The pairing of an aluminum anode with a cathode of high energy and power density determines the future of aluminum‐ion battery technology. The question is—“Is there any suitable cathode material ...which is capable of storing sufficiently large amount of trivalent aluminum‐ions at relatively higher operating potential?”. Graphene emerges to be a fitting answer. Graphene emerged in the research arena of aluminum‐ion battery merely three years ago. However, research progress in this front has since been tremendous. Outperforming all other known cathode materials, several remarkable breakthroughs have been made with graphene, in offering extraordinary energy density, power density, cycle life, thermal stability, safety and flexibility. The future of the Al–graphene couple is indeed bright. This Minireview highlights the electrochemical performances, advantages and challenges of using graphene as the cathode in aluminum‐ion batteries in conjugation with chloroaluminate based electrolytes. Additionally, the complex mechanism of charge storage in graphene is also elaborated.
Superpower: The electrochemical coupling of an aluminum anode with a graphene cathode holds extraordinary promise in delivering the much sought after utility demands of ultrahigh power density, ultralong durability, enhanced safety, and flexibility. This Minireview deals with the accomplishments and challenges of Al–graphene batteries.
Bio-oil is the liquid product of thermochemical liquefaction or pyrolysis of biomass. Thermochemical liquefaction (TCL) is a low temperature (250–350 °C) and high pressure (5–20 MPa) process ...particularly suited for high moisture feedstocks, whereas pyrolysis is accomplished at moderate to high temperatures (400–600 °C) and atmospheric pressure and requires drying of the feedstock. In this paper, we present experimental results that provide a critical comparison of TCL and slow pyrolysis processes for producing bio-oil from algae. TCL experiments were performed in a 1.8-L Parr reactor using algae slurry (80% moisture) and pyrolysis runs were carried out in an 8-L mild steel cubical reactor, using dried algal powder as received (∼4% moisture). Yields and composition of bio-oil, char, gases, and aqueous phase were evaluated and compared for TCL and pyrolysis. TCL resulted in higher bio-oil yields (∼41%), lower char yields (∼6.3%), and lower energy consumption ratio compared to pyrolysis, which resulted in 23–29% bio-oil, and 28–40% solids yields. Bio-oil obtained from TCL was found to have higher energy density and superior fuel properties such as thermal and storage stabilities, compared to pyrolysis bio-oil.
This paper studies the effect of first order chemical reaction and thermal radiation on hydromagnetic free convection heat and mass transfer flow of a micropolar fluid via a porous medium bounded by ...a semi-infinite porous plate with constant heat source in a rotating frame of reference. The plate is assumed to oscillate in time with constant frequency so that the solutions of the boundary layer are the same oscillatory type. The dimensionless governing equations for this investigation are solved analytically using small perturbation approximation. The effect of the various dimensionless parameters entering into the problem on the velocity, temperature and concentration profiles across the boundary layer are investigated through graphs. Also the results of the skin friction coefficient, couple stress coefficient, the rate of heat and mass transfer at the wall are prepared with various values of the parameters.
In this study, the economic and environmental benefits of stand-alone and grid integration are thoroughly analyzed with different system configurations of a PV/Wind/Diesel/Battery based hybrid energy ...system (HES) for five different climatic regions using hybrid optimization model for electric renewables (HOMER). A detailed techno-economic study of optimized hybrid systems is further examined by integrating the grid-connected option. The environmental benefits of HESs are discussed. The sensitivity of various sell-back price to the national grid is also investigated. Additionally, the barriers and opportunities of installing such projects in the off-grid regions are discussed. Results indicate that the cost of energy (COE, $/kWh) and the net present cost (NPC, $) of the stand-alone hybrid PV/Diesel/Battery for the Rajshahi region are slightly lower compared to other areas, considering the cost and environmental emissions. The same system in Chattogram shows great potential both financially and environmentally, over the other climatic zones. The grid-connected HES with the sell-back option offers significant cost-benefits (0.07$/kWh), even over the grid tariff (0.10$/kWh). Similar revenues can be attained with the grid-connected PV/Battery-based system as substantial amount of excess energy could be supplied to the grid facilities. In the grid integrated HES, around 45,582 kg-CO2/yr could be saved compared to grid only system, whereas this amount is 32,905 kg-CO2/yr over the stand-alone hybrid PV/Diesel/Battery one.
•The study investigates stand-alone hybrid PV/Diesel/Batt and grid-connected options.•Rajshahi region has the lower COE (0.28$/kWh) than the other region studied.•Grid-connected hybrid PV/Diesel/Batt option provides significant cost benefits.•Grid sell-back tariff higher than the grid purchase identifies a profitable venture.•Grid-connected hybrid system significantly reduces CO2 over grid-connected one.
This study investigates the potential application of hybridized energy system (i.e., PV/Wind/Diesel) with battery storage in the northern region of Bangladesh. A techno-economic feasibility of ...different system configurations is evaluated and an optimized system is selected using HOMER (Hybrid Optimization Model for Electric Renewable) software. The hybrid system is optimized to meet a remote stand-alone village community’s load demand of 242.56 kWh/day with a 51.52 kW peak load demand. The result of this study indicates that the optimized hybrid system consists of 73 kW PV arrays, a 57 kW Diesel generator, a 387 kWh nominal capacity battery bank, and 28 kW inverters have the minimum Cost of Energy (COE) of 0.37$/kWh and the Net Present Cost (NPC) of $357,284. The outcome also indicates that the optimized system reduces CO2 emission by around 62% in comparison with the kerosene used in a current situation and 67% with the grid connected system. Furthermore, the Life Cycle Emissions-LCE (kg CO2-eq/yr) production is considerably lower in PV/Batt/ICE system than the other system configurations. However, this system has a lower Duty Factor (DF) compared to Wind/Batt/Diesel and Batt/Diesel based system. Although this system is not comparable with the grid tariff, the proposed method is economically feasible than solar micro utility system, Wind/Batt/Diesel system, and Diesel generator only system. Additionally, the article discusses the social and economic benefits of implementing the hybridized system along with their barriers and challenges.
•Techno-economic feasibility of a hybridized energy system is carried out.•Cost of Energy, net present cost, operational and Life Cycle Emissions are analyzed.•Optimized system is economically viable in comparison to Solar Home Systems (SHSs).•The system configuration has sensible economical, environmental, and social benefits.
Nitrogen (N) is an essential element required for the growth and development of all plants. On a global scale, N is agriculture's most widely used fertilizer nutrient. Studies have shown that crops ...use only 50% of the applied N effectively, while the rest is lost through various pathways to the surrounding environment. Furthermore, lost N negatively impacts the farmer's return on investment and pollutes the water, soil, and air. Therefore, enhancing nitrogen use efficiency (NUE) is critical in crop improvement programs and agronomic management systems. The major processes responsible for low N use are the volatilization, surface runoff, leaching, and denitrification of N. Improving NUE through agronomic management practices and high-throughput technologies would reduce the need for intensive N application and minimize the negative impact of N on the environment. The harmonization of agronomic, genetic, and biotechnological tools will improve the efficiency of N assimilation in crops and align agricultural systems with global needs to protect environmental functions and resources. Therefore, this review summarizes the literature on nitrogen loss, factors affecting NUE, and agronomic and genetic approaches for improving NUE in various crops and proposes a pathway to bring together agronomic and environmental needs.
In a coalescence plus fragmentation approach we calculate the heavy baryon/meson ratio and the
p
T
spectra of charmed hadrons
D
0
,
D
s
and
Λ
c
+
in a wide range of transverse momentum from low
p
T
...up to about 10 GeV and discuss their ratios from RHIC to LHC energies without any change of the coalescence parameters. We have included the contribution from decays of heavy hadron resonances and also the one due to fragmentation of heavy quarks which do not undergo the coalescence process. The coalescence process is tuned to have all charm quarks hadronizing in the
p
T
→
0
limit and at finite
p
T
charm quarks not undergoing coalescence are hadronized by independent fragmentation. The
p
T
dependence of the baryon/meson ratios are found to be sensitive to the masses of coalescing quarks, in particular the
Λ
c
/
D
0
can reach values of about
1
÷
1.5
at
p
T
≈
3
GeV, or larger, similarly to the light baryon/meson ratio like
p
/
π
and
Λ
/
K
, however a marked difference is a quite weak
p
T
dependence with respect to the light case, such that a larger value at intermediate
p
T
implies a relatively large value also for the integrated yields. A comparison with other coalescence model and with the prediction of thermal model is discussed.
The functions of intrinsically disordered proteins (IDPs) are governed by relationships between information encoded in their amino acid sequences and the ensembles of conformations that they sample ...as autonomous units. Most IDPs are polyampholytes, with sequences that include both positively and negatively charged residues. Accordingly, we focus here on the sequence–ensemble relationships of polyampholytic IDPs. The fraction of charged residues discriminates between weak and strong polyampholytes. Using atomistic simulations, we show that weak polyampholytes form globules, whereas the conformational preferences of strong polyampholytes are determined by a combination of fraction of charged residues values and the linear sequence distributions of oppositely charged residues. We quantify the latter using a patterning parameter κ that lies between zero and one. The value of κ is low for well-mixed sequences, and in these sequences, intrachain electrostatic repulsions and attractions are counterbalanced, leading to the unmasking of preferences for conformations that resemble either self-avoiding random walks or generic Flory random coils. Segregation of oppositely charged residues within linear sequences leads to high κ -values and preferences for hairpin-like conformations caused by long-range electrostatic attractions induced by conformational fluctuations. We propose a scaling theory to explain the sequence-encoded conformational properties of strong polyampholytes. We show that naturally occurring strong polyampholytes have low κ -values, and this feature implies a selection for random coil ensembles. The design of sequences with different κ -values demonstrably alters the conformational preferences of polyampholytic IDPs, and this ability could become a useful tool for enabling direct inquiries into connections between sequence–ensemble relationships and functions of IDPs.
Understanding the interactions of silver nanoparticles (AgNPs) with the cell surface is crucial for the evaluation of bactericidal activity and for advanced biomedical and environmental applications. ...Biosynthesis of AgNPs was carried out through in situ reduction of silver nitrate (AgNO3) by cell free protein of Rhizopus oryzae and the synthesized AgNPs was characterized by UV–vis spectroscopy, high resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), ζ-potential analysis, and FTIR spectroscopy. The HRTEM measurement confirmed the formation of 7.1 ± 1.2 nm AgNPs, whereas DLS study demonstrated average hydrodynamic size of AgNPs as 9.1 ± 1.6 nm. The antibacterial activity of the biosynthesized AgNPs (ζ = −17.1 ± 1.2 mV) was evaluated against Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa. The results showed that AgNPs exhibited concentration dependent antibacterial activity and 100% killing of E. coli and P. aeruginosa achieved when the cells were treated with 4.5 and 2.7 μg/mL AgNPs, respectively for 4 h. Furthermore, the intracellular reactive oxygen species (ROS) production suppressed the antioxidant defense and exerted mechanical damage to the membrane. AgNPs also induced surface charge neutralization and altered of the cell membrane permeability causing nonviability of the cells. Atomic force microscopy (AFM) studies depicted alteration of ultrastructural and nanomechanical properties of the cell surface following interaction with AgNPs, whereas FTIR spectroscopic analysis demonstrated that cell membrane of the treated cells underwent an order-to-disorder transition during the killing process and chemical composition of the cell membrane including fatty acids, proteins, and carbohydrates was decomposed following interaction with AgNPs.
► Optimum liquefaction conditions were 350
°C temperature, 60
min time, 20% solids. ► Biocrude yield at optimum thermochemical liquefaction (TCL) was 39.9%. ► Carbon conversion efficiency for most ...TCL runs were
>93%. ► Biocrudes obtained at 350–380
°C had fuel properties close to the petroleum crude.
This study investigated the optimum thermochemical liquefaction (TCL) operating conditions for producing biocrude from
Spirulina platensis. TCL experiments were performed at various temperatures (200–380
°C), holding times (0–120
min), and solids concentrations (10–50%). TCL conversion at 350
°C, 60
min holding time and 20% solids concentration produced the highest biocrude yield of 39.9% representing 98.3% carbon conversion efficiency. Light fraction biocrude (B
1) appeared at 300
°C or higher temperatures and represented 50–63% of the total biocrude. Biocrude obtained at 350–380
°C had similar fuel properties to that of petroleum crude with energy density of 34.7–39.9
MJ
kg
−1 compared to 42.9
MJ
kg
−1 for petroleum crude. Biocrude from conversion at 300
°C or above had 71–77% elemental carbon, and 0.6–11.6% elemental oxygen and viscosities in the range 40–68 cP. GC/MS of biocrude reported higher hydrocarbons (C
16–C
17), phenolics, carboxylic acids, esters, aldehydes, amines, and amides.
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