Ugo Bardi

• University of Florence

Goessling et al. (1) link the record-breaking warming anomaly of 2023 to a global albedo decline due to reduced low-level cloud cover. What caused the reduction remains unclear. Goessling et al. considered several geophysical mechanisms, including ocean surface warming and declining aerosol emissions, but did not discuss the biosphere. We propose t...

Urban gardening mainly means growing edible vegetables in a town. This practice has been traditionally used for economic reasons (subsistence agriculture), but now it has also acquired educational, nutraceutical, therapeutic and social relevance. The educational aspect of urban gardening has been the subject of a proposal for the newly born Science...

The terrestrial water cycle links the soil and atmosphere moisture reservoirs through four fluxes: precipitation, evaporation, runoff, and atmospheric moisture convergence (net import of water vapor to balance runoff). Each of these processes is essential for sustaining human and ecosystem well‐being. Predicting how the water cycle responds to chan...

Limiting climate heating while meeting basic needs of all necessitates eliminating fossil carbon emissions. This paper discusses the dynamics of mobilizing materials required for large-scale deployment of renewable energy, which entail: 1) availability of resources in the environment and technosphere; 2) accessibility, which depends on resource qua...

The terrestrial water cycle links the soil and atmosphere moisture reservoirs through four fluxes: precipitation, evaporation, runoff, and atmospheric moisture convergence (net import of water vapor to balance runoff). Each of these processes is essential for human and ecosystem well-being. Predicting how the water cycle responds to changes in vege...

The terrestrial water cycle links the soil and atmosphere moisture reservoirs through four fluxes: precipitation, evaporation, runoff and atmospheric moisture convergence. Each of these fluxes is essential for human and ecosystem well-being. However, predicting how the water cycle responds to changes in vegetation cover, remains a challenge (Lawren...

The editors of Corrosion Management for a Sustainable Future, working in DNV’s Strategic Research and Innovation group at the time, examined facets of the materials lifecycle to help identify strategies that could be undertaken to mitigate the exponential increase in materials extraction and consumption that have characterized the rise of the moder...

Lettera aperta di 30 scienziati italiani al Presidente del Consiglio dei Ministri, Prof. Mario Draghi, a supporto di una vera transizione ecologica dell'economia nazionale post COVID-19 attraverso il Recovery Fund e il Piano Nazionale di Ripresa e Resilienza (PNRR).

Nobody has to tell you that when things go bad, they go bad quickly and seemingly in bunches. Complicated structures like buildings or bridges are slow and laborious to build but, with a design flaw or enough explosive energy, take only seconds to collapse. This fate can befall a company, the stock market, or your house or town after a natural disa...

20 years ago, in 1998, Scientific American published a paper by Colin J. Campbell and Jean H. Laherrère titled “The End of Cheap Oil” [1], starting a debate on oil depletion continuing to the present day. It was the return of a viewpoint on oil depletion which had been proposed more than 40 years before by Marion King Hubbert [2]⁠ and, in later yea...

The implementation of sustainability initiatives on campuses is an essential component of promoting sustainability in the higher education context. In addition to reflecting an awareness of environmental issues, campus programmes demonstrate how seriously universities take sustainability at the institutional level. There is a lack of truly interdi...

Nanoscience is a powerful tool to study matter at the scale where cooperative actions among atomic and molecular assemblies are effective, that is, in the nanometer range. Its application to technology is expected to bring new ways to improve our life by means of applications in the field such as environmental and material science, pharmacy, and me...

Journal of Population and Sustainability Journal Vol.2 No.2. Papers by: DAVID SAMWAYS - Anthropocentrism – The Origin of Environmental Degradation? UGO BARDI - A Seneca Collapse for the World’s Human Population? DOUGLAS E. BOOTH - Postmaterial Experience Economics, Population, and Environmental Sustainability. WILLIAM N. RYERSON - The Hidden Gem o...

Journal of Population and Sustainability Vol 2 No 1. Papers by: KERRYN HIGGS - Limits to Growth: Human Economy and Planetary Boundaries. JOEL E. COHEN - How Many People Can the Earth Support? JONATHON PORRITT AND COLIN HINES - Reflections on the Current Immigration Debate in the UK. JULIAN ROCHEBeyond the One-child Policy: A Response to Conly. UGO...

A novel aluminizing process based upon room temperature Al-electrodeposition from Ionic Liquids followed by diffusion heat treatment was applied on bare- and CoNiCrAlY-coated Inconel 738 (IN738). The aluminized samples were tested by isothermal oxidation at 1000 °C in air. The microstructural and chemical evolution of the samples were determined as...

In this study, we report on the effects of three common transition metal ions, i.e., Ni²⁺, Cu²⁺ and Fe³⁺ on the electrodeposition of aluminum from a chloroaluminate ionic liquid, evaluated by means of electrochemical and morphological investigation. Aiming at the determination of the morphological and chemical effects on the aluminum coatings, vari...

The essence of this book can be found in a line written by the ancient Roman Stoic Philosopher Lucius Annaeus Seneca: "Fortune is of sluggish growth, but ruin is rapid". This sentence summarizes the features of the phenomenon that we call "collapse," which is typically sudden and often unexpected, like the proverbial "house of cards." But why are s...

The concept that mineral resources are finite and irreplaceable is relatively modern, probably expressed for the first time by Georg Bauer (also known as Agricola) in the sixteenth century. In a more general sense, the idea that all natural resources are finite seems to have appeared for the first time in economics with the work of Thomas Malthus,...

The statuary group of Perseus and Medusa by Benvenuto Cellini, kept in the “Loggia de’ Lanzi” in Florence, Italy, is a major artistic and metallurgical feat. The present paper will outline the several links between the monumental casting work and the political and cultural situation of the time. In particular, it will describe the symbolism of the...

"Overshoot" is a concept that has been debated from when it first been proposed. As a specific term, it goes back to William Catton's 1980 "Overshoot" book, but the idea goes back to earlier works, including "The Limits to Growth" of 1972, with perhaps the first clear and complete description of the idea by Garret Hardin with his 1968 paper titled...

The Anthropocene is a proposed time subdivision of the earth’s history correlated with the strong perturbation of the ecosystem created by human activity. Much debate is ongoing about what date should be considered as the start of the Anthropocene, but much less on how it will evolve in the future and what are its ultimate limits. It is argued here...

Peak minerals analizes the current trend in the extraction of 57 of the most common minerals with a Hubbert linearization models, in order to evaluate Ultimately Recoverable Resources and possible future dates in production peaks

This article reviews the findings of the 1972 report titled ‘The Limits to Growth’ and the debate that followed its publication. This study was one of the first attempts at quantifying how the world's economic system evolves as a function of the availability of natural resources, pollution, and population growth. The general conclusion was that the...

This article reviews the concept of ‘peak oil’ showing that it is a consequence of a combination of geological and economic factors that are normally present when exploiting a finite resource under a free (or nearly free) market conditions. The concept of peak oil is then analyzed in view of the reactions to the concept during the more than half a...

The Anthropocene is a proposed time subdivision of the earth's history correlated to the strong human perturbation of the ecosystem. Much debate is ongoing about what date should be considered as the start of the Anthropocene, but much less on how it can evolve in the future and what are its ultimate limits. It is argued here that the phenomena cur...

The transition from a fossil-based energy economy to one based on renewable energy is driven by the double challenge of climate change and resource depletion. Building a renewable energy infrastructure requires an upfront energy investment that subtracts from the net energy available to society. This investment is determined by the need to transiti...

The modern industrial cycle is mainly based on non-renewable mineral resources extracted from the Earth’s crust. After being processed and transformed into commodities, the products of mining become manufactured products which go through the economic system and are then discarded in the form of gaseous, liquid or solid waste. Eventually, the mass o...

Since the second half of the 20th century, various devices have been developed in order to reduce the emissions of harmful substances at the exhaust pipe of combustion engines. In the automotive field, the most diffuse and best known device of this kind is the “three way” catalytic converter for engines using the Otto cycle designed to abate the em...

We examine the trends in Healthy Life Years Expectancy (HLYE) at birth during the past few decades in Europe. We observe that several European countries show a significant drop in HLYE at birth starting from 2003; interrupting what had been a previous continuous increase. We discuss the possible causes of this drop, including a possible correlation...

Interfaces and surfaces are the regions where important events happen: catalysis, molecular recognition, charge transfer, polymerization, and many other critical processes take place at the boundary between one medium and another. In this article we discuss the interface (liquid/air) properties of ionic liquids (ILs) containing dissolved metal ions...

The aim of this work is to examine how energy parameters such as EROEI (energy return for energy invested) and net energy (energy produced minus energy spent) are related to progressive exploitation of a non renewable resource such as crude oil. ► By using a simple dynamic model, we find that EROEI is proportional to the amount of remaining resourc...

CoNiCrAlY coatings were produced by means of the vacuum plasma spraying (VPS) process onto CMSX-4 single crystal nickel superalloy disk substrates. As-sprayed samples were annealed at high temperatures in low vacuum. Three kinds of finishing processes were carried out, producing three types of samples: as-sprayed, mechanically smoothed by grinding,...

' Energy is the only universal ingredient in the natural and human worlds. And abundant as the energy source might be, we cannot avoid the physical fact that its use is irreversible and it cannot be recycled'

This paper reviews the historical development of both biogenic and non-biogenic petroleum formation. It also examines the recent claim that the so-called “abiotic” oil formation theory undermines the concept of “peak oil,” i.e. the notion that world oil production is destined to reach a maximum that will be followed by an irreversible decline. We s...

The journal Coatings is starting its activity as a peer-reviewed, open access journal. As editors, we believe that it will fulfill an important role in the community of researchers and developers in the field of coatings. There already exists several high quality journals dedicated to coatings, but none of them has “free access”, a characteristic t...

Two CoNiCrAlY powders with similar chemical composition and granulometry, but with different starting reactivity toward oxygen, were sprayed by High Velocity Oxygen Fuel (HVOF) onto Hastelloy X superalloy substrates obtaining coatings of comparable thickness. After spraying, samples were maintained at 1000 °C in air for different test periods up to...

Commercial CoNiCrAlY powders with the same chemical composition were sprayed by vacuum plasma spraying (VPS), air plasma spraying (APS) and high velocity oxygen fuel (HVOF) onto Hastelloy X superalloy substrates obtaining coatings of comparable thickness. After coating, samples were maintained at 1273 K in air for different periods up to 3000 h. Mo...

CoNiCrAlY powders with similar granulometry and chemical composition, but different starting reactivity toward oxygen, were sprayed onto superalloy substrates by High Velocity Oxygen-Fuel producing coatings of similar thicknesses. After spraying, samples were maintained at 1,273 K in air for different test periods of up to 5,000 hours. Morphologica...

This paper is dedicated to the study of electrodeposited aluminium layers as anticorrosion protective coatings on metallic substrates. The aim of this approach is to propose a non-toxic alternative to the traditional nickel–chromium coating, for anticorrosive and decorative purposes. Aluminium was electrodeposited on carbon steel substrates from ch...

In this paper we report the results of a study on the corrosion properties of carbon steel (UNI Fe360B) coated with a thin aluminium layer electrodeposited from ionic liquids and subsequently post-treated in an oxidizing environment. Two different types of treatments were investigated: thermal oxidation in air and electrochemical anodization. We fo...

The RAMseS project, under the European Commission's 6th Framework Program, is dedicated to the construction and test of low-power operations based on photovoltaic power and a multipurpose electric vehicle. In the present study, the life-cycle costs and economical indices for the vehicle during its life span were assessed, compared to those of a sta...

The RAMseS project, financed by the European Commission under the 6th framework Program, has the purpose of developing a solar powered agricultural vehicle in order to replace the conventional vehicles based on internal combustion engines (ICE). In the present study, we report a comparison of life-cycle emission between two systems; a conventional...

MCrAlY coatings are applied as bond coat for thermal barrier coating manufacturing or alone to protect the base materials of hot sections of power generation plants and aircraft engines from high temperature oxidation and hot corrosion condition. In function of the operating conditions of the component to be coated and/or of economical consideratio...

Knudsen high-temperature mass spectrometry was used to study the process of sublimation of a solid electrolyte (AgI)(0.5-)(AgPO(3))(0.5). Monoatomic iodine ions were found to be the dominant species in the electron ionization mass spectra below 600 degrees C. With an increase in temperature, the relative content of phosphorus oxide ions, mainly [PO...

Peak oil is a widely studied and discussed topic. Minerals show the same behavior,as a non renewable resource. Hubbert peak is discussed for some of themost commn elements

The AISI 304 and AISI 1018 steels (frequently used in solar collectors’ plants) in contact with four different ionic liquids (ILs) suitable as diathermic fluids, were studied. Immersion tests were performed at 220 °C (the working temperature in such plants) for 10 days. The corrosion morphologies of the steels were investigated by scanning electron...

The protective action of thin layers of aluminium electroplated on a carbon steel (UNI Fe360B) has been studied. The coatings were obtained via electroreduction, at room temperature, from an ionic liquid constituted by 1-butyl-3-methyl-imidazolium heptachloroaluminate. Coatings of different thickness, ranging from 10 to 40 μm, were obtained. Their...

The oxidation behaviour of NiCrAlY coatings made by laser cladding on Hastelloy X is presented in this study. Laser cladding is an alternative method to thermal spraying for the production of bond coats. Comparable dense layers with approximately zero porosity should improve the oxidation behaviour. The oxidation behaviour of the coated specimens w...

TiO2 thin coatings were prepared, on various substrates, through evaporation of metallic titanium in an oxidizing atmosphere by modified electric arc-physical vapor deposition (EA-PVD). The coatings were characterized chemically (by means of XPS and SIMS) and from the structural point of view (by means of XRD and Raman spectroscopy), in order to un...

The influence of temperature on the kinetics and the morphology of silver deposits obtained from an air and water-stable ionic liquid (the 1-butyl-3-methyl imidazolium tetrafluoroborate) was studied by means of cyclic voltammetry and chronoamperometry. The nucleation and growth mechanisms have been investigated and the effect of temperature evaluat...

The characterization of the interaction of an imidazolium based ionic liquid (IL) and the surface of the die-cast AZ91D Magnesium alloy was studied. The ionic liquid used was composed of 1-butyl-3-methyl-imidazolium as cation and bis (trifluoromethylsulfonyl) imide as anion. Variation of the surface average roughness by a profilograph was monitored...

The present paper argues that solar power technologies, such as photovoltaic panels and wind turbines, should be regarded as a form of agriculture in the paradigm named here “solar power agriculture”. These technologies share several features with traditional agriculture, for instance the basic process of energy conversion by collecting solar light...

The paper reports the experience on the use of the Femlab multiphysics software as a tool for the electrochemical education. The equation oriented structure of Femlab keeps a constant view on the physics of the process, a desirable property for educational purposes. The program allows the models set up starting from the basic equations governing th...

The corrosion behaviour of several metals and metal alloys (copper, nickel, AISI 1018 steel, brass, Inconel 600) exposed to a typical ionic liquid, the 1-butyl-3-methyl-imidazolium bis-(trifluoromethanesulfonyl) imide, ([C4mim][Tf2N]), has been investigated by electrochemical and weight-loss methods. Corrosion current densities have been determined...

The Hubbert model of crude oil production can describe several regional cases, but it is not yet generally accepted as being of validi for all cases, especially for the worldwide case of oil extraction. The present paper shows that the model is of general validity to describe cases in which a resource is depleted faster than it can be replaced, as...

The use of ionic liquids based on 1-buthyl-3-methyl-imidazolium as electrolytes in an activated carbon//poly(3-methylthiophene) hybrid supercapacitor was investigated. Preliminary results of the electrochemical characterization of electrodes sized for practical use in the supercapacitor and of a laboratory scale cell are reported and compared to th...

We investigate the Ir(110)-c(2×4)S adsorbate system using X-ray photoelectron diffraction. As proposed by a previous structure model based on a scanning tunneling microscopy experiment, we find that sulfur atoms of this superstructure enter the second adsorption layer. In contrast to the existing structure model the adatoms do not occupy on-top ads...

We report here the result of a study of different chemical stripping methodologies for ceramic coatings deposited by PVD on hard metal substrates. We show that an approach based on the study of the system by surface science techniques leads to the possibility of developing effective stripping methods as well as guidelines for improving the process....

Electrochemical Atomic Layer Epitaxy (ECALE) was used to obtain multi-atomic layers of CdS on a single crystal Ag(111) substrate. Electrochemical stripping measurements indicate that the amount of Cd and S in these films corresponds to the stoichiometric 1:1 ratio. This result was confirmed by X-ray photoelectron spectroscopy (XPS). Measurements pe...

A single-crystal FeSi(100) sample has been studied by means of X-ray photoelectron diffraction (XPD) and low-energy ion scattering (LEIS) in order to investigate the structure and the composition of the outermost atomic layers. XPD intensity plots for the Fe 2p and Si 2s core levels were acquired, and the experimental results were compared with the...

The surface composition of the phases formed when growing ultra-thin chromium films on the ZnO(0001̄) surface has been investigated by means of low energy ion scattering (LEIS) and X-ray photoelectron spectroscopy (XPS). Changes in the oxidation states of both zinc and chromium occurring during chromium deposition at room temperature show evidence...

At relatively high electron energies, the patterns observed in X-ray photoelectron diffraction (XPED) for light solids are dominated by “bands” corresponding to the main crystallographic planes in the crystal. These bands can be termed “Kikuchi-like” and occur for the same reasons that give rise to the well-known Kikuchi bands in electron diffracti...

The formation of a spinel phase was observed after chromium deposition on a ZnO single crystal substrate and subsequent annealing. The structure of the spinel and its epitaxial relationship with the substrate were investigated by using X-ray photoelectron diffraction. Experimental data are discussed on the basis of a single scattering cluster-spher...

Gold and gold−copper particles of sizes of the order of nanometers were prepared in reverse micelles, with different sizes of the water pool, by controlled chemical reduction of metal cations. The nanoclusters were characterized by a combination of dynamic light scattering (QELS), transmission electron microscopy, and X-ray photoelectron spectrosco...

This study examines the structure of the surface alloys that form at the surface of the system formed by depositing cobalt on the clean Pt(111) surface. Using mainly XPD as a structure-sensitive technique, surface alloys were observed to form in this system after annealing at temperatures of about 600 K or higher. When starting with a single atomic...

Ultrathin cobalt films were deposited by thermal evaporation on the Pt(110) surface at room temperature. The growth mechanism was studied by a combination of low energy He+ scattering (LEIS) and X-ray photoelectron spectroscopy (XPS). The results indicate that during the initial stages of growth cobalt forms a layer of single atomic thickness. X-ra...

Chloride layers of thickness of several atomic layers were prepared by low temperature reaction of Cl2 with a clean Cu(001) surface. The structure of the chloride layer was examined by X-ray photoelectron diffraction (XPD). The results of the comparison of experimental XPD data and calculations carried out using the single scattering cluster-spheri...

Cobalt was vapor deposited in vacuum on the clean Pd(001) surface. The growth mode and the structure of the overlayer were studied by low energy He+ ion scattering (LEIS), X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD). By examining the dependency of the LEIS signal as a function of the XPS one for various amounts...

After depositing a single atomic layer of cobalt on the Pt(111) surface, annealing at 600 K leads to the formation of a surface alloy of stable composition and structure. This phase was examined by crystallographic low energy electron diffraction finding that of the two topmost layers the first layer contains 20 at% of cobalt and the second one 80...

The atomic structure of the surface formed by depositing a single-atomic layer of cobalt on Pt(111) has been investigated using low-energy electron diffraction (LEED) crystallographic analysis. Cobalt grows at room temperature on the Pt(111) surface forming islands a single-atomic layer thick. The layer is ordered and it forms a 1×1 epitaxial phase...

The formation of surface alloys obtained by annealing ultrathin films of Sn deposited on the Pt(111) surface was investigated by low energy electron diffraction and X-ray photoelectron diffraction. The Pt(111)(2 × 2)-Sn and Pt(111)(√3 × √3)R30°-Sn form after deposition of amounts of Sn in the range from 0.2 to 1 ML and subsequent annealing at 1000...

Cobalt was deposited on the clean Pt(111) surface at room temperature by thermal evaporation. The overlayer growth mechanism and structure was examined by X-ray photoelectron diffraction, combined with X-ray photoelectron spectroscopy and low energy He+ scattering. During the initial stages of growth cobalt forms a uniform layer of a single atomic...

The overlayer of cobalt monoxide that forms upon low pressure oxidation of the (001) plane of a PtCo alloy was studied by X-ray photoelectron diffraction and other surface techniques. The analysis of the XPD data carried out using model calculations in the single scattering-plane wave approximation shows that the overlayer structure is similar to...

The oxidation of the Ni3Al alloy was studied by XPS, LEED and LEIS. At pressures of oxygen under approximately 5 × 10−5 Pa and at temperatures higher than approximately 700 K, a layer of Al2O3 grows on the surface forming islands of uniform thickness of the order of 5 Å. The structure of these islands is related to that of γ-alumina.

The surface composition and structure of , , and oriented single crystals of the ordered alloy Pt3Sn (Ll2 or Cu3Au-type) were determined using the combination of low energy electron diffraction (LEED) and low energy ion scattering spectroscopy (LEISS). The clean annealed surfaces displayed LEED patterns and Sn/Pt LEISS intensity ratios consistent w...

The structure of the oxide layer formed by low pressure oxidation of Ni3Al was studied by surface extended energy loss fine structure. The analysis permitted us to determine the oxygen-aluminum interatomic distance in the aluminum oxide overlayer. The value obtained is compatible with the formation of Al2O3 and confirms the data on this system obta...

The surface composition and structure of 〈111〉 and 〈100〉 oriented single crystals of the ordered alloy Pt3Sn (Ll2 or Cu3Au-type) were determined using a combination of low-energy electron diffraction (LEED) and low-energy ion scattering spectroscopy (LEISS). The clean annealed surfaces displayed p(2 × 2) and c(2 × 2) LEED patterns, respectively, an...

Recently, it has been shown that the Lotka-Volterra model can be used for a quantitative description of the exploitation of non renewable resources in a free market economy [Bardi and Lavacchi 2009]. The present paper examines how the model describes the behavior of the system in terms of energy return for energy invested (EROEI) and Net Energy (en...