Energy efficiency and decarbonization for container fleet in international shipping based on IMO regulatory frameworks: A case study for South Korea

ABSTRACTThis study investigates the impact and potential of ship’s energy efficiency and decarbonization in Korean container shipping following the IMO regulatory framework. The IMO started implementing the EEXI (Energy Efficiency eXisting-ship Index) and CII (Carbon Intensity Indicator) regulations for the existing vessels on 1 November 2022. The government of South Korea announced a national plan called “the 2030 Greenship-K initiative” to boost the shipbuilding and shipping industries. This plan describes 140 merchant vessels with green ship technologies that will be required for sustainable shipping. The Korean container fleet needs to examine the impact of the IMO regulations through eco-friendly technologies like engine power limitation, energy-saving devices, alternative maritime fuels, etc. It is necessary to select an eco-friendly technology based on the marginal abatement cost for the fleet. Five case studies are considered on which alternative is beneficial for ship decarbonization. The most favorable alternative seems to be an LNG fuel retrofit for the EEXI and CII regulations for the Korean container fleet

Multi-Criteria Assessment of Spatial Robust Water Resource Vulnerability Using the TOPSIS Method Coupled with Objective and Subjective Weights in the Han River Basin

This study developed a multi-criteria approach to spatially assess the robust water resource vulnerability in sub-basins and applied it to the Han River basin. The Intergovernmental Panel on Climate Change (IPCC) suggested three factors of vulnerability; namely, exposure, sensitivity and adaptive capacity were used in this study with respect to water quantity and quality. In this study, 16 water quantity indicators and 13 water quality indicators were selected to identify the vulnerability using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. Environmental and socioeconomic data were obtained from the national statistics database, and hydrological data were simulated using the calibrated Soil and Water Assessment Tool (SWAT) model. Expert surveys and Shannon entropy method were used to determine subjective and objective weights for all indicators, individually. As a result, water quantity-vulnerable sub-basins were associated with high water use and water leakage ratios. Water quality-vulnerable sub-basins were associated with relatively high values of maximum consecutive dry days and heatwave days. The water quantity indices of both weighting methods showed relatively similar spatial distributions, while the distribution of water quality indices was distinct. These results suggest that considering different weighting methods is important for assessing the robust water resource vulnerability of sub-basins

High-performance bifunctional electrocatalyst for iron-chromium redox flow batteries

Despite a variety of advantages over the presently dominant vanadium redox flow batteries, the commercialization of iron-chromium redox flow batteries (ICRFBs) is hindered by sluggish Cr2+/Cr3+ redox reactions and vulnerability to the hydrogen evolution reaction (HER). To address these issues, here, we report a promising electrocatalyst comprising Ketjenblack (KB) carbon with embedded bismuth nanoparticles (Bi-C). The uniform incorporation of Bi nanoparticles into KB carbon via a simple reduction process excellently promotes the electrochemical activity of Cr2+/Cr3+ redox reactions while retarding the HER. A combination of experimental analysis and density functional theory (DFT) calculations indicates that these phenomena are attributable to the synergistic effect of Bi and KB, which inhibits hydrogen evolution and provides active sites to enhance the Cr2+/ Cr3+ redox reaction, respectively. An ICRFB cell containing the Bi-C catalyst as the negative electrode exhibits a high energy efficiency of 86.54% with excellent capacity retention during charge-discharge cycling at room temperature. This study offers an intelligent hybrid material as a useful design principle for electrocatalysts capable of addressing the critical problems in ICRFBs.

The experience of device failure after cochlear implantation

Abstract Background The present study describes the treatment of patients at a tertiary institution who experienced device failure after Cochlear Implantation (CI), as well as identifying prodromic symptoms that could assist in the timely identification and management of device failure. Study design Retrospective database review (January 2000–May 2017). Setting Single tertiary hospital. Methods Factors recorded included the etiology of hearing loss; age at first and revision CI surgeries; surgical information, including operation time and approach; electrical outcomes after implantation; device implanted; symptoms of device failure; history of head trauma; and audiologic outcomes as determined by categories of auditory performance (CAP). Results From January 2000 to May 2017, 1431 CIs were performed, with 27 (1.9%) undergoing revision surgeries due to device failure. The most common etiology of hearing loss was idiopathic (12/27), followed by cochlear hypoplasia (5/27). Mean age at initial CI was 11.8 (1–72) years, with 21 being pre-lingual and 6 being post-lingual. Of the total devices initially implanted, 80.5% were from Cochlear, 15.9% from MED-EL, and 3.5% from Advanced Bionics. The failure rates of these devices were 1.3%, 3.1%, and 10.0%, respectively. The most suggestive symptom of device failure was intermittent loss of signal. Mean CAP scores were 5.17 before reimplantation and 5.54 and 5.81 at 1- and 3-years, respectively, after reimplantation. Conclusion The most suggestive symptom preceding device failure was intermittent loss of signal. Patients who present with this symptom should undergo electrical examination for suspected device failure. Audiologic outcomes showed continuous development despite revision surgeries

The Potential of Bovine Colostrum-Derived Exosomes to Repair Aged and Damaged Skin Cells

In this study, we examined the potentially beneficial effects of bovine colostrum-derived exosomes on UV-induced aging and damage in three major resident skin cells including keratinocytes, melanocytes, and fibroblasts. The treatment with colostrum exosomes prevented the UV-induced generation of intracellular reactive oxygen species in epidermal keratinocytes. In UV-stimulated melanocytes, colostrum exosomes could also significantly reduce the production of the protective skin-darkening pigment melanin, which may help to reduce the risk of excessive melanin formation causing skin hyperpigmentation disorders. In the human dermal fibroblasts treated with colostrum exosomes, the expression of matrix metalloproteinases was suppressed, whereas increased cell proliferation was accompanied by enhanced production of collagen, a major extracellular matrix component of skin. Taken together, our findings indicate that bovine colostrum-derived exosomes having excellent structural and functional stability offer great potential as natural therapeutic agents to repair UV-irradiated skin aging and damage

Association between cotinine-verified smoking status and moderately increased albuminuria in the middle-aged and older population in Korea: A nationwide population-based study.

ObjectivesAlthough several self-reported questionnaire-based studies have found an association between smoking and moderately increased albuminuria, this result remains controversial. We investigated whether moderately increased albuminuria was associated with smoking status, verified by urinary cotinine (an objective biomarker of tobacco exposure), using population-based, nationally representative data.MethodsThis study included 2059 participants aged ≥ 50 years from the 2014 Korean National Health and Nutrition Examination Survey. Individuals with a urinary cotinine level ≥ 50 ng/mL were identified as cotinine-verified smokers. Moderately increased albuminuria was defined as a urine albumin-to-creatinine ratio ranging between ≥ 30 mg/g and ResultsAmong the study participants, 16.9% were cotinine-verified smokers, 84.8% of whom were men. After adjustment for multiple covariates, cotinine-verified smokers showed a significant positive association with moderately increased albuminuria (adjusted odds ratio: 4.37, 95% confidence interval: 1.63-11.71) compared with cotinine-verified non-smokers. The association between urinary cotinine and moderately increased albuminuria did not differ with age, sex, obesity, or comorbidities (P-value for interaction > 0.05 in all cases).ConclusionThis large-scale observational study showed that cotinine-verified smoking is associated with moderately increased albuminuria in the Korean middle-aged and older general population, suggesting that smoking must be strictly controlled to reduce the risk of moderately increased albuminuria