Improvement in Performance of a Thermochemical Heat Storage System by Implementing an Internal Heat Recovery System

A lab-scale prototype of a thermochemical heat storage system, employing a water-zeolite 13X as the working pair, is designed and optimized for providing hot tap water. During the hydration process, humid air is introduced to the packed bed reactor filled with dehydrated zeolite 13X, and the released heat of adsorption heats up the air passing through the reactor. The hot outflow air is led to an air-to-water heat exchanger integrated in a water tank and heats up the water. The residual heat in the exhaust air is used to preheat the reactor inflow in an air-to-air heat exchanger. The temperatures of all system components are measured, and the thermal powers and heat losses are calculated. Experiments are performed in the system with and without using the heat recovery, and improvement in performance of the heat storage system is investigated

Design of a thermochemical heat storage system for tap water heating in the built environment

Replacing the use of fossil fuel by solar energy, as one of the most promising sustainable energy sources, is of high interest, because of climate change and depletion of fossil resources. However, to reach high solar fractions and to overcome the mismatch between supply and demand of solar heat, storage of solar energy is necessary. A reliable method for long term heat storage is to use thermochemical materials, TCMs. The heat storage process is based on a reversible adsorption-desorption reaction of water vapor on the TCM, which is exothermic in one direction and endothermic in the reverse direction. In this research, Zeolite 13X is used as TCM. The system is an open sorption heat storage system for providing hot tap water. In the experimental test setup, the humid air is provided in a bubble column by blowing air from bottom of the column. The exothermic hydration process starts with humid air entering into a packed bed reactor filled with zeolite 13X. The reactor is a vertical cylindrical tank which is made of steel; it has a layer of Teflon inside and has a layer of insulation outside. The temperature profile in the reactor is measured as a function of time both along the flow direction and perpendicular to the flow by thermocouples. In addition, input and output temperatures and humidity are measured. In the resulting adsorption reaction between water vapor and TCM, energy is released. This released energy heats up the air flow which passes through the reactor and the hot output air flow is used to heat up the water in a water tank. The water tank is also a vertical cylindrical tank which is made of steel and has a layer of insulation outside. The hot output air from the reactor passes through a coiled tubing inside the water tank to heat up water. The temperature of the water in the tank is measured at two different heights. A problem in open solid sorption systems using air as heat transport medium is the limited temperature step which can be achieved in the sorption bed. In the present study this problem is solved using a heat recovery system enabling higher output air temperatures. The residual heat in the exhaust air is used to preheat the reactor inflow, in an air-to-air heat exchanger. In the endothermic dehydration process, the hydrated zeolite is dried with hot air. In this study, a lab-scale prototype TCM based heat storage system is designed and optimized, which, by making use of a heat recovery loop, is able to provide hot tap water. Results of the experimental investigation on charge-discharge cycles will be presented.<br/

A meso-scale ultrasonic milli-reactor enables gas–liquid-solid photocatalytic reactions in flow

The handling of solid reagents, catalysts and by-products is a daunting challenge in continuous-flow micro- and milli-reactors. Suspensions tend to settle over time leading to irrevocable clogging of the reaction channels. Herein, we describe our efforts to develop an ultrasonic milli-reactor which can handle such challenging solid-containing transformations. The reactor consists of a Langevin-type transducer, a sonotrode and an irradiating cylinder, on which a coiled glass capillary (12.88 mL) was attached. The ultrasonic milli-reactor was combined with an LED illuminating box and its efficacy was showcased in the photocatalytic aerobic oxidation of benzyl alcohol enabled by TiO2 particles exposed to UV-A irradiation. Ultrasound irradiation generates cavitation bubbles and causes a vigorous oscillation of both the cavitation and the Taylor bubbles. This improves the liquid mixing, the gas–liquid mass transfer and ensures resuspension of the settled particles. Moreover, these effects enhance the photon absorption by the semiconductor catalyst, which has an overall positive effect on the photocatalytic transformation

Indications and clinical outcome in pediatric tracheostomy:Lessons learned

Objective: Indications for tracheostomy have changed over the last decades and clinical outcome varies depending on the indication for tracheostomy. By gaining more insight in the characteristics and outcome of the tracheostomized pediatric population, clinical care can be improved and a better individual prognosis can be given. Therefore, we studied the outcome of our pediatric tracheostomy population in relation to the primary indication over the last 16 years. Methods: We retrospectively included children younger than 18 years of age with a tracheostomy tube in the Erasmus Medical Center, Sophia children's hospital. The primary indication for tracheostomy, gender, age at tracheostomy, age at decannulation, comorbidity, mortality, closure of a persisting tracheocutaneous fistula after decannulation, surgery prior to decannulation and the use of polysomnography were recorded and analyzed. Results: Our research group consisted of 225 children. Reasons for a tracheostomy were first divided in two major diagnostic groups: 1) airway obstruction group (subgroups: laryngotracheal obstruction and craniofacial anomalies) and 2) pulmonary support group (subgroups: cardio-pulmonary diseases and neurological diseases). Children in the airway obstruction group were younger when receiving a tracheostomy (3.0 months vs. 31.0 months, p &lt; 0.05), they were tracheostomy dependent for a longer time (median 21.5 months vs. 2.0 months, p &lt; 0.05) and they required surgery more often (74.5% vs. 8.3%, p &lt; 0.05) than the children in the pulmonary support group. The decannulation rate of children with a laryngotracheal obstruction is high (74.8%), but low in all other subgroups (craniofacial anomalies; 38.5%, cardio-pulmonary diseases; 34.6% and neurological diseases; 52.9%). Significantly more children (36.7%) died in the pulmonary support group due to underlying comorbidity, mainly in the cardio-pulmonary diseases subgroup. Surgery for a persisting tracheocutaneous fistula was performed in 34 (37.8%) children, with a significant relationship between the duration of the tracheostomy and the persistence of a tracheocutaneous fistula. No cannula related death occurred during this study period. Conclusion: Main indications for a tracheostomy were airway obstruction and pulmonary support. Children in the airway obstruction group were younger when receiving a tracheostomy and they were tracheostomy dependent for a longer period. Within the airway obstruction group, the decannulation rate for children with laryngotracheal stenosis was high, but low for children with craniofacial anomalies. In the pulmonary support group, the decannulation rate was low and the mortality rate was high. Surgery for a persisting tracheocutaneous fistula was frequently needed.</p

Sorption heat storage for long-term low-temperature applications: A review on the advancements at material and prototype scale

Sorption heat storage has the potential to store large amounts of thermal energy from renewables and other distributed energy sources. This article provides an overview on the recent advancements on long-term sorption heat storage at material- and prototype- scales. The focus is on applications requiring heat within a temperature range of 30–150 °C such as space heating, domestic hot water production, and some industrial processes. At material level, emphasis is put on solid/gas reactions with water as sorbate. In particular, salt hydrates, adsorbents, and recent advancements on composite materials are reviewed. Most of the investigated salt hydrates comply with requirements such as safety and availability at low cost. However, hydrothermal stability issues such as deliquescence and decomposition at certain operating conditions make their utilization in a pure form challenging. Adsorbents are more hydrothermally stable but have lower energy densities and higher prices. Composite materials are investigated to reduce hydrothermal instabilities while achieving acceptable energy densities and material costs. At prototype-scale, the article provides an updated review on system prototypes based on the reviewed materials. Both open and closed system layouts are addressed, together with the main design issues such as heat and mass transfer in the reactors and materials corrosion resistance. Especially for open systems, the focus is on pure adsorbents rather than salt hydrates as active materials due to their better stability. However, high material costs and desorption temperatures, coupled with lower energy densities at typical system operating conditions, decrease their commercial attractiveness. Among the main conclusions, the implementation within the scientific community of common key performance indicators is suggested together with the inclusion of economic aspects already at material-scale investigations.This project receives the support of the European Union, the European Regional Development Fund ERDF, Flanders Innovation & Entrepreneurship and the Province of Limburg. TU/e has received funding from European Union’s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES). The results of this study can contribute to the development of educational material within INPATH-TES

Energy density and storage capacity cost comparison of conceptual solid and liquid sorption seasonal heat storage systems for low-temperature space heating

Sorption heat storage can potentially store thermal energy for long time periods with a higher energy density compared to conventional storage technologies. A performance comparison in terms of energy density and storage capacity costs of different sorption system concepts used for seasonal heat storage is carried out. The reference scenario for the analysis consisted of satisfying the yearly heating demand of a passive house. Three salt hydrates (MgCl2, Na2S, and SrBr2), one adsorbent (zeolite 13X) and one ideal composite based on CaCl2, are used as active materials in solid sorption systems. One liquid sorption system based on NaOH is also considered in this analysis. The focus is on open solid sorption systems, which are compared with closed sorption systems and with the liquid sorption system. The main results show that, for the assumed reactor layouts, the closed solid sorption systems are generally more expensive compared to open systems. The use of the ideal composite represented a good compromise between energy density and storage capacity costs, assuming a sufficient hydrothermal stability. The ideal liquid system resulted more affordable in terms of reactor and active material costs but less compact compared to the systems based on the pure adsorbent and certain salt hydrates. Among the main conclusions, this analysis shows that the costs for the investigated ideal systems based on sorption reactions, even considering only the active material and the reactor material costs, are relatively high compared to the acceptable storage capacity costs defined for different users. However, acceptable storage capacity costs reflect the present market condition, and they can sensibly increase or decrease in a relatively short period due to for e.g. the variation of fossil fuels prices. Therefore, in the upcoming future, systems like the ones investigated in this work can become more competitive in the energy sector.This project receives the support of the European Union, the European Regional Development Fund ERDF, Flanders Innovation & Entrepreneurship and the Province of Limburg. TU/e has received funding from European Union’s Horizon 2020 research and innovation programme under grant agreement Nº 657466 (INPATH-TES). The results of this study can contribute to the development of educational material within INPATH-TES

Ornamental plants, 1988: a summary of research

Follow-up evaluation of Cyanazine, Terbacil and Metolachlor slow-release herbicide tablets on woody landscape crops / E. M. Smith and S. A. Treaster -- Tolerance of daylily and peony to Surflan, Devrinol and Treflan / E. M. Smith and S. A. Treaster -- Growth response of euonymus, juniper and azalea treated with differing rates of Osmocote 18-6-12 / E. M. Smith and S. A. Treaster -- Evaluation of Ronstar wettable powder on woody landscape crops / E. M. Smith and S. A. Treaster -- An evaluation of Ronstar plus Diflufenican on container-grown landscape crops / E. M. Smith and S. A. Treaster -- Prodiamine evaluation in container-grown landscape / E. M. Smith and S. A. Treaster -- Evaluation of flowering crabapple susceptibility to apple scab in Ohio-1987 / E. M. Smith and S. A. Treaster -- Field study of root zone heating systems in greenhouses / M. F. Brugger and R. H. Zondag -- Costs of producing field rapid-growing evergreens (]uniperus) in Ohio / R. D. Taylor, H. H. Kneen, E. M. Smith, D. E. Hahn and S. Uchida -- Costs of producing field ornamental trees (Malus) in Ohio / R. D. Taylor, H. H. Kneen, E. M. Smith, D. E. Hahn and S. Uchid

Trauma, Memory and Religion

How can we screen trauma? This question might lead the perception of documentary films about atrocities in the 20th and 21st centuries, like S21 THE KHMER ROUGE KILLING MACHINE (Rithy Panh, CAMB/FR 2003) about Cambodia, THE LOOK OF SILENCE (Joshua Oppenheimer, ID/DK 2014) about Indonesia or DAS RADIKAL BÖSE (Stefan Ruzowitzky, AT 2013) about Nazi-Europe. A concern that may emerge as we watch films on atrocities is whether these artistic representations perhaps guide the public away from what “really happened”. There certainly is a huge gap between, on the one hand, the immediate experience of the event that lies behind the interpretative screening and, on the other hand, watching the director’s material while neither being a part nor ever having been part of the event. Yet often filmic representations are not intended to show what happened; instead they present case studies to be explored in the present. Often the films contain an inherent critique of genocidal violence and present humanistic perspectives on obedience. Mostly, these films underline the humanity of the victims, seeking to give names, faces and biographies so that they are much more than just numbers. What appears on the screen therefore challenges the audience with a moral question: what would you do