Top Level Mesh

This paper will cover our report on the Top Level Mesh. We have built a web-based system for mesh network management. This system allows network utilities to be used from a web-based interface to monitor and manage the transfer of data. The system runs primarily on Raspberry Pis using Raspbian Linux. Users can access the system through web browsers to both configure the system and interact with the data on the network. We discuss our motivation for the project, design decisions made, technologies used and more throughout this report. We conclude with some lessons learned and future work to be done

Hourly measurement method for radon progeny volumetric activity in air

A method of radon progeny volumetric activity hourly measurement in air was created. A radiometer, which measures the activity of a filter band through which air is sucked, was installed in a hermetic metal frame. Radiometer data was recorded and sent to the computer. The time of suction and the time for the filter band to turn were programmed by electronic stopwatches. This created an opportunity to estimate the hours for self‐contained measurement and to leave the device in a room for any time. This hourly measurement method measured radon and radon progeny volumetric activity and evaluated its change and dependency on meteorological parameters. The radon progeny volumetric activity value varies from 62 Bq/m3 (in the cellar) to 27 Bq/m3 (on the second floor) in the ventilated air, and from 273 Bq/m3 (in the cellar) to 149 Bq/m3 (on the second floor) in the unaired room. The values in the ventilated air and in the unaired rooms differ approximately 4–5 times. It is also determined that volumetric activity depends on wind intensity, temperature and humidity. Radono skilimo produktų tūrinių aktyvumų ore nuolatinių matavimų metodas Santrauka. Sukurtas trumpaamžių radono skilimo produktų tūrinių aktyvumų nenutrūkstamo matavimo metodas. Hermetiniame metaliniame korpuse įtaisytas radiometras, matuojantis slenkančios filtrinės juostos, pro kurią siurbiamas oras, aktyvumą. Radiometro duomenys visą laiką siunčiami ir įrašomi į kompiuterį. Siurbimo ir juostos persukimo laikai užprogramuoti elektroniniais laikmačiais. Taip sudaryta galimybė palikti dirbti prietaisą patalpoje bet kuriam laikui, nustačius, kad matavimai vyktų nustatytomis valandomis. Taikant šį nenutrūkstamo matavimo metodą, išmatuoti radono ir jo trumpaamžių skilimo produktų tūriniai aktyvumai patalpose ir įvertinta jų priklausomybė bei pokyčiai nuo aplinkos meteorologinių parametrų. Išmatuotos trumpaamžių skilimo produktų tūrinių aktyvumų vertės patalpose kinta nuo 62 Bq/m3 (rūsyje) iki 27 Bq/m3 (antrame aukšte) – išvėdintose patalpose, ir nuo 273 Bq/m3 (rūsyje) iki 149 Bq/m3 (antrame aukšte) – neišvėdintose patalpose. Vertės išvėdintose ir neišvėdintose patalpose skiriasi maždaug 4-5 kartus. Nustatyta tiesioginė tūrinio aktyvumo priklausomybė nuo vėjo intensyvumo, temperatūros ir santykinės drėgmės. Reikšminiai žodžiai: radonas, trumpaamžiai radono skilimo produktai, tūrinis aktyvumas, alfa dalelės, matavimo metodas. Метод непрерывного измерения объемной активности продуктов распада радона в воздухе Резюме. Создан метод непрерывного измерения объемной активности короткоживущих продуктов распада радона. В герметичном металлическом корпусе поставлен радиометр, измеряющий активность с помощью скользящего ленточного фильтра, через который засасывается воздух. Данные радиометра все время фиксируются компьютером. Время засасывания воздуха и скольжения ленты запрограммированы электронными счетчиками. Таким образом, создана возможность самостоятельной работы прибора в помещении в течение любого времени, предварительно установив необходимые часы работы. Используя этот метод, в помещении была измерена объемная активность радона и его короткоживущих продуктов распада, определена их зависимость от метеорологических параметров. Измеренные в помещении значения объемной активности короткоживущих продуктов распада колеблются от 62 Бк/м3 (в подвале) до 27 Бк/м3 (на втором этаже) – в проветриваемых помещениях и от 273 Бк/м3 (в подвале) до 149 Бк/м3 (на втором этаже) в непроветриваемых помещениях. Значения в проветриваемых и непроветриваемых помещениях различаются примерно в 4–5 раз. Установлена прямая зависимость объемной активности от интенсивности ветра, температуры и относительной влажности. Ключевые слова: радон, короткоживущие продукты распада радона, объемная активность, альфа-частицы, метод измерения. First Published Online: 14 Oct 201

Front Dynamics with Delays in a Spatially Extended Bistable System: Computer Simulation

Front dynamics with delays in a spatially extended bistable system of the reaction-diffusion type is studied by the use of nonlinear partial differential equation (PDE) of the parabolic type. The response of the self-ordered front, joining two steady states of the different stability in the system, to the multi-harmonic (step-like) force is examined. The relaxation rate of the system, that characterizes the delayed response of the front to the alternating current (ac) drive, is found to be sensitive to the peculiarities (shape) of the rate function (nonlinearity) of the governing PDE. By using computer simulations of the drift motion of the ac driven bistable front (BF) we are able to show that the characteristic relaxation time of the system decreases with the increasing outer slope parameters of the rate function and is not sensitive to the inner one

Towards Patterned Protein Based Nanoparticle Arrays

To meet the exponential growth in the demand for data storage, capacity innovations in hard drive disk (HDD) technologies must be sought. A bit-pattern media (BPM) approach is the frontier of HDD storage technology. It consists of metallic nano-scale patterns of less than 10 nm with 20 nm periodicity and has the potential to significantly increase the data storage density, where each patterned island acts as a single bit. The conventional nano-scale manufacturing methods have so far failed to produce such patterns at scale. There are proteins in nature that can self-assemble into nano-patterns at the desired feature sizes without high energy input under ambient conditions. It is proposed here that a bio-inspired approach could provide useful input to the BPM field by constructing a nano-scale pattern using protein self-assembly exclusively. The project looks to the field of magnetic nanoparticle biomineralisation with attempts to functionalise the protein constructed patterns. The work here characterises a known, unusually rigid rod-like protein domain G52- E-G53 (originating from the SasG protein found in Staphyloccocus aureus) as a building block for protein pattern construction by creating extended linear assemblies through genetic fusion with two orthogonal pairs of coiled-coil forming a-helices. The assembly is validated through a robust series of biophysical and microscopy investigations. The G52-E-G53 coiled-coil constructs are also granted the ability to specifically interact with magnetite nanoparticles through a fusion with a known magnetite binding peptide. Initial work is also performed to create two-dimensional patterns using G52-E-G53 as a rigid linker. The work also shows strong evidence that a magnetite binding peptide and iron nucleation membrane protein Mms6 can be used as genetic fusions to impart improved biomineralisation/particle binding capacity to a well characterised S-layer protein SgsE. Modularity of a different magnetite binding peptide is also demonstrated with respect to different loop displaying scaffold proteins. Lastly, phage display is used to discover three new seven amino acid peptides for CoPt L10 nanoparticle binding and biomineralisation with one of the peptides showing evidence of improving magnetic properties of CoPt chemical synthesis products. Together this multi-pronged approach demonstrates substantial leads that could be the basis of a field of magnetic mineral templating on protein patterns using specific magnetic nanoparticle binding moieties

The Use of "OD" for Managing Change in Government Organizations

ln today's global environment change has becomethe norm rather than the exception. ln this type ofenvironment organizations need to become learningand changing if they are to be effective. The paperdiscusses the nature and the process of change. Itconsiders the concepts of learning organizations andhow to create these organizations and concludes bypresenting some "OD" techniques practiced inLithuania

Geminate carbon monoxide rebinding to a c-type haem

International audienceA chemically modified form of cytochrome c (cyt. c), termed carboxymethyl cytochrome c (cm cyt. c), possesses a vacant sixth coordination site to the haem iron that is available to bind external ligands. We present data on the rapid flash photolysis of CO from the ferrous haem iron of cm cyt. c and describe the kinetics and spectral transitions that accompany the recombination. This was achieved using 30-femtosecond laser pulses and a white light continuum to monitor spectral transitions. Whereas the photo-dissociation quantum yield is close to 1, the yield of CO escape from the protein (the apparent quantum yield, φ) relative to myoglobin (φ = 1) is small due to rapid geminate recombination of CO. On ligand photo-dissociation the haem undergoes a spin-state transition from low-spin ferrous CO bound to penta-coordinate high-spin. Subsequently the system reverts to the CO bound form. The data were fitted with a minimum number of exponentials using global analysis. Recombination of CO with the haem iron of cm cyt. c is multiphasic (τ = 16 ps, 120 ps and 1 ns), involving three spectrally distinct components. The fraction of haem (0.11) not recombining with CO within 4 ns is similar to the value of φ (0.12) measured on the same preparation by the "pulse method" (M. Brunori, G. Giacometti, E. Antonini and J. Wyman, Proc. Natl. Acad. Sci. USA, 1973, 70, 3141-3144, ). This implies that no further geminate recombination occurs at t > 4 ns. This unusually efficient CO-haem geminate recombination indicates the sterically hindered ("caged") nature of the distal haem pocket in cm cyt. c from which it is difficult for CO to escape. The large geminate phase may be contrasted with the behaviour of myoglobin in which geminate recombination is small. This is in general agreement with the well-documented extensive structural dynamics in myoglobin that allow ligand passage, and a higher structural rigidity in cyt. c imposed by the restraints of minimising reorganisation energy for electron transfer (M. Brunori, D. Bourgeois and D. Vallone, J. Struct. Biol., 2004, 147, 223-234, ). The high pH ferrous form of cm cyt. c is a low-spin species having a lysine bound to the central iron atom of the haem (M. Brunori, M. Wilson and E. Antonini, J. Biol. Chem., 1972, 247, 6076-6081; G. Silkstone, G. Stanway, P. Brzezinski and M. Wilson, Biophys. Chem., 2002, 98, 65-77, ). This high pH (pH 8) form of deoxy cm cyt. c undergoes photo-dissociation of lysine (although the proximal histidine is possible) after photo-excitation. Recombination occurs with a time constant (τ) of 7 ps. This is similar to that observed for the geminate rebinding of the Met80 residue in native ferrous cyt. c (τ 6 ps) following its photo-dissociation (S. Cianetti, M. Negrerie, M. Vos, J.-L. Martin and S. Kruglik, J. Am. Chem. Soc., 2004, 126, 13932-13933; W. Wang, X. Ye, A. Demidov, F. Rosca, T. Sjodin, W. Cao, M. Sheeran and P. Champion, J. Phys. Chem., 2000, 104, 10789-10801, )

The investigation of tobacco smoke influence on the changes of indoor radon and its short-lived decay products volumetric activities

The changes of radon and its short-lived decay products were investigated in accommodations under natural living conditions and in tobacco smoke-filled premises. The measured radon and its short-lived decay products volumetric activities, aerosol particle concentration in the air, radioactive equilibrium factor, unattached fraction factor values are presented. It was identified that the increase of aerosol particles concentration in the air (in smoke-filled premises) determines the increase of the unattached nuclides of radon short-lived decay products attached to aerosol particles (the average values of radioactive equilibrium factor varied from 0.35 to 0.72). In this case, larger volumetric activity of the alpha particles is registered. Therefore larger amount of radon progeny is inhaled in smoke-filled premises and there is an increased possibility of damaging the organism. Positive correlation (r = 0.9) between the radioactive equilibrium factor and aerosol particle concentration in the air of accommodation, as well as negative correlation (r = −0.64) between the radioactive equilibrium factor and unattached fraction factor have been determined. Seasonal changes of the radioactive equilibrium factor are presented