Levels Of Energy Input Research Articles

Effect of ElectroSpark Process Parameters on the WE43 Magnesium Alloy Deposition Quality

This research aims to investigate the effects of process parameters on the quality of WE43 coatings deposited on homologue substrate by ElectroSpark Deposition (ESD) technology. ESD is new technology used to apply coatings or for the restoration and refurbishment of worn or damaged high valued parts. The depositions were processed using five different levels of Energy input (Es, Spark Energy). The microstructure of both the base material and deposits cross-section were characterized by optical and scanning electron microscopies. Also, X-ray diffraction technique was used. In addition, stereological studies of the through-thickness heterogeneities of the deposits (e.g., voids) were performed. The mechanical properties were evaluated by Vickers micro-hardness. The results show that the deposits exhibited a fine grained microstructure due to the rapid solidification. The average micro-hardness values of the deposits are lower than that of the substrate and distributed in a small range (49–60 HV). The lower hardness of the deposits respect to the base material is due to the presence of defectiveness such as spherical, laminar and random shaped voids. The defects area percentage inside the deposits remains well below than 11%. All the deposits were mainly affected by laminar morphology defects. The results indicate that the deposits defectiveness decreases as the energy input increases.

Influence of process parameters on the correlation between in-situ process monitoring data and the mechanical properties of Ti-6Al-4V non-stochastic cellular structures

Selective Laser Melting (SLM) facilitates the formation of complex, stochastic or non-stochastic, metallic cellular structures. There is a high level of interest in these structures recently, particularly due to their high strength to weight ratios and osteoconductive properties. While the ability to in-situ monitor the SLM process is of key importance for future quality control methods.In this work lattice structures were fabricated, using the single exposure scanning strategy, on a Renishaw 500M SLM machine. The build process was also monitored using a co-axial in-situ process monitoring system.It was found that by increasing the energy input, through increasing the laser power and/or exposure time, the lattice strut diameters, within the 1.5 mm diamond unit cells, increased from 119 to 293 μm, resulting in the major pore diameter decreasing from 1106 to 932 μm. The effect of systematically altering the laser beam spot size on the cellular structures was also evaluated. It was observed that by doubling the laser beam spot size, that there was a 17% reduction in strut diameter and a 22% reduction in mechanical strength of the structures. It was also observed that at constant energy input levels, the lattice structures created using a focused laser exhibited an 81% lower mechanical strength than the structures created using a de-focused laser. Thus, demonstrating that the mode of energy input is critical to achieving the desired strength in these structures.Based on the outputs from the in-situ monitoring system, a broadly linear correlation was obtained between the laser input energy, the associated process monitoring data generated and the mechanical strength of the lattice structures.

Spatio-temporal transpiration patterns reflect vegetation structure in complex upland terrain

Topography exerts control on eco-hydrologic processes via alteration of energy inputs due to slope angle and orientation. Further, water availability varies with drainage position in response to topographic water redistribution and the catena effect on soil depth and thus soil water storage capacity. Our understanding of the spatio-temporal dynamics and drivers of transpiration patterns in complex terrain is still limited by lacking knowledge of how systematic interactions of energy and moisture patterns shape ecosystem state and water fluxes and adaptation of the vegetation to these patterns. To untangle the effects of slope orientation and hillslope position on forest structure and transpiration patterns, we measured forest structure, sap flux, soil moisture, throughfall and incoming shortwave radiation along two downslope transects in a forested head water catchment in south-east Australia. Our plot locations controlled for three systematically varying drainage position levels (topographic wetness index: 5.0, 6.5 and 8.0) and two levels of energy input (aridity index: 1.2 and 1.8). Vegetation patterns were generally stronger related to drainage position than slope orientation, whereas sap velocity variations were less pronounced. However, in combination with stand sapwood area, consistent spatio-temporal transpiration patterns emerged in relation to landscape position, where slope orientation was the primary and drainage position the secondary controlling factor. On short temporal scales, radiation and vapor pressure deficit were most important in regulating transpiration rates, whereas soil water limitation only occurred on shallow soils during summer. The importance of stand structural parameters increased on longer time scales, indicating optimization of vegetation in response to the long-term hydro-climatic conditions at a given landscape position. Thus, vegetation patterns can be conceptualized as a ‘time-integrated’ predictor variable that captures large fractions of other factors contributing to transpiration patterns.

A study on welding mode transition by electrical detection of laser-induced plasma at varying energy levels

The transition between heat conduction and deep penetration laser welding is investigated by the electrical detection of laser-induced plasma with an electrical passive probe. A further improved physical model based on plasma sheath effect is established to clarify the mechanism of plasma electrical signal. Different electrical signals are detected at varying levels of laser input energy and analyzed in the time and frequency domains. The amplitudes and the fluctuation frequency of the collected signals are demonstrated to be effective in reflecting the electron temperature and the plasma oscillation features respectively. These assessments are identical with the experimental results obtained by a high-speed camera. Combined with the signal characteristics and the weld profiles at different laser powers, the critical state and laser power density of mode transition are discussed and identified by an analytic calculation model.

Allomaternal care, brains and fertility in mammals: who cares matters

The expensive brain hypothesis predicts that the lowest stable level of energy input sets the upper limit to a species’ brain size. This prediction receives comparative support from the effects of experienced seasonality (including hibernation) and diet quality on mammalian brain size. Here, we test another prediction, which concerns the temporal stability of energy inputs. Allomaternal care in mammals can be provided by breeding males or other helpers (usually earlier offspring). Male care should be stable and reliable since otherwise no breeding would occur. Care by others, in contrast, should fluctuate, as the availability of helpers often varies. One would therefore predict, other things being equal, that the presence of male care in addition to maternal care should show positive correlated evolution with brain size, whereas care by others would not. However, because females can readily respond through litter size adjustments to variable amounts of energy inputs, helper inputs may be used to increase fertility. A detailed comparative analysis of a large sample of mammals (N = 478 species) showed that male help is correlated with the evolution of larger brains, whereas alloparental help is correlated with higher fertility, but only in species where male care is also present (as in cooperative breeders). Humans evolved an unusual form of multi-family cooperative breeding, which involves stable and reliable care by both fathers and alloparents. This combination helps to explain why humans differ from the other apes in having both an extremely large brain and a relatively high reproductive output. Allomaternal care provides breeding females with energy, directly or indirectly, and so would be expected to affect fertility and/or brain size. Which path evolution actually took remains controversial, partly because previous studies did not separate between care provided by the breeding male (paternal care) and care by non-breeding helpers (alloparental care). We distinguish between them because we expect that selection only favours increased brain size if the increase in energy available to the female is predictable and constant. Using a sample of 478 mammals, we show that paternal care, which is both reliable and stable, shows correlated evolution with brain size, whereas alloparental care, which fluctuates with varying availability of helpers, is correlated with higher fertility. Thus, constraints on brain size, imposed by its high-energy costs, may predict brain size better than the fitness benefits of improved cognitive abilities per se.

Selective laser melting of Ti-5Al-2.5Sn alloy with isotropic tensile properties: The combined effect of densification state, microstructural morphology, and crystallographic orientation characteristics

In this study, three different levels of laser energy inputs (Ev) were used for selective laser melting of Ti-5Al-2.5Sn alloy and the as-deposited tensile properties along the vertical direction with respect to deposition layers were found to be statistically identical to those along the horizontal direction for all the samples. Densification states, microstructures, and crystallographic orientation characteristics of the different samples, as well as their contributions to the isotropic properties were researched. The results first indicated that near spherical pores would form at the relatively high Ev (208 J/mm3) whereas lack-of-fusion defects would generate at the relatively low Ev (51 J/mm3). When the moderate Ev (167 J/mm3) was used, samples with very few defects could be fabricated. Then, it was seen that samples built at 51 and 167 J/mm3 presented a martensite (α′)-dominated microstructure in which the boundaries of columnar prior-β were decorated by grain-boundary α (αGB). When Ev increased to 208 J/mm3, a duplex microstructure composed of α′ and massive α (αM) would form within prior-β matrix of the as-deposited samples. An overall increasing trend in prior-β’s width with the increase of Ev was also identified. Afterwards, it was proved that there was no strong texture within all the samples and this was one cause of the isotropic properties. Besides, for samples built at 51 J/mm3, the negative influence of lack-of-fusion on vertical properties cooperated with the adverse effect of large quantities of αGB on horizontal properties, promoting the obtainment of isotropic properties. For samples built at 167 J/mm3, not only the high densification degree but also the significantly increase in prior-β’s width and the resultant decrease in αGB’s content helped to eliminate significant anisotropy. For samples built at 208 J/mm3, both the near spherical pores which resulted in near-identical bearing areas on different sections and the absent of αGB contributed to the isotropic properties. This paper can provide some basis for the laser additive manufacturing of titanium products with isotropic properties.

Morphology Control by Pulsed Laser in Chemical Deposition Illustrated in ZnO Crystal Growth

The control of pulsed-laser-induced deposition was studied with the case of ZnO crystallization in a hydrothermal reaction. Crystal orientation, morphologies, and growth rate were observed to vary under different pulsed-laser irradiation conditions. Different energy barriers during nucleation and crystal growth processes were determined by stepped changes of input energy levels of a pulsed laser with the corresponding observations of the states of the material. Therefore, by precisely adjusting the pulsed-laser energy that overcomes a particular energy barrier, ZnO crystals with desired orientation and morphology could be obtained on a seedless substrate in a catalyst-free environment. Crystals varied in morphologies showed different behavior in laser-induced growth, and growth rates were orders of magnitude higher than those of other hydrothermal reactions. By analyzing crystal growth characteristics in the reaction/diffusion-limited region, a set of guidelines were defined to tune the dimensions of ZnO ...

Sources of China’s Fossil Energy-Use Change

Technology improvement related to energy conservation and energy mix low-carbonization is a critical approach for tackling global warming in China. Therefore, we attempt to identify the technology factors of China’s energy consumption change between 2007 and 2012, when China’s economy started slowing. This study proposes a new refined structural decomposition analysis (SDA) based on a hybrid multi-regional input–output (MRIO) model. The technology factors are expressed through the energy input level effect, energy composition effect, and non-energy input effect. We find that the energy level effect was the primary driver for energy reduction, saving 1205 million tonnes of standard coal equivalent (Mtce) of energy, while 520 Mtce was offset by energy composition and non-energy input effects. The sector analysis shows that the energy input level, energy composition, and non-energy input effects of electricity, the chemical industry, and metallurgy are noteworthy. In addition, the sector contribution to energy-use change, by province, related to the three effects, is also studied. From these results, we propose policy suggestions for further energy saving, in order to achieve China’s energy target through technology improvements by the higher priority contributors identified.

Joining Aluminium Alloy 5A06 to Stainless Steel 321 by Vaporizing Foil Actuators Welding with an Interlayer

Direct aluminium–stainless steel joints are difficult to create by the vaporized foil actuator welding (VFAW) method because brittle intermetallic compounds (IMCs) tend to form along the interface. The use of an interlayer as a transition layer between the two materials with vast difference in hardness and ductility was proposed as a solution to reduce the formation of the IMCs. In this work, VFAW was used to successfully weld sheet aluminium alloy 5A06 to stainless steel 321 with a 3003 aluminium alloy interlayer. Input energy levels of 6 kJ, 8 kJ, 10 kJ, and 12 kJ were used and as a trend, higher energy inputs resulted in higher impact velocities, larger weld area, and better mechanical properties. In lap-shear and peel testing, all samples failed at the interface of the interlayer and target. At 10 kJ energy input, flyer velocities up to 935 m/s, lap-shear peak load of 44 kN, and peel load of 2.15 kN were achieved. Microstructure characterization and element distribution were performed, and the results show a wavy pattern created between the flyer and interlayer which have similar properties, and the interface between the interlayer and target was dominated by element diffusion and IMCs identified mainly as FeAl3 and FeAl. The results demonstrate VFAW is a suitable joining method for dissimilar metals such as aluminium alloy and stainless steel, which has a broad and significant application prospect in aerospace and chemical industry.

Hydrocarbon recovery using ultra-microporous fluorinated MOF platform with and without uncoordinated metal sites: I- structure properties relationships for C2H2/C2H4 and CO2/C2H2 separation

In this work, the reticular chemistry approach was implemented on a very stable ultra-microporous fluorinated MFFIVE-1-Ni MOFs to unveil the effect of subtle changes of the structure-employment of different fluorinated inorganic block on the adsorption of C2H2, C2H4 and CO2. A series of variable temperature single C2H2, C2H4 and CO2 adsorption isotherms and mixed gas adsorption column breakthrough experiments for different C2H2/C2H4 and CO2/C2H2 gas pair systems were carried out on the two isoreticular NbOFFIVE-1-Ni and AlFFIVE-1-Ni, containing respectively [NbOF5]2− and [AlF5]2− inorganic building blocks. The introduction of potential open metal site in a very confined pores led to favoring interaction of C2H2 but lowering the interaction with CO2, which resulted in enhancement of C2H2/C2H4 selectivity at low C2H2 concentration but a decrease in CO2/C2+ selectivity. The comparison of the C2H2/C2H4 and CO2/C2H2 separation performances with the structures of the MFFIVE-1-Ni MOFs provides useful information to shed light on the relationship between the structural features of this MOF platform and C2H2/C2H4 and CO2/C2H2 separation properties. This is a critical step in the wanted rational discovery/design of materials with enhanced performances for C2H2 recovery from C2H4 and CO2 at different concentration and having different level of input energy for recycling.

Assessment of nanofibre dustiness by means of vibro-fluidization

Dustiness testing probes for the propensity of a powdery material to release dust particles following agitation. For high aspect-ratio materials like nanotubes, the most important dust fraction is that of potentially carcinogenic fibres (WHO-fibres). We developed the fluidizer particularly for fibres that makes use of vibro-fluidization in order to effectively disentangle single fibres and agglomerates of multi-walled carbon nanotube powders. Counting rules for morphological characterization of collected particles by means of electron microscopy were established, allowing quantifying the WHO-fibre fraction. Dustiness tests on 15 different multi-walled carbon nanotubes were performed using two different levels of energy input for each material. The fluidizer accomplished bubbling fluidization for 13 out of the 15 multi-walled carbon nanotubes, resulting in continuous aerosol generation with stable particle number concentration and a high fraction of single fibres. Dustiness measurands like average particle number concentrations varied by three orders of magnitude. Morphological characterization of particles on aerosol samples proved to be essential to overcome the limitations of the applied aerosol instruments in quantifying the WHO-fibre fraction, therefore allowing material ranking based on associated risk. The materials showed strong ordering discrepancy when ranked based on total dustiness and WHO-fibre dustiness. Several multi-walled carbon nanotubes showed WHO-fibre concentrations high enough to potentially cause workplace exposure at hazardous concentration levels in case powders are handled carelessly.

Photocatalytic Micro/Nanomotors: From Construction to Applications.

Synthetic micro/nanomotors (MNMs) are a particular class of micrometer or nanometer scale devices with controllable motion behavior in solutions by transferring various energies (chemical, optical, acoustic, magnetic, electric, etc.) into mechanical energy. These tiny devices can be functionalized either chemically or physically to accomplish complex tasks in a microcosm. Up to now, MNMs have exhibited great potential in various fields, ranging from environmental remediation, nanofabrication, to biomedical applications. Recently, light-driven MNMs as classic artificial MNMs have attracted much attention. Under wireless remote control, they can perform reversible and repeatable motion behavior with immediate photoresponse. Photocatalytic micro/nanomotors (PMNMs) based on photocatalysts, one of the most important light-driven MNMs, can utilize energy from both the external light source and surrounding chemicals to achieve efficient propulsion. Unlike other kinds of MNMs, the PMNMs have a unique characteristic: photocatalytic property. On one hand, since photocatalysts can convert both optical and chemical energy inputs into mechanical propulsion of PMNMs via photocatalytic reactions, the propulsion generated can be modulated in many ways, such as through chemical concentration or light intensity. In addition, these PMNMs can be operated at low levels of optical and chemical energy input which is highly desired for more practical scenarios. Furthermore, PMNMs can be operated with custom features, including go/stop motion control through regulating an on/off switch, speed modulation through varying light intensities, direction control through adjusting light source position, and so forth. On the other hand, as superoxide radicals can be generated by photocatalytic reactions of activated photocatalysts, the PMNMs show great potential in environment remediation, especially in organic pollutant degradation. In order to construct more practical PMNMs for future applications and further extend their application fields, the ideal PMNMs should be operated in a fully environmentally friendly system with strong propulsion. In the past decade, great progress in the construction, motion regulation, and application of PMNMs has been achieved, but there are still some challenges to realize the perfect system. In this Account, we will summarize our recent efforts and those of other groups in the development toward attractive PMNM systems. First, we will illustrate basic principles about the photocatalytic reactions of photocatalysts and demonstrate how the photocatalytic reactions affect the propulsion of PMNMs. Then, we will illustrate the construction strategies for highly efficient and biocompatible PMNMs from two key aspects: (1) Improvement of energy conversion efficiency to achieve strong propulsion of PMNMs. (2) Expansion of the usable wavelengths of light to operate PMNMs in environment-friendly conditions. Next, potential applications of PMNMs have been described. In particular, environment remediation has taken major attention for the applications of PMNMs due to their photocatalytic properties. Finally, in order to promote the development of PMNMs which can be operated in fully green environments for more practical applications, an outlook of key challenges and opportunities in construction of ideal PMNMs is presented.

Transition in a separation bubble under tonal and broadband acoustic excitation

Transition and flow development in a separation bubble formed on an airfoil are studied experimentally. The effects of tonal and broadband acoustic excitation are considered since such acoustic emissions commonly result from airfoil self-noise and can influence flow development via a feedback loop. This interdependence is decoupled, and the problem is studied in a controlled manner through the use of an external acoustic source. The flow field is assessed using time-resolved, two-component particle image velocimetry, the results of which show that, for equivalent energy input levels, tonal and broadband excitation can produce equivalent changes in the mean separation bubble topology. These changes in topology result from the influence of excitation on transition and the subsequent development of coherent structures in the bubble. Both tonal and broadband excitation lead to earlier shear layer roll-up and thus reduce the bubble size and advance mean reattachment upstream, while the shed vortices tend to persist farther downstream of mean reattachment in the case of tonal excitation. Through a cross-examination of linear stability theory (LST) predictions and measured disturbance characteristics, nonlinear disturbance interactions are shown to play a crucial role in the transition process, leading to significantly different disturbance development for the tonal and broadband excited flows. Specifically, tonal excitation results in transition being dominated by the excited mode, which grows in strong accordance with linear theory and damps the growth of all other disturbances. On the other hand, disturbance amplitudes are more moderate for the natural and broadband excited flows, and so all unstable disturbances initially grow in accordance with LST. For all cases, a rapid redistribution of perturbation energy to a broad range of frequencies follows, with the phenomenon occurring earliest for the broadband excitation case. By taking nonlinear effects into consideration, important ramifications are made clear in regards to comparing LST predictions and experimental or numerical results, thus explaining the trends reported in recent investigations. These findings offer new insights into the influence of tonal and broadband noise emissions, resulting from airfoil self-noise or otherwise, on transition and flow development within a separation bubble.

Hibernation constrains brain size evolution in mammals.

The expensive brain hypothesis predicts that the lowest stable level of steady energy input acts as a strong constraint on a species' brain size, and thus, that periodic troughs in net energy intake should select for reduced brain size relative to body mass. Here, we test this prediction for the extreme case of hibernation. Hibernators drastically reduce food intake for up to several months and are therefore expected to have smaller relative brain sizes than nonhibernating species. Using a comparative phylogenetic approach on brain size estimates of 1104 mammalian species, and controlling for possible confounding variables, we indeed found that the presence of hibernation in mammals is correlated with decreased relative brain size. This result adds to recent comparative work across mammals and amphibians supporting the idea that environmental seasonality (where in extremis hibernation is necessary for survival) imposes an energetic challenge and thus acts as an evolutionary constraint on relative brain size.

The effect of strain rate on particle breakage characteristics

Strain rate has drawn great research attention in the area of material mechanics. However, thus far the effects of strain rate on the breakage characteristics of rocks or mineral particles were seldom studied. The applied strain rate is one of the key factors causing the variation in breakage environment, and hence the understanding of strain rate's effect on particle breakage is important to the development of a generic breakage model that isolates the rock properties from the breakage environment. This study systematically investigated the characteristics of single particle breakage at different strain rates. The rock samples from four narrow size fractions were used for carrying out impact and compression tests at variable energy input levels. The energy-size reduction relationships for impact and compression breakage were developed, respectively, and the appearance functions for these two breakage mechanisms were also developed based on previous and current work. The results suggest that the sample breaks easier at lower strain rates and the significance of the particle size effect strongly depends on the strain rate. It is demonstrated that the strain rate has an important influence on the progeny size distribution, but the significance of this influence reduces as the energy input increases. It is also found that the sample breaks with a higher energy efficiency at lower strain rates. The strain rate may affect the initiation and propagation of the cracks originate from small flaws and hence results in the difference in the breakage characteristics.

Vibration energy harvesting from impulsive excitations via a bistable nonlinear attachment—Experimental study

Abstract A bistable nonlinear electromagnetic energy harvester coupled to an impulsively excited primary linear oscillator has been experimentally investigated. The design of the energy harvesting system was guided by a preliminary numerical study, which predicted a favorable dynamic regime for harvesting purposes. The harvesting system consisted of a lightweight permanent magnet, moving within a stationary coil, nonlinearly coupled to a grounded, weakly damped linear oscillator through a prebuckled, bistable slender steel beam which exhibited both cubic nonlinear and negative linear stiffness behaviors in transverse response along its weak axis. This paper provides the results of an experimental investigation, illustrating the capacity of the bistable element to dramatically enhance harvesting efficiency when subjected to broadband, low-amplitude vibration, executing large amplitude oscillations between the two stable equilibrium positions. Single and repeated impulses of varying amplitude applied to the LO are employed as system inputs, and it is shown, both experimentally and through numerical simulations, that robust harvesting efficiency is achieved primarily through periodic cross-well oscillations, particularly at low levels of input energy.

The influence of energy input on the particle size of disintegrated excess sludge in the ultrasonic disintegration process.

The objective of this research was to examine the influence of energy input on the particle size distribution of disintegrated sludge. The change of particle size distribution indicates the deagglomeration of flocs and disruption of micro-colonies. As the digestibility of sludge increases with dispersion, particle size analysis is an important factor in evaluating the disintegration process. Four different levels of energy input were used in the research: 10-100 kWh·m-3. All samples showed significant changes as far as dispersion (kdCST = 22.98-74.67, kdFCOD = 3.23-18.46), lysis (kdSCOD = 4.22-12.09), acidification (kdVFAs = 1.78-12.61), nitrogen release (kdTN = 4.02-21.61) indicators were concerned. Results indicate the gradual decrease of measured particle size with increasing energy input. The energy supplied to the disintegration process primarily promotes deagglomeration and with the rise of energy input, the destruction of cells. For EV = 50 and 100 kWh·m-3 an increased occurrence of lysis effects and increase in particle fraction <99.9 μm was noted. The highest efficiency evaluated by increase of filtered chemical oxygen demand (FCOD) and soluble COD (SCOD) per unit of volumetric energy - ΔCOD and ΔSCOD (mgO2·Wh-1) was obtained for Ev = 10 WhL-1, which corresponds to the most significant change in particle size distribution. The volume of particles <99.9 μm rose from 1.92% for non-disintegrated sludge to 26.62% for volumetric energy 100 kWh·m-3.

Glycogen Synthesis and Metabolite Overflow Contribute to Energy Balancing in Cyanobacteria

Understanding how living cells manage high-energy metabolites such as ATP and NADPH is essential for understanding energy transformations in the biosphere. Using light as the energy input, we find that energy charge (ratio of ATP over ADP+ATP) in the cyanobacterium Synechocystis sp. PCC 6803 varies in different growth stages, with a peak upon entry into the rapid growth phase, as well as a positive correlation with light intensity. In contrast, a mutant that can no longer synthesize the main carbon storage compound glycogen showed higher energy charge. The overflow of organic acids in this mutant under nitrogen depletion could also be triggered under high light in nitrogen-replete conditions, with an energy input level dependency. These findings suggest that energy charge in cyanobacteria is tightly linked to growth and carbon partition and that energy management is of key significance for their application as photosynthetic carbon dioxide-assimilating cell factories.

Energetic, Exergetic, and Economic Analysis of MED-TVC Water Desalination Plant with and without Preheating

Desalination is the sole proven technique that can provide the necessary fresh water in arid and semi-arid countries in sufficient quantities and meet the modern needs of a growing world population. Multi effect desalination with thermal vapour compression (MED-TVC) is one of most common applications of thermal desalination technologies. The present paper presents a comprehensive thermodynamic model of a 24 million litres per day thermal desalination plant, using specialised software packages. The proposed model was validated against a real data set for a large-scale desalination plant, and showed good agreement. The performance of the MED-TVC unit was investigated using different loads, entrained vapour, seawater temperature, salinity and number of effects in two configurations. The first configuration was the MED-TVC unit without preheating system, and the second integrated the MED-TVC unit with a preheating system. The study confirmed that the thermo-compressor and its effects are the main sources of exergy destruction in these desalination plants, at about 40% and 35% respectively. The desalination plant performance with preheating mode performs well due to high feed water temperature leading to the production of more distillate water. The seawater salinity was proportional to the fuel exergy and minimum separation work. High seawater salinity results in high exergy efficiency, which is not the case with membrane technology. The plant performance of the proposed system was enhanced by using a large number of effects due to greater utilisation of energy input and higher generation level. From an economic perspective, both indicators show that using a preheating system is more economically attractive.

A combined process of non-thermal plasma and a low-cost mineral adsorber for VOC removal and odor abatement in emissions of organic waste treatment plants

Gaseous emissions from organic waste treatment processes are substantial contributors to global ammonia and greenhouse gas emissions. Regarding complexity of the waste gas mixture, low concentration levels of the single compounds, and their high odor relevance, non-thermal plasma (NTP) processes are an adequate technique for the treatment of such emissions. However, performance tests of NTPs were mainly carried out with artificial low-volume gas flows and highly experimental plasma catalysts. A combined process of a non-thermal plasma and a readily available low-cost halloysite-containing mineral adsorber for VOCs removal and odor abatement was tested for emission treatment of two organic waste treatment plants. The process revealed average removal rates for VOCs, ammonia, and methane of 62.9 %, 15.9 %, and 30.1 % at the first site and 43.2 %, 22.2 %, and 34.8 % at the second site at specific input energy (SIE) levels of 2.1–2.2 kWh 1000 m−3. Additional odor analysis in the latter case revealed a high potential for odor abatement of 95.9–98.3 % at similar SIE levels.