Search

Already today, at about 1°C of global warming, we observe a regional intensification of extreme weather events. While the short-term economic impacts of these events are well documented, little is known about their impacts on economic growth in the long-term. Using a three-way fixed-effects panel model, an outlier-robust regression, and ``people exposed'' as exogenous predictor, we study the short-, medium-, and long-term impacts of tropical cyclones and fluvial floods on per-capita GDP growth for a set of 158 countries for the period 1971--2010. To understand how the observed impacts depend upon the countries' development level, we divide countries into four groups based on the inequality-adjusted human development index. We further decompose national gross domestic product (GDP) into i) its national income components and ii) its sectoral contributions enabling us to single out income components as well as sectors that are most important for impact transmission. On the global level, weather extremes of both categories have significant negative short-, medium-, and long-term impacts on economic growth; over 15 years, long-term growth losses from severe tropical cyclones accumulate to -6.6% and are about five times larger than growth losses from severe fluvial floods (-1.2%). For both event categories, we find growth losses to depend non-monotonously upon development level challenging the common narrative that development can generally protect against disaster losses. Across all levels of development, investment, international trade are the most important transmission channels. Further, in poor countries growth losses mainly result from declines in agriculture and manufacturing growth. Our results provide guidance and decision support for the implementation of evidence-based coping and adaptation strategies, for instance, for the design of National Adaptation Plans for developing countries.

While the short-term economic impacts of extreme weather events are well documented, little is known about their impacts and transmission channels on economic growth in the long run. Using panel data regressions and national shares of people exposed to tropical cyclones and fluvial floods as exogenous predictors, we find output growth losses from severe tropical cyclones and fluvial floods to accumulate to −6.5% and −5.0% over 15 years, respectively. We further observe a strongly non-linear increase of these losses with disaster intensity. To understand how the observed impacts depend on the countries’ development level, we implement a country-specific regression framework. While we find evidence that higher development can prevent economic growth losses from fluvial floods, this is not the case for tropical cyclones. Further, we systematically study the economic and non-economic transmission channels through which these events impact on economic growth in the long run. We find that rising household consumption and government expenditure are the main growth-loss mitigating channels, whereas rising investment is the main growth-loss amplifying channel in the period 1971–2010.

Erosion is one of the predominant hazards in coastal Bangladesh. For implementing effective adaptation and mitigation strategies, assessment of risk to coastal erosion is crucial. This study aimed to assess the levels of risk to coastal erosion in the Meghna estuary, a major erosion-prone area in the coastal region of the country impacted by abrupt changes in hydrological and geomorphological conditions. Using physical, environmental, and socio-economic geospatial data, this is the first attempt in assessing erosion risk and characterizing three main risk components: hazard, vulnerability, and exposure at a regional extent in the estuary. A total of 19 indicators were considered, and statistical methods assisted with the Analytic Hierarchy Process (AHP) were used for the construction of hazard, vulnerability, and exposure indices, which were then integrated to calculate erosion risk comprehensively at the lowermost administrative unit (union) level throughout the study area. The results of hazard and vulnerability analyses depicted 35.72% and 46.69% areas as highly hazard-prone and highly vulnerable to erosion, respectively. Assessment of the exposure index exhibited 42.25% area as highly exposed to coastal erosion in the estuary. Finally, the results quantified different levels of risk as very high (14.91%), high (19.36%), moderate (23.40%), low (23.91%), and very low (18.41%). Among 161 coastal unions, 45 unions were identified as high to very high erosion risk-prone areas, located in the coasts of Bhola, Noakhali, and Barishal districts including their major islands. The validation result confirmed a reasonable level of acceptance of the calculated risk map, despite several data limitations. The geospatial distribution of different risk categories presented in this paper can assist relevant authorities with reliable spatial information in formulating improved erosion risk mitigation policies in the most dynamic estuary of the country.

Water is present in most technical applications of polyurethane (PU) adhesives, both from atmosphere and as adsorbate on the substrate. Hence, studies on the fundamental adhesion mechanisms have not only to cover the PU monomers but possible secondary reaction products like amines and ureas on the given substrate as well. In this work, diluted solutions of the monomer 4,4′-methylene diphenyl diisocyanate (4,4′–MDI) in tetrahydrofuran (THF) are exposed to the native surfaces of Au, Al and Cu in dried air. The resulting monomer adsorbate layers on the metals are stored in dried air for several hours. Therefore, any water essentially originates from the native metal surfaces. The chemical structure and the orientation of the adsorbed monomer molecules are evaluated in situ as a function of storage time by infrared external reflection absorption spectroscopy (IR-ERAS). A sequence of rinsing cycles with pure THF helps to discriminate between physisorbed and chemisorbed molecules. The changes of the spectra with storage time are significant and specific for each of the metal substrates. They reveal the formation of urea-like species which are easily removed by THF. Hence, they do not contribute to adhesion. The remaining isocyanate molecules adhere strongly and specifically to the substrates. The corresponding strong spectral modifications point to a chemical adhesion mechanism.

In modern production systems, customized mass production of complex products, such as automotive or white goods, is often realized at assembly lines with a high degree of manual labor. For firms that apply assembly systems, the assembly line balancing problem (ALBP) arises, which is to assign optimally tasks to stations or workers with respect to some constraints and objectives. Although the literature provides a number of relevant models and efficient solution methods for ALBP, firms, in most cases, do not use this knowledge to balance their lines. Instead, the planning is mostly performed manually by numerous planners responsible for small sub-problems. This is because of the lack of data, like the precedence relations between the tasks to be performed. Such data is hard to collect and to maintain updated. Klindworth, Otto, and Scholl (2012) proposed an approach to collect and to maintain the data on precedence relations between tasks at a low cost, as well as to produce new high-quality feasible assembly balances based on this data. They utilize the knowledge on former production plans available in the firm. However, due to reliance on the single source of information, their concept needs long warming-up periods. Therefore, we enhance the concept by incorporating multiple sources of information available at firms, as the modular structure, and present guidelines on how to conduct valuable interviews. The proposed interview enhancements improve the achieved results significantly. As a result, our approach generates more efficient new feasible assembly line balances without requiring such long warming-up periods.

Priority rule-based methods (PRBMs) rely on problem-specific knowledge to construct good solutions in a very short time. They can be used as stand-alone procedures or can be integrated into (partial) enumeration procedures, like branch and bound or dynamic programming, and heuristic solution methods. PRBMs are especially important for solving NP-hard optimization problems. In this paper, we formulate general design principles on how to construct good-performing PRBMs, based on a thorough computational investigation. Our principles allow to construct effective PRBMs already ad hoc, i.e. without time-consuming data mining algorithms. We conduct our analysis on the example of the NP-hard Simple Assembly Line Balancing Problem (SALBP), on which with small modifications most situations in the planning of assembly lines are based. We also provide a cross-validation of our results and illustrate the application of the formulated principles.

Recently, the importance of correctly designed computational experiments for testing algorithms has been a subject of extended discussions. Whenever real-world data is lacking, generated data sets provide a substantive methodological tool for experiments. Focused research questions need to base on specialized, randomized and sufficiently large data sets, which are sampled from the population of interest. We integrate the generation of data sets into the process of scientific testing. Until now, no appropriate generators or systematic data sets have been available for the assembly line balancing problem (ALBP). Computational experiments were mostly based on very limited data sets unsystematically collected from the literature and from some real-world cases. As a consequence, former performance analyses often come to contradictory conclusions and lack on statistical evidence. We introduce SALBPGen, a new instance generator for the simple ALBP which can be applied and extended to any generalized ALBP, too. Unlike most generators, SALBPGen takes into account usual properties of precedence graphs in manufacturing. It is very flexible and able to create instances with very diverse structures under full control of the experiment’s designer. We also propose new challenging data sets, as shown with the new direct measure of instance’s hardness called trickiness. By two exemplary computational experiments, we illustrate how important insights can be gained with the help of the systematically generated data sets.

World markets are highly interlinked and local economies extensively rely on global supply and value chains. Consequently, local production disruptions, for instance caused by extreme weather events, are likely to induce indirect losses along supply chains with potentially global repercussions. These complex loss dynamics represent a challenge for comprehensive disaster risk assessments. Here, we introduce the numerical agent-based model acclimate designed to analyze the cascading of economic losses in the global supply network. Using national sectors as agents, we apply the model to study the global propagation of losses induced by stylized disasters. We find that indirect losses can become comparable in size to direct ones, but can be efficiently mitigated by warehousing and idle capacities. Consequently, a comprehensive risk assessment cannot focus solely on first-tier suppliers, but has to take the whole supply chain into account. To render the supply network climate-proof, national adaptation policies have to be complemented by international adaptation efforts. In that regard, our model can be employed to assess reasonable leverage points and to identify dynamic bottlenecks inaccessible to static analyses.

Lateral ‘ballast stones’ of empty cases of loticSilo pallipescaddis larvae had a weak, positive effect on current resistance when intact cases were compared with those devoid of their extra stones. However, this ballast effect made up only 2·5% of the current resistance of cases inhabited by larvae. Small bullhead,Cottus gobioand brown trout,Salmo truttapreferentially attacked larvae in cases from which the lateral stones had been removed. Increased survival because of reduced attack frequency should be more important than a slightly lowered risk of being pushed away by the current.Silo pallipeslarvae did not show any flexible case-building behaviour: neither different current regimes nor odour from bullheads affected the mass or width, respectively, of the cases constructed.

Reactions of the 3-acylindoles 5, 10 , and 15 with α-amino-α′-diphenylphosphinoyl-substituted carbanions gave rise to the 2′-amino-substituted 3− and 2-vinylindoles 7, 12 , and 17 by way of the isolable carbinols 6 , 11 , and 16 . The heterocyclic dienes 7 , 12 , and 17 readily underwent Diels-Alder reactions with N -phenylmaleimide.

First reactions of 3-(1,2,3,6-tetrahydropyrid-4-yl)-indoles 1 with a variety of carbo- and heterodienophiles are described. These reactions provide a new access to heterocyclic functionalized indoles and pyrido[c]annellated carbazoles, compounds of interest as potential antidepressive and antitumor active agents.