Dispersed Form Research Articles

Carbon Nitride Thin Films as All-In-One Technology for Photocatalysis

Organic π-conjugated polymers are promising heterogeneous photocatalysts that involve photoredox or energy transfer processes. In such settings, the materials are usually applied in the form of dispersion in liquid medium, which is bound to certain technological limits of applicability. Herein, we present an innovative approach using carbon nitride thin films prepared via chemical vapor deposition at different vessel walls and using them as batch and microfluidic photoreactors. This approach allows us not only to fabricate technologically relevant and reusable devices but also to improve photophysical properties of carbon nitride, such as the singlet–triplet energy gap and lifetime of triplet excited states, when the material is assembled in thin films. These morphological changes are employed to maximize the performance of the materials in photocatalytic reactions, in which the carbon nitride thin films show at least 1 order of magnitude higher activity per area unit compared to photocatalysis using suspended particles.

Current State‐of‐the‐Art in the Interface/Surface Modification of Thermoelectric Materials

AbstractThermoelectric (TE) materials are prominent candidates for energy converting applications due to their excellent performance and reliability. Extensive efforts for improving their efficiency in single‐/multi‐phase composites comprising nano/micro‐scale second phases are being made. The artificial decoration of second phases into the thermoelectric matrix in multi‐phase composites, which is distinguished from the second‐phase precipitation occurring during the thermally equilibrated synthesis of TE materials, can effectively enhance their performance. Theoretically, the interfacial manipulation of phase boundaries can be extended to a wide range of materials. High interface densities decrease thermal conductivity when nano/micro‐scale grain boundaries are obtained and certain electronic structure modifications may increase the power factor of TE materials. Based on the distribution of second phases on the interface boundaries, the strategies can be divided into discontinuous and continuous interfacial modifications. The discontinuous interfacial modifications section in this review discusses five parts chosen according to their dispersion forms, including metals, oxides, semiconductors, carbonic compounds, and MXenes. Alternatively, gas‐ and solution‐phase process techniques are adopted for realizing continuous surface changes, like the core–shell structure. This review offers a detailed analysis of the current state‐of‐the‐art in the field, while identifying possibilities and obstacles for improving the performance of TE materials.

A Comprehensive report on Solid Dispersions by Factorial Design

The drugs of present use are lipophilic. Hence there is a need to surge the solubility of these drugs. To encounter this necessity one of the approaches is the formulation of drugs in form of Solid dispersions. Solid dispersions are a type of dispersion having one or extra one API in a torpid carrier at a solid state. We focused on the importance of solid dispersions in pharmaceutical formulation by using factorial design as it was easy to formulate. These solid dispersions are organized by several practises such as solvent technique, supercritical fluid technique and kneading tactic, etc., by referring the several journals, literature and pharmacy magazines we came to know that Solid dispersion are used to improve the solubility of the poor water-soluble drugs and also its bioavailability. At last, we conclude that through these Solid dispersions we can boost the Therapeutic efficiency of hydrophobic drugs by achieving greater solubility.

Universal Scalings in Two-Dimensional Anisotropic Dipolar Excitonic Systems.

Low-dimensional excitonic materials have inspired much interest owing to their novel physical and technological prospects. In particular, those with strong in-plane anisotropy are among the most intriguing but short of general analyses. We establish the universal functional form of the anisotropic dispersion in the small k limit for 2D dipolar excitonic systems. While the energy is linearly dispersed in the direction parallel to the dipole in plane, the perpendicular direction is dispersionless up to linear order, which can be explained by the quantum interference effect of the interaction among the constituents of 1D subsystems. The anisotropic dispersion results in a E^{∼0.5} scaling of the system density of states and predicts unique spectroscopic signatures including: (1)disorder-induced absorption linewidth, W(σ)∼σ^{2.8}, with σ the disorder strength, (2)temperature dependent absorption linewidth, W(T)∼T^{s+1.5}, with s the exponent of the environment spectral density, and (3)the out-of-plane angular θ dependence of the peak splittings in absorption spectra, ΔE(θ)∝sin^{2}θ. These predictions are confirmed quantitatively with numerical simulations of molecular thin films and tubules.

The power of agents in a dispersed system – The Shapley-Shubik power index

In this paper, dispersed knowledge – accumulated in several decision tables is considered. Dispersion of knowledge is not a part of the work of the system. We assume that the knowledge is already in the dispersed form when it provides to the system. An advanced process of detecting the relations between the decision tables and constructing coalitions is used. The purpose of this paper is to use the measure to determine the strength of the coalition. With this method, a simple method of combining vectors of decisions generated based on local decision tables was applied. The purpose of using the Shapley-Shubik index was to reduce the computational complexity compared to the approach proposed in the earlier papers. In this paper, the results of experiments are presented, and the two approaches are compared. Based on these results, some conclusions have been drawn.

Microsponges for controlled release and enhanced oral bioavailability of carbamazepine

The oral absorption and hence the oral bioavailability of carbamazepine (CBZ) is variable even after administration of rapidly dissolving formulation. This problem was attributed to supersaturation of CBZ and transformation to the less soluble carbamazepine dihydrate (CBD). Accordingly, formulation of sustained release products of CBZ is a promising approach to overcome this problem. Microsponges are an emerging formulation which can help in this direction. The aim of this work was to optimize the composition of microsponges for better encapsulation and sustained release of CBZ for oral administration. CBZ microsponges were prepared using quasi emulsion solvent diffusion technique with varying composition of ethyl cellulose and polyvinyl alcohol (PVA). Microsponges were evaluated using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction. Production yield, entrapment efficiency and surface morphology of microsponges were assessed in addition to drug release. Optimum formulation was administered orally to albino rabbits to evaluate the oral bioavailability with reference to unprocessed CBZ. The Instrumental analysis reflected the encapsulation of CBZ in amorphous or molecularly dispersed form in the microsponges. The size and entrapment efficiency of the microsponges increased with increasing polymer contents. This was associated with reduction in CBZ release. Optimum formulation enhanced the oral absorption of CBZ. This was manifested by 2.6-fold increase in the area under the plasma concentration versus time curve compared to that of unprocessed CBZ. The study introduced microsponges as promising carriers for sustained oral delivery of CBZ.

Sleeping in the Cinema

Abstract In the 1940s and 50s, Weegee shot a considerable number of photographs in New York City's movie theaters. These photos contribute important insights on the history of cinema spectatorship in the form of visual arguments about the movie audience. This article places the images in dialogue with theories and histories of the disembodied spectator. It discusses the photographer's particular fascination with sleeping moviegoers. The sleepy filmgoer embodies simultaneously the model and counter-model of spectatorial attention. This figure focalizes a strand of theory that associates filmic reception with scattered, dispersive forms of attention that stray from aesthetic or disciplinary norms of absorption.

Optimisation of Tensile Strength and Weight Loss via Taguchi and Response Surface Method for Natural Rubber Latex Film Consisting Cassava Peel as a Bio-Based Filler

Disposal latex and synthetic rubber gloves is troublesome such that disposal via incineration and land fill may release poisonous gasses and contaminate soil and water, respectively. As solution to latex and synthetic rubber, biodegradable glove is extensively studied. A bio-based filler is extracted from food waste and blended into natural rubber latex (NRL) as a composite NRL. The effect of biodegradability of composite NRL was studied by varying the loading of bio-based filler in a form of starch dispersion and blended into NRL mixture. Herein some amount of starch can be extracted from cassava peel to be incorporated in NRL for a sustainable and yet biodegradable glove. Previous work on incorporation of cassava-peel filler in NRL has shown a biodegradability without compromising the pristine strength of NRL film at 50% loading starch. In this project, tensile strength and weight loss of prepared composite NRL films were optimised via Taguchi and Response Surface Method (RSM) by means of Design Expert software by varying starch/filler loading, curing temperature and curing drying duration. Due to inadequate data, the optimisation from that previous prepared composite NRL was compared with similar work which utilising NRL and bio-based filler. For Pulungan (2020) study, it can be concluded that the tensile strength of cassava peel starch biodegradable film has the best condition at 50°C to 60°C at approximately 5.5 hours. Elongation optimum conditions shows contrast value of temperature and time. Meanwhile, for Wendy (2020) study, it shows the best percentage loading of cassava-peel starch is at 20% to achieve high stress and strain at break. The optimised mechanical properties via Taguchi and RSM are rather different and hence validation on mechanical properties at above mentioned conditions need to be performed experimentally.

Quantitative Spectrophotometric Estimation of Prednisolone in Tablet Dosage Form Using Eco-friendly Green Solvent and by applying Beer-Lambert’s Law Mathematical Equation Method

Prednisolone is a widely used synthetic glucocorticoid drug used in the treatment of allergies, inflammatory conditions, auto-immune disorders, acute and chronic obstructive pulmonary disease, rheumatoid arthritis, systemic lupus erythematosus, dermatitis, eye inflammation, asthma and multiple sclerosis. A simple and economical method was developed using eco-friendly green solvent. In this developed method the eco-friendly green solvent used was ethanol which is available easily. The method was projected to quantitative estimation and assay of Prednisolone in Prednisolone dispersible tablet dosage form. The amount and percent label claim of Prednisolone in tablet dosage form was estimated using Beer-Lambert’s law. Specific absorbance (A1%1cm) of Prednisolone is 415 at lambda max of 243 nm. The method developed was validated as per ICH guidelines. The proposed method was found to be simple, accurate, sensitive, precise, linear and rugged. The method obeys Beer-Lambert’s Law in the concentration range of 2.5-20μg/mL, as the r2 value was found to be 1.000. The mean percent recovery was found to be within acceptable range as per ICH guidelines. Hence the developed method can be used in regular quantitative analysis. The developed method acquires only one green solvent, low cost analytical equipment and the percent label claim can be calculated in the assay of Prednisolone tablets without using any standards solution or standard graph by just employing specific absorbance value in Beer-Lambert’s law, thereby concentration of drug can be calculated. As this method is simple, economical and eco-friendly it can be used elegantly and routinely in analytical laboratories and industries for estimation of Prednisolone in tablet formulation.

MoO3/TiO2 catalyst with atomically dispersed O-Mo-O structures toward improving NH4HSO4 poisoning resistance for selective catalytic reduction of nitrogen oxides

Slow progress in discovering new catalysts to circumvent the problem of ammonium bisulfate (NH4HSO4, ABS) poisoning has hindered further development of selective catalytic reduction (SCR) technology of NOx with ammonia (from numerous industrial processes) in afterburning systems at temperatures below dew point of ABS (typically between 280 °C and 320 °C). Recently, we have explored the use of atomically dispersed Mo species on TiO2 particles (hereafter denoted as MoO3/TiO2) as highly efficient catalyst for NH3-SCR reaction. In the present study, it will be shown that this type of catalyst is highly resistant to ABS poisoning for NH3-SCR reaction, overcoming a major issue afflicting the application of commercial V2O5-WO3/TiO2 catalyst at temperatures below the dew point of ABS. Aberration-corrected scanning transmission electron microscopy (STEM) suggests that most of the Mo species are present in atomically dispersed form in the MoO3/TiO2 catalyst. SO2 oxidation measurements show that the MoO3/TiO2 catalyst exhibits a substantially lower SO2 oxidation rate compared to the commercial V2O5-WO3/TiO2, mitigating ABS formation. Furthermore, decomposition of ABS on MoO3/TiO2 surface is found to be extremely facile. Temperature-programmed surface reaction (TPSR) with NO shows that the decomposition temperature of ABS over MoO3/TiO2 is 70 °C lower than that found on the commercial V2O5-WO3/TiO2 catalyst. Our investigations provide valuable information for the development of NH3-SCR catalysts with exceptional resistance to ABS poisoning for NOx emission control.

Features of the structure formation processes and synthesis of strength for Portland cement compositions modified with nanocarbonate additives

The work shows the results of studying the features of the structure formation process when nano-carbonate additives of different physical states are added to Portland cement and the establishment of the appropriate technology for their introduction, which provides the best conditions for the synthesis of artificial stone. It was found that the introduction of nanocarbonate additives in the form of dispersion provides better kinetics of the cement stone strength gain, and the effect of the introduction of dispersion exceeds the effect of the introduction of powder on 7th day by (43 … 48)%, on 28th day - (27… 30)% and 365th day by (25… 29)%. The using of the dispersion is more economically efficient, while preventing the aggregation of particles provides a directed synthesis of crystal-chemically similar compounds. The nanocarbonate additive acts as a substrate for the directional formation of hydrosilicate phases, providing microreinforcement and the formation of a more homogeneous and improved structure of artificial stone at both nano- and micro-levels.

Movement patterns of the White‐tailed Sea Eagle (Haliaeetus albicilla): post‐fledging behaviour, natal dispersal onset and the role of the natal environment

Exploratory movements and natal dispersal form essential processes during early life history stages of raptors, but identifying the factors shaping individual movement decisions is challenging. Global positioning system (GPS) telemetry thereby provides a promising technique to study movement patterns on adequate spatio‐temporal scales. We analysed data of juvenile White‐tailed Sea EaglesHaliaeetus albicilla(WTSE) in north‐east Germany (n = 24) derived from GPS tracking to extensively analyse movements between fledging and emigration from the natal territory. Our goal was to determine the time point of fledging, characterize pre‐emigration movements and the onset of natal dispersal while investigating the influence of the natal environment. WTSE fledged at an average age of 72 days and showed strong excursive behaviour during the post‐fledging period regarding the number, distance and duration of excursions, yet with high individual variability. Excursive behaviour did not differ between sexes. On average, WTSE left the parental territory 93 days after fledging. The quantity of excursive behaviour delayed the timing of emigration and WTSE tended to postpone their emigration when foraging water was accessible within the boundaries of their parental territory. The overall results suggest that young WTSE assess the quality of the natal environment via pre‐emigration movements and stay in their territory of origin for as long as internal and external conditions allow for it. Our study is one of the first to characterize post‐fledging and natal dispersal movements of young WTSE to such an extent and applies modern techniques to understand related movements in relation to the natal environment. The results emphasize the urgent necessity for the extension of currently existing nest protection periods and guaranteeing sustainable management of potential breeding and foraging grounds for WTSE. Ultimately, the results are relevant for all large raptor species sensitive to human‐related disturbance, as they support the increasing importance of regulations with spatio‐temporal specifications for breeding populations of large raptors in densely human‐inhabited areas with increasing alteration of land.

Arsenic Forms in Soils of Various Settings in the Historical Ore Mining and Processing Site of Radzimowice, Western Sudetes

This study, carried out in Radzimowice, a historical As mining site, analyzed the speciation and mineralogical As forms in soils, in different locations, as related to rock weathering processes and associated environmental risk. Four soil groups, including those on mine dumps, and in the stream valley, as well as stream sediments, were examined. The screening performed on 52 samples showed an extremely low actual As solubility, except for soils at reducing conditions. Nine samples were subjected to mineralogical analysis by microscopy and X-ray diffraction (XRD), and sequential extraction according to Wenzel. The results indicated that in all samples, As was associated mainly with amorphous Fe oxides, that constituted up to 66% of total As. Scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS) analysis performed on 3 representative samples revealed that the dump material contained the grains of primary As minerals, mainly arsenopyrite and loelingite, rimmed and encrusted with goethite. Stream sediments and the alluvial soil contained large amounts of (hydroxy)Fe-oxides, in which As was present in sparse scorodite grains and in highly dispersed forms associated with goethite and amorphous compounds of various compositions. The diversity of As species makes forecasting of its environmental fate difficult, therefore further research should focus on As transformations, particularly under reducing conditions.

Synthetic nanostructured wollastonite: Composition, structure and “in vitro” biocompatibility investigation

This article describes an original sol-gel (template) method for the synthesis of a dispersed form of nanostructured wollastonite (CaSiO3), its gold nanoparticles (40–60 nm) functionalized form CaSiO3/Au-NPs, and its composite in the composition with 20 mass% of hydroxyapatite CaSiO3/HAp and synthetic hydroxyapatite, that are widely used in medicine for the reconstruction and regeneration of bone defects. The method provides the formation of porous silica carcass in samples with an average pore size of 100–160 nm due to the application of polymer siloxane-acrylate as a pore-forming template. The authors studied the processes of template destruction and phase formation in the composition of samples using TGA/DTA/DSC (thermogravimetric analysis/differential thermal analysis/differential scanning calorimetry), and XRD (X-ray diffraction analysis). The methods of SEM (scanning electron microscopy), low-temperature nitrogen adsorption, and mercury porosimetry were used to identify the morphology and study the structural characteristics (Sspec and Vpor, pore size distribution) for dispersed nanostructured samples based on wollastonite and hydroxyapatite. An “in vitro” model was used to study the functional activity (metabolism and cytokine production) of innate immune cells (neutrophils and macrophages) in contact with the obtained samples and to evaluate the viability of cells, the activity of ATPase activity, the number of cationic proteins, and apoptosis of cells. The study is novel for these systems and contributes to the existing knowledge on the biocompatibility for “in vivo” model, which provides a complex evaluation of the quality of wollastonite biomaterials used as grafts.

Supersaturating drug delivery systems containing fixed-dose combination of two antihypertensive drugs: Formulation, in vitro evaluation and molecular metadynamics simulations

The purpose of this study was to associate the poorly water-soluble antihypertensive drugs candesartan cilexetil (CC) and hydrochlorothiazide (HCTZ) as fixed-dose combination, in the form of ternary Amorphous Solid Dispersions (ASD), using hydroxypropylmethylcellulose acetate succinate (HPMCAS) type M as polymeric carrier. The potential of the system to generate and to maintain supersaturation of both drugs was also evaluated. The ASDs were prepared by ball milling technique and solid-state characterization was performed by differential scanning calorimetry (DSC), Fourier transformed infrared spectroscopy (FTIR) and X-ray powder diffraction (XRPD). Interaction between drugs and polymer in solid-state was evaluated by molecular metadynamics simulations. In vitro supersaturation profiles were determined in biorelevant medium. Physicochemical stability of ASDs was also evaluated under different storage conditions. Amorphization of both drugs was confirmed by solid-state characterization techniques. Molecular metadynamics simulations indicated that CC has stronger interaction with HMPCAS than HCTZ. In vitro supersaturation studies have shown that ternary ASDs could generate and maintain supersaturation of both drugs in biorelevant medium. The polymer reduced the desupersaturation of both drugs. Ternary ASDs also showed physicochemical stability over a period of 90 days, demonstrating the potential of the polymer in reducing the drugs recrystallization over the time. Ternary ASDs of CC, HCTZ and HPMCAS can be considered a promising system to associate the drugs as fixed-dose combinations. Also, these systems generate and maintain supersaturation of both drugs in biorelevant medium, with great storage stability. HPMCAS M was a good carrier for reducing the desupersaturation of associated HCTZ and CC.

Creating diversity markets through economization: The politics and economics of difference in neoliberal organizations

In this article, I argue that the economization of social differences in the workplace is a political practice. I examine how, after the dismantling of corporate bureaucracies and affirmative action policies, diversity professionals create economic justifications for practices they regard as creating racial equity. Insofar as they do this to conveniently create markets for their expertise, diversity professionals work with, through, and around neoliberal logics, principles, and norms of the for‐profit firm. In asking why their strategies “work” in the era of the socially dispersed corporate form, I reflect on what it means for an American society to place more social value on the pursuit of profit than on racial justice.

Dispersión y transporte de propágulos micorrícicos en el bosque seco tropical

Los animales son un factor importante en la dispersión de propágulos de los hongos formadores de micorrizas en los ecosistemas de bosque seco tropical. En la presente revisión bibliográfica, se hace énfasis en las diferentes formas de dispersión que pueden realizar los animales por medio de la ingesta o adherencia a estructuras externas para dispersar los propágulos de micorrizas tanto horizontal como verticalmente. La mayoría de las publicaciones provienen de estudios realizados en diversos ecosistemas (tundra, selva, sabanas y praderas), sin embargo, en esta revisión se puso especial énfasis en los estudios que reportan aquellos grupos de organismos que se encuentran en el ecosistema de bosque seco tropical. En el caso de los invertebrados, se evidencia el potencial de dispersión de los hongos micorrícicos en los diferentes estadios de desarrollo de los animales, así como por su movilidad en actividades realizadas para su alimentación y construcción de madrigueras. La dispersión efectiva de hongos micorrícicos se efectúa especialmente por medio de colémbolos, ácaros, lombrices de tierra, nemátodos, hormigas, isópodos, diplópodos, crustáceos, dípteros, avispas, escarabajos y saltamontes. La dispersión fúngica también puede verse favorecida por diferentes grupos de vertebrados, como los mamíferos, aves, reptiles y anfibios. Destacándose principalmente los roedores y las aves, quienes dispersan hongos micorrícicos a largas distancias por el consumo de propágulos adheridos a sus alimentos y estructuras externas. La literatura evidencia la importancia de la fauna en la dispersión de hongos micorrícicos en los ecosistemas de bosque seco. La presente revisión promueve la disminución de las brechas de conocimientos en torno a la dispersión de estructuras fúngicas, dinámicas especializadas y funcionamiento espacial del ecosistema.

Enhancing therapeutic potential of poor aqueous soluble herbal drugs through solid dispersion-An overview

BackgroundPoorly water-soluble medicaments continue to be a challenging, however, significant class of herbal drugs for the management of an extensive range of ailments. Solid dispersion (SD) has emerged as one of the most effective formulation approaches to enhance the dissolution of poorly water-soluble herbal drugs. Formulation of solid dispersion is one of the most effective methods to enhance the aqueous solubility of highly lipophilic drugs which belong to BCS class II and IV. An amorphous form of the drug is more unstable and highly soluble in water and is attained by formulating solid dispersion. PurposeThis review explains various physicochemical properties, criteria for carrier selection, and causes of instability of solid dispersion to improve the therapeutic potential of poorly water-soluble herbal drugs. MethodologyTo classify and explain some newer techniques used nowadays along with solid dispersion which could prevent recrystallization and precipitation of drug. Some herbal drugs with high therapeutic value and poor aqueous solubility were also enlisted which could be formulated in the form of solid dispersion to have better oral bioavailability. ResultsThe solid dispersions studies have revealed better performance for the dissolution which might be due to its alteration from crystalline to amorphous form in addition to the adherence of hydrophilic carriers to the surface of poorly water-soluble herbal drugs. These techniques will assist in the formation of a more stable solid dispersion. ConclusionThe application of solid dispersion technique in enhancing the aqueous solubility of poorly aqueous soluble herbal drugs should direct to the constant and enhanced bioavailability, leading to an enhanced therapeutic potential.

In Vitro Drug Release, Permeability, and Structural Test of Ciprofloxacin-Loaded Nanofibers.

Nanofibers of the poorly water-soluble antibiotic ciprofloxacin (CIP) were fabricated in the form of an amorphous solid dispersion by using poly(vinyl pyrrolidone) as a polymer matrix, by the low-cost electrospinning method. The solubility of the nanofibers as well as their in vitro diffusion were remarkably higher than those of the CIP powder or the physical mixture of the two components. The fiber size and morphology were optimized, and it was found that the addition of the CIP to the electrospinning solution decreased the nanofiber diameter, leading to an increased specific surface area. Structural characterization confirmed the interactions between the drug and the polymer and the amorphous state of CIP inside the nanofibers. Since the solubility of CIP is pH-dependent, the in vitro solubility and dissolution studies were executed at different pH levels. The nanofiber sample with the finest morphology demonstrated a significant increase in solubility both in water and pH 7.4 buffer. Single medium and two-stage biorelevant dissolution studies were performed, and the release mechanism was described by mathematical models. Besides, in vitro diffusion from pH 6.8 to pH 7.4 notably increased when compared with the pure drug and physical mixture. Ciprofloxacin-loaded poly(vinyl pyrrolidone) (PVP) nanofibers can be considered as fast-dissolving formulations with improved physicochemical properties.

Space–time wave packets violate the universal relationship between angular dispersion and pulse-front tilt

Introducing angular dispersion into a pulsed field tilts the pulse front with respect to the phase front. There exists between the angular dispersion and pulse-front tilt a universal relationship that is device-independent, and also independent of the pulse shape and bandwidth. We show here that this relationship is violated by propagation-invariant space-time (ST) wave packets, which are pulsed beams endowed with precise spatiotemporal structure corresponding to a particular form of angular dispersion. We demonstrate theoretically and experimentally that ST wave packets represent, to the best of our knowledge, the first example in optics of non-differentiable angular dispersion, resulting in pulse-front tilt that depends on the square-root of the pulse bandwidth.