Front propagation and arrival times in networks with application to neurodegenerative diseases

Many physical, epidemiological, or physiological dynamical processes on networks support front-like propagation, where an initial localized perturbation grows and systematically invades all nodes in the network. A key question is then to extract estimates for the dynamics. In particular, if a single node is seeded at a small concentration, when will other nodes reach the same initial concentration? Here, motivated by the study of toxic protein propagation in neurodegenerative diseases, we present and compare three different estimates for the arrival time in order of increasing analytical complexity: the linear arrival time, obtained by linearizing the underlying system; the Lambert time, obtained by considering the interaction of two nodes; and the nonlinear arrival time, obtained by asymptotic techniques. We use the classic Fisher-Kolmogorov-Petrovsky-Piskunov equation as a paradigm for the dynamics and show that each method provides different insight and time estimates. Further, we show that the nonlinear asymptotic method also gives an approximate solution valid in the entire domain and the correct ordering of arrival regions over large regions of parameters and initial conditions.

Temperate Coastal Microbial Communities Rapidly Respond to Low Concentrations of Partially Weathered Diesel

Diesel is frequently encountered in coastal ecosystems due to land run-off from road surfaces. The current study investigates how partially weathered diesel at environmentally relevant concentrations, as may be seen during a run-off event, affect coastal microbial communities. A mesocosm experiment using seawater from the Bedford Basin, Nova Scotia, was followed for 72 h after the addition of partially weathered diesel. Sequencing data suggests partially weathered diesel acts quickly to alter the prokaryotic community, as both opportunistic (Vibrio and Lentibacter) and oil-degrading (Colwellia, Sulfitobacter, and Pseudoalteromonas) bacteria proliferated after 24 h in comparison to the control. In addition, total prokaryotes seemed to recover in abundance after 24 h, where eukaryotes only ceased to decrease slightly at 72 h, likely because of an inability to adapt to the oil-laden conditions, unlike the prokaryotes. Considering there were no highly volatile components (benzene, toluene, ethylbenzene, and xylene) present in the diesel when the communities were exposed, the results indicate that even a relatively small concentration of diesel run-off can cause a drastic change to the microbial community under low energy conditions. Higher energy conditions due to wave action may mitigate the response of the microbial communities by dilution and additional weathering of the diesel.

Absorption properties of bromide photo-thermo-refractive glasses doped with Ytterbium

In this work bromide photo-thermo-refractive glasses with different Ytterbium concentration were explored. It is shown that UV irradiation and subsequent heat treatment of samples with Yb 2 mol.% causes significant red-shift absorption line from 410 nm with temperature lower than Tg to 517 nm with temperature Tg +60 °C. For small concentration of Yb (0,1 mol. %) maximum red-shift in plasmon resonance absorption band is shown as 485 nm and it is the same for heat treatment temperatures from Tg +20 °C to Tg +60 °C.

Effect of electrical poling on the structural, dielectric and photoluminescence properties of small concentration of Ho+3 substituted NBT

The effect of electrical poling on the room temperature structural, dielectric and photoluminescence properties of small concentration (i.e. 0.5 mole%) of Ho+3 substituted sodium bismuth titanate ferroelectric material (Na0.5Bi0.495Ho0.005TiO3 abbreviated as NBT-0.5Ho) has been investigated. Its crystal structure was found to be the mixture of two phases of rhombohedral (R3c) and monoclinic (Cc) in which monoclinic (Cc) coexisted as major phase. Comparative study of X-ray diffraction (XRD) patterns of electrically poled and unpoled specimens of NBT-0.5Ho revealed that electric field irreversibly transformed crystal structural of dominant Cc (≈-94.05% phase fraction) phase to R3c (≈70.6% phase fraction) as major phase. Dielectric value and its dispersion with frequency were significantly decreased in poled specimen which is ascribed to electric field driven structural change. Two photoluminescence (PL) emissions at 655nm and 756nm were obtained in NBT-0.5Ho. PL intensity was considerably tuned in effect of electrical poling in term of quenching. Obtain quenching is correlated with induced structural ordering towards higher symmetry phase (R3c) in effect of electric poling which is confirmed from XRD analysis. Obtained additional functionality of photoluminescence in the NBT-0.5Ho ferroelectric material and its tuning in effect of electric field opens the possibility in the material for optoelectronic devices applications.

Effects of white vinegar on carbohydrate contents in hepatorenal tissues in rats.

White vinegar is mildly acidic with a pH of 2-3 that has long been used as a relish and traditional medication that depends on its concentration. Yet even a small amount of white vinegar in a small concentration may cause serious poisoning. Recently, many sorts of white vinegar have been developed using fundamental sources and technologies to satisfy customer needs. This study was aimed to investigate the effects of white vinegar on carbohydrate contents in hepatorenal tissues in rats. Thirty female rats were used, they were divided into three groups, group 1 was given distilled water as the normal control group, group 2 was given white vinegar with a dose (1 ml/kg (5 %)) and group 3 was given white vinegar with a dose (1 ml/kg (10 %)) for two weeks. PAS stain in all treated tissues showed a decrease in carbohydrate contents when compared with the control group. In conclusion, white vinegar consumption has adverse effects on carbohydrate contents in hepatic and renal tissues in rats, hence the quantity of white vinegar should be discouraged or reduced.

PICKERING EMULSION TECHNOLOGY IN FABRICATE CELLULOSE FOAM FROM OIL PALM EMPTY FRUIT BUNCH WASTE

PICKERING EMULSION TECHNOLOGY IN FABRICATE CELLULOSE FOAM FROM OILPALM EMPTY FRUIT BUNCH WASTE. Cellulose from the oil palm empty fruit bunch (OPEFB) waste can make a porous material. This study aims to make cellulose foam with Pickering emulsion technology used cellulose nanofiber as a Pickering agent. The mechanism of Pickering emulsion is learned from foamability and stability of foam in the presence of various concentrations of surfactant. The result showed that using Pickering emulsion technology only needed surfactant with a small concentration to improve foamability and stability. The addition of CNF indeed improved the stability and foamability with the Pickering effect. The stability test shows that the foam stabilized with CNF appeared to be relatively stable. In contrast to the CNF free system, the foams were collapse in three days tested. Structures of foam was characterized using an optical microscope and showed that the foam was composed into two- or three dimensional microstructures formed by gas bubble of wet foam in random orientations. This process generated the lightweight Cellulose foam from OPEFB waste, with a density of 0.07 g/cm3. Using Pickering emulsion technology to make cellulose foam can be one way to overcome OPEFB waste and this foam is potential for various applications.

Ultrathin Silicon Nanowires for Optical and Electrical Nitrogen Dioxide Detection

The ever-stronger attention paid to enhancing safety in the workplace has led to novel sensor development and improvement. Despite the technological progress, nanostructured sensors are not being commercially transferred due to expensive and non-microelectronic compatible materials and processing approaches. In this paper, the realization of a cost-effective sensor based on ultrathin silicon nanowires (Si NWs) for the detection of nitrogen dioxide (NO2) is reported. A modification of the metal-assisted chemical etching method allows light-emitting silicon nanowires to be obtained through a fast, low-cost, and industrially compatible approach. NO2 is a well-known dangerous gas that, even with a small concentration of 3 ppm, represents a serious hazard for human health. We exploit the particular optical and electrical properties of these Si NWs to reveal low NO2 concentrations through their photoluminescence (PL) and resistance variations reaching 2 ppm of NO2. Indeed, these Si NWs offer a fast response and reversibility with both electrical and optical transductions. Despite the macro contacts affecting the electrical transduction, the sensing performances are of high interest for further developments. These promising performances coupled with the scalable Si NW synthesis could unfold opportunities for smaller sized and better performing sensors reaching the market for environmental monitoring.

Multianalytical Assessment of Armour Paints—The Ageing Characteristics of Historic Drying Oil Varnish Paints for Protection of Steel and Iron Surfaces in Sweden

The characteristics of armour paints, historically used to protect ferrous industrial heritage, are explored. Amour paints contain lamellar and highly reflexive pigments of micaceous iron oxide (MIO) and metallic, leafing aluminium, bound in linseed oil and linseed oil–tung oil mixtures, on an inhibitive and soap-forming linseed oil primer (red lead). It is the first study of the binding media used for historical armour paints and investigates the chemical and physical ageing of armour paints using a multianalytical approach. Naturally aged examples are compared to accelerated aged replica armour paint, and to historical paints. The ageing and degradation reactions are assessed by complementary GC–MS and FTIR, together with measurements of wettability, hardness and surface colour. The historical paint formulations include linseed oils and alkyd binders. The results confirm that the leafing effect of aluminium pigments results in only a small concentration of binder at the surface: the paints studied reflect light and form a strong chemical and physical barrier. Linseed oils and tung oil mixtures have been proven to be suitable for the production of armour paints, but the evaluation of ageing and assessment of physical changes will require further investigation.

Development of Instant Linear Gel for Coal Bed Methane Gas Operations

Previously we prepared fracturing linear gel with fossil diesel, bio-diesel and also used suspending, anti-settling agents and emulsifiers. But through this research, a novel and efficient method for the preparation of linear gel directly mixed with water, guar gum and sodium acetate together instantly. In this instead of diesel, we used water and no need to mix anti-settling agents, suspending agents, emulsifiers that resulted in 30 viscosity linear gel. Ammonium persulphate or Ammonium peroxidisulphate and enzyme-G are used for oxidation purposes to break the gel gradually at a particular static temperature. The degradation pattern observed from the breaker test showed that a reduction in gel viscosity depends on time, temperature & breaker concentration. Observations from experiments revealed that a small concentration of breakers provides rapid break compared to oxidative breakers. This article, designing of fracturing fluids describes how to use the fluid's viscosity generated by the gelling agents like guar gum for CBM operations.