Dicynodontia represent the most diverse tetrapod group during the Late Permian. They survived the Permo-Triassic extinction and are central to understanding Permo-Triassic terrestrial ecosystems. ...Although extensively studied, several aspects of dicynodont paleobiology such as, neuroanatomy, inner ear morphology and internal cranial anatomy remain obscure. Here we describe a new dicynodont (Therapsida, Anomodontia) from northern Mozambique: Niassodon mfumukasi gen. et sp. nov. The holotype ML1620 was collected from the Late Permian K5 formation, Metangula Graben, Niassa Province northern Mozambique, an almost completely unexplored basin and country for vertebrate paleontology. Synchrotron radiation based micro-computed tomography (SRµCT), combined with a phylogenetic analysis, demonstrates a set of characters shared with Emydopoidea. All individual bones were digitally segmented allowing a 3D visualization of each element. In addition, we reconstructed the osseous labyrinth, endocast, cranial nerves and vasculature. The brain is narrow and the cerebellum is broader than the forebrain, resembling the conservative, "reptilian-grade" morphology of other non-mammalian therapsids, but the enlarged paraflocculi occupy the same relative volume as in birds. The orientation of the horizontal semicircular canals indicates a slightly more dorsally tilted head posture than previously assumed in other dicynodonts. In addition, synchrotron data shows a secondary center of ossification in the femur. Thus ML1620 represents, to our knowledge, the oldest fossil evidence of a secondary center of ossification, pushing back the evolutionary origins of this feature. The fact that the specimen represents a new species indicates that the Late Permian tetrapod fauna of east Africa is still incompletely known.
Due to the shortening on natural water resources, reclaimed wastewater will be an important water supply source. However, suitable technologies must be available to guaranty its proper detoxification ...with special concern for the emerging pharmaceutical and personal care products that are continuously reaching municipal wastewater treatment plants. While conventional biological systems are not suitable to remove these compounds, ozone, due to its interesting features involving molecular ozone oxidation and the possibility of generating unselective hydroxyl radicals, has a wider range of action on micropollutants removal and water disinfection. This paper aims to review the studies dealing with ozone based processes for water reuse by considering municipal wastewater reclamation as well as natural and drinking water treatment. A comparison with alternative technologies is given. The main drawback of ozonation is related with the low mineralization achieved that may lead to the production of reaction intermediates with toxic features. The use of hydrogen peroxide and light aided systems enhance ozone action over pollutants. Moreover, scientific community is focused on the development of solid catalysts able to improve the mineralization level achieved by ozone. Special interest is now being given to solar light catalytic ozonation systems with interesting results both for chemical and biological contaminants abatement. Nowadays the integration between ozonation and sand biofiltration seems to be the most interesting cost effective methodology for water treatment. However, further studies must be performed to optimize this system by understanding the biofiltration mechanisms.
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•Reclaimed wastewater is becoming an important source of fresh water.•Pharmaceuticals and personal care products are a concern on quality of reused water.•Ozone removes such compounds even if with low mineralization.•Ozonation is a suitable alternative specially when integrated with biofiltration.•Ozonation is compared with other alternatives for water recovery.
The semicircular canal (SC) system of the inner ear detects head angular accelerations and is essential for navigation and spatial awareness in vertebrates. Because the bony labyrinth encloses the ...membranous labyrinth SCs, it can be used as a proxy for animal behavior. The bony labyrinth of dicynodonts, a clade of herbivorous non-mammalian synapsids, has only been described in a handful of individuals and remains particularly obscure. Here we describe the bony labyrinth anatomy of three Endothiodon cf. bathystoma specimens from Mozambique based on digital reconstructions from propagation phase-contrast synchrotron micro-computed tomography. We compare these findings with the bony labyrinth anatomy of their close relative Niassodon. The bony labyrinths of Endothiodon and Niassodon are relatively similar and show only differences in the shape of the horizontal SCs and the orientation of the vertical SCs. When compared to extant mammals, Endothiodon and Niassodon have highly eccentric SCs. In addition, the Endothiodon SCs are nearly orthogonal. An eccentric and orthogonal SC morphology is consistent with a specialization in rapid head movements, which are typical of foraging or feeding behaviors. Furthermore, we estimate the body mass of these Endothiodon specimens at ~116 to 182 kg, based on the average SC radii calculated using a linear regression model optimized by the Amemiya Prediction Criterion. Our findings provide novel insights into the paleobiology of Endothiodon which are consistent with the peculiar feeding mechanism among dicynodonts presumed from their multiple postcanine toothrows.
Battery-to-battery (B2B) wireless charging can take place in many scenarios, such as using a mobile phone to charge another mobile phone, wearable devices, or low-power sensor nodes. To facilitate ...this wireless power transfer (WPT) function with the minimum additional cost, we propose a monolithic reconfigurable bidirectional WPT transceiver designed for the first time in CMOS, which can be reconfigured between a differential class-D power amplifier (PA) and a full-wave rectifier. Meanwhile, we employed a maximum current charging mode to maximize the B2B charging efficiency, by directly charging the loading battery with the rectifier, and by powering the PA with the sourcing battery. Then, we reduced the number of cascaded WPT stages from five in the conventional design to three. This bidirectional WPT transceiver fabricated in 0.35 μ m CMOS occupies 3.9 mm 2 of silicon area. The bidirectional WPT function, verified at 6.78 MHz with only one off-chip capacitor, exhibits peak efficiencies of 91.5% and 58.6% for the receiver and the overall system, respectively, when the output power is 1.55 W.
This article presents a low-dropout regulator (LDO), with analog-proportional (AP) and digital integral (DI) controls. The design concerns are discussed at first, on how to improve the load transient ...response, enhance the power supply rejection (PSR), and reduce the limit cycle oscillation (LCO). For a good output dc accuracy, the DI section is implemented with shift-register-based coarse- and fine-tuning loops. Meanwhile, the AP section, based on a low-supply flipped-voltage follower (FVF), can respond fast to the load step and input supply ripple. A replica loop is used to define the steady-state output current of AP, allowing a sufficient dynamic swing against the supply ripple. To lower the load current range with no LCO, the AP section will output all the current at very light load. An error amplifier (EA) with moderate gain is added to improve the light-load output accuracy. This EA also improves the PSR by approximately 6 dB. Fabricated in a 65-nm CMOS process, a 65-mV undershoot is measured with a 0-10-mA load current step under 0.6-V supply voltage and 50-mV dropout. Due to the fast AP, a 5-MHz operation clock is applied to the digital section, reducing the overall quiescent current to 29 <inline-formula> <tex-math notation="LaTeX">\mu \text{A} </tex-math></inline-formula>. A 0.37-ps figure of merit (FoM) is then achieved. A −22-dB PSR at 1 MHz is measured at 0.6-V supply, 100-mV dropout, and 10-mA load current.
This paper presents a reconfigurable cross-connected (CC) wireless power transceiver (TRX) operating at 6.78 MHz and implemented for bidirectional device-to-device (D2D) charging with high efficiency ...and small system volume. We propose, for the first time, a CC topology applied to a differential class-D power amplifier for significant switching loss reduction. Two delay-locked loops (DLLs) for each power NMOS transistor form the reconfigurable controller, realizing the adaptive deadtime control in the transmitter (TX) mode and the off-delay compensation in the receiver (RX) mode, leading to high power conversion efficiency and safe operation. To realize the inductive load for the TX mode in the whole coupling range at the resonant frequency, we use an on-chip tunable capacitor. Furthermore, we also study the power link efficiency in the D2D direct charging system and verify that the near-maximum power link efficiency can be inherently achieved in this scenario. The proposed wireless power TRX, fabricated in a 0.35-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> CMOS process with 5-V devices, measured a peak D2D total efficiency of 77.2% when the output power is 0.7 W. The maximum charging power is 2.74 W with a total efficiency of 62.7% and the maximum transmission distance is 24 mm, both measured.
Agro-industrial wastewater management becomes a major task while environmental regulations are becoming stricter worldwide. Agro-industrial wastewaters are known by high content of organic pollutants ...that cause an adverse effect on the water bodies. Industries are looking for efficient, easy-to-use and affordable treatment processes. Sulfate radical based advanced oxidation processes (S-AOPs) are arising as suitable alternatives for agro-industrial effluents treatment. In this review, the major findings regarding the application of this technology for real agro-industrial wastewater depuration are discussed. Moreover, these technologies are compared as an alternative to Fenton's process, which is a widely studied advanced oxidation process and with high efficiency in the treatment of agro-industrial effluents. The studies already carried out are promising, but there is still a great lack of studies in this area and using this technique.
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•Can SRbAOP be an alternative to the Fenton process for wastewater treatment?•SRbAOP are arising as suitable alternatives for agro-industrial effluents treatment.•SRbAOP have similar efficiency to Fenton’s for POME and OMW effluents depuration.•By-products toxicity must be accounted when developing new oxidation technologies.•Pilot-studies are required to understand and optimize SRbAOP technologies.
High-performance microprocessors need high current (ampere-level), high accuracy, and fast-response power supplies. Comparing to analog and digital low-dropout (LDO) regulators, the switching LDO can ...be a better candidate for such requirements, as it can drive large power transistor(s) fast and accurately. However, conventional switching LDOs need large load capacitance to reduce the output ripple, which restricts their applications. This article presents a 1.5-A fully-integrated switching LDO for microprocessors, with an easily scalable load capability. Here, we introduce three techniques together to relief the output capacitance requirement: 1) four-phase 500-MHz pulsewidth modulation (PWM) with inherent current balancing; 2) current-limited power cells resisting processor voltage and temperature (PVT) variations; and 3) hybrid fast-slow power transistors. Therefore, we reduce significantly the load capacitance to maximum load current ratio <inline-formula> <tex-math notation="LaTeX">C_{\mathrm {L}} / I_{\mathrm {MAX}} </tex-math></inline-formula> when compared with the prior switching LDOs. Also, the proposed dual-loop architecture not only achieves a fast transient response, but also provides high-accuracy regulation. In addition, we design the tunable active voltage positioning (AVP). Fabricated in 28-nm CMOS, the proposed switching LDO measures a maximum 70-mV undershoot with a 1-A load current step with 10-ns edge time. The measured load regulation is 1 mV/A and the line regulation is 1.5 mV/V. Also, we obtain a good power supply rejection (PSR) of −63 dB at 10 kHz and −20 dB at 1 MHz. The PWM automatically moves to a pulse-skipping mode at light load, reducing the quiescent current to 1.8 mA, while the peak current efficiency is 99.27%.
This paper presents a single-stage tri-path buck converter with reduced inductor current and self-balanced flying capacitor voltage. The proposed converter introduces capacitor paths to reduce the ...average inductor current and inductor current ripple, hence decreasing the conduction loss. Operating with two states per conversion cycle, it exhibits a relatively low voltage conversion ratio of <inline-formula> <tex-math notation="LaTeX">{D} </tex-math></inline-formula>/(1 <inline-formula> <tex-math notation="LaTeX">+\,\,2{D} </tex-math></inline-formula>). Besides, it realizes a self-balanced flying capacitor voltage in the charge redistribution phase. Similar to the conventional buck converter, the proposed converter in continuous-current mode only has two complex poles. Therefore, we design a Type-III compensator to obtain a good transient response. Moreover, the circuit does not require extra supplies for gate drivers due to the reutilization of the flying capacitor voltages, eliminating additional circuit and power overheads. The proposed converter, validated in a 65-nm standard CMOS technology, regulates a 0.7 V - 1 V output voltage from a 3.3 V - 4 V input voltage, delivering a maximum output power of 270 mW. The peak efficiency is 84%, with a switching frequency up to 5 MHz.
This article proposes a reconfigurable single-stage regulating asymmetrical full-wave step-down rectifier (SDR) for fast wireless charging. The SDR is reconfigurable into a step-up power amplifier ...(SUPA) for device-to-device (D2D) wireless charging. The SDR and SUPA can have a direct connection with the battery without an additional voltage regulator module (VRM). With the single-stage structure, the transmitting (TX) and receiving (RX) ac voltages across the resonant coil can be boosted, which greatly reduces the coil currents and losses, improving the D2D charging power. A reconfigurable controller for the TX/RX mode selection, as well as the switching timing control, is designed. The chip is fabricated in 0.35-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> CMOS that contains 20-V devices. For the asymmetrical operation, one GaN device is used for the high current path. Also, zero-voltage switching (ZVS) is realized for all the power transistors with one small (180 nH in the 4015 package) power inductor. The bidirectional D2D WPT system achieves a maximum charging power of 5.1 W with a D2D total efficiency of 46.3% and a charging distance of 1.6 cm. Finally, the peak total efficiency is 51.4% with a charging power of 3.4 W and a charging distance of 1 cm.
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