Degradation Effects Related to the Hole Transport Layer in Organic Solar Cells

The influence of the hole transport layer on device stability in polymer:fullerene bulk‐heterojunction solar cells is reported. Three different hole transport layers varying in composition, dispersion solvent, electrical conductivity, and work function were used in these studies. Two water‐based hole transport layers, poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) and polyaniline:poly(styrene sulfonate), and one isopropyl alcohol‐based polyaniline:poly(styrene sulfonate) transport layer were investigated. Solar cells with the different hole transport layers were fabricated and degraded under illumination. Current–voltage, capacitance–voltage, and capacitance–frequency data were collected at light intensities of 16, 30, 48, 80, and 100 mW cm^?2 over a period of 7 h. Device performance and stability were compared between nonencapsulated and encapsulated samples to gain understanding about degradation effects related to oxygen and water as well as degradation mechanisms related to the intrinsic instability of the solar cell materials and interfaces. It is demonstrated that the properties of the hole transport layer can have a significant impact on the stability of organic solar cells.     

Inflammation, oxidative stress, and obesity

Obesity is a chronic disease of multifactorial origin and can be defined as an increase in the accumulation of body fat. Adipose tissue is not only a triglyceride storage organ, but studies have shown the role of white adipose tissue as a producer of certain bioactive substances called adipokines. Among adipokines, we find some inflammatory functions, such as Interleukin-6 (IL-6); other adipokines entail the functions of regulating food intake, therefore exerting a direct effect on weight control. This is the case of leptin, which acts on the limbic system by stimulating dopamine uptake, creating a feeling of fullness. However, these adipokines induce the production of reactive oxygen species (ROS), generating a process known as oxidative stress (OS). Because adipose tissue is the organ that secretes adipokines and these in turn generate ROS, adipose tissue is considered an independent factor for the generation of systemic OS. There are several mechanisms by which obesity produces OS. The first of these is the mitochondrial and peroxisomal oxidation of fatty acids, which can produce ROS in oxidation reactions, while another mechanism is over-consumption of oxygen, which generates free radicals in the mitochondrial respiratory chain that is found coupled with oxidative phosphorylation in mitochondria. Lipid-rich diets are also capable of generating ROS because they can alter oxygen metabolism. Upon the increase of adipose tissue, the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), was found to be significantly diminished. Finally, high ROS production and the decrease in antioxidant capacity leads to various abnormalities, among which we find endothelial dysfunction, which is characterized by a reduction in the bioavailability of vasodilators, particularly nitric oxide (NO), and an increase in endothelium-derived contractile factors, favoring atherosclerotic disease.     

Integration of hydrological and habitat simulation methods to define minimum environmental flows at the basin scale

New environmental policies establish the need to maintain the ecological integrity of freshwater ecosystems. The hydrologic regime is a key element in determining river processes and therefore the definition of environmental flow regimes (EFR) is essential to achieve this goal. The EFR can be broadly defined as the water required to sustain freshwater and estuarine ecosystems, and the human livelihood that depend on these ecosystems. Nevertheless, the role of the EFR and the methods to calculate them has not been clearly stated in many countries. This paper sets out a procedure to calculate EFRs, which includes not only a minimum flow, but also a temporal variability of this flow. The procedure integrates the results of hydrologic and habitat simulation methods in a temporal scale that takes into consideration the natural hydrologic seasonality while providing a certain level of flexibility to regulate water resources still meeting the requirements of the Spanish Water Planning legislation. The results highlighted the advantages of using different methodological approaches to calculate EFRs. Therefore, this study concludes the validity of a relatively simple hydrologic method for defining minimum environmental flows at a period of maximum hydrologic stress, but also the need to consider different approaches to take into account as many ecosystem elements as possible.     

Compacted artificially cemented soil-acid leachate contaminant interactions: breakthrough curves and transport parameters

The transport of contaminants through compacted artificially cemented soil subjected to acid leachate contaminant percolation was analyzed by means of laboratory column tests. The effect of cement content, degree of acidity and hydraulic gradient were evaluated after permeation of several pore volumes of acid leachate contaminant flow through the soil. The pH, electric conductivity and solute breakthrough curves were considered throughout the study. The results showed that the increase of cement content increases the solute pore volumes needed before breakthrough occurred. An increase of the degree of acidity of the percolate and of the hydraulic gradient cause a reduction in the pore volumes needed before breakthrough occurred. The larger the soil cement content, the longer the time required to reach maximum effluent solute concentration. The hydraulic conductivity slightly increased due to cement addition and reduced with increasing degree of acidity of the percolate. Finally, it is possible to state that cement addition to the soil was responsible for increasing retardation coefficient (R) and distribution coefficient (k_d) values, meaning that the artificially cemented soils have higher capability to retard the propagation of the contamination and amplified affinity with dissolved acid contaminant.     

A novel framework based on a data-driven approach for modelling the behaviour of organisms in chemical plume tracing

We propose a data-driven approach for modelling an organism''s behaviour instead of conventional model-based strategies in chemical plume tracing (CPT). CPT models based on this approach show promise in faithfully reproducing organisms’ CPT behaviour. To construct the data-driven CPT model, a training dataset of the odour stimuli input toward the organism is needed, along with an output of the organism’s CPT behaviour. To this end, we constructed a measurement system comprising an array of alcohol sensors for the measurement of the input and a camera for tracking the output in a real scenario. Then, we determined a transfer function describing the input–output relationship as a stochastic process by applying Gaussian process regression, and established the data-driven CPT model based on measurements of the organism’s CPT behaviour. Through CPT experiments in simulations and a real environment, we evaluated the performance of the data-driven CPT model and compared its success rate with those obtained from conventional model-based strategies. As a result, the proposed data-driven CPT model demonstrated a better success rate than those obtained from conventional model-based strategies. Moreover, we considered that the data-driven CPT model could reflect the aspect of an organism’s adaptability that modulated its behaviour with respect to the surrounding environment. However, these useful results came from the CPT experiments conducted in simple settings of simulations and a real environment. If making the condition of the CPT experiments more complex, we confirmed that the data-driven CPT model would be less effective for locating an odour source. In this way, this paper not only poses major contributions toward the development of a novel framework based on a data-driven approach for modelling an organism’s CPT behaviour, but also displays a research limitation of a data-driven approach at this stage.     

Enthalpic and Entropic Mechanisms Related to Water Sorption of Yogurt

Moisture sorption isotherms of plain, concentrated, freeze-dried, and freeze-dried concentrated yogurts at 20, 35, and 50°C were used to calculate integral properties. Enthalpy-entropy compensation for all yogurt preparations showed two isokinetic temperatures. The first isokinetic temperature was observed at low moisture contents and was controlled by changes in the entropy of water, whereas the second isokinetic temperature was considered to be enthalpy-driven and was of the same magnitude for all yogurt products (T_B2  = 327.4 ± 0.7 K). Application of the Dubinin-Radushkevich equation suggested that the moisture zone controlled by entropy was produced when adsorption ocurred in the micropore range.     

Kinetic modelling of 1, 3, 5-triisopropylbenzene catalytic cracking using a CREC Riser Simulator emulating FCC operation: The C/O ratio effect

The present study establishes the suitability of a kinetic model for the catalytic cracking of 1, 3, 5-triisopropylbenze (TIPB) using the data obtained in the Chemical Reactor Engineering Centre (CREC) Riser Simulator. The postulated kinetic model accounts for both the TIPB and the various major products formed experimentally, such as: 1, 3-diisopropylbenzene, isopropylbenzene, benzene, propylene, and coke. It is proven that the proposed kinetics is suitable to describe the chemical concentration changes in a CREC Riser Simulator at various reaction times, partial pressures, temperatures, and C/O (catalyst/feedstock) ratios. It is demonstrated that the proposed kinetics simulates well the experimental data from the CREC Riser Simulator, including an experimentally observed C/O optimum ratio. It is anticipated that this type of kinetic model, accounting for intrinsic kinetics, coke deactivation, and diffusional phenomena, could have significant value in establishing the influence of catalyst solid fluxes, at set hydrocarbon feed fluxes, in both industrial riser and downer fluid catalytic cracking (FCC) units.     

Delta Opioid Receptor and Its Peptide: A Receptor-Ligand Neuroprotection

In pursuit of neurological therapies, the opioid system, specifically delta opioid receptors and delta opioid peptides, demonstrates promising therapeutic potential for stroke, Parkinson’s disease, and other degenerative neurological conditions. Recent studies offer strong evidence in support of the therapeutic use of delta opioid receptors, and provide insights into the underlying mechanisms of action. Delta opioid receptors have been shown to confer protective effects by mediating ionic homeostasis and activating endogenous neuroprotective pathways. Additionally, delta opioid agonists such as (D-Ala 2, D-Leu 5) enkephalin (DADLE) have been shown to decrease apoptosis and promote neuronal survival. In its entirety, the delta opioid system represents a promising target for neural therapies.     

Oxygen Distribution of Fluorine-doped Tin Oxide Films Coated on Float Glass along Depth Before and After Heat Treatment

Fluorine-doped tin oxide (FTO) films were deposited on float glass to create low-emissivity glass (low-E glass) by atmospheric pressure chemical vapor deposition (APCVD). Heat treatments were carried out to assess its antioxidant properties. The surface morphology, crystal structure, and the oxygen and tin concentrations in the FTO films were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), Auger electron spectrometer (AES), and X-ray photoelectron spectroscopy (XPS), respectively. The results indicated that the electrical properties determined by the four-point probe method remained constant up to 600°C with increasing temperature. The FTO films exhibited nonstoichiometry with a ratio of [O]/[Sn] >2 on the top surface and <2 in the film. The sheet resistance of the film strongly depended on the oxygen concentration on the film surface. When the heating temperature reached 700°C, the sheet resistance increased rapidly from 9.4 to 86.7 Ω/□ with a concomitant increase in the oxygen concentration on the top surface.