Oxidation of Ethanol to Acetic Acid by Supported PtCu Nanoparticles Stabilized by a Diamine Ligand.

Diamine-capped PtCu nanoparticles have been synthesized by the simultaneous reduction of the corresponding bis-imine metal complexes with hydrogen and supported onto a high-surface-area carbon. The obtained heterogeneous catalyst was tested in thermally conducted aerobic oxidation of ethanol to acetic acid in water as well as in the electrochemical oxidation of ethanol. Both types of catalyses mediated by the PtCu alloy confirmed a notable increase in catalytic activity compared to the pure Pt- and Cu-based counterparts due to a clear bimetallic effect.

Demonstrating Quantum Microscopic Reversibility Using Coherent States of Light.

The principle of microscopic reversibility lies at the core of fluctuation theorems, which have extended our understanding of the second law of thermodynamics to the statistical level. In the quantum regime, however, this elementary principle should be amended as the system energy cannot be sharply determined at a given quantum phase space point. In this Letter, we propose and experimentally test a quantum generalization of the microscopic reversibility when a quantum system interacts with a heat bath through energy-preserving unitary dynamics. Quantum effects can be identified by noting that the backward process is less likely to happen in the existence of quantum coherence between the system's energy eigenstates. The experimental demonstration has been realized by mixing coherent and thermal states in a beam splitter, followed by heterodyne detection in an optical setup. We verify that the quantum modification for the principle of microscopic reversibility is critical in the low-temperature limit, while the quantum-to-classical transition is observed as the temperature of the thermal field gets higher.

A Study of the Radiation Tolerance and Timing Properties of 3D Diamond Detectors.

We present a study on the radiation tolerance and timing properties of 3D diamond detectors fabricated by laser engineering on synthetic Chemical Vapor Deposited (CVD) plates. We evaluated the radiation hardness of the sensors using Charge Collection Efficiency (CCE) measurements after neutron fluences up to 1016 n/cm2 (1 MeV equivalent.) The radiation tolerance is significantly higher when moving from standard planar architecture to 3D architecture and increases with the increasing density of the columnar electrodes. Also, the maximum applicable bias voltage before electric breakdown increases significantly after high fluence irradiation, possibly due to the passivation of defects. The experimental analysis allowed us to predict the performance of the devices at higher fluence levels, well in the range of 1016 n/cm2. We summarize the recent results on the time resolution measurements of our test sensors after optimization of the laser fabrication process and outline future activity in developing pixel tracking systems for high luminosity particle physics experiments.

Remarkable stability of a molecular ruthenium complex in PEM water electrolysis.

The dinuclear Ru diazadiene olefin complex, [Ru2(OTf)(µ-H)(Me2dad)(dbcot)2], is an active catalyst for hydrogen evolution in a Polymer Exchange Membrane (PEM) water electrolyser. When supported on high surface area carbon black and at 80 °C, [Ru2(OTf)(µ-H)(Me2dad)(dbcot)2]@C evolves hydrogen at the cathode of a PEM electrolysis cell (400 mA cm-2, 1.9 V). A remarkable turn over frequency (TOF) of 7800 molH2 molcatalyst -1 h-1 is maintained over 7 days of operation. A series of model reactions in homogeneous media and in electrochemical half cells, combined with DFT calculations, are used to rationalize the hydrogen evolution mechanism promoted by [Ru2(OTf)(µ-H)(Me2dad)(dbcot)2].

Waste Face Surgical Mask Transformation into Crude Oil and Nanostructured Electrocatalysts for Fuel Cells and Electrolyzers.

A novel route for the valorization of waste into valuable products was developed. Surgical masks commonly used for COVID 19 protection by stopping aerosol and droplets have been widely used, and their disposal is critical and often not properly pursued. This work intended to transform surgical masks into platinum group metal-free electrocatalysts for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) as well as into crude oil. Surgical masks were subjected to controlled-temperature and -atmosphere pyrolysis, and the produced char was then converted into electrocatalysts by functionalizing it with metal phthalocyanine of interest. The electrocatalytic performance characterization towards ORR and HER was carried out highlighting promising activity. At different temperatures, condensable oil fractions were acquired and thoroughly analyzed. Transformation of waste surgical masks into electrocatalysts and crude oil can open new routes for the conversion of waste into valuable products within the core of the circular economy.

Structural and Functional Characteristics of Color Vision Changes in Choroideremia.

Color vision is considered a marker of cone function and its assessment in patients with retinal pathology is complementary to the assessments of spatial vision [best-corrected visual acuity (BCVA)] and contrast detection (perimetry). Rod-cone and chorioretinal dystrophies-such as choroideremia-typically cause alterations to color vision, making its assessment a potential outcome measure in clinical trials. However, clinical evaluation of color vision may be compromised by pathological changes to spatial vision and the visual field. The low vision Cambridge Color Test (lvCCT) was developed specifically to address these latter issues. We used the trivector version of the lvCCT to quantify color discrimination in a cohort of 53 patients with choroideremia. This test enables rapid and precise characterization of color discrimination along protan, deutan, and tritan axes more reliably than the historically preferred test for clinical trials, namely the Farnsworth Munsell 100 Hue test. The lvCCT demonstrates that color vision defects-particularly along the tritan axis-are seen early in choroideremia, and that this occurs independent of changes in visual acuity, pattern electroretinography and ellipsoid zone area on optical coherence tomography (OCT). We argue that the selective loss of tritan color discrimination can be explained by our current understanding of the machinery of color vision and the pathophysiology of choroideremia.

Coherent Superpositions of Photon Creation Operations and Their Application to Multimode States of Light.

We present a concise review of recent experimental results concerning the conditional implementation of coherent superpositions of single-photon additions onto distinct field modes. Such a basic operation is seen to give rise to a wealth of interesting and useful effects, from the generation of a tunable degree of entanglement to the birth of peculiar correlations in the photon numbers and the quadratures of multimode, multiphoton, states of light. The experimental investigation of these properties will have an impact both on fundamental studies concerning, for example, the quantumness and entanglement of macroscopic states, and for possible applications in the realm of quantum-enhanced technologies.

Interlayer Coordination of Pd-Pd Units in Exfoliated Black Phosphorus.

The chemical functionalization of 2D exfoliated black phosphorus (2D BP) continues to attract great interest, although a satisfactory structural characterization of the functionalized material has seldom been achieved. Herein, we provide the first complete structural characterization of 2D BP functionalized with rare discrete Pd2 units, obtained through a mild decomposition of the organometallic dimeric precursor [Pd(η3-C3H5)Cl]2. A multitechnique approach, including HAADF-STEM, solid-state NMR, XPS, and XAS, was used to study in detail the morphology of the palladated nanosheets (Pd2/BP) and to unravel the coordination of Pd2 units to phosphorus atoms of 2D BP. In particular, XAS, backed up by DFT modeling, revealed the existence of unprecedented interlayer Pd-Pd units, sandwiched between stacked BP layers. The preliminary application of Pd2/BP as a catalyst for the hydrogen evolution reaction (HER) in acidic medium highlighted an activity increase due to the presence of Pd2 units.

Experimental Certification of Nonclassicality via Phase-Space Inequalities.

In spite of its fundamental importance in quantum science and technology, the experimental certification of nonclassicality is still a challenging task, especially in realistic scenarios where losses and noise imbue the system. Here, we present the first experimental implementation of the recently introduced phase-space inequalities for nonclassicality certification, which conceptually unite phase-space representations with correlation conditions. We demonstrate the practicality and sensitivity of this approach by studying nonclassicality of a family of noisy and lossy quantum states of light. To this end, we experimentally generate single-photon-added thermal states with various thermal mean photon numbers and detect them at different loss levels. Based on the reconstructed Wigner and Husimi Q functions, the inequality conditions detect nonclassicality despite the fact that the involved distributions are nonnegative, which includes cases of high losses (93%) and cases where other established methods do not reveal nonclassicality. We show the advantages of the implemented approach and discuss possible extensions that assure a wide applicability for quantum science and technologies.

Entangling Macroscopic Light States by Delocalized Photon Addition.

We present a scheme, based on the delocalized heralded addition of a single photon, to entangle two or more distinct field modes, each containing arbitrary light states. A high degree of entanglement can in principle endure light states of macroscopic intensities and is expected to be particularly robust against losses. We experimentally establish and measure significant entanglement between two identical weak laser pulses containing up to 60 photons each.

Evaluation of manufacturing process parameters causing multilayer tablets delamination.

The aim of this study was to evaluate the influence of tableting process parameters, i.e. turret rotation speed, pre-compaction and main compaction pressures, and their interactions on layer adhesion of bilayer tablets. The elastic recovery after compaction was used as estimation for the elasticity of the material. Three potential pharmaceutical formulations were evaluated as combinations of immediate (microcrystalline cellulose, lactose, calcium phosphate, pregelatinized starch) and controlled drug release excipients (ethyl cellulose, hydroxypropyl methylcellulose, polyvinyl acetate/polyvinylpyrrolidone). A 3-levels 3-factors central composite Design of Experiment was performed on each formulation, with layer adhesion selected as response. A custom-made shear test was used to determine the tablet tendency to delaminate. Main compaction and turret rotation speed were the most important parameters to be optimized during tablet manufacturing. Main compaction was the principal parameter leading to delamination in case of formulations with plastic materials, particularly at high pressures where the difference in elasticity of excipients had a major impact and was followed by turret rotation speed. The rotation speed did not have an effect on layer adhesion in the case of formulations with brittle excipients.

Effect of Electrode Shape and Flow Conditions on the Electrochemical Detection with Band Microelectrodes.

In this work, we report the analysis of the electrochemical detection of electroactive species with band microelectrodes that operate under controlled convection. The study focuses on the determination of the collection efficiency of the analyte as a function of inlet flow velocity and microband geometry (inlaid, bumped and recessed), also providing a straightforward method for the theoretical determination of the lower detection limit. The analysis has been carried out by simulating the dimensionless mass transport with the finite element method, delivering the stationary limiting current density. Simulations have been performed on systems consisting of single and double band electrodes to investigate the trail effect on the electrochemical detection. We show that the obtained dimensionless results can be easily turned into dimensional data, providing a tool for the design of devices. The proposed method is general and can easily be extended to systems with different geometry.

Novel hydrophilic matrix system with non-uniform drug distribution for zero-order release kinetics.

A decrease in the release rate over time is typically encountered when dealing with hydrophilic matrix systems for oral prolonged release due to progressive increase of the distance the drug molecules have to cover to diffuse outwards and reduction of the area of the glassy matrix at the swelling front. In order to solve this issue, a novel formulation approach based on non-uniform distribution of the active ingredient throughout the swellable polymer matrix was proposed and evaluated. Various physical mixtures of polymer (high-viscosity hypromellose) and drug tracer (acetaminophen), having decreasing concentrations of the latter, were applied by powder-layering onto inert core seeds. The resulting gradient matrices showed to possess satisfactory physico-technological characteristics, with spherical shape and consistent thickness of the layers sequentially applied. The non-uniform matrix composition pursued was confirmed by Raman mapping analysis. As compared with a system having uniform distribution of the drug tracer, the multi-layer formulations were proved to enhance linearity of release. The simple design concept, advantageous technique, which involves no solvents nor high-impact drying operations, and the polymeric material of established use make the delivery platform hereby proposed a valuable strategy to improve the performance of hydrophilic matrix systems.

Measurement-Induced Strong Kerr Nonlinearity for Weak Quantum States of Light.

Strong nonlinearity at the single photon level represents a crucial enabling tool for optical quantum technologies. Here we report on experimental implementation of a strong Kerr nonlinearity by measurement-induced quantum operations on weak quantum states of light. Our scheme coherently combines two sequences of single photon addition and subtraction to induce a nonlinear phase shift at the single photon level. We probe the induced nonlinearity with weak coherent states and characterize the output non-Gaussian states with quantum state tomography. The strong nonlinearity is clearly witnessed as a change of sign of specific off-diagonal density matrix elements in the Fock basis.

Influence of Drug Brittleness, Nanomilling Time, and Freeze-Drying on the Crystallinity of Poorly Water-Soluble Drugs and Its Implications for Solubility Enhancement.

The aim of this study was to assess whether wet bead milling of dexamethasone and tacrolimus suspensions leads to a lower degree of crystallinity of nanocrystals, and if the degree of crystallinity affects the drug solubility, in addition to particle size. Powder X-ray diffraction (XRD) was used to determine the degree of crystallinity of the particles, which decreased during milling until reaching a plateau: the particles had ∼79% degree of crystallinity after 5 h milling. Different milling times were required for the two drugs in order to reach their plateaux, 2 h for dexamethasone and 3 h for tacrolimus. These results could be explained with the brittleness of the drugs. Dexamethasone was more brittle than tacrolimus, with an apparent elastic modulus of 16 GPa compared to ∼12 GPa of tacrolimus. Freeze-drying the nanosuspensions resulted in a reduction in the degree of crystallinity to ∼35% for dexamethasone and to ∼45% for tacrolimus in comparison to non-freeze-dried particles. Solubility studies were performed with a Sirius® inForm based on in situ UV/VIS spectroscopy. The reduced degree of crystallinity of nanocrystals after milling was responsible, in addition to the nanoparticle size, for the solubility increase. Indeed, while the smallest particle size (394 nm for dexamethasone and 240 nm for tacrolimus) did not always result in the highest increase in solubility (factor of 1.04 for dexamethasone and 1.3 with tacrolimus), the smallest degree of crystallinity was always characteristic of the maximum solubility obtained (factor of 1.15 for dexamethasone and 1.7 for tacrolimus).

Heat treated carbon supported iron(ii)phthalocyanine oxygen reduction catalysts: elucidation of the structure-activity relationship using X-ray absorption spectroscopy.

This paper focuses on studying the influence of the heat treatment on the structure and activity of carbon supported Fe(ii)phthalocyanine (FePc/C) oxygen reduction reaction (ORR) catalysts under alkaline conditions. The FePc macrocycle was deposited onto ketjen black carbon and heated treated for 2 hours under inert atmosphere (Ar) at different temperatures (400, 500, 600, 700, 800, 900 and 1000 °C). The atomic structure of Fe in each sample has been determined by XAS and correlated to the activity and ORR mechanisms determined in electrochemical half cells and in a complete H2/O2 anion exchange membrane fuel cells (AEM-FC). The results show that the samples prepared at 600 and 700 °C have the highest electrochemical catalytic activity for the ORR, consistent with the findings that the FeN4 active sites are thermally stable up to 700 °C, confirmed by both XANES linear combination fittings and EXAFS fittings. Upon annealing at temperatures above 800 °C, the FeN4 structure partially decomposes to small iron nanoparticles. The transition from the FeN4 structure to metallic Fe results in a significant loss in ORR activity and an increase in the production of undesirable HO2- during catalysis.

Disorder and dephasing as control knobs for light transport in optical fiber cavity networks.

Transport phenomena represent a very interdisciplinary topic with applications in many fields of science, such as physics, chemistry, and biology. In this context, the possibility to design a perfectly controllable experimental setup, where to tune and optimize its dynamics parameters, is a challenging but very relevant task to emulate, for instance, the transmission of energy in light harvesting processes. Here, we experimentally build a scalable and controllable transport emulator based on optical fiber cavity networks where the system noise parameters can be finely tuned while maximizing the transfer efficiency. In particular, we demonstrate that disorder and dephasing noise are two control knobs allowing one to play with constructive and destructive interference to optimize the transport paths towards an exit site. These optical setups, on one side, mimic the transport dynamics in natural photosynthetic organisms and, on the other, are very promising platforms to artificially design optimal nanoscale structures for novel, more efficient, clean energy technologies.

Universal Continuous-Variable State Orthogonalizer and Qubit Generator.

We experimentally demonstrate a universal strategy for producing a quantum state that is orthogonal to an arbitrary, infinite-dimensional, pure input one, even if only a limited amount of information about the latter is available. Arbitrary coherent superpositions of the two mutually orthogonal states are then produced by a simple change in the experimental parameters. We use input coherent states of light to illustrate two variations of the method. However, we show that the scheme works equally well for arbitrary input fields and constitutes a universal procedure, which may thus prove a useful building block for quantum state engineering and quantum information processing with continuous-variable qubits.

Efficient noiseless linear amplification for light fields with larger amplitudes.

We suggest and investigate a scheme for non-deterministic noiseless linear amplification of coherent states using successive photon addition, (â(†))(2), where â(†) is the photon creation operator. We compare it with a previous proposal using the photon addition-then-subtraction, ââ(†), where â is the photon annihilation operator, that works as an appropriate amplifier only for weak light fields. We show that when the amplitude of a coherent state is |α| ≳ 0.91, the (â(†))(2) operation serves as a more efficient amplifier compared to the ââ(†) operation in terms of equivalent input noise. Using ââ(†) and (â(†))(2) as basic building blocks, we compare combinatorial amplifications of coherent states using (ââ(†))(2), â(†4), ââ(†)â(†2), and â(†2)ââ(†), and show that (ââ(†))(2), â(†2)ââ(†), and â(†4) exhibit strongest noiseless properties for |α| ≲ 0.51, 0.51 ≲ |α| ≲ 1.05, and |α| ≳ 1.05, respectively. We further show that the (â(†))(2) operation can be useful for amplifying superpositions of the coherent states. In contrast to previous studies, our work provides efficient schemes to implement a noiseless amplifier for light fields with medium and large amplitudes.