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Microbial fuel cells (MFCs) are a green technology that can directly convert electrical energy from chemical energy contained in organic wastewater. Rice is the most popularly consumed food in Asia. Rice washing before cooking produces an enormous amount of domestic sewage. Rice washing wastewater (RWW) contains various organic matters, minerals, and vitamins. Therefore, in this study, we utilized RWW as biofuel to operate a floating MFC (FMFC). The FMFC was designed with the air-cathode floating on the biofuel and the anode immersed in the biofuel. This design enables the device to float on wastewater sources and to harvest electricity directly from that source. Baker’s yeast and bacteria existing in a natural pond (natural bacteria) were used as biocatalysts. Experimental results showed that the FMFC could generate electricity from RWW using both the baker’s yeast and natural bacteria. The maximum power density ow the FMFC using the baker’s yeast was 1 mW/m2.

The quasi-dynamic mooring line model is a new approach to assess the mooring line tension that considers the static solution of the catenary shape, but updates the distributed vertical force along the mooring line as a function of the external forces, drag and inertial, acting on the line. In this way, an updated apparent weight is applied to the static solution of the catenary shape that improves significantly the solution obtained by the quasi-static approach, with an equivalent computational cost. Then, the model improves the tension solution of the quasi-static models by using that updated weight of the mooring, achieving results much closer to the dynamic models than the standard quasi-static ones. To appraise the improvement of the results, a parametric analysis within a wide range of mooring physical parameters is conducted. The error of the quasi-static tension of one cycle is less than 20% only for the 18% of the simulations, while the quasi-dynamic model produces an error less than 20% for the 84% of simulations. In addition, the model can predict the slack phenomenon.

Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven MD provides a route for the practical application of seawater desalination at a small scale. In this work, we focus on floating MD modules with a solar heating bag as the power source, and perform proof-of-principle experiments on the MD performance under various conditioning parameters, including feed flow rate, feed temperature, salinity, air gap, and sea waves. The results indicate that floating solar-driven MD modules are feasible in terms of permeate flux and salt rejection ratio, and the upward evaporation MD configuration leads to a better performance in terms of permeate flux. The simulation and experiments also show that the natural sea waves disturb the heating bag and the MD module floating on the surface of seawater, and effectively enhance the feed circulation and transport in the system.

There is an increasing interest in Floating PV (FPV) plants thanks to their advantages compared with ground and rooftop PV systems, mainly related to very limited land use, evaporation reduction, and improvement of the energy performance. The PV modules installed on water surfaces have a natural cooling due to the microclimate in which they operate, which reduces thermal power losses. Furthermore, they can be equipped with simple and effective forced active water cooling systems which further improve FPVs performance. The objective of this study is to develop and validate mathematical models capable of estimating the performance of bifacial and monofacial PV modules installed on water surfaces. Starting from the energy balances of the PV modules, different scenarios are simulated, such as mono and bifacial systems installed on the rooftop, mono, and bifacial FPV systems in presence of natural (or passive) and forced (or active) cooling. The models are validated against experimental data acquired in FPV systems installed in the Enel Innovation Lab by Enel Green Power, Catania (Italy). The obtained results show an energy gain due to bifaciality of 5.24%. The passive cooling in the FPV increases the energy collected by 3% (maximum obtainable of 6.4%) and 2.6% for the bifacial and monofacial technology respectively. Active cooling in FPVs increases the collected energy by 9.7% (maximum achievable of 13.5%) and 9.5% for the bifacial and monofacial respectively.

This paper presents a new dynamic inflow model for vertical-axis wind turbines (VAWTs). The model uses the principle of Duhamel's integral. The indicial function of the inflow- and crossflow-induction required to apply Duhamel's integral is represented by an exponential function depending on the thrust coefficient and the azimuthal position. The parameters of this approximation are calibrated using a free wake vortex model. The model is compared with the results of a vortex model and higher fidelity computational fluid dynamic (CFD) simulations for the response of an actuator cylinder to a step input of the thrust and to a cyclic thrust. It is found that the discrepancies of the dynamic inflow model increase with increasing reduced frequency and baseline thrust. However, the deviations remain small. Analysing the application of a finite-bladed floating VAWT with non-uniform loading and validating it against actuator line CFD results that intrinsically include dynamic inflow shows that the new dynamic inflow model significantly outperforms the Larsen and Madsen model (which is the current standard in fully coupled VAWT models) and enhances the modelling of VAWTs.

The aim of this paper is to present an autobiographical account on the prospects and process of academic career in Nordic countries, and specifically in Sweden. The method used is biographical, or self-ethnographic, dealing with life transitions including struggles and experiences when making the career. The point of departure is the final step in the academic career, i.e. Professorship, and reconstruction of the life events backwards, both as diachronic, a moment in time, as well as synchronic, over time dimensions. This includes research initiation, PhD writing, Postdoc experience, habilitation, and struggling to get a position of a senior lecturer and finally a professor. Involvement in various projects and international networking are presented. Biographical work and learning are used to understand how a woman researcher is navigating in a difficult male dominated terrain, including both negative and positive experiences.

In patients with significant comorbid conditions, acute cholecystitis is managed through surgical intervention or with cholecystostomy tube placement (CTP). The literature is not definitive in its recommendations for cholecystectomy versus cholecystostomy. This case report describes a presentation of acute calculous cholecystitis managed with CTP. Over a 10-week period, due to complications with the tube, the decision was made to perform a cholecystectomy. Upon open surgical exploration, an atraumatic, ruptured, and chronically inflamed gallbladder was found without attachment to the subhepatic plate and, in essence, free “floating” in the peritoneum. To our knowledge, this is the first-known documented case report in the English medical literature. An elderly woman, with significant co-morbidities, following two months of antibiotic treatment for acute cholecystitis and subsequent percutaneous cholecystostomy tube placement and re-placements, underwent elective laparoscopic cholecystectomy, which was converted to open surgery. Upon exploration, a detached, “floating” gallbladder was found posterior to the transverse colon and removed after lysing extensive peritoneal adhesions. Subsequent to the cholecystectomy, the patient had uncomplicated recovery. The literature does not present a clear consensus on CTP use vs early cholecystectomy in high-risk patients with acute cholecystitis. This management decision is based primarily on the surgeon’s clinical judgment and the use of evidence-based risk assessment indices. The "floating gallbladder" is a rare, benign complication that affirms the importance of extensively assessing the risks and benefits of CTP as compared to cholecystectomy in the elderly and/or comorbid patient.

This paper presents results of numerical computations for \ud floating off-shore wind\ud turbines using, as an example, a machine of 10-MW rated power. The hydrodynamic\ud loads on the support platform are computed using the Smoothed Particle Hydrodynamics method, which is mesh-free and represents the water and \ud floating structures as a set\ud of particles. The aerodynamic loads on the rotor are computed using the Helicopter\ud Multi-Block \ud ow solver. The method solves the Navier-Stokes equations in integral\ud form using the arbitrary Lagrangian-Eulerian formulation for time-dependent domains\ud with moving boundaries. The motion of the \ud floating off-shore wind turbine is computed\ud using a Multi-Body Dynamic Model of rigid bodies and frictionless joints. Mooring\ud cables are modelled as a set of springs and dampers. The loosely coupled algorithm\ud used in this work is described in detail and the obtained results are presented.

Modeling is essential for designing control and making prediction. For the case of floating offshore wind turbine, providing a model that is validated is a challenging task as testing prototypes in the field are expensive and difficult and it may cause loss of turbine. For this reason, wind turbines are scaled down to be tested at a wind and wave laboratory where deep sea environment is realized after scaling. In this paper, theoretical hydro-elastic model of a floating offshore wind turbine is presented. The hydro-elastic model that is simulated both by a Simulink model and by high fidelity wind turbine simulation tool, FAST, is then verified by laboratory experiments. A comparison is performed to show the model dynamics compared with the experimental results. Presented results show that the model of the laboratory-scale wind turbine correctly represents the main dynamic behavior of the theoretical model.

Leading wind turbine manufacturers are increasingly looking at the possibilities of sending offshore wind turbines to deep seas. This can be done using a Floating Offshore Wind Turbine (FOWT). Therefore FOWT is an interesting and timely field of study. The aim of the paper is to use System Identification (SI) to make a data-driven-based model for the FOWT system, located in Offshore Wind & Wave Laboratory at Aalborg University. This is achieved by conducting experiments and analyzing the data. SI is used to analyze data from the experiments and obtain different models. These models are then evaluated based on the fit, the frequency response, autocorrelation and crosscorrelation. Eventually, an AutoRegressive Moving Average and Extra input (ARMAX) model is shown to be the most accurate amongst the analyzed models.

The efficiency and profitability of Floating, Production, Storage and Offloading platform (FPSO) terminals depends on various factors such as LNG liquefaction process type, system reliability and maintenance approach. This review is organized along the following research questions: (i) what are the economic benefit of FPSO and how does the liquefaction process type affect its profitability profile?, (ii) how to improve the reliability of the liquefaction system as key section? and finally (iii) what are the major CBM techniques applied on FPSO. The paper concluded the literature and identified the research shortcomings in order to improve profitability, efficiency and availability of FPSOs.

In this paper, recent advances in Ocean Nuclear Power Plants (ONPPs) are reviewed, including their general arrangement, design parameters, and safety features. The development of ONPP concepts have continued due to initiatives taking place in France, Russia, South Korea, and the United States. Russia’s first floating nuclear power stations utilizing the PWR technology (KLT-40S) and the spar-type offshore floating nuclear power plant designed by a research group in United States are considered herein. The APR1400 and SMART mounted Gravity Based Structure (GBS)-type ONPPs proposed by a research group in South Korea are also considered. In addition, a submerged-type ONPP designed by DCNS of France is taken into account. Last, issues and challenges related to ONPPs are discussed and summarized.

BACKGROUND Floatation-REST (Reduced Environmental Stimulation Therapy), an intervention that attenuates exteroceptive sensory input to the nervous system, has recently been found to reduce state anxiety across a diverse clinical sample with high levels of anxiety sensitivity (AS). To further examine this anxiolytic effect, the present study investigated the affective and physiological changes induced by Floatation-REST and assessed whether individuals with high AS experienced any alterations in their awareness for interoceptive sensation while immersed in an environment lacking exteroceptive sensation. METHODS Using a within-subject crossover design, 31 participants with high AS were randomly assigned to undergo a 90-minute session of Floatation-REST or an exteroceptive comparison condition. Measures of self-reported affect and interoceptive awareness were collected before and after each session, and blood pressure was measured during each session. RESULTS Relative to the comparison condition, Floatation-REST generated a significant anxiolytic effect characterized by reductions in state anxiety and muscle tension and increases in feelings of relaxation and serenity (p < .001 for all variables). Significant blood pressure reductions were evident throughout the float session and reached the lowest point during the diastole phase (average reduction >12 mm Hg). The float environment also significantly enhanced awareness and attention for cardiorespiratory sensations. CONCLUSIONS Floatation-REST induced a state of relaxation and heightened interoceptive awareness in a clinical sample with high AS. The paradoxical nature of the anxiolytic effect in this sample is discussed in relation to Wolpe’s theory of reciprocal inhibition and the regulation of distress via sustained attention to present moment visceral sensations such as the breath.

Gastroretentive levofloxacin (LVF) floating mini-tablets for the eradication of Helicobacter pylori (H. pylori) were prepared using the matrix forming polymer hydroxypropyl methylcellulose (HPMC K100M), alone or with Carbopol 940P in different ratios by wet granulation technique. Buoyancy of mini-tablets was achieved by an addition of an effervescent mixture consisting of sodium bicarbonate and anhydrous citric acid to some formulations. The prepared mini-tablets were evaluated for weight variation, thickness, friability, hardness, drug content, in vitro buoyancy, water uptake and in vitro release. The optimized formula was subjected to further studies: FT-IR, DSC analysis and in vivo examination in healthy volunteers. The prepared mini-tablets exhibited satisfactory physicochemical characteristics. Incorporation of gas-generating agent improved the floating parameters. HPMC K100M mini-tablet formulation (F1) offered the best controlled drug release (>8h) along with floating lag time 24h. The obtained DSC thermograms and FT-IR charts indicated that there is no positive evidence for the interaction between LVF and ingredients of the optimized formula. The in vivo test confirmed the success of the optimized formula F1 in being retained in the stomach of the volunteers for more than 4h. LVF floating mini-tablets based on HPMC K100M is a promising formulation for eradication of H. pylori.

Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor, primarily used for the treatment of hypertension, congestive heart failure, and heart attack. It belongs to BCS class III having a half-life of 12 hrs and 25% bioavailability. The purpose of the present work was to develop a press-coated, floating-pulsatile drug delivery system. The core tablet was formulated using the super-disintegrants crosprovidone and croscarmellose sodium. A press-coated tablet (barrier layer) contained the polymer carrageenan, xanthan gum, HPMC K4M, and HPMC K15M. The buoyant layer was optimized with HPMC K100M, sodium bicarbonate, and citric acid. The tablets were evaluated for physical characteristics, floating lag time, swelling index, FTIR, DSC, and in vitro and in vivo behavior. The 5% superdisintgrant showed good results. The FTIR and DSC study predicted no chemical interactions between the drug and excipients. The formulation containing xanthan gum showed drug retaining abilities, but failed to float. The tablet containing HPMC K15M showed a high swelling index. The lag time for the tablet coated with 200 mg carrageenan was 3±0.1 hrs with 99.99±1.5% drug release, with 140 mg HPMC K4M, the lag time was 3±0.1 hrs with 99.71±1.2% drug release, and with 120 mg HPMC K15M, the lag time was 3±0.2 hrs with 99.98±1.7% drug release. The release mechanism of the tablet followed the Korsmeyer-Peppas equation and a first-order release pattern. Floating and lag time behavior have shown good in vitro and in vivo correlations.

Venous thrombosis in newborns in pediatric surgery is rare. Aim of the article: description of the case of treatment of a newborn with a floating thrombus of the right atrium. This article reports the case of a 26-day-old child with a floating right atrium thrombus with a background of late neonatal sepsis, septicemia, osteomyelitis of the proximal humerus, severe anemia and bacterial endocarditis. Primary cause of the right atrial thrombus was a complicated course of pregnancy with anemia, inflammatory disease and colpitis of the mother in the obstetric history. Features of presented case: surgical removal of thrombus with cardiopulmonary bypass. Conclusion ― Thrombosis of the heart cavities in newborns is a rare and dangerous condition, requiring urgent treatment. The presence of a floating thrombus in the heart cavity, is an indication for the surgical removal of a thrombus.

As the offshore wind power sector moves to deeper waters, new foundation concepts are being developed. The European Wind Energy Association (EWEA) has created a task force under its Offshore Wind Industry Group, to look specifically at the issues revolving around the development of deep offshore and new foundation concepts. Within this paper a comprehensive presentation of state-of-the-art concepts and their maturity is provided. In addition the main technical, economic and political challenges are discussed and recommendations are provided to accommodate the sustainable development of the deep offshore wind sector in Europe.

Airborne Wind Energy Converters (AWECs) are promising devices that, thanks to tethered airborne systems, are able to harvest energy of winds blowing at an altitude which is not reachable by traditional wind turbines. This paper is meant to provide an analysis and a preliminary evaluation of an AWEC installed on a floating offshore platform. A minimum complexity dynamic model is developed including a moored heaving platform coupled with the dynamics of an AWEC in steady crosswind flight. A numerical case study is presented through the analysis of different geometrical sizes for the platform and for the airborne components. The results show that offshore AWECs are theoretically viable and they may also be more efficient than grounded devices by taking advantage of a small amount of additionally harvested power from ocean waves.

This paper will describe the design of a temporary emergency floating footbridge, to be made when the infrastructure is destroyed by a flood, hurricane, tsunami or any other disaster. The bridge is made of identical floating modules. The modules are composed of prefabricated elements: two trusses, a pontoon and the footpath. The height of the trusses is integrated with the handrail. The sides of the pontoons are inclined to stack these elements during transport. The modules are assembled at the site. A completed module is fastened to the other modules of the bridge. The completed bridge is floated into position. Thanks to the combination of trusses and pontoons, the deformations under expected loadings are reduced considerately. Structurally the pontoons can be considered as flexible supports for the trussed bridge, spanning between the river banks.

This study aimed to develop hydrophilic matrix based controlled release gastroretentive drug delivery system of ofloxacin and conducting its in vitro and in vivo evaluations. Effervescent floating gastroretentive drug delivery system of ofloxacin was prepared utilizing Box–Behnken statistical design with 3 factors, 3 levels and 15 experimental trials. Formulation optimization was done by setting targets on selected responses. In vivo studies were carried out for the optimized formulation with 12 healthy human volunteers and obtained pharmacokinetic parameters were compared with the marketed once daily formulation, “Zanocin OD”. Optimized formulation showed satisfactory controlled in vitro drug release for more than 12 h with excellent buoyancy properties (floating lag time 16 h). Optimized and marketed formulations were found to have similar in vitro release profile (f2 = 79.22) and also were found to be bioequivalent. Serum ofloxacin concentration was well maintained above its reported minimum inhibitory concentrations for most of the pathogens for sufficiently longer duration. Cmax and AUC values of optimized formulation were found to be significantly higher than of marketed product despite their bioequivalence. Bettertherapeutic effect can be expected since ofloxacin exhibits concentration dependent killing. Hence, gastroretention can be a promising approach to enhance bioavailability of ofloxacin with narrow absorption window in upper GIT.

Floating drug delivery is considered as the most effective amongst the several approaches of gastro retentive drug delivery systems. The short gastric residence times (GRT) and unpredictable gastric emptying times (GET) are the two most important parameters that play a vital role in improving the bioavailability of drugs those are having an absorption window at the stomach. The floating drug delivery approach is a low-density system that may be effervescent or Non-Effervescent type with sufficient buoyancy to flow over the gastric contents and remain buoyant in the stomach without affecting the stomachicemptyingrate fora prolonged duration. Floating dosage forms include tablets, granules, capsules, microspheres, microparticle, etc. are few formulations available commercially. A comprehensive summary of different floating drug delivery and its present status has been highlighted in this review.