The emergence and evolution of life on our planet was possible because the sun provides energy to our biosphere. Indeed, all life forms need energy for existence and proliferation in space and time. ...Light-energy conversion takes place in photosynthetic organisms that evolve in various environments featuring an impressive range of light intensities that span several orders of magnitude. This property is achieved by the evolution of mechanisms of efficient energy capture that involved development of antenna pigments and pigment–protein complexes as well as the emergence of various strategies on the organismal, cellular, and molecular levels to counteract the detrimental effects of high light intensity on the delicate photosynthetic apparatus. Darwin was one of the first to describe the behaviour of plants towards light. He noticed that some plants try to avoid full day-light and called this reaction paraheliotropism. However, it was only in the second half of the 20th century, when scientists began to discover the structure and molecular mechanisms of the photosynthetic machinery, that the reasons for paraheliotropisms became clear. This review explains the need for the evolution of light adaptations using the example of higher plants. The review focuses on short-term adaptation mechanisms that occur on the minute scale, showing that these processes are fast enough to track rapid fluctuations in light intensity and that they evolved to be effective, allowing for the expansion of plant habitats and promoting diversification and survival. Also introduced are the most recent developments in methods that enable quantification of the light intensities that can be tolerated by plants.
•The single-site mean-field formalism for segregation in multicomponent alloys is outlined.•Surface segregation is calculated for the (111) surface in austenitic steel and FeMnCrCoNi alloy.•In both ...alloys, strong surface segregation of Ni and anti-segregation of Cr is predicted.
Segregation modelling in multicomponent random alloys within the single-site mean-field approximation is considered. As an example, the surface segregation in austenite Fe70Cr20Ni10 and equimolar Fe20Mn20Co20Cr20Ni20 random fcc alloy towards the (111) facet is calculated using ab initiomultiple scattering technique in the coherent potential approximation (CPA). The results show a very similar trend in both alloys: relatively strong surface segregation of Ni and strong anti-segregation of Cr. However, in the case of Fe70Cr20Ni10, the reversal of the surface enrichment from Ni to Fe is observed at 1750 K, while the surface of FeMnCoCrNi is Ni-rich up to 2500 K.
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•Consolidated the underlaying notions of SPR sensors centred on Kretschmann principle supported by pictorial illustrations.•The impact of gold and silver nanoparticles on the ...performance of SPR sensor are scrutinised.•Dissected the upshot of magnetic and 2-D nanomaterials on the augmentation of SPR activity.•Analysed contemporary trends on quantification of biomolecule and the latitudes of future investigation.•Consequences of coupling SPR with various surface modes in augmenting performance of the sensor is elucidated.
The necessity for the development of highly sensitive and selective detection techniques for the investigation of biomolecules are inevitable. Surface plasmon resonance (SPR) based biosensor has developed as a sustainable and commercially applicable tool for this investigation. The detection of biomolecules, that are either toxic or useful to the environment, and the early diagnosis of disease biomarkers together come up with the key for better living. The exploration of this should give the prime concern for the real-time detection techniques that are cost-effective and least time-consuming. Here, we have briefly introduced the properties, classifications and characteristics of nanomaterials and that of the biosensors, we carefully analysed the properties of nanomaterials that can enhance sensor’s activity. We have given much importance to the recent development in the field of biosensing and the role of different nanomaterials including gold, silver, magnetic and 2D nanomaterials in enhancing the properties of SPR sensors under various configurations with explaining the principle and mechanism of SPR in brief. Along with this, we have addressed the phase matching schemes for SPR and the coupling of SPR with other modes such as guided modes, phonon polariton and defect modes in enhancing performance. The role of other plasmons such as Tamm plasmons and Bloch surface waves are also included in the review.
Photosystems I and II convert solar energy into the chemical energy that powers life. Chlorophyll a photochemistry, using red light (680 to 700 nm), is near universal and is considered to define the ...energy "red limit" of oxygenic photosynthesis. We present biophysical studies on the photosystems from a cyanobacterium grown in far-red light (750 nm). The few long-wavelength chlorophylls present are well resolved from each other and from the majority pigment, chlorophyll a. Charge separation in photosystem I and II uses chlorophyll f at 745 nm and chlorophyll f (or d) at 727 nm, respectively. Each photosystem has a few even longer-wavelength chlorophylls f that collect light and pass excitation energy uphill to the photochemically active pigments. These photosystems function beyond the red limit using far-red pigments in only a few key positions.
The necessity for advancement in the field of energy storage devices is inevitable due to the forthcoming exhaustion in the availability of primitive hydrocarbon deposits. Benign and ecological ...renewable sources can opt as the perfect substitution for fossil fuels as a remedy for sustainability, which can be stored to meet the overflowing energy demand. Even a single spark in the development of energy storage devices can be viewed as an explosion in the execution of future energy concerns. This review is a token of recent progress in the arena of two-dimensional material-based supercapacitors for energy storage applications, manuscript starts with the need for energy storage devices in the anticipation of upcoming energy catastrophe. A brief introduction to the capacitors along with their classification under various parameters and their peaks and valleys in storing energy are included in the review. The chief attention of the appraisal stands on the capacitors employing the pseudo mechanism but those based on electrochemical double layer and faradaic mechanism are also included along with performance evaluation. The role of various 2D materials including graphene, molybdenum-based TMDs, tungsten-based TMDs, MXene, two-dimensional metal-oxides and phosphides in enhancing the charge storage performance are scrutinized in the review.
•Investigated the underlaying concepts of supercapacitors supported by pictorial illustrations.•The impact of graphene-based compounds, TMDCs, and MXene on the performance of supercapacitors are scrutinized.•Dissected the upshot of two-dimensional metal-oxides and metal-phosphides on the augmentation of SPR activity.•An integrated overview of various two-dimensional materials in altering the electrochemical behaviour is presented.•Analyzed challenges on commercialisation of supercapacitors and the latitudes of future investigation.
Geodiversity can be defined as either number of geological heritage types or qualitative characteristics of the unique geological environment. Geodiversity can be used for the purposes of science, ...education, and tourism, and, thus, this is a precious resource requiring efficient exploitation for production of socio-economic benefits. Geoparks are ideal instruments of the geodiversity resource exploitation. Their efficacy on the international scale is clear, but their role in countries is yet to be discussed. The assessment of the dominant geological heritage types in all geoparks (members of the UNESCO Global Geoparks) of seven countries with their big number (China, France, Germany, Italy, Japan, Spain, and the United Kingdom) suggest that about a half of the known types are represented in the geoparks of each of these countries. However, the exploitation of the geodiversity resource on the national level is not full because some types are missed and those available differ by the relative importance. It appears that the UNESCO Global Geopark network does not match the national interests ideally (partly because the UNESCO initiative is not aimed at the national level by definition). It is recommended that countries should develop their own policy of efficient geodiversity resource exploitation via geopark creation. As much geological heritage types as possible should be represented in geoparks, and the very ideas of geodiversity and geoparks should be promoted actively among the broad public and the policy-makers.
•Geodiversity – number of types of geological phenomena on a given area.•Geodiversity is a nationally-important geological resource.•Geoparks are important for this resource exploitation.•True importance of geoparks for geodiversity exploitation in countries is limited.•National policy should be developed to exploit geodiversity resource efficiently.
Phase equilibria in alloys to a great extent are governed by the ordering behavior of alloy species. One of the important goals of alloy theory is therefore to be able to simulate these kinds of ...phenomena on the basis of first principles. Unfortunately, it is impossible, even with present day total energy software, to calculate entirely from first principles the changes in the internal energy caused by changes of the atomic configurations in systems with several thousand atoms at the rate required by statistical thermodynamics simulations. The time-honored solution to this problem that we shall review in this paper is to obtain the configurational energy needed in the simulations from an Ising-type Hamiltonian with so-called effective cluster interactions associated with specific changes in the local atomic configuration. Finding accurate and reliable effective cluster interactions, which take into consideration all relevant thermal excitations, on the basis of first-principles methods is a formidable task. However, it pays off by opening new exciting perspectives and possibilities for materials science as well as for physics itself. In this paper we outline the basic principles and methods for calculating effective cluster interactions in metallic alloys. Special attention is paid to the source of errors in different computational schemes. We briefly review first-principles methods concentrating on approximations used in density functional theory calculations, Green's function method and methods for random alloys based on the coherent potential approximation. We formulate criteria for the validity of the supercell approach in the calculations of properties of random alloys. The generalized perturbation method, which is an effective and accurate tool for obtaining cluster interactions, is described in more detail. Concentrating mostly on the methodological side we give only a few examples of applications to the real systems. In particular, we show that the ground state structure of Au3Pd alloys should be a complex long-period superstructure, which is neither DO22 nor DO23 as has been recently predicted.
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•Gas sensors and its genera discoursed prudently.•Various gas sensing mechanism illustrated aptly.•Cited the prominence of recurrent review on volatile organic compounds, namely ...Toluene, Ethanol, Formaldehyde.•Analyzed the current trends and scope of detection of various volatile organic compound using sensors.•Overviewed the significance of utilizing nanomaterials in gas sensing.
The presence of toxic and harmful gases utterly dangers human health and environmental well-being. Selective detection of these gases is immediately required to meet the demands of society. A promising and presently thriving area for monitoring volatile organic compounds (VOCs) and combustible gases stems from the evolution of detection strategies meld with metal-oxide-based nano-materials. Even though the prevailing literature in nanoscience covers numerous reports on chemical sensing merged with nanotechnology, a few have focused on gas detection. This review takes the lead to study, categorize, and inspect the progressive gas detection approaches accessible in literature. Each gas sensing technique is analyzed based on the detection principle and is reviewed on various aspects such as gas detection, sensitivity, response /recovery time, sensor parameters, procedural complexity, detection variables, and sensor characteristics. Furthermore, this investigation serves as a valuable reference for researchers to recognize the mechanism behind the gas sensor’s fundamental facets. Concisely, this review elucidates the state of this field and induces/propels further research in this field.
The strontium–aluminium–hexaferrite was substituted with the divalent ions (Mg/Cu) with the chemical formula of Sr
1–
x
M
x
Al
2
Fe
10
O
19
(M = Mg, Cu;
x
= 0.1, 0.2), and all the samples were ...synthesized via sol–gel auto combustion method. The thermal studies disclosed endothermic and exothermic peaks and showed magnetic phase transition behaviour in the range of 350–450 °C. The particles are shaped in a hexagonal structure with space group P63/mmc and the crystallize size ranges between 44 and 53 nm. The field-emission scanning microscopy revealed the platelet-like morphology of the particles. The magnetic studies disclosed the fine range of magnetic saturation (40.87–49.76 emu/g) and coercivity values (4619–7647 Oe). The particles own single-domain arrangement and decent energy product value (0.32–0.38 MGO
e
), implying their potential application in permanent magnets. The lower dielectric constant values at high-frequency range suggest their potential employment in microwave applications.
A formalism for the vacancy formation energies in random alloys within the single-site mean-filed approximation, where vacancy-vacancy interaction is neglected, is outlined. It is shown that the ...alloy configurational entropy can substantially reduce the concentration of vacancies at high temperatures. The energetics of vacancies in random Cu sub(0.5) Ni sub(0.5) alloy is considered as a numerical example illustrating the developed formalism. It is shown that the effective formation energy increases with temperature, however, in this particular system it is still below the mean value of the vacancy formation energy, which would correspond to the vacancy formation energy in a homogeneous model of a random alloy, such as given by the coherent potential approximation.
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