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This study aimed to analyze the distribution of judo matches in the Tokyo 2020 Olympic Games, considering matches in the regular duration (≤4 min) and during the extra time (the golden score) according to sex, scores, penalties, phases of competition, weight categories, and judo techniques. The data were extracted from the Official Results Books of the Olympic Games in Tokyo 2020. The combats were divided in matches that were finished in the regular duration and that were finished by the golden score, with a total of 450 matches. The Chi-square test was used to identify the association between all variables and different groups of matches duration, with the level at p < 0.05. The main results demonstrated significant association, considering sex and frequency of matches in the regular time (χ2 = 6.59; p = 0.010) for female athletes. The majority of matches ended in the 3–4 min (χ2 = 204.16; p < 0.001), scores were mostly awarded in the regular time and penalties in the golden score (χ2 = 48.72; p < 0.001), and few matches ended by the golden score for heavyweight athletes (χ2 = 15.16; p = 0.019). Therefore, a high number of matches ended in the golden score in the Olympic Games Tokyo 2020, with a high number of penalties in this competition.

The Covid-19 crisis has caused several social-related issues; the sanitary is, perhaps, the most significant one. Lockdowns and vaccination were implemented to fight the Covid-19 virus. From a sustainability perspective, Covid-19 has been considered a meaningful crisis driver that has affected nations' economies and social and natural capitals. The literature presents clues that effects appear to be different among countries. Recognizing its importance as public policies for sustainability, this study aims to assess how the sustainability of countries has changed after Covid-19, focusing on countries' economic power that reflects their capacity to face the crisis. A sample of 89 countries is considered, and 2019-2020 are set as base years for data gathering, which covers the first year of the Covid-19 crisis. Sustainability is conceptually supported and represented by a 3-D cube. The natural environment is expressed by the ecological footprint (EF) method, the economic capital by the gross domestic product (GDP), and the social capital by the happiness index. Results show that sustainability of economies was negatively affected after first year of Covid-19 crisis, but in different magnitudes, according to nations' economic power. While the sustainability of the wealthiest economies was slightly changed during 2019-2020 but maintained within the named 'useful-order' world (environmentally unsustainable, productive, and happy), the poorest economies pushed about 169 million people into the worst performance, reaching the 'ineffective' world (environmentally unsustainable, unproductive, and unhappy). Numbers highlight the inequalities of sustainability performance among countries, according to their capacity to face the Covid-19 crisis. The shield of the richest evaluated countries comprising 5 % of the world population is more powerful than the shield of the poorest evaluated countries carrying 67 % of the world population. Results claims for efforts to make different policies and provide economic support differently for countries, since although we are all under the same storm, but in different boats.

Vertical transmission of SARS-CoV-2 has already been described, while clinical consequences to the fetus are still under investigation. This article reports a case of systemic fetal inflammatory response and pericardial effusion. As far as is known, this is the first case of fetal/neonatal cardiac complications related to SARS-CoV-2 infection.

Iron oxidation and removal from groundwater is a necessary and costly process in drinking water production. In most cases, iron removal is done via aeration, succeeded by precipitation. Most systems for aeration are based on increasing the interfacial area via injecting air in the system or spraying. Both methods have disadvantages, like clogging and formation of aerosols. In this study, a new vortex-based flow-through reactor consisting of a cylindrical tank with an impeller located at the bottom was studied regarding its aeration and iron oxidation capabilities in groundwater. During the aeration experiments, the flow rate, impeller rotation and aerated volume were varied. A nondimensional constant α was proposed to relate the system’s physical characteristics and its aeration capabilities, expressed in dissolved oxygen and system volumetric mass transfer coefficient (KLa). Three distinct operational regimes were defined: formation, complete and bubble regime. These regimes showed very specific characteristics regarding the air–water interface structure and the area to volume ratio, resulting in different aeration capabilities and iron oxidation efficiency values. The system presented KLa values similar to commercially available aeration systems, especially inside the bubble regime. By using dimensionless coefficients, the presented analysis provided the basis for the design of continuous impeller aeration and oxidation systems of arbitrary size.

This special volume of the JCLP is mainly built upon articles presented at the 6th International Workshop Advances in Cleaner Production held in Sao Paulo, Brazil, in 2017. The event had provided a progressive interdisciplinary meeting for knowledge advance and information trade. Papers in this issue cover a broad range of perspectives of cleaner production strategies and practices, and a special focus was placed upon the type of contribution – practical, conceptual/practical, conceptual - and the scale of their coverage – local, regional and global. The papers provide understanding on the research intended to systematically include cleaner production in the path sustainability, and identifies the extent to which cleaner production practitioners directly and indirectly provide local, regional and global solutions. Key results of this introductory article include research on: efficient and responsive use of energy and resources; the search for reduced emissions, the role of managerial support and environmental assessments, and the implementation/analysis of closed-loop systems of materials.

The objective of this paper is to assess the sustainability of the agricultural production chain of rice (Oryza sativa L.) in Brazil and Cuba, using a conceptual model that considers five sectors of sustainability supported in the Goals Programming philosophy as multicriteria analysis tools. A synthetic sustainability indicator is constructed to support decision-making through the benchmarking process to contribute the environmental, economic and social sustainability of rice farming. As results, Brazil shows a greater sustainability based on better availability of environmental resources for rice cultivation, a lower relative environmental load, better economic and productive performance, poorer employment and wage policies and higher satisfaction of the social demand for rice. On the other hand, Cuba shows a deficit of environmental resources, higher relative environmental load, low economic and productive performance, better employment and wage policies, and unsatisfied social demand for rice.

The lack of proper sludge withdrawal routines has been one of the main causes of solids washout and consequent deterioration of effluent quality from up-flow anaerobic sludge blanket (UASB) reactors treating sewage in developing countries. The establishment of an adequate sludge withdrawal routine depends on the knowledge of the sludge mass inside the reactor, but for this, it is necessary to continuously monitor the solid’s profile along the height of the digestion compartment of such reactors. Knowing the sludge concentration at the highest point of this compartment, immediately before the passage of the liquid to the settling compartment, allows the definition of more robust strategies for sludge discharge, in order to not exceed the retention capacity (storage) of solids in the reactor. To couple with that, a low-cost ultrasound sensor was developed and tested with the aim of monitoring total solids concentration inside UASB reactors. Bench and demo-scale tests were performed to validate the developed technology. Results have shown that the sensor can provide real-time values of total solids inside the reactor with 0.1% accuracy up to 1% total solids content.

Thermal disinfection is probably the oldest water treatment method ever used. Similarly to other disinfection processes, it targets the inactivation of pathogenic (micro)organisms present in water, wastewater and other media. In this work, a pilot-scale continuous-flow thermal disinfection system was investigated using highly contaminated hospital wastewater as influent without any pre-treatment step for turbidity removal. The results proved that the tested system can be used with influent turbidity as high as 100 NTU and still provide up to log 8 microbial inactivation. Further results have shown energy consumption comparable to other commercially available thermal disinfection systems and relatively low influence on the investigated physical–chemical parameters.

The 2017 International Workshop on Advances in Cleaner Production held in Sao Paulo, Brazil, May 24–26, 2017, promoted an assisted discussion workshop directed by Donald Huisingh. The workshop focused on the role of the Advances in Cleaner Production Network to meet the United Nations Sustainable Development Goals. Discussions with the workshop participants were oriented around five basic subjects: 1. The main objective of the Advances in Cleaner Production Network; 2. The international collaboration in research planning, implementation and in dissemination of research findings; 3. The inclusion of researchers from under-represented regions of the world; 4. The future collaboration among members and 5. The new activities to help society to “Accelerate the Transition to Equitable, Sustainable, Livable, Post-Fossil Carbon Societies.” Furthermore, the participants were asked on which specific set of Sustainable Development Goals they mostly contribute through their research, in order to draw a picture of the main scientific contributions of the Network to the SDGs enterprise. Challenges that emerged from the workshop involved the need for value-added communication and collaboration among members, and further progress in both theoretical and practical cleaner production approaches. Concerning the generation and sharing of new viewpoints, the main issue that emerged was the variety of positive connections that should be strengthened among potential collaborators. Improving and expanding the helpfulness of online sharing platforms and social media, mostly for managing discussion opportunities, was underlined for expanding the partnerships and in improving the networking. This paper reports and shares the results of the assisted discussions to reach our dynamically growing scientific community and to encourage, engage and empower researchers throughout the world to work in partnerships under the umbrella of the SDGs.

Technology change is a well-known strategy used by Cleaner Production (CP) practitioners, and it refers to modifications in the process and/or equipment to increase production efficiency and reduce waste and emissions. These changes can range from small, low-cost options to the replacement of processes that involve large capital investments. The improvements and advantages of the new alternatives must be evaluated in a way to measure and assure its real benefits. This work presents an emergy evaluation of a fasteners manufacturing company planning to replace the zinc-coating process by a water-based organo-metallic coating process. Accounting for the use of resources and the environmental services to dilute the Cr (VI) in the effluent, the study shows that the effluent treatment is efficient and that the emergy invested by the environment to dilute the Cr (VI) released is lower than 0.1% of the emergy used in the coating process. The case study is an example of the application and evaluation of CP options (good operational practices, material and raw material changes, technological modifications, and product change) and is presented to motivate product manufacturers to prioritize environmental performance assessments to their products and services equally as well as to save manufacturers substantial time and efforts during their first attempts to implement CP actions.

Over the last 30 years, distance learning has rapidly spread in developed countries, and to niche markets in developing countries. In Brazil, approximately 5 million people are currently either achieving formal education or corporate training, or obtaining specific knowledge and skills on a wide range of subjects, via distance learning. Motivated by the ongoing expansion of the Brazilian federal chain of public schools, several new campuses, extra classrooms and distance teaching centers have been built, as a function of the intensive promotion of social inclusion by means of education, and specifically allocated budget. Concomitantly, a considerable number of papers discussing reduction of energy and materials consumption in university campuses have been published. Intended as a contribution to this discussion, this work evolves from a comparison of the implicit environmental cost – i.e. the use of natural resources as the prime-matter of infrastructural and operational material, and source of energy to human work-in forming management technicians in a classroom course, and in a distance learning course, obtained from the results of two case studies carried out at a Federal Institute campus in Brazil. The groups were selected for their relative closeness in proportion of attending students. Data were collected by means of measurements and interviews, and a synthesis of the use of natural resources by both modes was obtained by using the emergy accounting method, and then compared. The emergy method was also used to assess current use and underuse rates of the available infra-structural resources. Scenarios based on different numbers of students and teaching staff attending capacity for both modes, distance learning and classroom, were created and compared. Results point out that, under the current configurations, forming a management technician via distance teaching requires a 90% higher environmental support than via classroom teaching. The scenarios, however, do indicate a turning point.

Understanding the potential prosperity of municipal economies, the welfare and the role of trade of these economies is an important issue in a world in which more than 50% of the population lives in urban centers. ABC Paulista groups three cities which act as production centers combining the abundance of labor and knowledge with the proximity to big consumer centers. The emergy approach recognizes the existence of deterministic principles in economic systems but emphasizes the role of resources, energy and environment. This approach was applied to ABC Paulista to evaluate municipal potential prosperity in the context of the energy resource constraints and showed that ABC municipalities are not autonomous and depend almost entirely on external resources. Indices for assess the human carrying capacity and the standards of living showed that only 2% of the population could be sustained indefinitely by the local emergy. The results lead to the idea that ABC can be seen as an “industry”, which holds the know-how and assets transforming raw materials into vehicles and chemicals that are feedback to the surrounding system. However, the analysis of ABC trade shows that both the Brazilian and the foreign markets take advantage when buying from ABC suggesting that the search for the chances of the prolongation of this specific urban settlement may require different policies and management designs.

The agribusiness contributes significantly to the Brazilian domestic production, and the search for environmentally friendly systems, exploring the maximum possible use of renewable resources and reducing the use of non-renewable ones, affects the agribusiness' productivity and competitivity. An agribusiness producing corn, eggs, pork and milk was evaluated using emergy accounting. The effects of the (des)integration of the production processes on the efficiency and environmental sustainability of the system were assessed using seven scenarios. The first is the existing integrated system and the others are scenarios in which one of the productive subsystems is removed. Efficiency is measured by the global productivity relative to the amount of protein produced. The most environmentally advantageous scenario, in terms of sustainability and productivity, is the one in which pork production is increased and egg production is ceased. This result suggests that increasing integration per se cannot assure gains in environmental sustainability. The integrated management of the residues of the poultry and pig production as organic fertilizer resulted an advantage for the seven scenarios. The scenarios presented should help to evaluate organizational innovations and to identify trade-offs that could influence the environmental performance of agricultural integrated systems.

Milk is one of the most important food in the world, being consumed in natura or supporting the dairy industry. In Brazil, specifically, the milk supply chain corresponds to about 20% of its agro-industrial gross domestic product; however, the productivity of most domestic milk production systems are still characterized as low. In view of this, the Brazilian government supports training programs to increase milk productivity and economic returns, however, sustainability issues are usually left in the background. This work uses emergy environmental accounting to study the sustainability of milk production systems in the southern region of Minas Gerais state, Brazil, aiming at two specific goals: (i) verifying their individual environmental performance based on emergy indices, and (ii) exploring alternatives for the development of milk production under a regional perspective. Results from a cluster analysis evidenced the existence of five main milk production systems in the region (G1–G5), including differences in productivity, handling, feed diet, infrastructure, and administrative control. Emergy indicators point to the G3 system (small-scale, family-managed) as the best performer concerning renewability (28%), yield (EYR 1.72), investment (EIR 1.39), environmental load (ELR 2.46), and sustainability (ESI 0.70); however, the G2 system should be promoted when equally considering ESI and efficiency for a decision. Under a regional perspective, increasing milk productivity will also increase a system's dependence on fossil-based resources, which results in an uneven emergy matching and in a less efficient use of emergy. On the other hand, pursuing the increase of sustainability for milk production by optimizing the regional EIR would result in an expansion of the G3 system in 96% of all milking areas and the production would decrease by about 57%. Such trade-off claims for different policies in accordance with societal objectives in different periods. Besides diagnosing and ranking the milk production systems according to their environmental performance, this work also provides important subsidies for decision-makers regarding a strategic plan towards a sustainable milk production under a regional perspective.

Arsenic contamination of groundwater is a major public health concern worldwide. The problem has been reported mainly in southern Asia and, especially, in Bangladesh. Slow-sand filters (SSF) augmented with iron were proven to be a simple, low-cost and decentralized technique for the treatment of arsenic-contaminated sources. In this research, three pilot-scale SSF (flowrate 6 L·h−1) were tested regarding their capability of removing arsenic from groundwater in conditions similar to those found in countries like Bangladesh (70 µg As(III) L−1, 26 °C). From the three, two filters were prepared with mixed media, i.e., sand mixed with corrosive iron matter (CIM filter) and iron-coated sand (ICS filter), and a third conventional SSF was used as a reference. The results obtained showed that the CIM filter could remove arsenic below the World Health Organization (WHO) guideline concentration of 10 µg·L−1, even for inlet concentrations above 150 µg·L−1. After 230 days of continuous operation the arsenic concentration in the effluent started increasing, indicating depletion or saturation of the CIM layer. The effluent arsenic concentration, however, never exceeded the Bangladeshi standard of 50 µg·L−1 throughout the whole duration of the experiments.

When a high-voltage direct-current is applied to two beakers filled with water or polar liquid dielectrica, a horizontal bridge forms between the two beakers. This experiment was first carried out by Lord Armstrong in 1893 and then forgotten until recently. Such bridges are stable by the action of electrohydrodynamic (EHD) forces caused by electric field gradients counteracting gravity. Due to these gradients a permanent pumping of liquid from one beaker into the other is observed. At macroscopic scale several of the properties of a horizontal water bridge can be explained by modern electrohydrodynamics, analyzing the motion of fluids in electric fields. Whereas on the molecular scale water can be described by quantum mechanics, there is a conceptual gap at mesoscopic scale which is bridged by a number of theories including quantum mechanical entanglement and coherent structures in water – theories that we discuss here. Much of the phenomenon is already understood, but even more can still be learned from it, since such “floating” liquid bridges resemble a small high voltage laboratory of their own: The physics of liquids in electric fields of some kV/cm can be studied, even long time experiments like neutron or light scattering are feasible since the bridge is in a steady-state equilibrium and can be kept stable for hours. It is also an electro-chemical reactor where compounds are transported through by the EHD flow, enabling the study of electrochemical reactions under potentials which are otherwise not easily accessible. Last but not least the bridge provides the experimental biologist with the opportunity to expose living organisms such as bacteria to electric fields without killing them, but with a significant influence on their behavior, and possibly, even on their genome.

The great urban population growth generates several changes in life style, land use, energy demand and consequent environmental pressure. In this way, studies related to environmental sustainability of urban systems and the availability of natural resources are of major importance. EMergy is considered to be a powerful tool to environmental accounting and measures both natural and human resources to generate products and services. The evaluation through eMergy synthesis of cities, states, nations and its base resources provides large scale perspective to evaluation of environmental areas and can help selection of policies for public benefit. This preliminary study applies the eMergy synthesis to evaluate the sustainability of the cities that compose the ABC Paulista, accounting the local free renewable and the purchased resources that give support to the cities.

In this study, a multinozzle electrohydrodynamic atomization device was designed and studied for electrosprays in the simple-jet mode. Results have shown that the proposed device produces droplets with similar diameter in all nozzles, that the electric field creates a unique dispersion of the charged droplets and that it can operate under relatively high humidity conditions.

Experiments were conducted in order to study and characterize electrohydrodynamic atomization in the simple-jet mode for inviscid liquids. The operational window of this mode regarding the electric potential and liquid flow rate is presented. From the data it could be concluded that this mode can be divided by the characteristics of its breakup mechanism and that these characteristics are a function of the liquid Weber number and the electric Bond number for a given setup. Additionally we were also able to calculate the average charge per droplet and define the average size of primary and satellite droplets. The dispersion of the spray was also studied regarding its relation to the liquid Weber number and to the electric Bond number. We conclude that simple-jet mode electrosprays are a good option for applications which require monodisperse micrometer droplets with high throughput.

Experiments were conducted in order to investigate the influences of flow rate, applied voltage, and electric conductivity on droplet size and size distribution of water electrosprays in the simple-jet mode. The results show that the electric potential decreases significantly the relative standard deviation (RSD) of the spray size distribution, with the best result obtained for Weber number, We?=?3.3 (240?ml/h) when the RSD decreases from 0.50 at 0?kV to 0.18 at 5?kV. We conclude that simple-jet mode electrosprays are a good option for applications which require monodisperse micrometer droplets with high throughput.

When a high voltage is applied to a liquid pumped through a needle, charged microdroplets can be formed, which are carried along the electric field lines. This phenomenon is called electrohydrodynamic atomization (EHDA), or simply electrospray. In this work we show that in the case of water, droplets may reverse their paths flying back toward the liquid meniscus, sometimes making contact with it. Such reverse movement is caused by polarization of the water inside the strong electric field. To understand this phenomenon we developed a way to calculate the droplet charge using its trajectory obtained by high-speed imaging. The values found showed that these droplets are charged between 2.5% and 19% of their Rayleigh limit.

When high voltage is applied to pure water filled into two beakers close to each other, a connection forms spontaneously, giving the impression of a floating water bridge 1-8. This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the charge and mass transfer through the water bridge are investigated with schlieren visualization and laser interferometry. It can be shown that the addition of a pH dye increases the H+ and OH- production with subsequent electrolysis, whereas schlieren and interferometric methods reveal another mechanism where charge and mass transfer appear to be coupled. Whereas this mechanism seems to be responsible for the electrolysis-less charge and mass transfer in the water bridge, it is increasingly superseded by the electrochemical mechanism with rising conductivity. Thus it can be shown that a pH dye does only indirectly visualize the charge transfer in the water bridge since it is dragged along with the water flow like any other dye, and additionally promotes conventional electrochemical conduction mechanisms, thereby enhancing electrolysis and reducing the masscoupled charge transport and thus destabilizing the bridge.

An entomological survey conducted in 2002 in Guinea Bissau aimed i) to study the distribution of the members of Anopheles gambiae Giles complex (Diptera: Culicidae) throughout four ecological areas extended from mangrove to savannah ii) to evaluate the insecticide susceptibility status of these malaria vectors exposed to permethrin 0.75% and DDT4%, and finally iii) to investigate the occurrence and the spread of the Leu-Phe knock down resistance (kdr) gene associated with pyrethroid and DDT resistance within these vector populations. Adult female mosquitoes issued from indoor morning collections were tested using WHO procedures, test kits and impregnated papers to assess their insecticide susceptibility status. Tested specimens were identified by PCR assays and characterized for the kdr gene. Malaria vectors were mainly dominated elsewhere by An. gambiae s.s. (both S and M molecular forms) living in sympatry with low proportion of An. melas in the littoral. An. gambiae s.s. tested populations were fully susceptible both to permethrin 0.75% and to DDT 4% irrespective to their location and ecotypes. The Leu-Phe kdr mutation was detected at low frequency only in two sites respectively urban (Bissau) and Guinea-savannah (Gabu) areas. It occurred only in the S molecular form in Gabu (at the frequency of 0.14) and both in the S and M molecular forms in Bissau at the frequency of 0.06 and 0.02 respectively. These results suggested that the populations of An. gambiae s.s., the most frequent malaria vector in Guinea Bissau, still remain cross-susceptible to pyrethroids and DDT This susceptibility status and the frequency of resistance mechanism such as the kdr mutation must be monitored in the future particularly in the urban and savannah areas with continuous and intensive use of insecticides.

Universidade de Campinas. Faculdade de Ci?ncias M?dicas. Hemocentro and Departamento de Cl?nica M?dica. S?o Paulo, SP, Brasil. Universidade de Campinas. Faculdade de Ci?ncias M?dicas. Hemocentro and Departamento de Cl?nica M?dica. S?o Paulo, SP, Brasil. Universidade de Campinas. Faculdade de Ci?ncias M?dicas. Hemocentro and Departamento de Cl?nica M?dica. S?o Paulo, SP, Brasil. Minist?rio da Sa?de. Funda??o Nacional de Sa?de. Instituto Evandro Chagas. Bel?m, PA, Brasil. Minist?rio da Sa?de. Funda??o Nacional de Sa?de. Instituto Evandro Chagas. Bel?m, PA, Brasil. Universidade de Campinas. Faculdade de Ci?ncias M?dicas. Hemocentro and Departamento de Cl?nica M?dica. S?o Paulo, SP, Brasil. Universidade de Campinas. Faculdade de Ci?ncias M?dicas. Hemocentro and Departamento de Cl?nica M?dica. S?o Paulo, SP, Brasil. Universidade de Campinas. Faculdade de Ci?ncias M?dicas. Hemocentro and Departamento de Cl?nica M?dica. S?o Paulo, SP, Brasil. We analyzed the frequency of the C282Y and H63D mutations in the HFE gene in 227 individuals from Brazil comprising 71 Caucasians, 91 racially mixed Caucasian African-derived Amerindians (both populations from Southeast Brazil), 85 African-derived subjects (from Northeast Brazil) and 75 Parakan? Indians. Allelic frequency of the mutation C. 845G6A (C282Y) was 1.4% in the Caucasian population, 1.1% in the African-derived population, 1.1% in the racially mixed normal controls and 0% in the Parakan? Indians. In the African-derived population, the C282Y mutation was present on chromosomes bearing the haplotype 6/1h according to Beutler and West (1997). Allelic frequency of the mutation C. 187C6G (H63D) was 16.3% in the Caucasian population, 7.5% in the African-derived population, 9.8% in the racially mixed controls and 0% in the Amerindians. The presence of these mutations in the African-derived population reflects the fact that these subjects may have undergone a non-identified racial admixture in their past history. The absence of both defects in the Amerindians suggests that these mutations have emerged after the migration of Polynesians to America, or that they may not have reached the Polynesian population until after the migration to America had occurred.

We report on the infrared emission of aqueous bridges under the application of high dc voltage (‘floating water bridge’) over the range between 400 and 2500 cm−1 (4.0–10.3 µm). Comparison with bulk water of the same temperature reveals an additional broad peak at ∼2200 cm−1 as well as water vapour emission lines. Two complementary explanations are presented for the broad peak: first, a cooperative proton transfer comprising an orientational motion along the direction of conduction is suggested. Second, the electrolysis-less current flow is explained by a proton/defect-proton band mechanism, which is in line with the cooperative proton transfer. The water vapour emissions occur due to collision ionization of space charges with micro- and nano-droplets which are electrosprayed from the liquid/gas interface.

When a high-voltage direct-current is applied to two beakers filled with water or polar liquid dielectrica, a horizontal bridge forms between the two beakers. In this work such bridges made of methanol, ethanol, 1-propanol and 2-propanol are investigated with polarimetry and thermography. Whereas methanol, ethanol and 1-propanol bridges become warm like a water bridge, a 2-propanol bridge cools down relative to the surroundings. It is shown how the different stability of the primary and secondary alcoholate ions and the resulting small difference in conductivity between 1-propanol and 2-propanol is responsible for this novel effect.

International audience; When high voltage is applied to pure water filled into two beakers close to each other, a connection forms spontaneously, giving the impression of a floating water bridge [ 1]-[8 ]. This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the behavior of this phenomenon under reduced gravity conditions during a parabolic flight is presented by the means of high speed imaging with fringe projection. An analysis of the behavior is presented and compared to theoretical considerations. Supplementary video clips for the sequences shown in figs. 2, 4, 5&6 as well as 7&8 are available. Introduction In 1893 Sir William Armstrong placed a cotton thread between two wine glasses filled with chemically pure water. After applying a high voltage, a watery connection formed between the two glasses, and after some time, the cotton thread was pulled into one of the glasses, leaving, for a few seconds, a rope of water suspended between the lips of the two glasses [ 1 ]. As gimmick from early days of electricity this experiment was handed down through history until the present authors learned about it from W. Uhlig, ETH Zürich [ 2 ]. Although easy to reproduce, this watery 2 connection between the two beakers, which is further referred to as 'floating water bridge ' holds a number of interesting static and dynamic phenomena [ 3]-[8 ]. At macroscopic scale several of these phenomena can be explained by modern electrohydrodynamics, analyzing the motion of fluids in electric fields (see, e.g., the Maxwell pressure tensor considerations by Widom et al. [ 9 ], or the text book on Electrohydodynamics by Castellanos [ 10]). On the molecular scale water can be described by quantum mechanics (e.g. [ 11 ], [ 12]). The gap at mesoscopic scale is bridged by a number of theories including quantum mechanical entanglement and coherent structures in water, theories which are currently discussed (e.g. [ 13]-[17 ] for water in general, and [ 18 ] specifically for the water bridge). Previous experiments [ 3 ] suggested a possible change of the water micro structure inside the water bridge ; first neutron scattering experiments [ 5 ] showed no difference in the microdensity of a D 2 O bridge compared to the bulk ; recent 2D neutron scattering experiments [ 6 ] indicated a preferred molecular orientation within a floating heavy water bridge ; detailed optical investigations [ 7 ] suggested the existence of a mesoscopic bubble network within the water bridge ; and a Raman scattering study on vertical water bridges reported on a polarized water structure induced by the electric field [ 19 ]. A comprehensive review about water bridge research was published recently [ 20 ]. The properties of water at mesoscopic scales have drawn special attention due to their suggested importance to human physiology [ 21 ]. In this work, the first reduced gravity experiments with the floating water bridge are presented. The data gathered with high speed imaging and fringe projection are discussed, the overall behavior is described and compared to theoretical considerations. Experimental The experiments were carried out onboard the PH-NLZ Fairchild Metro II Research Aircraft of the NLR (Nationaal Lucht- en Ruimtevaartlaboratorium - The National Aerospace Laboratory of the Netherlands), Hangar 3, Schiphol, on a specially designed set-up (see Fig. 1). All apparatus were mounted on an aluminum alloy plate provided by the NLR using struts and mountings certified for aviation and safe for accelerations up to 9G. The set-up contained a constant current regulated high voltage power supply (0-20kV) with a 250kΩ/500MΩ voltage divider. Instead of beakers two closed bottles with an additional opening in the sidewall were used. The bottles were 3 mounted on a movable stage in order to manually create water bridges of different length. The water bridge was formed between the sidewall openings of the bottles. The bottles were filled with milli-Q water (conductivity < 1µS/cm) up to ~2mm below these openings. For all experiments, the initial temperature of the water was ~19°C, which was the onboard air temperature. Due to the short duration of the experiments (< 1 min), no significant temperature change was to be expected [ 7 ]. As electrode material, 2 x 2 cm² platinum plates were submerged into the water. One electrode was raised to high potential (+20kV), the other was grounded to the aircraft's general ground. A 42nF ceramic capacitor was connected parallel to the electrodes.