The emerging of renewable energy demands energy storage. Redox flow batteries are inherently suited for large-scale applications, but their market penetration is thwarted by the high materials cost. ...In contrast, membrane-less and single-flow soluble lead flow batteries (SLFBs) are more economical to scale up and free of expensive noble metals. However, lifespan of SLFBs reported so far is limited to approximately 200 cycles under normal flow conditions, which is insufficient for long-term operation in utility applications.
Failures of SLFBs are believed to be associated with PbO
2
deposition/dissolution at the positive electrode. Although failure mechanisms are not well understood, passivation and shedding of PbO
2
are suggested to decrease efficiency of SLFBs. Formation of a passivation layer of non-stoichiometric PbOx is found to be correlated to proton activities. PbO
2
deposits of poor adherence and low quality are also observed to occur when the electrolyte is high in acidity. We therefore employ sodium acetate (NaOAc) as electrolyte additive, and successfully extend the cycle life of SLFBs by over 50%.
In this study, effects of acetate additive on electroplating of PbO
2
are investigated. Surface morphology and mechanical strength of electroplated PbO
2
via electrolyte with and without NaOAc are examined by scanning electron microscopy (SEM) and nano-indentation, respectively. Acetate-assisted electrolyte is found to substantially enhance deposited film strength and leads to a more integrated and smoother surface. Crystal structures, grain sizes, and grain orientations of plated PbO
2
are analyzed via x-ray diffraction (XRD) and electron back scatter diffraction (EBSD), and very different phase distributions and grain orientations are observed for electrolyte with and without NaOAc. Electroplating and oxygen evolution kinetics are further investigated by rotating disk electrode (RDE) experiments. Our findings elucidate acetate additive effects on electroplating of PbO
2
in SLFB systems and shed lights on battery life extension.
Resistive memory-based computing-in-memory (CIM) has been considered as a promising solution to accelerate convolutional neural networks (CNN) inference, which stores the weights in crossbar memory ...arrays and performs in-situ matrix-vector multiplications (MVMs) in an analog manner. Several techniques assume that a whole crossbar can operate concurrently and discuss how to efficiently map the weights onto crossbar arrays. However, in practice, the accumulated effect of per-cell current deviation and Analog-to-Digital-Converter overhead may greatly degrade inference accuracy, which motivates the concept of Operation Unit (OU), by which an operation per cycle in a crossbar only involve limited wordlines and bitlines to preserve satisfactory inference accuracy.
With OU-based operations, the mapping of weights and scheduling strategy for parallelizing CNN convolution operations should take the cost of communication overhead and resource utilization into consideration to optimize the inference acceleration. In this work, we propose the first optimization framework named SPATEM, that efficiently executes MVMs with OU-based operations on ReRAM-based CIM accelerators. It decouples the design space into tractable steps, models the expected inference latency, and derives an optimized spatial-temporal-aware scheduling strategy. By comparing with state-of-the-arts, the experimental result shows that the derived scheduling strategy of SPATEM achieves on average 29.24% inference latency reduction with 31.28% less communication overhead by exploiting more originally unused crossbar cells.
This study observes abnormal returns of stock prices after companies announced the establishment of wastewater and waste heat recovery systems in East Asia from 2000 to 2018. The capital expenditure ...on the wastewater and waste heat recovery system and the expected impact on revenue are also considered, and the stock market is analyzed to verify whether there is an additional evaluation after the company carries out such carbon emission reduction activity. The study finds that after more than a decade of technological advancement and promoting carbon reduction behaviours, the market has shown more positive reactions to carbon reduction measures, such as wastewater and waste heat recovery systems. However, the additional positive reaction in the markets of developing countries is lower than in developed countries. For developing countries desiring domestic manufacturers to adopt more carbon emission reduction activities, the government may need to offer more policy incentives, which will encourage investors in the market to support manufacturers in actively investing in carbon reduction measures. Certainly, manufacturers will be more motivated to implement or cooperate with voluntary carbon reduction measures. In addition, this study does not consider the possible impact of carbon rights trading and carbon fees on improving manufacturers' active treatment of wastewater and waste heat recovery, which will be a direction worthy of future research.
Injection stretching-blow molding (ISBM) has been used widely to produce thousands of hollow plastics products, such as drink bottles, automobile tanks, containers, and so on. In this study, both ...experimental and CAE analysis were carried out to model ISBM of the 26g-600 ml and 28g-600 ml bottles. The experiment results show that 28g-600 ml bottles have more uniform bottle thickness.
Natural killer (NK) cells have the capacity to target tumors and are ideal candidates for immunotherapy. Viral vectors have been used to genetically modify in vitro expanded NK cells to express ...chimeric antigen receptors (CARs), which confer cytotoxicity against tumors. However, use of viral transduction methods raises the safety concern of viral integration into the NK cell genome. In this study, we used trogocytosis as a non-viral method to modify NK cells for immunotherapy. A K562 cell line expressing high levels of anti-CD19 CARs was generated as a donor cell to transfer the anti-CD19 CARs onto NK cells via trogocytosis. Anti-CD19 CAR expression was observed in expanded NK cells after these cells were co-cultured for one hour with freeze/thaw-treated donor cells expressing anti-CD19 CARs. Immunofluorescence analysis confirmed the localization of the anti-CD19 CARs on the NK cell surface. Acquisition of anti-CD19 CARs via trogocytosis enhanced NK cell-mediated cytotoxicity against the B-cell acute lymphoblastic leukemia (B-ALL) cell lines and primary B-ALL cells derived from patients. To our knowledge, this is the first report that describes the increased cytotoxicity of NK cells following the acquisition of CARs via trogocytosis. This novel strategy could be a potential valuable therapeutic approach for the treatment of B-cell tumors.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Network coding is a promising technology proven to improve the performance of wireless networks. To successfully design a quality-of-service (QoS)-satisfied routing protocol with network coding, the ...bandwidth consumption of a coding host should be determined. Furthermore, coding opportunities should be increased to improve network capacity. Nevertheless, it is challenging to determine whether a host can be a coding host and to determine the bandwidth consumption of a coding host in a mobile ad hoc network (MANET). In this paper, we first present and define the coding conditions to identify a coding host. The bandwidth consumption of a coding host is then estimated under the contention-based wireless networks with a random access mechanism. Finally, we propose a bandwidth-satisfied and coding-aware multicast routing protocol (BCMRP). By taking into account the residual bandwidth of the carrier-sense neighbors of the forwarders, the proposed protocol can satisfy the bandwidth requirements of the requested flow and other ongoing flows. As a consequence of considering coding opportunities in multicast tree construction, the proposed multicast protocol can reduce the total bandwidth consumption. The simulation results show that BCMRP outperforms the prior multicast routing protocols in receiving ratio, admission ratio, and total bandwidth consumption.
GENERATION AND MANIPULATION OF MICRO DROPLETS Lin, Yen-Liang; Su, Yu-Chuan; Fan, Shih-Kang ...
International journal of microscale and nanoscale thermal and fluid transport phenomena,
01/2012, Letnik:
3, Številka:
2
Journal Article
Recenzirano
Recently, functional droplet-based microfluidic systems have played an important role in chemistry, biology, biomedicine, and industry applications due to their capabilities on uniform dosage ...control, multifunctional sample assay, reaction time reduction, and high throughput operation. The formation of micro droplets in gaseous or liquid environments can be achieved by either droplet ejection in atmosphere/vacuum, emulsification in microchannels, or electrokinetic forces on solid surfaces. This paper reviews some of the recently developed micro droplet generation techniques on the aspects of droplets generation principles, manipulation methods, technical capabilities, and potential applications. Advances in the capacity, efficiency, and stability of micro droplet generators provide the opportunity to realize lab on a chip (LOC) or digital micro fluidic (DMF) systems for versatile practical applications.
In this study, we develop a steady state and time-dependent exciton diffusion model including singlet and triplet excitons coupled with a modified Poisson and drift-diffusion solver to explain the ...mechanism of hyper triplet-triplet fusion (TTF) organic light-emitting diodes (OLEDs). Using this modified simulator, we demonstrate various characteristics of OLEDs, including the J-V curve, internal quantum efficiency, transient spectrum, and electric profile. This solver can also be used to explain the mechanism of hyper-TTF-OLEDs and analyze the loss from different exciton mechanisms. Furthermore, we perform additional optimization of hyper-TTF-OLEDs that increases the internal quantum efficiency by approximately 33% (from 29% to 40%).
This work studies the degradation mechanisms behind negative bias temperature instability (NBTI) in galliumnitride metal-insulator semiconductor high electron mobility transistors (GaN MIS-HEMT) ...under a wide range of temperature conditions (77K to 393K). The positive shift of threshold voltage increases with temperature from 77K to 303K, owing to the trapping of electrons in the silicon nitride (Si 3 N 4 ) bulk layer and at the Si 3 N 4 /aluminum gallium nitride (AlGaN) interface. Anomalously, the threshold voltage shift substantially reduces from 303K to 393K. Such an abnormal phenomenon could be attributed to additional hole trapping in Si 3 N 4 due to impact ionization. The occurrence of impact ionization can be further evidenced by the recovery behavior if the test devices. Accordingly, a comprehensive model is proposed to clarify the degradation behavior of NBTI for GaN MIS-HEMT under different temperature conditions.
This work studies the threshold voltage (VT) degradation mechanism of hot electron stress (HES) under semi-ON conditions in AlGaN/GaN high electron mobility transistors (GaN HEMTs). The drain current ...and drain voltage (ID-VD) transfer curves indicate that kink phenomenon will occur in the semi-ON regime. A long-term HES under conditions where the kink occurs illustrate that the degradation of the ID is caused by a VT shift. From the stress and recovery in HES under different conditions, it can be determined that the hole generation and pre-existing buffer traps recombination play a very important role. Silvaco simulation is also used to simulate the impact of different buffer trap positions on the ID-VG characteristic. Finally, a complete HES mechanism under the semi-ON regime is presented to explain the threshold voltage (VT) degradation.
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