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These days, there is a need to develop novel and emerging processing pathways that permit production of value-added substances and fuels considering sustainability aspects. In this sense, levulinic acid (LA) is one of the most promising biorefinery products. This paper presents environmental and safety assessments of LA production via acid-catalyzed dehydration (ACD) of biomass. The process was modeled by using Aspen Plus process simulation software based on a capacity of 132 000 tons per annum of banana rachis (main raw material). Likewise, environmental and safety assessments were developed. Parameters such as heats of reaction, explosivity, toxicity of substances, and operational conditions along with extended mass and energy balances were used to perform safety and environmental analyses. In this regard, the modeled topology showed an inherent safety index (ISI) score of 24 with an equal contribution of 12 points for both chemical inherent safety index (CIS) and process inherent safety index (PIS). ACD showed a good safety performance, with moderate concerns related to the handling of formic acid. Moreover, the waste reduction algorithm (WAR) was used to assess environmental performance and estimate potential environmental impacts (PEIs) of the simulated topology. It was performed considering four case studies to determine the influence of mass streams (case 1), product streams (case 2), energy streams (case 3), and simultaneous products and energy contribution (case 4). This analysis showed that for this process, the total inletting flow of impacts that enter was less than the amount of these that leave the system according to a generation rate of the PEI for case 1 (−1.89 × 102 PEI/h) and case 3 (−1.83 × 102 PEI/h). From the environmental viewpoint, the major concern is associated with the photochemical oxidation potential category because of the handling of volatile organic compounds through the process.

This paper presents a system that can reduce the water percentage of stingless bee honey with a microcontroller to control the drying process employing temperature, drying air speed, relative humidity, and optimized honey exposure surface. The main objective is to reduce water content in stingless bee honey at 22 % in order to prevent rapid fermentation and delay crystallization. This water reduction process is important to preserve the quality and extend the storage period of honey. The system comprises of a programmed microcontroller, a main insulated container, a 12 V and 400 ml/min peristaltic pump, a 2800 Watt hair dryer, a temperature and relative humidity sensor, an exhaust fan, a relative humidity control system made of a smaller insulated container and a thermoelectric Peltier cooler module, a perforated stainless steel tray, and a switching circuit / a controller circuit. In this system, the temperature control was achieved using an on-off controller. The results showed that stingless bee honey samples between 2 and 8 kg was processed, where the percentage of water dropped from between 29 – 28 % to 21.2% with dehydration rate of 53.39 g/h.

Reduction in post-harvest losses of fresh vegetables is a major objective of most of the cold chain programs. Drying is also an effective tool for reducing post-harvest loss. However, the existing industrial drying techniques are energy intensive in operation results emission of high green-house gases. Low-grade waste heat recovered from condenser of refrigeration system could be utilized for drying applications. The process consists an effective utilization of heat, obtained by the condensing unit of a refrigeration system in an intermittent manner with no external energy requirement. An experimental approach of vapour-compression based-refrigeration system has been performed for drying of onion sample. The drying was performed at average temperature of 43 °C. Moisture content was reduced to 12% (wb) after 24 h of drying. Average values of drying rate and SMER were found as 0.013 kg/h and 0.196 kg/kWh, respectively, at the mass flow rate of 0.268 kg/s. The overall drying process is energy efficient. This could be a promising future replacement of current industrial drying systems which are relatively more energy intensive.

Protein, the main component of extracellular polymeric substances, plays a vital role in sediment dewatering. Tannic acid (TA) can bind with protein, so was used as a new conditioner for sediment dewatering. The benefit of using TA as a conditioner for sediment dewatering and its mechanism were explored in this study. A series of laboratory-based experiments were conducted and the water content (Wc) of sediment cakes, specific resistance to filtration (SRF) and the filterable dehydration rate were used to evaluate the sediment dewaterability. The results showed that at the optimal dosage of 0.20 mmol/gTS (total solid), TA reduced Wc of sediment cakes by 12.3% and SRF by 70.6%, and increased the filterable dehydration rate by 9%. These results indicated TA effectively improved the dewatering performance of sediment. The conditioning mechanism study of TA supported that the protein content was reduced by combining with TA, and the bound water was gradually converted into free water. When TA was added in sufficient amount, the particle size gradually increased, large and dense aggregates were formed which enhanced the dewatering performance of the sediment. These results confirm the feasibility of using TA as an effective option for rapid dewatering of sediment and provide a reference for selecting the appropriate conditioner for sediment dewatering. Refereed/Peer-reviewed

Currently the world trend is to consume organic and healthy products, such as dehydrated food, being a constant especially in the United States of America and Europe. Dehydration is one of the most widely used techniques for food preservation, however, it is often argued that drying equipment has a shorter process time, which provides higher product quality, less contamination, higher added value, since certain technological variables that participate in the drying process can be managed (temperature, relative humidity, air flow, pre-treatments, etc.) This study exposes the construction of a heat pump dehydrator, through forced air convection, which operates in a closed environment, with total recirculation of the dehydrated air, controlling the temperature by means of a digital thermostat, which turns the heat pump on and off to maintain the programmed temperature, it also has temperature and humidity sensors in the dehydration chamber, located at the inlet of the evaporator and at the outlet of the condenser. The dehydration temperature was controlled and monitored in a range of 55 ° to 60 ° C, the minimum relative humidity was 15% in the dehydration chamber, when dehydrating mango peels and pulp. The minimum dehydration time was 8 hours, in the initial tests, obtaining a product with a homogeneous appearance and without apparent damage. An electrical consumption of the prototype was observed in the current configuration of 4.62 Amps. The air speed was 2.5 m / s.

Pickering emulsion systems have emerged as platforms for the synthesis of organic molecules in biphasic biocatalysis. Herein, the catalytic performance was evaluated for biotransformation using whole cells exemplified for the dehydration of n‐octanaloxime to n‐octanenitrile catalysed by an aldoxime dehydratase (OxdB) overexpressed in E. coli. This study was carried out in Pickering emulsions stabilised solely with silica particles of different hydrophobicity. We correlate, for the first time, the properties of the emulsions with the conversion of the reaction, thus gaining an insight into the impact of the particle wettability and particle concentration. When comparing two emulsions of different type with similar stability and droplet diameter, the oil‐in‐water (o/w) system displayed a higher conversion than the water‐in‐oil (w/o) system, despite the conversion in both cases being higher than that in a “classic” two‐phase system. Furthermore, an increase in particle concentration prior to emulsification resulted in an increase of the interfacial area and hence a higher conversion., The dehydration of n‐octanaloxime to n‐octanenitrile catalysed by an aldoxime dehydratase (OxdB) overexpressed in E. coli is carried out in Pickering emulsions stabilised solely with silica particles of different hydrophobicity. The effects of particle wettability and particle concentration are evaluated with respect to the conversion of the reaction.

This work presents the dehydration behaviour of the stevia leaves dried in an indirect active solar dryer (IASD). The newly developed IASD comprises of a solar air heater (double pass), a parallel flow cabinet with six trays and a blower. The dryer was designed with a loading density of 3.1 kg/m2. The stevia leaves attained the desired moisture (6.5% w.b), in 7 h when dried in the developed IASD. The energy efficiency of the drying chamber and pick up efficiency of the dryer were found as 31.5% and 77.5%, respectively. The net CO2 mitigation potential of the system was evaluated as 55.2 tons for 10-year lifespan of the dryer. The carbon credit earned varies from ₹12,561 to ₹50,245, which is quite high. The energy payback time (EPBT) for the dryer was estimated as 0.5 year. Antioxidant activity of the solar-dried samples was about 92.1 µmol of TE per g, which is quite high as compared to the open sun-dried samples value of 69.3 µmol of TE per g of the sample

The drying characteristics of a thin layer of tomato slices in a double slope solar dryer and open drying were studied and compared their results to best suit agricultural products to avoid post-harvest and consumer wastage. In this investigation, the double slope solar dryer was found to be better than the open sun dehydration in colour, odour and aroma which went unchanged along with a shorter drying time compared to the open sun drying process for a similar quality of the tomato slices. Tomato slices dehydrated in the double slope solar dryer were safeguarded from rain, bugs and the slices were also of better quality for consumption by human beings. It is also eco-friendly as renewable energy (solar) was used for the operation. The moisture content of the tomato slices decreased from 94.4 to 13% on wet basis within 7 h in double slope solar dryer and 10 h in open sun drying respectively. The effective moisture removal depends on the diffusivity that was additionally portrayed by the Arrhenius relationship. The effective moisture diffusivity of tomato was in the range of 3.84 × 10−10 to 5.87 × 10−09 m2/s and the activation energy of slices from 36.87 to 46.44 kJ/mol. This dryer setup can also be utilized for dehydrating different agricultural items. Likewise, it is frugal in development and can be assembled economically with locally available materials.

Background: Successful obturation in the primary teeth demands complete dryness of the root canal system. Aim: The purpose of this study was to determine the effect of 95% ethanol as the final irrigant before root canal obturation in primary teeth. Materials and methods: A total of 20 extracted primary mandibular canines were biomechanically prepared and pre-obturated volume of each tooth was assessed using spiral computed tomography (CT). The specimens were divided into two groups (n = 10): group 1, Metapex group; group 2, zinc oxide eugenol group. Each group was further divided randomly into two subgroups (n = 5): subgroup 1, canals were dried with 95% ethanol; subgroup 2, canals were blot dried with paper points with the last one appearing dry. All canals were obturated and the postobturated volume of each tooth was measured. The percentage of obturated volume (POV) was calculated using the formula: (postobturated volume/preobturated volume) × 100. The POV between the groups was statistically analyzed using Mann-Whitney test and Wilcoxon Signed rank test appropriately. Results: Root canals that were dried with ethanol showed better obturation than using paper points alone and the difference was statistically significant in both group 1 (p < 0.001) and group 2 (p < 0.002). Conclusion: Drying of the root canal system with 95% ethanol can result in better obturation in the primary teeth. How to cite this article: Thiruvenkadam G, Asokan S, John B, Geetha Priya PR. Effect of 95% Ethanol as a Final Irrigant before Root Canal Obturation in Primary Teeth: An in vitro Study. Int J Clin Pediatr Dent 2016;9(1):21-24.

With conventional technique for crude oil dehydration, demulsifying agent or "Demulsifier" is used to separate oil, water and emulsion layers at a certain temperature condition. By this method, it leads to demulsifier loss in a crude oil product. The new concept of the dehydration is to recycle and reuse the demulsifer with minimal investment. With this concept, carbonate-based ionic liquids (CBILs) will be used as a demulsifier to separate emulsions and water in oil, resulting in a decrease in OPEX from demulsifier injection. In addition, CBILs represent versatile, green and easy-to-prepare chemicals. Laboratory test results show that the emulsion between oil and water is able to break within 15 minutes at 60°C which is comparable to conventional demulsifier. Moreover, the cost of CBILs is lower than conventional demulsifier. Therefore, this chemical is proved to be more attractive.

Algae cultivation has multiple potential applications including biofuel production, wastewater treatment, and carbon capture. However, dewatering and dehydration remain a challenge for commercialization. Research has focused mainly on microalgae, but filamentous algae have recently gained attention due to their larger size and thus relative ease of harvesting. The drying mechanics of filamentous algae has yet to be fully understood and optimized. This study investigated the drying behavior of the filamentous algae Oedogonium at 50℃, 60℃ and 70℃. The moisture content of triplicate samples of microalgae and Oedogonium (intact filaments, fractured filaments, and aggregated forms) was measured during drying. Intact Oedogonium filaments were fractured using a food blender. Intact Oedogonium had an average shorter falling rate phase and higher diffusivity then microalgae at all temperatures, resulting in a 15%, 8.3%, and 11% faster total average drying time at 50℃, 60℃ and 70℃ respectively. Fractured Oedogonium further had a shorter falling rate phase than intact Oedogonium at 50℃ and 60℃ where its average total drying time was respectively 18% and 9% faster, but the effect of the fracturing treatment reduced with increasing temperature and became negligible at 70℃. Thus, Oedogonium appears to dry more effectively than microalgae, and fracturing Oedogonium results in faster dehydration at lower temperatures. These findings could help optimize industrial drying and assist in the commercialization of algae cultivation.

Made available in DSpace on 2021-07-14T10:21:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-16. Added 1 bitstream(s) on 2021-07-14T11:28:20Z : No. of bitstreams: 1 S0101-20612020005024203.pdf: 987432 bytes, checksum: 57ef3270f799f6ba8de358c92cd68f3e (MD5) The cagaita is a native fruit from Brazilian Cerrado region. Among conservation techniques and to increase shelf life of the fruit, foam bed drying becomes ideal. This study adjusted mathematic models of foam drying of the cagaita pulp at different temperatures to determine the net diffusion coefficient and the activation energy of this process. As the foam layer drying has a shorter drying time due to the greater exposure of the surface area to the air, it allows the application of lower dehydration temperatures, so it used 40, 50, 60 and 70 °C, the data observed were better fitted to the Midilli model. The net diffusion coefficient increased with temperature and the activation energy was 25.368 kJ mol-1. Universidade Estadual Paulista Instituto Federal Goiano Universidade Estadual Paulista

Organic waste is still of great value and its transformation into biodegradable polymers is part of the circular economy strategy. The main objective of this research was to evaluate different variables that were analyzed through a tree decision method in order to obtain a biomaterial developed through the conversion of orange peels into a biopolymer. The analysis and assessment include different particle sizes of the orange peel powder, different starch types, different cooling, and dehydration processes. The variables that resulted in the best biopolymer were as follows: particle size of the orange peel powder: 250 micrometers, potato starch and corn starch in a ratio of 0:100, cooling of the mixture at room temperature, and finally the application of a dehydration process.

According to the operating features of the centrifuge, this study analyzes the main factors affecting its dehydration effect. At the same time, this study also derived the relationship between the dehydration effect and its main factors, analyzing how the main factors affect the dehydration effect, and carried out practical verification. The final results show that the sieve basket with high rotating speed, high trepanning rate and reasonable clearance of components are beneficial to improve the dehydration effect. In addition, the improvement of the trepanning rate of sieve basket has a significant influence on the enhancement of dehydration effect.

Drying is known as the best method to preserve fruits, vegetables, and herbs, decreasing not only the raw material volume but also its weight. This results in cheaper transportation and increments the product shelf life, limiting the food waste. Drying involves the application of energy in order to vaporize and mobilize the moisture content within the porous products. During this process, the heat and mass transfer occurs simultaneously. The quality of dehydrated fruits, vegetables, and aromatic herbs is a key problem closely related to the development and optimization of novel drying techniques. This review reports the weaknesses of common drying methods applied for fruits, vegetables, and aromatic herbs and the possible options to improve the quality of dried products using different drying techniques or their combination. The quality parameters under study include color, bulk density, porosity, shrinkage, phytochemicals, antioxidant capacity, sugars, proteins, volatile compounds, and sensory attributes. In general, drying leads to reduction in all studied parameters. However, the behavior of each plant material is different. On the whole, the optimal drying technique is different for each of the materials studied and specific conditions must be recommended after a proper evaluation of the drying protocols. However, a novel or combined technique must assure a high quality of dried products. Furthermore, the term quality must englobe the energy efficiency and the environmental impact leading to production of sustainable dried products.

In order to treat faecal sludge from ventilated improved pit (VIP) latrines, eThekwini Municipality (Durban, South Africa) developed an infrared dryer, 'LaDePa' (Latrine Dehydration Pasteurization). Parameters that influence its operation were investigated using a laboratory-scale replica of the full-scale machine. For this, faecal sludge collected from VIP latrines was pelletized and dried under different operating conditions. Drying curves were obtained by plotting medium wave infrared intensity (MIR), height of emitters above the belt, air flowrate and pellet diameter against the residence time. These curves were then used to determine the drying rate and energy consumption. The results show that the drying rate increased while the energy consumption decreased by increasing the power of the MIR emitters and decreasing the size of the pellets. For example, the drying time to get a moisture content of 0.8 g water/g dry solid was shortened from 27 to 6 min while the energy consumption for this reduced from 1.5 to 0.8 kWh after increasing the MIR power from 1.5 to 3.3 kW. Similar drying curves were obtained by varying the distance between the pellets and MIR emitters, and adjusting intensity of the MIR radiation to obtain the same temperature in the drying zone. It was also observed that higher airflow rates enhanced mass transfer rates, but led to a cooling effect. No effect on the drying rate was observed after pre-drying the sludge or adding sawdust. The study shows that for the process to be efficient, the MIR intensity should be high enough for fast drying to occur (T ≥ 150°C), but without causing thermal degradation (T ≤ 220°C). The height of emitter above the belt and the pellet size should be as small as possible (8 mm); airflow rate should be optimised to maximize the mass transfer rate and minimize the cooling effect. Keywords: drying medium infrared radiation VIP sludge LaDePa

Plants that experience a lack of sufficient irrigation undergo hydric stress, which causes the modification of their mechanical properties. These changes include a complex network of chemical and physical signals that interact between plant-plant and plant-environment systems in a mechanism that is still not well understood, and that differs among species. This mechanical response implies different levels of vibration when the plant experiences structural modifications from self-hydraulic adjustments of flux exchange at specific frequencies, with these carrying behavioral information. To measure these signals, highly sensitive instrumentation that allows the decoding of displacement velocity and displacement of plants, which is possible through calibrated equipment such as 3D scanning laser vibrometers, is necessary. Laser vibrometry technology allows for noninvasive measurements in real-time. Physiological changes could reasonably affect the biomechanical condition of plants in terms of the frequency (hertz) and intensity of the plant’s vibration. In this research, it is proposed that the frequency changes of a plant’s vibration are related to the plant’s hydric condition and that these frequency vibrations have the ecological potential to communicate water changes and levels of hydric stress. The peak of the velocity of plant displacements was found to vary from 0.079 to 1.74 mm/s, and natural frequencies (hertz) range is between 1.8 and 2.6 Hz for plants with low hydric stress (LHS), between 1.3 and 1.6 Hz for plants with medium hydric stress (MHS), and between 6.7 and 7.8 Hz for plants with high hydric stress. These values could act as preliminary references for water management using noninvasive techniques and, knowledge of the range of natural frequencies of hydric stress risk in chili pepper crops can be applied in precision agriculture practices.

Although fleshy fruit is mainly made up of water, little is known about the impact of its water status on sugar metabolism and its composition. In order to verify whether fruit water status is an important driver of carbohydrate composition in tomato fruit, an adaptation of the SUGAR model proposed previously by M. Génard and M. Souty was used. Two versions of the model, with or without integrating the influence of fruit water content on carbohydrate metabolism, were proposed and then assessed with the data sets from two genotypes, Levovil and Cervil, grown under different conditions. The results showed that, for both genotypes, soluble sugars and starch were better fitted by the model when the effects of water content on carbohydrate metabolism were taken into consideration. Water content might play a regulatory role in the carbon metabolism from sugars to compounds other than sugars and starch in Cervil fruit, and from sugars to starch in Levovil fruit. While water content influences tomato fruit carbohydrate concentrations by both metabolism and dilution/dehydration effects in the early developmental stage, it is mainly by dilution/dehydration effects in the late stage. The possible mechanisms underlying the effect of the fruit water content on carbohydrate metabolism are also discussed., The dynamics of soluble sugars and starch during fruit development are better simulated by considering the effects of water content on carbohydrate metabolism.

The difficulty of residual sludge dehydration is the major problem in sewage treatment. The reduction of moisture content in sludge can reduce the sludge volume significantly and is conducive to the subsequent disposal of sludge. As an organic polymer flocculant, chitosan (CTS) is widely used in water and waste water treatment. In this study, CTS was used in sludge treatment to improve the sedimentation and dehydration properties of sludge. When treated with CTS, the moisture content of sludge cake decreased from 85.9% to 83.0%, the SV30 decreased to about 1/2, and the sludge volume reduced to 82.9%. Further analysis showed that the zeta potential (ζ-potential) of the sludge changed from negative value to positive value, and the D50 of the sludge was larger than that of the raw sludge. In addition, when the moisture content of the sludge cake was reduced to the lowest, the concentration of extracellular polymeric substances (EPS) and SCOD was the largest and the |ζ| decreased to the lowest. CTS improved the dehydration and sedimentation performance of sludge mainly by factors of electrical neutralization, adsorption bridging and dissolution of EPS.

Cast-tape drying (CTD) is a suitable process for the dehydration of fruit pulps to obtain leathers, flakes or powders. This study investigated the production of mango leathers by CTD, as well as their physical characteristics and acceptability. Drying curves were evaluated for mango pulp with and without starch addition (5 g dry starch/100 g dry mango pulp). Resulting mango leathers were conditioned at different relative humidity (RH), and their textures were assessed by mechanical-acoustic measurements and correlated to sensory analyses. Starch addition did not influence the drying time (18 min). Mango leathers conditioned at 22.5% RH were very crisp and preferred by consumers, independent of the starch addition. The texture was the attribute that most influenced consumer's choice and was well correlated with the number of force and sound peaks, as well as with sound pressure level. Therefore, CTD is an adequate drying process to produce mango leathers at relatively short times.

The objective of this study was to evaluate the chemical and oxidative stability of dried macaúba (Acrocomia totai) fruit in different air conditions and stored for up to 120 days. The macaúba fruits were collected, sanitized, dried at the temperatures of 40, 50, 60 and 70 °C and stored in raffia bags at room temperature. Drying at higher temperatures resulted in pulps with a darker and orangish color and pulp oil with lower titratable acidity contents and acidity indices. Throughout storage, there was an increase in the acidity index of pulp oil and a reduction in the ascorbic acid and carotenoid contents in the pulp. Drying and storage reduced the ascorbic acid and carotenoid contents of the pulp. Drying at lower temperatures results in pulps with a higher free-radical sequestering ability. Pulp oil quality was compromised by drying and storage time. Newly harvested macaúba fruits can be dried at 40, 50, 60 or 70 °C and stored for up to 120 days without compromising nut oil quality. Este trabalho teve por objetivo avaliar a estabilidade química e oxidativa de frutos de macaúba desidratados em diferentes condições e armazenados por até 120 dias. Os frutos de macaúba “Acrocomia totai” foram coletados, sanitizados, desidratados nas temperaturas de 40, 50, 60 e 70 °C e armazenados em sacos de ráfia em temperatura ambiente. A secagem em temperaturas mais elevadas resultou em polpas com coloração mais escura e alaranjada, porém com menor acidez titulável e índice de acidez do óleo da polpa. Durante o armazenamento houve aumento do índice de acidez do óleo da polpa e redução do teor de ácido ascórbico e carotenoides da polpa dos frutos. A secagem e o tempo de armazenamento dos frutos diminuíram o teor de ácido ascórbico e de carotenoides da polpa. A secagem em temperaturas mais baixas resultou em polpas com maior capacidade de sequestrar radicais livres. A qualidade do óleo da polpa foi comprometida pela secagem e tempo de armazenamento. Frutos de macaúbas recém coletados podem ser desidratados a 40, 50, 60 ou 70 °C e armazenados por até 120 dias, sem comprometer a qualidade do óleo da amêndoa.

Dehydration of isopropanol applying batch heteroazeotropic distillation with toluene as entrainer (E) is investigated. The composition of the feed is near to that of the isopropanol (A)-water (B) azeotrope. The effects of recycling the entrainer and the off-cut are studied by dynamic simulation with a professional flow-sheet simulator. Three consecutive batches (one production cycle) is studied. Both operational modes (Mode I: decantation after distillation and Mode II: decantation during distillation) are simulated. For Mode II, calculations are performed both for Strategy A (distillate from the aqueous (E-lean) phase only) and Strategy B (partial withdrawal of the organic (Erich phase), as well). The E-rich phase, the final column hold-up and the off-cut (Mode II only) are recycled to the next batch. The influence of the following parameters are determined: quantity of entrainer, reflux ratios of the steps. The variations caused by the recycling in the 2nd and 3rd batches are also shown. The best results (lowest specific energy demand and highest recovery of A) are obtained by Mode II, Strategy A. Recycling increases the recovery, and drastically diminishes the entrainer consumption. However, it makes the production slower and decreases the quantity of fresh feed that can be processed.

The conversion of sugars, derived from waste polysaccharide biomass, to commodity chemicals by fermentation or catalytic hydrogenation, oxidation or dehydration or combinations thereof are reviewed.

Anaerobic granular sludge (AGS) has been applied for most highly efficacy anaerobic digestion systems like upflow anaerobic sludge blanket and expanded granular sludge bed reactors. As a by-product from these systems, AGS is prospected as a promising resource for energy and nutrients recovery from wastewater. In this study, hydrothermal carbonization (HTC) of AGS was investigated at different temperatures (160–240 °C) regarding the distributions of C, N and P in the hydrothermal products to maximize the utilization efficiency of AGS. Elemental composition and fuel characteristics of the hydrochar were evaluated. Results indicated that the percentages of C in hydrochar increased from 43.79% to 49.81% with the increase in HTC temperature, while N showed an opposite trend, decreasing from 9.58% to 5.49%. The higher heating value of hydrochar increased up to a maximum of 24 MJ/kg at 240 °C from 20 MJ/kg at 160 °C. However, the hydrochar yield decreased remarkably from 62% to 32%. As a result, the highest net energy output was about 6.86 MJ/kg achieved at 160 °C. Results from the van Krevelen diagram suggested that dehydration and decarboxylation reactions occurred during the HTC of AGS. In addition, the thermogravimetric analysis implied that the combustion of the produced hydrochar could be completed in two phases rather than the one phase as the raw AGS. With regard to other resources utilization, HTC was proved to be effective for AGS to immobilize and recycle phosphorus. The increase in HTC temperature exerted a limited effect on P distribution, resulting in less than 5% being released into the liquid at all tested HTC temperatures. Most of P were immobilized into the produced hydrochar where the bioavailable P fractions > 80%.

Objective WHO recommends optimisation of available interventions to reduce deaths of under‐five children with diarrhoea and dehydration (DD). Clinical networks may help improve practice across many hospitals but experience with such networks is scarce. We describe magnitude and patterns of changes in processes of care for children with DD over the first 3 years of a clinical network. Methods Observational study involving children aged 2–59 months with DD admitted to 13 hospitals participating in the clinical network. Processes of individual patient care including agreement of assessment, diagnosis and treatment according to WHO guidelines were combined using the composite Paediatric Admission Quality of Care (PAQC) score (range 0–6). Results Data from 7657 children were analysed and improvements in PAQC scores were observed. Predicted mean PAQC score for all the hospitals at enrolment was 59.8% (95% CI: 54.7, 64.9) but showed a wide variation (variance 10.7%, 95% CI: 5.8, 19.6). Overall mean PAQC score increased by 13.8% (95% CI: 8.7–18.9, SD between hospitals: ±8.2) in the first 12 months, with an average 0.9% (95% CI: 0.3–1.5, SD ± 1.0) increase per month and plateaued thereafter, and changes were similar in two groups of hospitals joining the network at different times. Conclusion Adherence to guidelines for children admitted with DD can be improved through participation in a clinical network but improvement is limited, not uniform for all aspects of care and contexts and occurs early. Future research should address these issues.

The article gives the classification of plant materials, focuses on starch-containing raw materials, in particular, sweet potato roots, chemical composition, existing drying methods. The results of studies of heat-water treatment and the process of convective dehydration of root crops are presented. Energy-efficient two-stage drying modes have been developed, in which the coolant temperature in the first stage of the process is 80 ... 100 °С, in the second – 55 ... 70 °С, the material temperature during dewatering 50 ... 60 °С. reduction of drying time, reduction of heat losses to 15 %, production of dried products with high organoleptic characteristics

An alkali based method has been optimised and proposed to extract the cellulosic fibres from the corn husks. Physicochemical and morphological properties of the fibres extracted from corn husk have been studied in detail, and compared with the well-explored cellulosic fibre, like cotton and ligno-cellulosic fibre, like jute. Scanning electron microscopy and energy dispersive X-ray were used to study the surface and cross-sectional morphology and the elemental analysis of the corn-husk fibres and compared with cotton and jute fibres. The analysis showed that the morphological and the physico-chemical properties of the extracted corn husk fibres are comparable with ligno-cellulosic jute fibre. Also, improvement in thermal stability of corn husk fibre was obtained by application of the agro-waste banana pseudostem sap (BPS). BPS treated corn husk fibre showed the limiting oxygen index (LOI) value of 32 against the LOI value of 21 for the control corn fibre. In vertical burning test BPS treated corn yarn showed self extinguishing behaviour and 50 mm char length whereas control corn yarn was burnt within 1 min with flame and afterglow. TG analysis of the BPS treated corn yarn showed more than 30% weight retention at 450 °C compared to the 20% weight retention of the control corn yarn at the said temperature. In addition, major mass loss peak in TG curve has been shifted from 350 to 300 °C after BPS treatment (signature of the dehydration effect of the treated corn yarn). The flame retardant treatment process is comparatively simple and cost-effective, as add-on remains only at 8% and the BPS is available in large quantity in many countries.

New technology of small-sized fish processing is substantiated with shock loads that provides splitting of fish meat to fiber particles and their separating from skin and skeleton bones. The separation is realized by straining the water pulp, then the resulting suspension is thickened and the mince is produced in continuous centrifuges with screw discharging. Technological and physical-chemical characteristics of small-sized fish species are discussed. The main principles of the muscle tissue disintegration are considered, parameters of the disintegrator and rational modes of the process are determined. Optimal constructive solutions of certain units and the whole system of machines are designed for the most effective processing. Rational operating modes of washing and dehydration of the muscle tissue are determined taking into account parameters of the intermediate crushed raw materials, as size of the particles and content of dry and dense substances. To improve the process of dehydration, an operation of preliminary thickening of the minced suspension is proposed and size of the net cloth is selected for better separation of the minced mass from washing waters. Centrifuges for final separation of the mince are recommended. Possibility of partial replacement of the fresh water for washing with the seawater is considered. Organoleptic and technical-chemical properties of the produced mince are assessed and its biological value is evaluated. The mince corresponds to requirements for the washed fish mince. In the tests of a full-automated processing line, its output reached 16 % of the raw materials. Recommendations for the mince using for manufacturing of ready-made food products are given. Initial requirements for the raw materials and design documentation for the system of machines (processing line) for processing of small-sized fish are presented.

Dehydrating large amounts of sludge produced by sewage treatment plants is difficult. Microwave pretreatment can effectively and significantly improve the dewaterability and hydrogen production of sludge subjected to anaerobic digestion. The aim of this study was to investigate the effects of different microwave conditions on hydrogen production from anaerobic digestion and dewaterability of sludge. Based on an analysis of the electric field distribution, a spiral reactor was designed and a continuous microwave system was built to conduct intermittent and continuous experiments under different conditions. Settling Volume, Capillary Suction Time, particle size, and moisture content of the sludge were measured. The results show that sludge pretreatment in continuous experiments has equally remarkable dehydration performance as in intermittent experiments; the minimum moisture content was 77.29% in the intermittent experiment under a microwave power of 300W and an exposure time of 60sec, and that in the continuous experiment was 77.56% under a microwave power of 400W and an exposure time of 60sec. The peak measured by Differential Scanning Calorimeter appeared earliest under a microwave power of 600W and an exposure time of 180sec. The heat flux at the peak was 4.343W/g, which is relatively small. This indicates that microwave pretreatment induced desirable effects. The maximum yield of hydrogen production was 7.967% under the conditions of microwave power of 500W, exposure time of 120sec, and water bath at 55°C. This research provides a theoretical and experimental basis for the development of a continuous microwave sludge-conditioning system.

The optimal condition for osmo-dehydrated kinnow product from kinnow fruit slices with peel by simultaneous osmo-convective dehydration was evaluated. The process parameters used for sugar osmosed samples were; osmotic process temperature (35–75 °C), solution concentration (55–75°Brix), immersion time (150–270 min) and convective drying temperature (45–65 °C). A Central Composite Rotatable Design was employed to assess the different Osmo-convective parameters. The optimized conditions for developed kinnow product were found to be osmotic process temperature 65 °C, convective drying temperature 50 °C, concentration 61°Brix and immersion time 187 min.

Gas-pressurized (GP) torrefaction of biomass, proposed in our previous work, has a much higher oxygen removal efficiency compared to conventional torrefaction, but how the pressure promoted the deoxygenation remains unclear. In this work, the GP torrefactions under different partial pressures of volatiles (Pvol) and total pressures (Ptot) were conducted. The results revealed that the Pvol was the root cause rather than the Ptot of the acceleration of biomass decomposition and deoxygenation for the first time. This process can be regarded as a self-promoted deoxygenation process, and consisted of three stages. Stage 1 was the volatiles formation stage, where hemicellulose decomposed, volatiles formed and the Pvol increased. Stage 2 was self-promoted dehydration stage, where the hydroxyl in biomass was dramatically removed. Stage 3 was structure rearrangement stage, where the aromatic structure formed. The stage 2 and stage 3 were highly correlated with the Pvol, and resulted in the deep deoxygenation of biomass. This study should be not only suitable for the GP torrefaction, but can also be extended to pressurized pyrolysis and gasification of biomass.

Ethanol dehydration to diethyl ether makes it suitable for diesel engines by improving its cetane number, autoignition temperature, flammability limits, and petrodiesel miscibility. Therefore, the present investigation aimed at analyzing the ethanol dehydration process in a continuous reactor from thermodynamic, economic, and environmental perspectives. An integrated soft computing approach was also used to model and optimize the ethanol dehydration conditions. The effects of three reaction variables, i.e., weight hourly space velocity (WHSV), dehydration temperature, and dehydration pressure, were thoroughly analyzed on the exergy, exergoeconomic, and exergoenvironmental indicators. The WHSV was the most influential variable on the exergetic indicators investigated, while the studied indicators were hardly affected by the dehydration pressure. The optimal dehydration temperature, pressure, and WHSV were found to be 398 °C, 82.3 bar, and 2.96 1/h, respectively. At the selected optimal ethanol dehydration conditions, the process exergy efficiency was found to be 22.7%. The cost and environmental impact of unit product exergy at the optimal ethanol dehydration conditions were 95.0 USD/GJ and 85.7 mPts/GJ, respectively. Generally, it could be deduced that chemical biofuel plants could be well understood and optimized using the exergy-based approaches, particularly exergoeconomic and exergoenvironmental methods.

Energy-saving separation processes for ethylene glycol (EG) were investigated. These processes were a basic separation process (BSP), a first-grade energy-saving process (FEP), and a secondary energy-saving process (SEP). The optimal operating parameters for each process were determined through multiple indicator analysis-based energy, exergy, environment, and economic performance. The energy analysis results indicated that the steam consumption of EG dehydration decreased from 12.21% to 0.64%, and the steam consumption of EG refined (EGR) decreased from 20.89% to 3.20%. Furthermore, the total steam consumption for the SEP was 30.49% lower than that of the BSP. The exergy analysis showed that the 50.69% exergy destruction and the 15.64% exergy loss recorded for the SEP were lower than those for BSP, which were 43.42% and 9.50% lower than for the FEP. Both the flow rate and cost of waste gas emissions for the SEP were reduced by 31.18%. The total annual cost (TAC), operating cost (OC), and equipment cost for the SEP were 2.95 × 106 $/y, 3.47 × 106 $/y and 4.06 × 106 $/y, respectively. The TAC and OC of the SEP process decreased by 11.20% and 13.16%, respectively, compared to the benchmarked BSP process. The novel SEP process shows high energy efficiency, low economic cost, and low exergy loss, and has great industrial application prospects compared to the benchmarked process.

The physical mechanisms of heat and mass transfer enhancement by ultrasound have been identified by people. Basically, the effect of 'cavitation' induced by ultrasound is the main reason for the enhancement of heat and mass transfer in a liquid environment, and the acoustic streaming and vibration are the main reasons for that in a gaseous environment. The adsorbent regeneration and food drying/dehydration are typical heat and mass transfer process, and the intensification of the two processes by ultrasound is of complete feasibility. This paper makes an overview on recent studies regarding applications of power ultrasound to adsorbent regeneration and food drying/dehydration. The concerned adsorbents include desiccant materials (typically like silica gel) for air dehumidification and other ones (typically active carbon and polymeric resin) for water treatment. The applications of ultrasound in the regeneration of these adsorbents have been proved to be energy saving. The concerned foods are mostly fruits and vegetables. Although the ultrasonic treatment may cause food degradation or nutrient loss, it can greatly reduce the food processing time and decrease drying temperature. From the literature, it can be seen that the ultrasonic conditions (i.e., acoustic frequency and power levels) are always focused on during the study of ultrasonic applications. The increasing number of relevant studies argues that ultrasound is a very promising technology applied to the adsorbent regeneration and food drying/dehydration.

This paper aims at presenting a comprehensive perusal on hot air and microwave drying of medicinal herbs through investigating the dehydration behaviour, mathematical modelling, energy characteristics and essential oil yield of peppermint leaves drying. For our study the leaves were dried using microwave at power levels of 200, 400, 600, and 800 W, and hot air at temperatures of 50, 60 and 70 °C. The dehydration process of the leaves in microwave drying method occurred in an accelerating rate period at the start followed by a falling rate period while; convective drying took place in the falling rate period entirely. Six mathematical models were fitted into the experimental data and the Midilli and Kucuk model best described the drying curves. The lowest effective moisture diffusivity (1.809×10 −9 m 2 s −1 ) belonged to hot air drying at 50 °C, while the highest (110.552×10 −9 m 2 s −1 ) belonged to microwave drying at 800 W. The activation energy for microwave and hot air drying was determined to be 1.89 W g −1 and 12.46 K J mol −1 , respectively. Specific energy consumption for microwave and convective drying of the peppermint leaves were ranged from 4.581 to 5.890 M J kg w −1 , and from 42.721 to 64.712 M J kg w −1 , respectively. The maximum and minimum oil yields were obtained from the leaves dried at air temperature of 70 °C and microwave power at 800 W, respectively.

Hitherto, the iron content after cold-rolling sludge dehydration in iron and steel enterprises has reached up to 60%. However, it contains a lot of chlorine, which is the source of dioxins. And the presence of chlorine makes the cold-rolling sludge possess highly corrosivity, causing great trouble in the reproduction process. Therefore, dechlorinating experiments on cold-rolling sludge are of great significance. In this paper, we proposed an efficient way to dechlorinate the cold-rolling sludge by using high-temperature roasting method. XRD, SEM and other analytical methods were carried out to characterize the sludge. For comparison, the samples were heated from 200 to 500 °C for 2 h under air atmosphere. The dechlorinating efficiency reaches a very high value of 99%, and the main phase of final product is Fe2O3. In addition, we analysed the reaction mechanism and clarified the removal form of chlorine in the roasting process. These findings open up a promising avenue for steel enterprises to deal with cold-rolling sludge.