One approach to formalizing the process of information dissemination based on diffusion-limited aggregation

This article examines one of the approaches to the formalization of information dissemination processes based on the diffusion-limited aggregation model, using elements of cellular automata and their analogs. The model describes the dynamics of the information dissemination process without the influence of the mass media by taking into account the facts of information exchange that occurs during communication between participants of an arbitrary target audience. It is believed that the process is characterized by the property of self-similarity. An approach is proposed that makes it possible to study the dynamics of information dissemination processes, taking into account the attitude of the group members to each other and the attitude of the participants to the input information. As a result, an assessment of the effectiveness of the information dissemination process was obtained, which allows drawing conclusions regarding the success of information promotion measures. To demonstrate the processes of information dissemination modeled on the basis of the approach, the results of numerical experiments are presented, in which the implementation of the information exchange procedure for each person is limited to three members of the target group. Pages of the article in the issue: 61 - 66 Language of the article: Ukrainia

Effect of eucalyptus gass wasp, Leptocybe invase Fisher & La Salle (Hymenoptera: Eulophidae) on wood basic density of three Eucalyptus species in Tanzania

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Nonlinear Evolutionary Problem of Filtration Consolidation With the Non-Classical Conjugation Condition

Finite-element solutions of the initial-boundary value problem for a nonlinear parabolic equation in an inhomogeneous domain with the conjugation condition of a non-ideal contact were found. The initial boundary value problem is a mathematical model of an important technical problem of filtration consolidation of inhomogeneous soils. Inhomogeneity is considered in terms of the presence of thin inclusions, physicochemical characteristics of which differ from those of the main soil. The problem of longterm consolidation is especially pronounced in soils with low filtration coefficient. Low permeability of the porous medium causes deviation from the linear relationship between the pressure gradient and the filtration rate.Weak formulation of the problem is suggested, and the accuracy of the approximate finite element solution, its existence and uniqueness are substantiated for the case of Darcy’s nonlinear law. A test example and the effect of the nonlinear filtration law for thin inclusion on the dynamics of scattering of excess pressures in the entire area of the problem are considered

A Search for Planets Transiting the M Dwarf Debris Disk Host, AU Microscopii

We present high cadence, high precision multi-band photometry of the young, M1Ve, debris disk star, AU Microscopii. The data were obtained in three continuum filters spanning a wavelength range from 4500\AA to 6600\AA, plus H$\alpha$, over 28 nights in 2005. The lightcurves show intrinsic stellar variability due to starspots with an amplitude in the blue band of 0.051 magnitudes and a period of 4.847 days. In addition, three large flares were detected in the data which all occur near the minimum brightness of the star. We remove the intrinsic stellar variability and combine the lightcurves of all the filters in order to search for transits by possible planetary companions orbiting in the plane of the nearly edge-on debris disk. The combined final lightcurve has a sampling of 0.35 minutes and a standard deviation of 6.8 millimags (mmag). We performed Monte Carlo simulations by adding fake transits to the observed lightcurve and find with 95% significance that there are no Jupiter mass planets orbiting in the plane of the debris disk on circular orbits with periods, P $\le 5$ days. In addition, there are no young Neptune-like planets (with radii 2.5$\times$ smaller than the young Jupiter) on circular orbits with periods, P $\le 3$ days.Comment: accepted to MNRA

Thermolysis and Kinetics of Scrap Tyre and Bagasse for Energy Utilization

The increase of energy demand has brought concern to find alternative fuel that will at least sustain the requirement. Bagasse and scrap tyre are waste generated in our industrial activities, which can be used in energy production to subsidize the demand. This paper, aim to study the decomposition behaviour and kinetics of biomass (bagasse) and scrap tyre as preliminary stage of fuel sample analysis to be considered for energy production in gasification/combustion or pyrolysis facilities. The behaviour demonstrated with thermogravimetric analyzer (TGA), shows that all samples have high volatile amount release, 84.21% for bagasse and 85.08% for scrap tyre, which means all are suitable for pyrolysis. However, scrap tyre is most suitable for gasification or combustion due to its high energy content, high ash content and low moisture than bagasse. The determined kinetic parameter were activation energy (E) and pre-exponential factor (A) for hemicellulose/oil as first release composite and cellulose/elastomer as second composite of the analyzed bagasse/scrap tyre samples. The hemicelluloses of bagasse exhibited highest value of activation energy and pre-exponential factor (E=178.191 kJ/mol, and A=1.74×10 16 ) than oil of scrap tyre (E=41.113 kJ/mol, and A= 495.5), which means bagasse is suitable candidate for gasification process due to high operating temperature. With this respect of the study, all candidates may be suitable for pyrolysis or gasification/combustion process. However, for environmental consideration scrap tyre is not suitable due to high sulphur (S) and nitrogen (N) content resulting to high emission ofSOX and NOX 

Do Smoothing Activities Indicate Higher or Lower Financial Reporting Quality? Evidence from Effective Tax Rates

Prior literature is mixed as to whether smoothing through accruals indicates higher or lower financial reporting quality (Tucker and Zarowin 2006; Jayaraman 2008; Dechow et al. 2010). Motivated by the unique inter-temporal features and reporting incentives of tax expense, we provide new evidence on this debate by examining the link between smoothing of GAAP effective tax rates (ETRs) and the likelihood of financial restatements. Different from earnings smoothing’s insignificant relation with restatements, we find that ETR smoothing through tax accruals is associated with a lower likelihood of financial restatement and lower likelihood of tax-related financial reporting fraud. Further investigation reveals that such negative associations are stronger in firms with a higher level of discretion in tax reporting and when the demand and monitoring for transparent reporting is higher. We also document corroborating evidence that smoothing through tax accruals increases the informativeness of GAAP ETRs for predicting future cash ETRs. Collectively, our results contribute to the financial reporting and tax literatures by providing evidence that smoothing activities pertaining to tax accruals are consistent with higher financial reporting quality

Susceptibility of Eucalyptus Species and Clones to Red Gum Lerp Psyllid, Glycaspis brimblecombei, (Hemiptera: Psyllidae) in Mbizi Forest Plantation, Tanzania

Glycaspis brimblecombei is a sap-sucking insect that feeds on Eucalypts. The pest is native to Australia. The nymph feeds on eucalypt leaves and secretes honeydew with which they construct a waxy cover (called a lerp) around themselves. This cover is whitish and conical in shape and shelters the insects until the adult stage. The insect is considered a serious pest that causes leaf discoloration, severe leaf drop, twig dieback and some tree mortality on some Eucalyptus species. In October 2016, the red gum lerp psyllid was recorded for the first time in Mbizi forest plantation in Tanzania infesting Eucalyptus camaldulensis and different Eucalyptus clones. A study was conducted to determine the susceptibility of Eucalypt germplasm to the insect pest. Results showed that E. camaldulensis was more infested followed by GC 514, GC 167, GC 584, GC 15, GC 785 clones while GC 940 was the least infested. Eucalyptus grandis was not infested. Stakeholders can be able to use the susceptibility grouping of the Eucalyptus germplasm to determine what to plant in areas of red gum lerp psyllid infestation. Similar research work should be carried in all major host tree growing areas to determine susceptibility groups for the areas

A Review on Tree Species Suitability for Wood Fuel in Kilimanjaro Region

Wood energy provides 92% of Tanzania’s national energy needs. Wood is the standard cooking fuel for the majority of Tanzanian households and also an important energy source for small-scale rural industries. This paper focuses on suitability of tree species as wood-fuel in Kilimanjaro region mainly through literature review. Results show that when choosing wood for heat energy production, wood moisture content and basic density have to be considered as they affect amount of available heat per unit volume of fuel (calorific value).  The moisture content or any water in the wood has to boil away before the wood will burn, and this will reduce the net energy released as useful heat. Hardwood species are generally denser than softwood species and dense woods will burn for longer than less dense woods. For the purpose of this paper, wood basic density was used as a criterion for selecting tree species suitable for wood fuel in Kilimanjaro region.  The study has revealed that Acacia xanthophloea, Eucalyptus maidenii, Cordia africana, Casuarina equisetifolia, Terminalia superba, Senna siamea, Bauhinia petersiana, Azadirachta indica, Albizia versicolar and Ficus benjamina are among the tree species suitable for wood fuel in Kilimanjaro by having higher basic density than 500kg/m3.  It is recommended that the suitable tree species for wood-fuel uses should be raised and managed by villagers in order to have enough stock for planting. Establishment of demonstration plots for suitable trees for wood fuel in Kilimanjaro region is also recommended.

The Evolution of the VASIMR Engine

Our future deep space explorers face many daunting challenges but three of these loom high above the rest: Physiological debilitation, radiation sickness and psychological stress. Many countermeasures are presently being considered to ameliorate these difficulties however, in the long run, two important new developments are required: abundant space power and advanced propulsion. The development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) addresses these important areas of need. The VASIMR is a high power, radio frequency-driven magneto plasma rocket, capable of very high exhaust velocities. In addition, its unique architecture allows in-flight mission-optimization of thrust and specific impulse to enhance performance and reduce trip time. A NASA-led, research team, involving industry, academia and government facilities is pursuing the development of this concept in the United States. The technology can be validated, in the near term, in venues such as the International Space Station, where it can also serve as both a drag compensation device and a plasma contactor for the orbital facility. Other near-Earth applications in the commercial and scientific satellite sectors are also envisioned. This presentation covers the present status of the technology, plans for its near term deployment and a vision for its future evolution

Lunar lander conceptual design

This paper is a first look at the problems of building a lunar lander to support a small lunar surface base. A series of trade studies was performed to define the lander. The initial trades concerned choosing number of stages, payload mass, parking orbit altitude, and propellant type. Other important trades and issues included plane change capability, propellant loading and maintenance location, and reusability considerations. Given a rough baseline, the systems were then reviewed. A conceptual design was then produced. The process was carried through only one iteration. Many more iterations are needed. A transportation system using reusable, aerobraked orbital transfer vehicles (OTV's) is assumed. These OTV's are assumed to be based and maintained at a low Earth orbit (LEO) space station, optimized for transportation functions. Single- and two-stage OTV stacks are considered. The OTV's make the translunar injection (TLI), lunar orbit insertion (LOI), and trans-Earth injection (TEI) burns, as well as midcourse and perigee raise maneuvers