Search results for "Density"

The impact of the age of vines on soil hydraulic conductivity in vineyards in eastern Spain

2017

Soil infiltration processes manage runoff generation, which in turn affects soil erosion. There is limited information on infiltration rates. In this study, the impact of vine age on soil bulk density (BD) and hydraulic conductivity (Ks) was assessed on a loam soil tilled by chisel plough. Soil sampling was conducted in the inter row area of six vineyards, which differed by the age from planting: 0 (Age 0; just planted), 1, 3, 6, 13, and 25 years (Age 1, Age 3, Age 6, Age 13, and Age 25, respectively). The One Ponding Depth (OPD) approach was applied to ring infiltration data to estimate soil Ks with an α* parameter equal to 0.012 mm-1. Soil bulk density for Age 0 was about 1.5 times greate…

Characterization of defect density states in MoOx for c-Si solar cell applications

Layers of MoOx have been deposited by thermal evaporation followed by post-deposition annealing (PDA). The density of states (DOS) distributions of the MoOx films were extracted deconvoluting the absorption spectra, measured by a phothermal deflection spectroscopy setup, including the small polaron contribution. Results revealed a sub-band defect distribution centered 1.1 eV below the conduction band; the amplitude of this distribution was found to increase with PDA temperature and film thickness.

Influence of M23C6 carbides on the heterogeneous strain development in annealed 420 stainless steel

2020

Understanding the local strain enhancement and lattice distortion resulting from different microstructure features in metal alloys is crucial in many engineering processes. The development of heterogeneous strain not only plays an important role in the work hardening of the material but also in other processes such as recrystallization and damage inheritance and fracture. Isolating the contribution of precipitates to the development of heterogeneous strain can be challenging due to the presence of grain boundaries or other microstructure features that might cause ambiguous interpretation. In this work a statistical analysis of local strains measured by electron back scatter diffraction and …

Dynamic Stabilization of the Ligand-Metal Interface in Atomically Precise Gold Nanoclusters Au68 and Au144 Protected by meta-Mercaptobenzoic Acid

2017

Ligand-stabilized, atomically precise gold nanoclusters with a metal core of a uniform size of just 1–3 nm constitute an interesting class of nanomaterials with versatile possibilities for applications due to their size-dependent properties and modifiable ligand layers. The key to extending the usability of the clusters in applications is to understand the chemical bonding in the ligand layer as a function of cluster size and ligand structure. Previously, it has been shown that monodispersed gold nanoclusters, stabilized by meta-mercaptobenzoic acid (m-MBA or 3-MBA) ligands and with sizes of 68–144 gold atoms, show ambient stability. Here we show that a combination of nuclear magnetic reson…

European Panel on Low Density Lipoprotein (LDL) Subclasses: A Statement on the Pathophysiology, Atherogenicity and Clinical Significance of LDL Subcl…

2011

Item does not contain fulltext Aim of the present Consensus Statement is to provide a comprehensive and up to-date document on the pathophysiology, atherogenicity and clinical significance of low density liproproteins (LDL) subclasses. We sub-divided our statement in 2 sections. section I discusses the pathophysiology, atherogenicity and measurement issues, while section II is focused on the effects of drug and lifestyle modifications. Suggestions for future research in the field are highlighted at the end of section II. Each section includes Conclusions.

Oxidative stress and small, dense low-density lipoproteins: current and future perspectives

2019

Small, dense low-density lipoproteins (LDLs) are more susceptible to oxidation than their larger, more buoyant counterparts and therefore the biological modification of these LDL particles may, in part, be responsible for their atherogenic properties. Kotani et al. found that at multiple regression analysis there was an independent and significant inverse correlation between the mean LDL particle size and the oxidative stress status; notably, the authors adjusted not only for the traditional cardiovascular risk factors, but also for drug treatments. Higher levels of small, dense LDL concentrations significantly contribute to atherosclerosis, and lipoprotein size and subfractions may refine …

Density Functional Theory Investigation on the Nucleation and Growth of Small Palladium Clusters on a Hyper-Cross-Linked Polystyrene Matrix

2014

Density functional theory calculations were employed to investigate the nucleation and growth of small palladium clusters, up to Pd9, into a microcavity of the porous hyper-cross-linked polystyrene (HPS). The geometries and the electronic structures of the palladium clusters inside the HPS cavity, following the one-by-one atom addition, are affected by a counterbalance between the Pd–phenyl (Pd−Φ) and Pd–Pd interactions. The analysis performed on energetics, cavity distortions, and cluster geometries indeed suggest that the cluster growth is dominated by the Pd−Φ interactions up to the formation of Pd4 aggregates, whereas the metal–metal interactions actually rule the growth of the larger c…

Selective Acrolein Hydrogenation over Ligand-Protected Gold Clusters : A Venus Flytrap Mechanism

2022

The catalytic partial hydrogenation of α,β-unsaturated aldehydes is an ideal reaction to understand the selectivity between two different functional groups Here the two functional groups are C═C and C═O, and the hydrogenation of C═O is preferentially desired due to the importance of the issuing products, unsaturated alcohols, in fine-chemical industries. Using density functional theory calculations, we investigate the catalytic competency toward this reaction of a Au nanocluster in the presence of protecting ligands that offer higher stability and the possibility for the uniform distribution of size-selected clusters in the catalytic system. meta-Mercaptobenzoic-acid-protected-protected Au …

A homemade device for linear sucrose gradients

2008

We have developed a simple and inexpensive device to obtain linear sucrose gradients with commonly used laboratory materials--a syringe, a flask, a plastic tube, and a piece of Pongo (Play-Doh). Refractive index values measured on sucrose fractions collected using our system demonstrate both the linearity and reliability of the gradients obtained.

Recent Developments in the Chiral Brønsted Acid-catalyzed Allylboration Reaction with Polyfunctionalized Substrates

2016

Asymmetric allylboration has played a central role in organic synthesis ever since the pioneering work by Hoffman and Brown, having found applications in the total synthesis of many natural products. A new dawn for this 40 year-old reaction occurred with the beginning of the new century when the first catalytic asymmetric methods came into play. In less than one decade, several methodologies, able to achieve the desired homoallylic alcohols with ee ranges in the high 90s, were developed. Among them, in the present account, we will disclose our contribution to the development of the chiral binolphosphoric-derived BrOnsted acid-catalyzed allylboration of aldehydes originally reported by Antil…