kJ Of Energy Research Articles

Synergistic effect of carbothermal reduction and sodium salts leaching in the process of iron recovery from copper slag

Copper slag is mostly considered a waste material and around 41wt% of total iron content present in it is lost. Iron is mostly present in copper slag as fayalite (Fe2SiO4). In this study, Iron was recovered by the decomposition of Fe2SiO4 using the synergistic effect of carbothermal reduction and sodium salts leaching for the first time. The results showed that 68.39% of iron was recovered from copper slag by carbothermal reduction at 1000oC for 1hr. The iron recovery increased to 83.45, 93.39 and 97.8%, respectively, after further 1hr leaching by 2M NaOH, 1M Na2CO3 and 2M NaOH+1M Na2CO3 at 100oC. The leaching results indicated that the increased NaOH concentration from 1 to 2M improved the removal of silica, which in turn led to higher iron recovery. The increase of Na2CO3 concentration from 1 to 2M showed a negative effect on iron recovery. The combination of 2M NaOH and 1M Na2CO3, however, led to the highest iron recovery of 97.8% because NaOH+Na2CO3 gives Na2O that is easier to react with SiO2 with only -194.3kJ energy requirement. Mass balance calculations indicated that before the leaching process, 345kg mass was lost, whereas, after the leaching process the amount of discarded waste was only 260.8g. Therefore, the present study not only provides 97.8% iron recovery but also reduces the discharge of secondary solid waste due to no addition of additives.

Influence of Ultrasonic Cavitation on Botryococcus Braunii Growth

This study investigates ultrasonic energy’s impact on enhancing the growth of Botryococcus braunii (B. braunii) microalgae. Microalgae, known for their advantages in greenhouse gas mitigation and biomass conversion, were subjected to various stressors, including ultrasonic waves, to optimize productivity. Ultrasonic waves induce acoustic cavitation, increasing membrane permeability and substrate conversion. The study examined the impact of energy and maximum pressure resulting from bubble collapse on the relative specific growth rate of B. braunii microalgae. It was observed that reproduction showed a promotive trend until the energy surpassed 30 kJ. However, when ultrasonic energy reached 18.2 kJ, reproduction was inhibited due to the maximum pressure generated during bubble bursting, which reached 5.7 µN/µm2, leading to the suppression of reproduction upon encountering bubble collapse events. Under specific ultrasonic conditions (15.1 kJ energy, maximum pressure of 45.5 × 105 Pa), a maximum specific growth rate of 0.329 ± 0.020 day−1 in a two-day interval boosted B. braunii microalgae biomass productivity. These findings advance our understanding of ultrasonic wave effects on microalgae reproduction and underscore the potential for optimizing ultrasonic parameters to enhance biomass production.

Contribution of Infant Food Pouches and Other Commercial Infant Foods to the Diets of Infants: A Cross-sectional Study

BackgroundAlthough considerable concern has been expressed about the nutritional implications of infant food pouches, how they impact infant diet has not been examined. ObjectivesThe objective of this study was to determine the contribution of infant food pouches specifically, and commercial infant foods generally, to nutrient intake from complementary foods in infants. MethodsTwo multiple-pass 24-h diet recall data were collected from 645 infants (6.0–11.9 mo) in the First Foods and Young Foods New Zealand studies. Detailed information was obtained on commercial infant food use, including pouches, and nutrient composition was calculated through recipe modeling. ResultsThe diverse sample (46.1% female; 21.1% Māori, 14.1% Asian, and 54.6% European) was aged (SD) 8.4 (0.9) mo. More than one-quarter of households had high socioeconomic deprivation. Almost half (45.3%) of infants consumed an infant food pouch on ≥1 recall day [mean (SD), 1.3 (0.9) times/d], obtaining 218 (124) kJ of energy on each eating occasion. Comparable numbers for all commercial infant and toddler foods (CITFs) were 78.0%, contributing 2.2 (1.6) and 140 (118) kJ of energy. Infant food pouches provided 25.5% of the total energy from complementary foods in those infants who consumed pouches on the recall days but just 11% in all infants. Median percentage contribution of infant food pouches to nutrient intake from complementary foods in consumers ranged from <1% (added sugars and retinol) to >30% (carbohydrate, total sugars, fiber, vitamin A, and vitamin C). CITF contributed 21.4% of energy from complementary foods for infant consumers, with median percentage contribution ranging from 0.1% (retinol) to 40.3% (iron). ConclusionsInfant food pouches make relatively small contributions to energy intake in infants but are important sources of carbohydrates, fiber, and vitamins A, C, and B-6. Almost half of the total sugars consumed from complementary foods is provided by these pouches.This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12620000459921.

Design of a pyrolyser model for the conversion of thermoplastics into fuels

This study focuses on alternatives to the sustainable management of plastic wastes through the development of a pyrolyser model, adapted to the recycling of plastics into fuel. It is a batch reactor, fixed bed, designed and built for the extraction of pyrolysis oil that can be recycled into petrol or diesel. The pyrolyser consists of a reactor with a volume of 0.0424 m3 and a copper spiral condenser with 2.31 m length. The plastics used for this study were Low Density PolyEthylene (LDPE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET). They were collected from surrounding companies, washed, sampled, cut and sieved. Two different sizes of pyrolysis material: 1–3 cm (G1) and 3–7 cm (G2) were obtained and tested. The pyrolysis reactor and the plastics entering at an ambient temperature of 25 °C were heated. Plastics were then melted at 110 °C and vaporised at 450 °C. The hot vapour produced circulated through a copper coil and condensed. The resulting liquid was called pyrolysis oil. The results of this study show that the pyrolysis of LDPE, PP and PS yields two liquids: the heavy and majority fraction which arelike the conventional diesel and the light fraction which is like gasoline. Yields of 6–12.4% for the light fraction and 43.2–63.8% corresponding to the heavy fraction are observed. PE has the highest yield, 63.8% for the heavy fraction and 12.4% for the light fraction. The study further underscores that the size of the pyrolysis material influences the yields, i.e. an increase of 12.5, 9.1 and 7 % for LDPE, PS and PP respectively when the size of the pyrolysis material is increased from G2 to G1. In contrast, the results of PET have shown a liquid that solidifies 46 s later. It was also noticed that 2061.34 kJ of energy was required to pyrolyse 1 kg of plastic and produce 0.762 l of fuel. The simple physico-chemical characterisation of the majority fraction shows a great similarity with diesel fuel, as the distillation went beyond 200 °C. Therefore, we can say that the diesel fraction is similar to diesel fuel. We equally observed a high cetane number (52.1–55.1) and a high calorific value (42.9–55.5 MJ/kg). Consequently, there are some points of non-conformity with the European 590 standard and Cameroonian specifications for diesel fuel. These include a low density (767.8–815.1 kg/m3) and a low viscosity at 40 °C (1.108–1.346 mm2/S). A thorough physico-chemical analysis will complete this study before any recommendation for appropriate use.

Use of Topical Gaseous Nitric Oxide/Plasma Energy in the Treatment of Recalcitrant Wounds.

Nitric oxide (NO) is involved in many biological functions and has been demonstrated to be important in wound healing. When delivered to a wound in its gaseous state, NO stimulates vasodilatation and angiogenesis, inhibits platelet and erythrocyte aggregation, reduces leukocyte adhesion, and is an important anti-inflammatory and antimicrobial agent. Many patients with chronic and hard-to-heal wounds have a deficiency of NO in their tissues ,which may contribute to slow and even arrested healing. However, it has been difficult to use NO for treatment because of its short half-life, which is measured in seconds. A recently developed device provides a way to generate NO and combine it with a stream of plasma energy, which extends its half-life to the point that it can provide a clinical effect. This device creates NO from the ambient air, and no other gases are needed. The combination of atmospheric oxygen and nitrogen at a high temperature generated by an electric arc results in NO and plasma energy (N2 + O2 = 2NO + 181 KJ energy). After generation, the NO/plasma energy-containing gas flow is cooled to 18-20°C, and NO is delivered to the tissues in a "dose" between 800 and 1000 ppm. When NO gas was combined with the plasma energy stream, the NO was found to penetrate intact skin or tissue up to 3cm to treat an underlying problem. Studies have shown that NO/plasma energy therapy promotes healing. This report summarizes current applications of this unique approach in the treatment of chronic, hard-to-heal and infected wounds.

Design and experimental analysis on a single tank energy storage system integrated with a cooking unit using funnel system

The paper presents a new innovation in small scale thermal energy storage system suitable for cooking application. A single tank thermal energy storage system integrated with a cooking unit has been developed and the performance analysed. The system consists of a heat storage tank, a heating chamber referred to as a funnel, and the cooking unit. The heating chamber is a pipe made of cast iron, and on top of the pipe is a cylindrical container made of Aluminium. A heating element of 1.5 kW 220 V was inserted inside the funnel and was used for heating the oil. The top of the funnel allows a cooking pot to be inserted inside it. The funnel can be raised or lowered using screws connected to the top of the tank; this regulates the temperature at which oil begins to overflow into the heat storage tank. The heat storage tank is made of stainless-steel, and contains sunflower oil as a heat storage medium. During charging, a small volume of oil about 2 L was heated inside the funnel, and the temperature rose rapidly to about 150 °C in less than 15 min. The system allows for cooking to begin immediately after charging has been started. As heating continues, the hot oil overflows into the storage tank, and cold oil at the bottom of the tank flows into the funnel where it is heated. The storage tank had 18 L of sunflower oil. During discharge, the direction of oil flow reverses; hot oil flows from the top of the tank into the funnel. The hot and the cold oil do not mix during discharge, and therefore, the heat front is preserved. Cooking tests were demonstrated during charging and discharging cycles. About 453.6 kJ of energy was used in boiling 1.5 L of water in 10 min, and 1.04 MJ was used in boiling 1 kg of dry beans in about 2 h.

Heat sink effects in thyroid bipolar radiofrequency ablation: an ex vivo study

The study aimed to investigate heat sink effects in radiofrequency ablation (RFA) under thyroid-specific conditions. In an ex vivo model, bovine thyroid lobes were ablated using bipolar RFA with 2.0 kJ energy input at a power level set to 10 W (n = 35) and 25 W (n = 35). Glass vessels (3.0 mm outer diameter) placed within the ablation zone were used to deliver tissue perfusion at various flow rates (0, 0.25, 0.5, 1, 5, 10, 20 ml/min). Temperature was measured in the proximity of the vessel (Tv) and in the non-perfused contralateral region of the ablation zone (Tc), at equal distances to the ablation electrode (d = 8 mm). Maximum temperature within the perfused zone was significantly lowered with Tv ranging from 54.1 ± 1.5 °C (20 ml/min) to 56.9 ± 1.5 °C (0.25 ml/min), compared to Tc from 63.2 ± 3.5 °C (20 ml/min) to 63.2 ± 2.6 °C (0.25 ml/min) (10 W group). The cross-sectional ablation zone area decreased with increasing flow rates from 184 ± 12 mm2 (0 ml/min) to 141 ± 20 mm2 (20 ml/min) at 10 W, and from 207 ± 22 mm2 (0 ml/min) to 158 ± 31 mm2 (20 ml/min) in the 25 W group. Significant heat sink effects were observed under thyroid-specific conditions even at flow rates ≤ 1 ml/min. In thyroid nodules with prominent vasculature, heat dissipation through perfusion may therefore result in clinically relevant limitations to ablation efficacy.

The Consumption of Energy Drink and Its Potential Effect on Sleep Patterns: A Case Study in the Kumasi Metropolis

Background: The availability of energy drinks on the global market result from intensive marketing campaigns in the media. The purpose of this study was to evaluate the consumption of energy drink and its potential effect on sleep patterns of consumers.&#x0D; Methods: A descriptive cross-sectional design with self-administered questionnaire was used for this survey. An online survey using google forms was created for the validated questionnaires after pre-testing and the link shared on different social media platforms. Period of data collection lasted between January and September, 2020.&#x0D; Results: A total of 384 participants were involved in this study. From the study, prevalence of energy drink consumption in the metropolis is 61.5% (n=236). A percentage of 69.1 % (n=163) of the consumers are males relative to 30.9% (n=73) who are females. Results from the study indicate that most patronized energy drink in the metropolis has energy value per 100 ml of 158 kJ with no proteins and fats but an 8.9 g of carbohydrate. The caffeine content of this energy drink is 0.012% and 13% glucose syrup. A total of 29.6% (n=70) of energy drink consumers indicated it to be their preference. Least consumed energy drink (0.85%) has 30-35 mg/100 ml of caffeine with about 192 kJ energy value. Furthermore, results point out that 70.8% (n=167) of the consumers experienced change in sleep pattern. Although other factors may have caused this change in sleep pattern, Pearson Chi-Square result (x2 = 83.277, p≤0.01) reveals that indeed there is association between energy drink consumption and change in sleep pattern as majority of energy drink consumers indicated that they usually experience changes in wake-up time and/or bedtime.&#x0D; Conclusion: The study has demonstrated that majority of the youth in the Kumasi Metropolis consume energy drinks which ultimately causes change in their sleep pattern. This change can alter their daily activities and health status.

Thermodynamic prediction of biogas production and combustion: The spontaneity and energy conversion efficiency from photosynthesis to combustion

Due to inappropriate energy consumption and subpar waste management, the growing population leads to an increase in energy demand and environmental damage. The creation of biogas enhances the management of organic waste and provides renewable energy. The production of biogas, which is a mixture of several gases, primarily methane and carbon dioxide, occurs during the four phases of aerobic digestion (AD). The four stages are hydrolysis, acidogenesis, acetogenesis, and methanogensis. Biogas comprises 50–70% Methane, 25–40% carbon dioxide and remaining traces of gases. In this paper, these biogas production processes are not thoroughly studied utilizing thermodynamic principles. Using thermodynamic criteria, this article analyses and assesses why the aerobic digesting process is spontaneous. Entropy, enthalpy, and Gibbs free energy of reactions during the various stages of the formation of biogas are examined. At Standard Temperature and Pressure Conditions (STP), the combined four phases of biogas formation are exothermic and spontaneous based on the analysis of Entropy, enthalpy, and Gibbs free energy of reactions from balanced equations at standard conditions of temperature and pressure. A unit mole of glucose is used to compare the energy released during photosynthesis with the energy released during biogas burning. Three moles of methane can be produced from decomposition of glucose. The combustion of three moles of methane yields 2406.876 kJ energy and if the same amount of moles of biogas (60% methane and 40% carbon dioxide) burns the energy yield is reduced to 1604.584 kJ. From the energy captured by photosynthesis i.e., 2808.1 kJ/mol 57.141% of the energy is recovered in the biogas combustion process. This efficiency reaches to 85.711% if pure methane is burned. As the separation of methane from biogas, mixture in actual plants is not economically feasible the combustion of methane gas the ideal limit of the efficiency.

Energy-efficient cooperative resource allocation and task scheduling for Internet of Things environments

Offloading Internet of Things (IoT) tasks to the cloud for further processing might not always lead to an optimal execution time, particularly in situations such as resource contention, under-provisioning, over-provisioning, and fragmentation. In addition, dynamically optimizing the number of Virtual Machines (VMs) for resource scheduling in order to meet application requirements remains a major research challenge. Further, existing resource scheduling algorithms focus primarily on minimizing operational costs while maximizing resource sharing and utilization. Considering energy utilization as part of the resource allocation and scheduling process as an optimization objective for maintaining load balancing has often been neglected. To address these challenges and more, we propose a cooperative energy-aware resource allocation and scheduling strategy based on a Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) multi-criteria decision-making method. We used the Grid Workloads Archive dataset to evaluate our proposed TOPSIS-based Resource Allocation (TOPREAL) approach. Experimental results with respect to the allocation of VM resources when considering processing a large segment of tasks indicate that TOPREAL outperforms existing algorithms in terms of energy savings, with an average improvement of 40.25%, while maintaining an average improvement of 16.21% when it comes to execution time. Results also demonstrate that our method can save an average of 78.06 processing hours and 63,215 kJ of energy when compared to existing scheduling algorithms. These results demonstrate the effectiveness of our proposed model and the viability of using multi-criteria decision-making techniques such as TOPSIS to solve the resource allocation and scheduling problem in edge environments.

A New Electrohydraulic Hybrid Energy-Saving System Used on the Reversible Rolling Mills

In the face of the global energy crisis, the use of hybrid technology is an important way to achieve efficient energy storage and utilization. Hybrid systems have been successfully applied to automobiles and construction machinery, but no research study has been conducted on the design and application of energy recovery systems for reversible rolling mills. This article proposes a new type of noncoaxial parallel electrohydraulic hybrid drive system configuration for reversible rolling mills to save energy. It is proposed to collect the braking energy of the previous pass of the reversible rolling mill roll and the surplus power of the original primary drive motor and then start or accelerate the process for the next roll pass. A test experiment was established and the energy-saving efficiency of the proposed system was verified. By rolling 14 passes, 255.892 kJ of energy can be recovered. The overall energy efficiency rate is around 71.547%. The system will significantly promote energy saving, low carbon, green, and other aspects of the reversible rolling mills.

Highly Integrated μGC Based on a Multisensing Progressive Cellular Architecture with a Valveless Sample Inlet

Microscale gas chromatographs (μGCs) promise in-field analysis of volatile organic compounds (VOCs) in environmental and industrial monitoring, healthcare, and homeland security applications. As a step toward addressing challenges with performance and manufacturability, this study reports a highly integrated monolithic chip implementing a multisensing progressive cellular architecture. This architecture incorporates three μGC cells that are customized for different ranges of analyte volatility; each cell includes a preconcentrator and separation column, two complementary capacitive detectors, and a photoionization detector (PID). An on-chip carrier gas filter scrubs ambient air for the analysis. The monolithic chip, with all 16 components, is 40.3 × 55.7 mm2 in footprint. To accommodate surface adsorptive and low-volatility analytes, the architecture eliminates the commonly used inlet valve, eliminating the need for chemically inactive surfaces in the valves and pumps, allowing the use of standard parts. Representative analysis is demonstrated from a nonpolar 14-analyte mixture, a polar 12-analyte mixture, and a 3-phosphonate ester mixture, covering a wide vapor pressure range (0.005-68.5 kPa) and dielectric constant range (1.8-23.2). The three types of detectors show highly complementary responses. Quantitative analysis is shown in the tens to hundreds ppb range. With 200 mL samples, the projected detection limits reach 0.12-4.7 ppb. Limited tests performed at 80% humidity showed that the analytes with vapor pressures <12 kPa were unaffected. A typical full run takes 28 min and consumes 2.3 kJ energy for the fluidic elements (excluding electronics). By eliminating chip-to-chip fluidic interconnections and requiring just one custom-fabricated element, this work presents a path toward high-performance and highly manufacturable μGCs.

Comparing dusting and fragmenting efficiency using the new SuperPulsed thulium fiber laser versus a 120 W Holmium:YAG laser.

Holmium:YAG laser lithotripsy requires high amperage power and has an upper limit of frequency and a minimal fiber size. The technology utilizing thulium-doped fiber offers low pulse energy settings and high pulse frequencies up to 2,400 Hz. We compared the novel SuperPulsed thulium fiber laser (SOLTIVE™; Olympus) to a commercially available 120 W Ho:YAG laser. Bench-top testing was conducted with 125 mm3 standardized BegoStones (Bego USA). Time to ablate the stone into particles <1 mm was recorded for efficiency calculations. Finite energy was delivered, and resulting particle sizes were measured to determine fragmentation (0.5 kJ) and dusting (2 kJ) efficiencies. Remaining mass or number of fragments were measured to compare efficacy. SOLTIVE™ was faster at ablating stones to particles <1 mm (2.23±0.22 mg/s, 0.6 J 30 Hz short pulse) compared to Ho:YAG laser (1.78±0.44 mg/s, 0.8 J 10 Hz short pulse) (p<0.001). Following 0.5 kJ of energy in fragmentation testing, fewer particles >2 mm remained using SOLTIVE™ than Ho:YAG laser (2.10 vs. 7.20 fragments). After delivering 2 kJ, dusting (1.05±0.08 mg/s) was faster using SOLTIVE™ (0.1 J 200 Hz short pulse) than 120 W 0.46±0.09 mg/s (0.3 J 70 Hz Moses) (p=0.005). SOLTIVE™ (0.1 J 200 Hz) produced more dust particles <0.5 mm (40%) compared to 24% produced by the P120 W laser at 0.3 J 70 Hz Moses and 14% at 0.3 J 70 Hz long pulse (p=0.015). The efficacy of SOLTIVE™ is superior to the 120 W Ho:YAG laser by producing smaller dust particles and fewer fragments. Further studies are warranted.

An investigation on crashworthiness performance of adhesive bonding in automobile hybrid front bumper system subjected to high-speed impact

Adhesive bonding is widely used to join dissimilar materials and has proven its effectiveness so far. This study investigates the crashworthiness performances of the adhesive bonding in automobile hybrid front bumper system which connects the composite bumper beam and steel crash boxes by carrying out a series of numerical analyses. Initially, the ply thickness and orientation of the composite bumper beam were optimized to achieve impact properties as good as the steel bumper beam. Later, performances of three adhesives, namely, Araldite® AV138, 3M® DP8005, and Nagase Chemtex® XNR6852E-3 with stiff, ductile, and high toughness, respectively were evaluated for the proposed configuration of the hybrid front bumper system and the proper adhesive was selected correspondingly. Finally, optimization studies were performed for the top and the side adhesives in terms of the impact characteristics of the adhesives. The results of this study showed that it was possible to use the adhesive bonding to join dissimilar materials in the automobile hybrid front bumper system with the proper adhesive. Moreover, the crashworthiness performance of the hybrid front bumper system was highly affected from the design configurations of the adhesives. It was found that the optimum hybrid front bumper system (Case 1) exhibited peak crush force of 656 kN and absorbed 4.07 kJ energy. In addition, the top and side adhesives absorbed 0.073 and 0.13 kJ of energy, respectively, while 16.12% and 22.48% of the elements used in the top and side adhesives failed.

Latent and sensible heat thermal storage in a heat pipe-based evacuated tube solar dryer: A comparative performance analysis

A new solar dryer system that can work with multiple heat storage mediums was developed and conducted a comparative performance analysis. Latent and sensible heat thermal storage mediums can be accommodated in the drying system. The solar dryer consist of evacuated tubes with thermal storage unified heat pipe solar collector. A new heat pipe layout was developed and placed inside the collector by linking the evaporator sections of the heat pipe with a single heat pipe condenser segment linked to a chamber that can accommodate various types of thermal energy storage mediums. Two heat storage mediums like benzoic acid and therminol-55 were used during the study. A maximum of 118 °C drying air temperature was obtained from the system with Therminol-55 heat storage medium. The collector and dryer system has a maximum energy efficiency of 29 % and 24 % respectively. The Benzoic acid stored a maximum of 3069 kJ energy whereas therminol-55 stored a maximum of 1881 kJ. Drying experiments conducted using therminol-55 as the thermal storage medium needed 16 h to dry 1 kg of apple to 45 g, whereas Benzoic acid required 17 h of drying time. The drying system performed well with therminol-55.

Proximate Composition, Qualitative Phytochemical Screening and In-Vitro Antioxidant Potential of Triumfetta rhomboidea Leaves Extracts

Continuous exploration of medicinal plants for bioactive constituents is essential since the availability and activities of these compounds speaks volume of their possible medicinal benefits. This study evaluated the proximate composition, phytochemical constituents and antioxidant potential of Triumfetta rhomboidea leaf extract. Extraction of aqueous (AETR) and ethanol (EETR) extract were performed by maceration. Proximate composition of pulverized leaf sample was performed following Association of Official Analytical Chemists (AOAC) standards. Antioxidant capacity of extracts were evaluated by determining the total phenolics content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP) scavenging ability, reducing power (RP) and lipid peroxidation inhibition. Results of proximate analysis revealed 11.01 % moisture content, 3.38 % ash content, 15.15 % crude fiber, 7.34 % crude fat, 61.09 % carbohydrate content, 17.18 % protein content and 379.14 kJ energy value. The total phenol content in aqueous and ethanol extracts were 20.36 ± 0.27 and 12.66 ± 0.28 mg GAE/g, respectively. Total flavonoid was 18.18 ± 1.02 mg QE/g for aqueous and 22.27 ± 0.26 mg QE/g for ethanol extracts with antioxidant capacity of 16.34 ± 4.92 mg AAE/100 g and 48.16 ± 8.50 mg AAE/100 g, respectively. AETR demonstrated highest Fe (II) reducing ability with IC50 of 0.33 ± 0.04 and 0.36 ± 0.04 mg/mL for FRAP and RP activities. This study has demonstrated that T. rhomboidea leave possess biologically active constituents and could presumably perform free radical scavenging activities in reactive oxygen species related diseases. HIGHLIGHTS Triumfetta rhomboidea leaves demonstrated remarkable proximate composition and high energy value The aqueous extract demonstrated high saponin content compared to ethanol extract Aqueous solution (distilled water) has better extraction efficiency of phenolic compounds in leaves of Triumfetta rhomboidea compared to ethanol The aqueous extract exhibited high antioxidant potential compared to ethanol extract as revealed by the ferric reducing antioxidant power and reducing power GRAPHICAL ABSTRACT

A Solar, Thermal, and Piezoelectric Based Hybrid Energy Harvesting for IoT and Underwater WSN Applications

Background: There has been an increasing interest in the research community regarding the development of new energy harvesting systems/architectures for sensor networks deployed at critical locations. Various types of energy harvesting techniques like solar, thermal, aquatic, and wind energy harvesting systems are popular in the research community. It has been found in a survey that a single energy harvesting technique is not enough for the wireless sensor network, especially when the nodes are deployed in critical areas, like volcanoes, underwater, ocean, rivers, etc. Objective: This study aimed to explore energy solutions for perpetual, battery-less, and critical places where human intervention is impossible. Method: In this study, a hybrid energy harvesting solution using solar, pressure, and thermal has been proposed. An optimized framework has been proposed, implemented, and analyzed for the underwater sensor network application. Furthermore, mechanical and electrical schematic models have been designed, implemented, and realized. Result and Discussion: The physical parameters of solar, thermal, and piezoelectrical transducers have been analyzed along with mathematical equations to find the best possible solutions for the optimized framework. Conclusion: The model was theoretically implemented and investigated, and it was found that 22.3KJ of energy can be extracted in 24hrs from the proposed design, which guarantees a perpetual life of the sensor node.

Production of astaxanthin, ethanol and methane from Chromochloris zofingiensis microalga in an integrated biorefinery

Astaxanthin-rich carotenoids were produced from Chromochloris zofingiensis green alga through an integrated biorefinery. Simultaneous effects of high light intensity and nitrogen starvation resulted in the production of 10.2 mg total carotenoids per g biomass, including 80 % astaxanthin. A novel extraction method employing ultrasonic-milling pretreatment was then used to reduce the extraction time (33.5 min) and the amount of utilized solvent (30 mL ethanol per 1 g biomass). The extraction method provided the residual biomass with the same anaerobic digestibility as the raw biomass, accumulating 315 mL/g VS methane. Additionally, the residual biomass was hydrolyzed with four commercial enzymes providing a high glucose yield (78.2 %). Overall, the biorefinery consisted of producing ethanol from the algal biomass hydrolysate and biomethane from solids remaining after hydrolysis. Also, fermentation resulted in 8260 kJ energy, in addition to 10.2 g carotenoids from 1 kg biomass.

Rapid and Energy-Efficient Frontal Curing of Multifunctional Composites Using Integrated Nanostructured Heaters.

Current technologies for the manufacture of fiber-reinforced polymer composites are energy-intensive, environmentally unfriendly, and time-consuming and require expensive equipment and resources. In addition, composites typically lack key nonstructural functionalities (e.g., electrical conductivity for deicing, lightning strike protection, and structural health monitoring), which are crucial to many applications such as aerospace and wind energy. Here, we present a new approach for rapid and energy-efficient manufacturing of multifunctional composites without using traditional expensive autoclaves, ovens, or heated molds used for curing of composites. Our approach is predicated on embedding a thin conductive nanostructured paper in the composite layup to act as a resistive heater for triggering frontal polymerization of the matrix thermosetting resin of the composite laminate. Upon passing electric current, the nanostructured paper quickly heats up and initiates frontal polymerization, which then rapidly propagates through the thickness of the laminate, resulting in rapid curing of composites (within seconds to few minutes) irrespective of the size of the composite laminate. The integrated nanostructured paper remains advantageous during the service of the composite part by imparting new functionalities (e.g., deicing) to the cured composite, owing to its excellent electrical conductivity and electrothermal properties. In this work, we first study the influence of several composite processing parameters on the electrothermal properties of the nanostructured paper and determine the power required for rapid initiation of frontal polymerization. We then successfully fabricate a 10 cm × 10 cm composite panel within 1 min using only 4.49 kJ of energy, which is 4 orders of magnitude less than the energy consumed by the traditional bulk, oven-curing technique. Detailed experiments are conducted to provide an in-depth understanding of the effect of heater position, tooling material, and input power on frontal curing of composite laminates. The multifunctional response of produced composites is demonstrated by performing a deicing experiment, where a 50 × 50 × 3 mm3 cube of ice is completely melted within 3 min using an input power of 77 W.

Crashworthiness Assessment of Carbon/Glass Epoxy Hybrid Composite Tubes Subjected to Axial Loads.

The crashworthiness of composite tubes is widely examined for various types of FRP composites. However, the use of hybrid composites potentially enhances the material characteristics under impact loading. In this regard, this study used a combination of unidirectional glass–carbon fibre reinforced epoxy resin as the hybrid composite tube fabricated by the pultrusion method. Five tubes with different length aspect ratios were fabricated and tested, in which the results demonstrate “how structural energy absorption affects by increasing the length of tubes”. Crash force efficiency was used as the criterion to show that the selected L/D are acceptable of crash resistance with 95% efficiency. Different chamfering shapes as the trigger mechanism were applied to the tubes and the triggering effect was examined to understand the impact capacity of different tubes. A finite element model was developed to evaluate different crashworthiness indicators of the test. The results were validated through a good agreement between experimental and numerical simulations. The experimental and numerical results show that hybrid glass/carbon tubes accomplish an average 25.34 kJ/kg specific energy absorption, average 1.43 kJ energy absorption, average 32.43 kN maximum peak load, and average 96.67% crash force efficiency under quasi-static axial loading. The results show that selecting the optimum trigger mechanism causes progressive collapse and increases the specific energy absorption by more than 35%.