearity of Morison’s drag element, which results in non‐Gaussian loading and response distributions. This study would analyze advances achieved to date in a comprehensive probabilistic review of offshore fixed jacket-type platforms

Intertwining the arts and sciences to stimulate a creative mind

From the basic motion of a simple pendulum, which acts as a tool that turns a blank canvas into pure abstract art, this particular concept has been applied to science-related art to showcase its tremendous impact on scientific, psychological and educational fields. The Art and Science Program is a collaborative artistic program between the committees from the Chemical and Energy School of Engineering, UTM, and Sekolah Tun Fatimah (STF), with the aim of examining the impacts of the rotational motion of the pendulum which can generate mesmerizing art on blank mahjong papers. The outcome of the art has been influenced by various factors, such as the viscosity of the paint used, the flowrate of the paint drip, the velocity of the paint-pendulum-modelled dripper, the position of the release point, and the motion of the dripper arising from the resultant force of multiple interacting forces. By showing the interconnections between pendulum motion, gravitational force, potential and kinetic energies, and the fundamentals of fluid dynamics, artistic abstract paintings can be created from the science of mechanics. Intertwining the arts and sciences that has been the main focus of this program can garner greater appreciation, even embraced, as it results in a significant effect on the development of both creative and critical thinking among the participants and committees

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Tropical and subtropical Asia's valued tree species under threat

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affects the provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit vulnerability assessment (including overexploitation, fire, overgrazing, habitat conversion, and climate change) of 63 socio-economically important tree species selected from national priority lists and validated by an expert network representing 20 countries. Overall, 74% of the most important areas for conservation of these trees fall outside of protected areas, with species severely threatened across 47% of their native ranges. The most imminent threats are overexploitation and habitat conversion, with populations being severely threatened in an average of 24% and 16% of their distribution areas. Optimistically, our results predict relatively limited overall climate change impacts, however, some of the study species are likely to lose more than 15% of their habitat by 2050 because of climate change. We pinpoint specific natural forest areas in Malaysia and Indonesia (Borneo) as hotspots for on-site conservation of forest genetic resources, more than 82% of which do not currently fall within designated protected areas. We also identify degraded lands in Indonesia (Sumatra) as priorities for restoration where planting or assisted natural regeneration will help maintain these species into the future, while croplands in Southern India are highlighted as potentially important agroforestry options. Our study highlights the need for regionally coordinated action for effective conservation and restoration

The effect of polyethylene-octene elastomer on the morphological and mechanical properties of polyamide 6/ polypropylene nanocomposites

Rubber-toughened nanocomposites (RTNC) consisting of ternary blends of polyamide 6 (PA6), polypropylene (PP) and polyethylene-octene elastomer (POE) containing 4 wt% of organophilic modified montmorillonite were produced by melt compounding followed by injection moulding. The blend composition was kept constant (PA6/PP=70/30 parts by weight) while the POE content was varied between 5 and 20 w-t%. Maleated PP (PP-g-MA) was used as was used as compatibilizer. The morphology of the RTNC was studied by scanning electron microscopy and X-ray diffraction (XRD). The mechanical properties of RTNC were studied through tensile, flexural, Izod impact and facture toughness properties. While the tensile and flexural properties were found to decrease with the increasing concentration of POE, the toughness was significantly enhanced as compared to the neat PA6/PP blends. In general, the blends containing 10-15 wt% of POE had the best balance of stiffness, strength and toughness. The addition of 30 wt% of PP in the PA6 matrix improved the compatibility between PA6 and the rubber phase. XRD established that the organoclay was well dispersed (exfoliated) and preferentially embedded in the PA6 phase

The effect of calcium carbonate nanofiller on the mechanical properties and crystallisation behaviour of polypropylene

Polypropylene/calcium carbonate (PP/NPCC) nanocomposites were prepared using a co-rotating twin screw extruder at filler loadings of 5, 10 and 15 weight %. The impact strength and modulus of PP showed some improvement with the incorporation of the nanofiller while the tensile strength deteriorated. SEM photomicrographs showed evidence of NPCC agglomeration within the PP matrix, indicating that the level of shear stress generated during melt compounding was far from adequate to break-up the nanofiller. WAXD results showed the appearance of β-phase PP in the nanocomposites with 10 and 15 weight % NPCC. The influence of NPCC filler on the crystallisation behaviour of PP were also investigated using a DSC. Incorporation of NPCC shifted the crystallisation exotherms of PP towards higher temperatures, indicating that the nanofiller has acted as a nucleating agent for PP. The reduced values of half crystallisation times also implied that the introduction of NPCC has accelerated the crystallisation rate of PP

Analysis of indoor air pollutants checklist using environmetric technique for health risk assessment of sick building complaint in nonindustrial workplace

Purpose: To analyze and characterize a multidisciplinary, integrated indoor air quality checklist for evaluating the health risk of building occupants in a nonindustrial workplace setting. Design: A cross-sectional study based on a participatory occupational health program conducted by the National Institute of Occupational Safety and Health (Malaysia) and Universiti Putra Malaysia. Method: A modified version of the indoor environmental checklist published by the Department of Occupational Health and Safety, based on the literature and discussion with occupational health and safety professionals, was used in the evaluation process. Summated scores were given according to the cluster analysis and principal component analysis in the characterization of risk. Environmetric techniques was used to classify the risk of variables in the checklist. Identification of the possible source of item pollutants was also evaluated from a semiquantitative approach. Result: Hierarchical agglomerative cluster analysis resulted in the grouping of factorial components into three clusters (high complaint, moderate-high complaint, moderate complaint), which were further analyzed by discriminant analysis. From this, 15 major variables that influence indoor air quality were determined. Principal component analysis of each cluster revealed that the main factors influencing the high complaint group were fungal-related problems, chemical indoor dispersion, detergent, renovation, thermal comfort, and location of fresh air intake. The moderate-high complaint group showed significant high loading on ventilation, air filters, and smoking-related activities. The moderate complaint group showed high loading on dampness, odor, and thermal comfort. Conclusion: This semiquantitative assessment, which graded risk from low to high based on the intensity of the problem, shows promising and reliable results. It should be used as an important tool in the preliminary assessment of indoor air quality and as a categorizing method for further IAQ investigations and complaints procedures

Effect of Step Height On the Aeration Efficiency of Cascade Aerator System Using Particle Image Velocimetry

Aeration is an important parameter in water filtration system as it allows the transfer of oxygen to water through turbulence effect which subsequently increases air entrainment in the water. For water treatment application, aeration efficiency is measured to ensure continuous re-oxygenation of the unfiltered water. Aside from aeration, this paper also studies the flow patterns through the use of particle image velocimetry (PIV) setup. Through the use of real scale down physical model laboratory study is performed using PIV to obtain the velocity profile. These velocity profiles will then be used to calculate the aeration efficiency of the water in a cascade aerator system. Based on the findings, the aeration efficiency obtained from the PIV experiment has a maximum value at the lowest point of the cascade aerator system with a value of 0.0139 due to increase in mass flow rate as it moves through the steps with velocity of 0.418 m/s. Therefore, in the design of a cascade aerator system, it is advisable to increase the number of steps since it will increase the aeration efficiency of the system

Single Mode Fiber with Nickel-Acrylate Coating for Magnetic Field Sensing

The fabrication and characterization of a distributed magnetic field optical fiber sensor based on magnetostriction method is presented. A conventional single mode fiber (SMF) is coated with nickel-acrylate mixture, with volume ratio of 1:3. The coated SMF is characterized under scanning electron microscope (SEM) to observe the thickness and the morphology of the coating layer. The sensor response was measured by using the Rayleigh backscattering frequency shift method. The results show that the frequency shift is directly proportional to the applied magnetic field. At the magnetic field strength of 95 mT, the sensor response is −2 GHz of frequency shift. The sensitivity of the sensor is 0.09346 GHz/mT (below 10 mT) and 0.01008 GHz/mT (above 10 mT)