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The use of microturbines in irrigation applications represents a great opportunity for increasing sustainable energy generation. Irrigation systems have water flow that can be used to generate electricity based on microturbines that are acceptably configure such, that efficiency in crop irrigation is not affected. This research validates this use of microturbines through a system designed specifically for the characterization of microturbine generation technology. This system includes a closed water pumping circuit capable of working under, different water flow settings, as well as flow, pressure, and electricity generation sensors. For this system, the production range of the microturbines and the pressure loss associated with the various proposed configurations are characterized and specifically quantified for the best performance. After design and characterization of a scalable microturbine system, the feasibility and benefits of this application to supporting most relevant crops supplied by localized irrigation are analysed. The experiments demonstrate the greatest benefit with the implementation of 15 series microturbines each at 80 V, alongside non-Citrus fruit, where a favourable balance is achieved for the amortization period in vineyards and citrus fruit. The results validate a profitable and sustainable design for electricity generation, with return on investment rates of up to 53%. Therefore, this research offers real and extensive applications, while being scalable to rural, residential, urban and industrial settings.Key Points• Development of an experimental system for the characterization of water microturbines and validation in irrigation systems.• Design of a system to obtain clean energy from the pressure head excess of irrigation systems based on experimental characterization.• Analysis of the feasibility and investment of the application of the sustainable energy generation system to different crops.

Innovations are being developed with different additives in concrete mixtures to enhance their performance under certain conditions. This work models the split tensile strength through the electrical resistivity using a machine learning (ML) algorithm in different concrete mixtures. One of the most frequent nondestructive tests used on concrete is electrical resistivity (Er) for the simplicity of taking measurements on concrete elements. ML involves methods that provide solutions to advanced problems employing computational algorithms. This research employs a support vector regression algorithm, which can predict the split tensile strength value using a nondestructive test. The outcomes of this research exhibit a high correlation between electrical concrete resistivity and split tensile strength over 90%. Support vector regression algorithm achieves accuracy over 93% in the forecasting task. Of note is that the modified concrete contains starch as an addition to prove its performance compared to conventional concrete. Keywords: electrical resistivity; machine learning (ML); support vector regression; tensile strength.

Fano resonances of bilayer graphene could be attractive for thermoelectric devices. The special profile presented by such resonances could significantly enhance the thermoelectric properties. In this work, we study the thermoelectric properties of bilayer graphene single and double barrier structures. The barrier structures are typically supported by a substrate and encapsulated by protecting layers, reducing considerably the phonon thermal transport. So, we will focus on the electronic contribution to the thermal transport. The charge carriers are described as massive chiral particles through an effective Dirac-like Hamiltonian. The Hybrid matrix method and the Landauer–Büttiker formalism are implemented to obtain the transmission, transport and thermoelectric properties. The temperature dependence of the Seebeck coefficient, the power factor, the figure of merit and the efficiency is analyzed for gapless single and double barriers. We find that the charge neutrality point and the system resonances shape the thermoelectric response. In the case of single barriers, the low-temperature thermoelectric response is dominated by the charge neutrality point, while the high-temperature response is determined by the Fano resonances. In the case of double barriers, Breit–Wigner resonances dominate the thermoelectric properties at low temperatures, while Fano and hybrid resonances become preponderant as the temperature rises. The values for the figure of merit are close to two for single barriers and above three for double barriers. The system resonances also allows us to optimize the output power and the efficiency at low and high temperatures. By computing the density of states, we also corroborate that the improvement of the thermoelectric properties is related to the accumulation of electron states. Our findings indicate that bilayer graphene barrier structures can be used to improve the response of thermoelectric devices.

Many volatile compounds generated during the thermal processing of milk have been associated with cooked, stale, and sulfurous notes in milk and are considered as off-flavor by most consumers. A headspace solid-phase microextraction (HS-SPME)/gas chromatographic technique for the quantitative analysis of thermally derived off-flavor compounds was developed in this study. The extraction temperature, time, and sample amount were optimized using a randomized 23 central composite rotatable design with 2 central replicates and 2 replicates in each factorial point along with response surface methodology. Calibration curves were constructed in milk using the standard addition technique, and then used to quantify 20 off-flavor compounds in raw, pasteurized, and UHT milk samples with various fat contents. The concentrations of these volatiles in raw and pasteurized milk samples were not significantly different. However, dimethyl sulfide, 2-hexanone, 2-heptanone, 2-nonanone, 2-undecanone, 2-methylpropanal, 3-methylbutanal, heptanal, and decanal were found at higher concentrations in UHT milk as compared with raw and pasteurized milk samples. In addition, the concentration of methyl ketones was greater in UHT milk with higher fat content. The calculated odor activity values suggested that 2,3-butanedione, 2-heptanone, 2-nonanone, 2-methylpropanal, 3-methylbutanal, nonanal, decanal, and dimethyl sulfide could be important contributors to the off-flavor of UHT milk. The HS-SPME technique developed in this study is accurate and relatively simple, and can be used for the quantification of thermally derived off-flavor compounds in milk.

Objective: To compare the weight loss, change in quality of life (QOL) and safety of closed-loop gastric electrical stimulation (CLGES) versus adjustable gastric band (LAGB) in the treatment of obesity. Methods: This multicenter, randomized, non-inferiority trial randomly assigned the patients in a 2:1 ratio to laparoscopic CLGES versus LAGB and followed them for 1 year. We enrolled 210 patients, of whom 50 were withdrawn preoperatively. Among 160 remaining patients (mean age=39±11 years; 75% women; mean body mass index=43±6 kg m – 2 ) 106 received CLGES and 54 received LAGB. The first primary end point was non-inferiority of CLGES versus LAGB, ascertained by the proportion of patients who, at 1 year, fulfilled: (a) a ⩾20% excess weight loss (EWL); (b) no major device- or procedure-related adverse event (AE); and (c) no major, adverse change in QOL. Furthermore, ⩾50% of patients had to reach ⩾25% EWL. The incidence and seriousness of all AE were analyzed and compared using Mann–Whitney’s U- test. Results: At 1 year, the proportions of patients who reached all components of the primary study end point were 66.7 and 73.0% for the LAGB and CLGES group, respectively, with a difference of –6.3% and an upper 95% CI of 7.2%, less than the predetermined 10% margin for confirming the non-inferiority of CLGES. The second primary end point was also met, as 61.3% of patients in the CLGES group reached ⩾25% EWL (lower 95% CI=52.0%; P <0.01). QOL improved significantly and similarly in both groups. AE were significantly fewer and less severe in the CLGES than in the LAGB group ( P <0.001). Conclusions and relevance: This randomized study confirmed the non-inferiority of CLGES compared with LAGB based on the predetermined composite end point. CLGES was associated with significantly fewer major AE.

The removal of water from mines was one of the key issues that former miners had to deal with. Roman colonists brought new technology to the Iberian Peninsula that addressed this problem. However, they did not invent this technology because it had already been applied to the growth of other endeavours in the Hellenistic society throughout the Eastern Mediterranean. In the mine, the Archimedes screw, waterwheels, bucket pulleys, and Ctesibius pumps were the primary drainage systems. In this essay, the primary characteristics, and modes of operation of machines are examined. Without leaving out the most significant finds made in the southwest of the Iberian Peninsula, one of the regions with the longest history of mining exploitation. To serve as a foundation for future research in this field, this work compares the primary mining mechanisms in ancient Huelva on a qualitative and quantitative level by the implementation of a TOPSIS methodology, a multi-criteria decision analysis method.

In this work, we address the ubiquitous phenomenon of Fano resonances in bilayer graphene. We consider that this phenomenon is as exotic as other phenomena in graphene because it can arise without an external extended states source or elaborate nano designs. However, there are not theoretical and/or experimental studies that report the impact of Fano resonances on the transport properties. Here, we carry out a systematic assessment of the contribution of the Fano resonances on the transport properties of bilayer graphene superlattices. Specifically, we find that by changing the number of periods, adjusting the barriers height as well as modifying the barriers and wells width it is possible to identify the contribution of Fano resonances on the conductance. Particularly, the coupling of Fano resonances with the intrinsic minibands of the superlattice gives rise to specific and identifiable changes in the conductance. Moreover, by reducing the angular range for the computation of the transport properties it is possible to obtain conductance curves with line-shapes quite similar to the Fano profile and the coupling profile between Fano resonance and miniband states. In fact, these conductance features could serve as unequivocal characteristic of the existence of Fano resonances in bilayer graphene.

Volatile sulfur compounds have been reported to be responsible for the sulfurous off-flavors generated during the thermal processing of milk; however, their analysis has been a challenge due to their high reactivity, high volatility, and low sensory threshold. In this study, reactive thiols were stabilized and the volatile sulfur compounds in milk were extracted by headspace solid-phase microextraction, and analyzed by gas chromatography and pulsed-flame photometric detection. Calibration curves for 7 sulfur-containing compounds were constructed in milk by the standard addition technique. Raw, pasteurized, and UHT milk samples with various fat contents were analyzed. Compared with raw and pasteurized samples, UHT milk contained substantially higher concentrations of hydrogen sulfide, methanethiol, carbon disulfide, dimethyl trisulfide, and di-methyl sulfoxide. The high odor activity values calculated for methanethiol and dimethyl trisulfide suggested that these 2 compounds, in addition to di-methyl sulfide reported in a previous study, could be the most important contributors to the sulfurous note in UHT milk.

In group-living animals, mutual policing to suppress reproduction is an important mechanism in the resolution of conflict between selfish group members and the group as a whole. In societies of bees, ants, and wasps, policing against the production of males by other workers is expected when egg laying by workers decreases the average inclusive fitness of individual group members. This may result (i) from the relatedness of workers being lower to worker- than to queen-derived males or (ii) from a lowered overall colony efficiency. Whereas good evidence exists for policing behavior caused by genetic conflicts, policing caused by efficiency factors has not been demonstrated. We investigated the regulation of reproduction in the ant Platythyrea punctata, a species in which colonies are clones because workers are capable of producing female offspring by thelytokous parthenogenesis. Reproductive conflicts resulting from differences in genetic relatedness are therefore not expected, but uncontrolled reproduction by all workers could lead to the destruction of sociality. Here we show that worker policing by aggressive attacks against additionally reproducing workers keeps the number of reproducing workers low. Furthermore, through experimental manipulation of the number of brood items per colony, we show that worker policing can enhance group efficiency.