batterydata/paper-abstracts huggingface dataset:
Zinc–cerium redox flow batteries (ZCBs) are emerging as a very promising new technology with the potential to store a large amount of energy economically and efficiently, thanking to its highest thermodynamic open-circuit cell voltage among all the currently studied aqueous redox flow batteries. However, there are numerous scientific and technical challenges that must be overcome if this alluring promise is to turn into reality, from designing the battery structure, to optimizing the electrolyte compositions and elucidating the complex chemical reactions that occur during charge and discharge. This review article is the first summary of the most significant developments and challenges of cerium half-cell and the current understanding of their chemistry. We are certain that this review will be of great interest to audience over a broad range, especially in fields of energy storage, electrochemistry, and chemical engineering.
Composite electrodes were prepared by mixing, in the ratio 60/40 by weight, the powder of an electrochemically inhibited intermetallic compound (IMC), e.g. TiFe 50/50, TiNi 70/30 or TiNi 40/60 (alloy precursor grade) with Fe powder and pressing the mixture on to a Ni foam support. The charge capacity achieved in these composites was then compared with the capacity of “blank” electrodes in which the IMC had been replaced by an inactive metal (Ti or Ni). The blanks attained capacities in the range 150–200mAhg−1, although these values were largely exceeded by some IMC+Fe composites due, presumably, to storage on hydrogen. The electrocatalytic properties of Fe are probably not sufficient to explain the activation of hydrogen absorption in the inhibited IMC, since X-ray and energy-dispersive analysis (EDAX) of activated samples did reveal that deep modifications occurred in some composites, in which the formation of new phases may have been induced by charging–discharging cycles.
Metallic dendrite growth of metal anodes is a major concern in developing next-generation metal-ion batteries. Here the authors develop a cross-linked polyethylenimine as a metal host that enables electrokinetic effects for uniform metal deposition.
The desired performance characteristics and physical requirements of spacecraft batteries for planetary exploration are reviewed, particularly with respect to surface landers and rovers intended for near-future Mars missions. The use of lithium ion batteries is justified in terms of significant savings on mass and volume, and more importantly of superior low temperature performance deemed essential in the Mars lander and rover missions. Use of these batteries in planetary orbiters may require further improvements in their cycle life, especially at low depths of discharge. Various strategies currently being adopted to prolong the cycle life for orbiter applications, as well as, for extending their operating range down to temperatures as low as −30°C for more imminent Mars lander and rover missions are briefly discussed.
The incidence, progression and related risk factors for recent-onset knee pain (KP) remain uncertain. This study aims to examine the natural history of KP including incidence and progression and to identify possible phenotypes and their associated risk factors.
Non-equilibrium phase transformation and effect of interfacial Li flux on miscibility gap in two-phase transformation of LiFePO4 have been explored in this study. Our previously developed “Mushy-Zone” (MZ) model, accounting for sluggish Li diffusion across the two-phase interface, has been employed to study the non-equilibrium phase transformation in LiFePO4 materials of Li-ion batteries. Phase transformation rate, variation of two-phase miscibility gap, and interfacial Li composition profiles have been studied for different particle shapes at varying discharge rates. Sluggish Li flux across the two-phase interface, which is believed to be the origin of the kinetically-induced non-equilibrium phase transformation, has been calculated to explain the obtained results. It is found that small particle sizes (radii of 20 nm) and slow discharge rates tend to create homogenous phase transformation (i.e., shrunk or no miscibility gap). Two-phase transformation is remarkably delayed for spherical particles at low discharge rates, leading to a lower capacity compared to that of plated-shaped particles. However, at higher discharge rates spherical particles show better capacity.
LiMn1.5Ni0.5O4 cathode material was prepared by sol–gel method and annealed at 850°C for 15h. The prepared powder was coated with ZnO by dissolving zinc acetate in methanol and LiMn1.5Ni0.5O4 powder was mixed in this solution followed by the continuous stirring for 4h. The LiMn1.5Ni0.5O4 and ZnO-coated LiMn1.5Ni0.5O4 powder was structurally characterized using X-ray diffraction and scanning electron microscopy (SEM). The coin cell was fabricated using ZnO-coated LiMn1.5Ni0.5O4 as cathode materials, LiPF6, dissolved in ethylene carbonate (EC)/dimethyl carbonate (DMC) (1:1 wt ratio) as electrolyte, and Li foil as anode. It was found that ZnO-coated LiMn1.5Ni0.5O4 cathode materials had the initial discharge capacity of about 146mAhg−1. The discharge capacity retention after 50 cycles was found to be nearly 97%.
Silicon is a promising anode material for the next-generation of high-specific-energy lithium-ion batteries (LIBs), but commercial silicon still has difficulty in gaining both high rate capability and long cycle life for practical application due to poor electrical conductivity and an unstable solid electrolyte interface. Here, a simple electrode with bilayer-graphene-coated Si nanoparticles embedded in a porous current collector is adopted and exceptional electrochemical performance is obtained in lithium-ions batteries. A possible mechanism is analyzed from the insight provided from the conductivity balance between electrons and ions. Used as binder-free and additive-free anodes, the Si composite displays good rate capacity (up to 50 A g−1) and cycling stability (3000 cycles with ∼89% capacity retention). Coupled with a possible physical insight, economical and feasible fabrication process, the electrode designs developed are likely to stimulate more opportunities for the next-generation high-specific-energy LIBs with enhanced power. It is further demonstrated that even in a full-cell electrochemical test, it is stable for 260 cycles and 87% capacity retention is achieved.
As a fast emerging topic, van der Waals heterostructures can modify two-dimensional (2D) layered materials with desired properties, thus greatly extending the applications of these materials. Via state-of-the-art first-principles calculations, we systematically study four types of van der Waals heterostructures formed by monolayer graphene, h-BN, g-C3N4, and polyphenylene on ZrS2 nanosheets. A direct band gap can be obtained in the graphene/ZrS2 heterostructure, endowing graphene with the real ability to be applied in nanoelectronics, whereas the van der Waals interactions of graphene significantly broadens the optical absorption of ZrS2. The conduction band and valence band of the four heterostructures are contributed by the ZrS2 layer and the other layer, respectively, meaning good charge separation is achieved. We proposed that the strained h-BN/ZrS2 and g-C3N4/ZrS2 heterostructures satisfy fundamental aspects for photocatalytic water splitting, with the reduction and oxidation levels well inside their band gaps. By forming heterostructures with ZrS2, the optical properties of h-BN, g-C3N4 and polyphenylene show a remarkable improvement in the visible-light region. The findings in this study will be of broad interest in van der Waals heterostructure research and in the photocatalysis field.
The benefits of reducing the thermal effect of global warming and structural damage by severe storms have renewed interest and drives to heavyweight constructions. One type of heavyweight construction using earth-sheltered construction known as an ‘Earthship’ has been developed and pioneered by US architect Michael Reynolds and recently introduced to the UK. The ‘Earthship’ takes on the concept of an ‘independent vessel’, which operates on a self-sufficient basis and is constructed largely from recycled and reclaimed materials. Although there are up to 3000 globally, only two Earthships have been built in the UK – one in Brighton and one in Scotland. The publicity resulting from the planning approval granted in April 2007 for the construction of sixteen domestic Earthships at the seafront of Brighton have raised public awareness to this type of unconventional construction. A key feature of the Earthship design is the use of a thermal store, which acts as a seasonal heat buffer to absorb heat in the summer and to release heat in the winter, to regulate the room temperature. This paper reports on the initial findings of a long-term study on the thermal behaviour of the thermal store and its effect to the indoor environment. It introduces the design and construction principles of the Earthship and outlines the process and equipment used in the thermal monitoring of the building. Indicative results from the analyses of the data collected at the early stage are reported and discussed. Initial findings have demonstrated the effectiveness of the thermal charging and discharging of the earth-rammed thermal mass, which appeared to moderate the extreme external temperatures.
In this work, a simplified electrochemical and thermal model that can predict both physicochemical and aging behavior of Li-ion batteries is studied. A sensitivity analysis of all its physical parameters is performed in order to find out their influence on the model output based on simulations under various conditions. The results gave hints on whether a parameter needs particular attention when measured or identified and on the conditions (e.g. temperature, discharge rate) under which it is the most sensitive. A specific simulation profile is designed for parameters involved in aging equations in order to determine their sensitivity. Finally, a step-wise method is followed to limit the influence of parameter values when identifying some of them, according to their relative sensitivity from the study. This sensitivity analysis and the subsequent step-wise identification method show very good results, such as a better fitting of the simulated cell voltage with experimental data.
This article aims to share a practical experience of how to set up a simple framework for better medical equipment management at public hospitals and health centres in Uganda for the 2006–2009 period. Three steps approach was employed. At first, all available medical equipment was categorised in six operational conditions and that were indicated on the equipment by eye-catching colour coded stickers; from A to F. Secondary, based on the inventory from the first step, the requirements for maintaining the medical equipment were analyzed and the prioritised action plans were prepared within the available funds. Third, a simple reporting format was developed to enable the health facility managers to monitor and evaluate medical equipment management. As for the accountability, specific information and repair work done is detailed in the job card and summarized in the monthly/quarterly report which submitted to the health facilities and Ministry of Health. The stickers indicate updated operational conditions that draw users and managers attention. Inventory based medical equipment management improves the transparency and accountability regarding the maintenance jobs and the cost of expenditure and estimation. Action plan based on listed all requirements helps health facility managers to focus on priority services using the available resources more efficiently. This case study is value for health facility managers in public sector to put in place a cost effective planning with limited financial resources, especially in resource constrained settings.
Producing hydrogen (H2) by splitting water with fossil-free electricity is considered a grand challenge for developing sustainable energy systems and a carbon dioxide free source of renewable H2. Renewable H2 may be produced from water by electrolysis with either low efficiency alkaline electrolyzers that suffer 50–65% losses, or by more efficient acidic electrolyzers with rare platinum group metal catalysts (Pt). Consequently, research has focused on developing alternative, cheap, and robust catalysts made from earth-abundant elements. Here, we show that crystalline Ni5P4 evolves H2 with geometric electrical to chemical conversion efficiency on par with Pt in strong acid (33 mV dec−1 Tafel slope and −62 mV overpotential at −100 mA cm−2 in 1 M H2SO4). The conductivity of Ni5P4 microparticles is sufficient to allow fabrication of electrodes without conducting binders by pressing pellets. Significantly, no catalyst degradation is seen in short term studies at current densities of −10 mA cm−2, equivalent to ∼10% solar photoelectrical conversion efficiency. The realization of a noble metal-free catalyst performing on par with Pt in both strong acid and base offers a key step towards industrially relevant electrolyzers competing with conventional H2 sources.
Recent reports have concentrated on some androgens/antiandrogens and confirmed that certain chemicals have demonstrated androgenic/antiandrogenic activities in vitro. However, it is still unknown whether more chemicals in the human environment possess endocrine toxicity. 58A novel AR-mediated reporter gene assay based on LLC-MK2 cells was established by transiently co-transfecting with pARE-sv40-Luc, hAR-pcDNA3.1 and pRL-tk. pARE-sv40-Luc was constructed using a pGL3-promoter plasmid with three repeated androgen responsive elements. hAR-pcDNA3.1 was constructed using pcDNA3.1 with a hAR sequence. After transfection for 12 h, the culture medium was exposed to various concentrations of dihydrotestosterone (DHT) and other test chemicals (phthalic acid esters and dexamethasone) in order to measure the androgenic/antiandrogenic activity. The assay possessed a concentration-dependent response to DHT from 10−12 M to 10−6 M. Nilutamide concentrations of over 10−7 M completely blocked the luciferase expression induced by 10−9 M DHT. Other data showed that DBP, DEHP and MEHP possessed weak androgenic activity for certain concentration ranges, while DMP, DINP and DIBP did not show any androgenic activity. Moreover, five PAEs (DBP, DEHP, DINP, DIBP and MEHP) showed corresponding antiandrogenic activities for certain concentrations with an approximate tendency (MEHP > DBP > DEHP > DIBP > DINP). The assay is high-throughput, specific, and sensitive for the detection of androgenic/antiandrogenic chemicals. In addition, PAEs (especially transitional PAEs) exhibited corresponding androgenic/antiandrogenic activities for certain concentration ranges.
We here report a method for the facile and large scale preparation of lithium-ion battery anodes based on α-Fe2O3 (hematite) nanorods with different textural characteristics and surface composition. The method combines electrostatically driven self-assembly approaches with specific adsorption and magnetically easy to disrupt soft aggregates. Special emphasis has been set to correlate the textural characteristics (porosity) and surface composition (core, core–nanoshell and core–double nanoshells) of nanorods with their electrochemical response. Thus, we have shown that nanorods present a nanophase whose specific capacity strongly depends on the lithium transport distances (nanorods with slit-shape mesopores running along their long axis vs. non-porous or surface blocked nanorods). We have also shown that the capacity retention of this nanophase after several charge–discharge processes depends on maintaining the structural integrity of the nanorods. Essential for the success of this latter study has been the use of nanorods that offer a simple tool (oriented X-ray line broadening) to follow their electrochemical grinding. Our data suggest that α-Fe2O3 mesoporous nanorods could both operate at a voltage and retain a capacity similar to that of nanostructured lithium titanates anodes if actions are taken to prevent electrochemical grinding.
Processing of arsenopyrite ore took place at Blackwater Au mine, New Zealand, between 1908 and 1951 and no rehabilitation was undertaken after mine closure. High As concentrations in solid processing residues (up to 40wt% As) are due to secondary As minerals. Site pH regimes vary from 4.1 to circum-neutral. Originally, all processed As was present as arsenolite (arsenic trioxide polymorph, AsIII), a by-product of arsenopyrite roasting. Near the roaster, scorodite precipitated as a result of the high dissolved As concentration during arsenolite dissolution. The formation of scorodite has two major consequences. Firstly, the scorodite precipitate cements the ground in the vicinity of the roaster area, thereby creating an impermeable surface crust (up to 30wt% As) and encapsulating weathered arsenolite grains within the cement. Secondly, formation of scorodite temporarily immobilizes some of the dissolved As that is generated during nearby arsenolite dissolution. Where all the available arsenolite has dissolved, scorodite becomes soluble, and the dissolved As concentrations are controlled by scorodite solubility, which is at least two orders of magnitudes lower than arsenolite solubility. Downstream Eh conditions fall below the AsV/AsIII boundary, so that scorodite does not precipitate and dissolved As concentrations are controlled by arsenolite solubility. Dissolved As reaches up to 52mg/L in places, and exceeds the current WHO drinking water guideline of 0.01mg/L by 5200 times. This study shows that dissolved As concentrations in discharge waters at historic mine sites are dependent on the processing technology and associated mineralogy.
Recent explosive growth in computing and wireless communication technologies has led to an increasing interest in mobile ad hoc networks (MANET). Among the many challenges for MANET designers and users, data availability is a critical issue. Caching is considered as an effective solution for the availability problem. Although cooperative caching improves the data access by reducing access latency and bandwidth usage in MANETs, it still suffers from several hurdles and technical problems. This paper introduces a new cooperative caching strategy for MANETs, which is called Administrative Cluster-Based Cooperative Caching (ACCC). ACCC keeps at most two copies of the cached data items in each cluster. Moreover, it develops a new administrative module, which perfectly controls the caching process. ACCC is a cluster-based caching strategy, hence, it divides the network into a set of overlapping clusters. Each cluster is managed by a Cluster Manager (CM) as well as a Cluster Backup (CB). ACCC has several salient features that other techniques do not have such as: (i) the integration between CM and CB besides the integration among all the caching modules improves the data availability within the cluster, (ii) ACCC; maximizes the caching hit ratio, reduces access delay, and saves the battery power of network nodes. ACCC is simulated using Java Caching System JCS2 with the efficient platform Java Enterprise Edition EE8 using a client/server model. Experimental results have shown that ACCC outperforms recent cluster-based caching strategies as it introduces higher cache hit ratio as well as better data availability.
NEMB2010 will focus on the integration of engineering sciences, mechanical engineering, and nanotechnology to aid in addressing fundamental problems in biology and medicine and in developing devices for the early detection, imaging, and cure of diseases.
Objective This study investigated the use of 2 Synergy Micro-Pumps for full biventricular assist device (BiVAD) support. We examined right-sided and left-sided hemodynamic parameters over a range of right-sided and left-sided pump speeds in an acute, fibrillating, non-beating-heart model in sheep. Methods Five juvenile sheep (43 ± 2 kg) were implanted with two Synergy Micro-Pumps (CircuLite Inc, Saddle Brook, NJ), 1 in the right (RV) and 1 in the left ventricle (LV), through a median sternotomy. The RVAD outflow graft was anastomosed end-to-side to the pulmonary artery and the LVAD outflow to the ascending aorta. After surgical implantation of both pumps, ventricular fibrillation was induced and hemodynamic parameters were measured at 9 different levels of RVAD pump speed (from 20,000 to 28,000 rpm at 1,000-rpm increments), while the speed of the LVAD was set constant at 24,000, then at 26,000, and finally, at 28,000 rpm. Results At a fixed LVAD speed, RVAD and LVAD flow both increased identically as RVAD speed was increased. This was due to redistribution of blood volumes that resulted in resetting of pressure gradients across each pump and each vascular bed in a manner dictated by the pump pressure–flow characteristics. Results were similar with LVAD set at 24,000, 26,000, or 28,000 rpm. At the highest LVAD and RVAD speeds, flow averaged 3.1 ± 0.7 liters/min, and pressures in the right atrium, pulmonary artery, left atrium, and aorta averaged 2.2 ± 3.7, 24.4 ± 6.5, 22.4 ± 5.5, and 56.6 ± 8.5 mm Hg, respectively. Conclusion BiVAD support with the 2 Synergy Micro-Pumps is feasible and able to provide full hemodynamic support in sheep. This approach holds promise for providing biventricular partial support in humans and, in particular, for full support in small adults and children.
To date, conversion of chemical energy to electrical energy for portable power sources has primarily focused on available thermoelectric elements limited to low temperatures and, therefore, low Carnot efficiencies. With advances in thermoelectric (TE) and thermophotovoltaic (TPV) devices allowing higher hot side temperatures, there is an increasing need for small (cm3 scale, O(10–100) W chemical), stable platforms to fully oxidize practical liquid fuels with little pressure drop at high (∼800–1000°C), uniform temperatures. Hybrid heterogeneous/homogeneous (HH) reactors provide a means to achieve this. The heterogeneous nature of HH reactors offers inherent stability against reaction extinction while homogeneous reactions are capable of fully converting the fuel; combined, the net effect of HH operation shows promise to both intensify and stabilize a reactor subject to high throughput and heat losses. In this work, we examine the operation of a dodecane fueled parallel plate microreactor with platinum-coated walls targeted for TPV applications. Increasing the confinement of the reactor increases the rate of heat and mass transport to the catalytic walls and, simultaneously the reactor temperature and homogeneous reaction rates. It is shown that, by tuning the reactor confinement, it may be possible to deliver the high, uniform temperatures required for efficient thermal-to-electric power conversion with low diffusivity tactical fuels. Simplified models provide insight into the thermal behavior of the reactor and the role of homogeneous dodecane decomposition on reactor performance.
We successfully fabricated lithium titanate Li4Ti5O12 (LTO) thin film electrode at room temperature by aerosol deposition (AD) method. Agglomerated LTO powder with the size of 5–6 μm composed of primary sub-micron particles was used as raw material and deposited directly on a stainless steel substrate via room temperature impact consolidation (RTIC). X-ray diffraction patterns revealed that as-deposited LTO film has a same crystalline structure with raw powder and no secondary phases were formed during the deposition process. SEM observation showed that the film has porous structure consisted from LTO particles with the sizes of several 100 nm. As-deposited LTO film electrode showed good electrochemical property in liquid electrolyte. The discharge capacities of 159 mAh g−1 and 125 mAh g−1 were obtained at current density of 0.067 mA cm−2 (=0.5C rate) and 2.68 mA cm−2 (=20C rate). The former corresponds to 91% of theoretical capacity for LTO (=175 mAh g−1). The film electrode also showed good capacity retention, indicating that adhesion between the film and substrate are sufficiently strong.