Energy supply security in the EU: Benchmarking diversity and dependence of primary energy

We evaluate energy supply security in all the EU countries. For the first time a proxy indicators for diversity and concentration Shannon Wiener index and Herfindahl-Hirschman index and dependence metrics are used for the detailed primary energy fuel mix of all EU member states. The geographic coverage of this work allows for useful comparisons between countries and for a means of benchmarking against the indices. Overall, it is found that energy supply diversity in the EU has been significantly improved since 1990 by 14.2% (SWI) and 22.6% (HHI). We demonstrate the interrelations between dependence and diversity and the role of renewables on dependence and diversity. Renewable energy, particularly wind, solar and biomass has been the main driver for diversity growth and has a positive contribution to indigenous energy use; thus reducing energy import dependence. We argue that alongside renewable energy there exists a wide range of factors contributing to energy dependence and that renewable energy has had a positive contribution to almost all EU28 country's diversity

Energy Supply Sustainability For Island Nations: A Study on 8 Global Islands

Energy supply sustainability is a multifaceted challenge for all countries and especially for small island nations that might have limited adaptive capacity. Previous studies showed that islands experience energy scarcity and isolation from energy markets due to their remote location. Our focus is on a range of islands spread out globally: Malta, Cyprus, Curacao, Mauritius, Iceland, Jamaica, Trinidad and Tobago and Bahrain. They are selected for their varying energy development paradigms that facilitate cluster elicitation. For the first time, we combine the estimation of fuel mix diversity and energy import dependence with established metrics Shannon-Wiener index (SWI), Herfindahl-Hirschman index (HHI) and Energy Import Dependence to assess energy supply security. SWI and Energy Import Dependence are then presented against carbon intensity to highlight two angles of sustainable energy supply. We argue that islands are clustered to those that have fossil fuel reserves and are locked in low diversity, low dependence and high carbon intensity, those that rely almost exclusively on imported fossil fuel reserves and have low diversity and high dependence and high carbon intensity and finally those that have entered a decarbonization trajectory that allows them to reduce their fossil fuel import dependence, increase their diversity and reduce their carbon intensity

Energy Supply Security in Southern Europe and Ireland

Energy supply security is of paramount importance to all countries, however, not all countries present the same capacity to respond to energy security threats. Financial wealth is one of the means that can support access to energy resources and as such countries that have been hit the hardest by the 2008 financial crisis present energy supply vulnerabilities. We focus on Ireland, Portugal, Spain, Italy and Greece and find that they have continuously improved their energy supply diversity. At the same time, we argue that during, and as a result of the financial crisis our focus countries reduced their exposure to expensive imported resources predominantly in the transport sector and increased the role of renewables. Overall, we find improved supply security which could be strengthened further if financial resources were directed towards innovation for renewable energy sources

Energy and carbon intensity: A study on the cross-country industrial shift from China to India and SE Asia

The potential relocation of various industrial sectors from China to India and countries of the SE Asian region presents low cost opportunities for manufacturers, but also risks rising for energy demand and CO2 emissions. A cross-country shift of industrial output would present challenges for controlling emissions since India and SE Asian countries present higher industrial emissions intensity than China. We find that although there is a convergence in emissions intensity in the machinery manufacturing and paper and pulp industries, there are significant variations in all other industrial sectors. Indian emissions intensity is double that of China in the iron and steel and textile and leather industries and almost triple in the cement industry; Indonesian emissions intensity is almost double that of China in the non-metallic minerals and textile and leather industries and 50% higher in the chemical and petrochemical industry. We demonstrate that the expected higher emissions are driven by both a higher carbon fuel mix intensity in the recipient countries and higher energy intensity in their industrial activities. While industrial relocation could benefit certain countries financially, it would impose considerable threats to their energy supply security and capacity to comply with their Paris Agreement commitments

The case for islands’ energy vulnerability: Electricity supply diversity in 44 global islands

Energy supply security is a multifaceted challenge for all countries and especially for small island nations that might have limited adaptive capacity. Previous studies showed that islands experience energy scarcity and isolation from energy markets due to their remote location making energy supply security a challenging issue. We estimate energy supply diversity and concentration for 44 islands in order to provide an island specific benchmark approach for energy supply security. We use established metrics Shannon-Wiener index (SWI), Herfindahl-Hirschman index (HHI) with Energy Information Administration (EIA) fuel mix data. To confront the issues of supply security and sustainability we test energy diversity against energy and emissions intensity. The global character of the research along with the wide range of islands covered allows useful comparisons between countries and for a means of benchmarking against the indices while creating certain defined country clusters. Overall it is found that average island energy intensity increased by 23.4% with a corresponding increase of 12.4% on their emissions intensity for the period 2000–2015. On the other hand, diversity has improved by 21.3% (SWI) and by 2% (HHI) since 2000. We argue that fossil-fuel lock-in for islands must break in order to UN Sustainable Development Goal 7 to be achieved particularly for vulnerable island nations

The capacity to change the lightness of discolored tooth substrates by means of minimal-invasive restorations: perception by dentists, dental technicians and laypersons

PURPOSE To evaluate the minimal ceramic thickness needed to increase the lightness by one value by means of glass-ceramic restorations perceived by dental technicians, dentists, and laypersons. MATERIAL AND METHODS A total of 15 assessment pairs (reference and test samples) were formed using glass-ceramic blocks in four different colors. Each assessment pair was comprised of two underground blocks differing in one value of lightness. On top of the underground blocks, glass-ceramic platelets were cemented in five different thicknesses (0.1 to 0.5 mm) and in the same color as the reference. Dental technicians, dentists, and laypersons (n = 41/group) were asked to determine the presence of a color difference between the two samples under standardized lighting conditions. The threshold ceramic thickness was defined as the thickness at which ≥ 50% of the evaluators were not able to perceive a difference within an assessment pair. The thresholds were analyzed, and groups were compared by applying chi-square test (P < .05). RESULTS The majority of dentists and dental technicians (> 50%) detected a lightness difference between the test and reference samples up to a ceramic thickness of 0.5 mm. The majority of laypersons (≥ 50%) did not perceive a lightness difference with ceramic thickness of 0.5 mm. If separated by the different color changes, the threshold ceramic thickness started at 0.4 mm and varied within the groups of evaluators and by the lightness of the assessed color. CONCLUSION A considerable number of evaluators perceived a lightness difference when minimally invasive ceramic restorations of 0.5-mm thickness were applied. The threshold ceramic thickness, however, was reduced when the lightness of the substrate was lower

Survival and complication rates of two dental implant systems supporting fixed restorations: 10-year data of a randomized controlled clinical study

OBJECTIVES To compare clinical, radiographic, biological and technical long-term outcomes of two types of dental implants over a period of 10 years. MATERIALS AND METHODS Ninety-eight implants were placed in 64 patients, randomly allocated to one of two manufacturers (AST and STM). All implants were loaded with fixed restorations. Outcome measures were assessed at implant insertion (T$_{i}$), at baseline examination (T$_{L}$), at 1, 3, 5, 8 and 10 (T$_{10}$) years. Data analysis included survival, bone level changes, complications and clinical measures. RESULTS Re-examination was performed in 43 patients (23 AST and 20 STM) at 10 years. The implant level analysis was based on 37 (AST) and 32 (STM) implants. Survival rates of 100% were obtained for both groups. The median changes of the marginal bone levels between baseline and T$_{10}$ (the primary endpoint) amounted to a loss of 0.07 mm for group AST and a gain of 0.37 mm for group STM (intergroup p = 0.008). Technical complications occurred in 27.0% of the implants in group AST and in 15.6% in group STM. The prevalence of peri-implant mucositis was 29.7% (AST) and 50.1% (STM). The prevalence of peri-implantitis amounted to 0% (AST) and 6.3% (STM). CONCLUSIONS Irrespective of the implant system used, the survival rates after 10 years were high. Minimal bone level changes were observed, statistically significant but clinically negligible in favor of STM. Technical complications were more frequently encountered in group AST, while group STM had a higher prevalence of peri-implant mucositis

Masking capacity of minimally invasive lithium disilicate restorations on discolored teeth-The impact of ceramic thickness, the material's translucency, and the cement color.

OBJECTIVES To evaluate minimally invasive restorations' capacity to mask discolored teeth and explore the impact of ceramic thickness, translucency, and cement color. MATERIALS AND METHODS Twenty-four assessment pairs of naturally colored and discolored bovine dentin samples were formed, using lithium disilicate specimens in six different thicknesses (0.3-0.8 mm), two different translucencies (high, low), and two cements (transparent, tooth-colored). Evaluators assessed the color differences in each assessment pair, and the threshold for detecting a color difference was determined using sequential testing and the Bonferroni-Holm method. RESULTS A thickness of 0.6 mm effectively masked color differences using high translucent ceramic with transparent cement, detectable differences were still observed at 0.7/0.8 mm. A threshold thickness of 0.4 mm was seen using high translucent ceramic and tooth-colored cement, with color differences still discernible at 0.5 and 0.8 mm. A threshold thickness of 0.4 mm was detected using low translucent ceramic and transparent cement, while detectable differences persisted at 0.5, 0.7, and 0.8 mm. A 0.5 mm threshold thickness was observed when using low translucent ceramic and tooth-colored cement, and no detectable color differences were detected beyond this thickness. CONCLUSIONS Masking can be achieved with a thickness of 0.4-0.5 mm using a low translucent material and tooth-colored cement. CLINICAL SIGNIFICANCE Understanding the impact of ceramic thickness, translucency, and cement color can aid clinicians in making informed decisions for achieving the best esthetic outcomes while preserving tooth structure. Effective masking can be accomplished with ceramic thicknesses starting at 0.4 mm, especially when employing a low translucent material and tooth-colored cement. However, clinicians should be aware that discolorations may still be detectable in certain scenarios when using minimally invasive lithium disilicate restorations

Load-bearing capacity of pressable lithium disilicates applied as ultra-thin occlusal veneers on molars.

PURPOSE The aim was to investigate the load bearing capacity of different pressable lithium disilicates cemented as occlusal veneers on molars. MATERIALS AND METHODS One control group and six test groups were formed consisting of 20 specimens each (n = 20). The six test groups differed in the utilizing pressable lithium disilicate to fabricate occlusal veneers. As a control group, "group Lis", the lithium disilicate with the highest reported flexural strength was used (initial LiSi Press, GC Europe; Leuven, Belgium / flexural strength: 508 MPa). The test groups consisted of other pressable lithium disilicates with lower flexural strength values: "Ema" (IPS e.max press), "Vit" (VITA Ambria), "Liv" (Livento Press), "Amb" (Amber Press), "Mas" (Amber Press Master) and "Ros" (Rosetta SP)". After the preparation of 140 extracted human molars, which included the removal of the central enamel, the specimens were scanned using a desktop scanner. With the aid of a design software, the occlusal veneers were designed in a standardized thickness of 0.5 mm. To fabricate the restorations, all tested materials were processed using heat-pressing technique. All restorations were adhesively cemented. Afterwards, the specimens underwent cyclic fatigue during an aging procedure in a chewing simulator (1'200'000 chewing-cycles, 49 N force, 5-55°C temperature changes). Subsequently, the specimens were statically loaded and the load which was necessary to fracture the specimen (Fmax) were measured. Differences between the groups were compared applying the Kruskal-Wallis (KW) test and the Wilcoxon-Mann-Whitney-Test (WMW: p < 0.05). The two-parameter Weibull distribution values were calculated. RESULTS The fatigue resistance was 100% for the groups Lis, Vit, Liv, Amb, Mas and Ros, whereas the group Ema showed a fatigue resistance of 95%. The control group Lis showed median Fmax values of 2'328 N. The median Fmax values for the test groups ranged between 1'753 N (Vit) and 2'490 N (Ros). Statistically significant difference was observed among the groups Lis (control) and Vit (KW: p < 0.001). Weibull distribution presented the highest shape values for the group Ros (12.83) and the lowest values for the group Ema (4.71). CONCLUSION Regarding their load-bearing capacity different pressable lithium disilicates can be recommended to fabricate ultra-thin occlusal veneers on molars when restoring occlusal tooth wear