Influence of deicers on development of roadside grasses

Much emphasis has been, and is being, placed on establishment of vegetation along highway backslopes. Since control of erosion is of primary importance on backslopes, very little attention has been directed towards highway medians and foreslopes where the erosion problem is less. However, difficulties have already been encountered in many states, both in obtaining and in maintaining vigorous and attractive turf on medians on on shoulders along Interstate highways

Investigating the protective properties of concrete containing ash from coal combustion in a fluidized bed

The article reports the results of research on the protective properties of concrete with the addition of ash from hard coal combustion in a fluidized bed at a power plant in Katowice. Research was carried out on concentrated water extracts from disintegrated concrete using a polarization technique. The results were compared with those obtained in a similar way from concrete extracts without additives and with criteria including the delimiting values of the parameters of the electrochemical process. The results have shown that concrete incorporating 15% and 30% ash as cement replacement correctly protect reinforcement against corrosion. Betono su skysto kuro krosnyje sudegintos anglies pelenais apsauginių savybių tyrimas Santrauka Straipsnyje pateikti betono su Katowice gamykloje skysto kuro krosnyje sudegintos anglies pelenais apsauginių savybių tyrimų rezultatai. Taikant poliarizacijos technologiją buvo tiriamas vandens koncentratas, išskirtas iš suirusio betono. Rezultatai palyginti su panašių tyrimų rezultatais, kai taikant tokią pačią technologiją buvo tiriamas betonas be priemaišų. Rezultatai taip pat buvo palyginti pagal kriterijus, ivertinančius ribines elektrocheminio proceso parametrų reikšmes. Rezultatai parodė, kad, betone 15 ar 30 proc. cemento pakeitus pelenais, armatūra būna tinkamai apsaugota nuo korozijos. First Published Online: 16 May 2013 Reikšminiai žodžiai: apsauginės betono savybės, betono priedai, cementą pakeičiančios medžiagos, skysto kuro krosnyje sudegintos anglies pelenai, armatūros korozija, poliarizacijos kreivės, korozijos srovė, korozijos potenciala

A test of reinforcement corrosion progress in the presence of organic corrosion inhibitors

Test results for KCR and DME migrating inhibitor efficiency are presented. The method of linear polarization is used in the tests on loaded reinforced concrete elements. Various durations of inhibitor activity, cracked concrete cover and different levels of reinforcement corrosion development in test parts are taken into account. The inhibitors are only partly efficient at low levels of corrosion development at an early stage, however, after two years the protective work is not verifiable. In the case of intense reinforcement corrosion a reduction in its degree is not observed, even directly after inhibitors have been applied. Armatūros korozijos eksperimentiniai tyrimai naudojant organinės korozijos lėtiklius Santrauka Straipsnyje pateikti lėtiklių KCR ir DME efektyvumo eksperimentinių tyrimų rezultatai. Eksperimentiniuose tyrimuose apkrautiems betoniniams elementams taikyti tiesinės poliarizacijos metodai. Ivairios lėtiklių aktyvumo trukmės, supleišėjusio betono apsauginio sluoksnio ir skirtingų armatūros korozijos laipsnių išsivystymas eksperimentų dalyse yra įvertintas. Lėtikliai tik iš dalies veiksmingi esant žemam korozijos išsivystimo lygiui pradinėse stadijose, tačiau po dvejų metų jų apsauginis darbas nėra įrodytas. Kai yra didelė armatūros korozija, nėra nustatyta jos laipsnio sumažėjimo, netgi tuoj pat panaudojus lėtiklius. First Published Online: 16 May 2013 Reikšminiai žodžiai: betonas, lėtiklis, korozija, efektyvumas, apsauga, armatūra, gelžbetoni

Diffusion of organic substances inhibiting reinforcement corrosion in concrete

This paper will present the results of tests on the diffusion properties of the migrating inhibitor DME and KCR. The tests were done by determining the distribution of concentrations of inhibitors in concrete, and then the values of a reliable diffusion coefficient were calculated on the basis of the solution to the reverse-task diffusion equation. Inhibitors have shown very good diffusion properties, which were about 5 rows better than the properties of the inhibitors on the market. Inhibitors DME and KCR were able to quickly penetrate deep into the concrete through the entire thickness of reinforcement concrete cover. Straipsnyje pateikti eksperimentiniai difuzijos savybių rezultatai naudojant DME ir KCR inhibitorius. Atliekant bandymus buvo nustatytas inhibitorių koncentracijos pasiskirstymas betone ir patikimos difuzijos koeficiento vertės buvo apskaičiuotos sprendžiant atvirkštinį difuzijos lygties uždavinį. Inhibitoriai parodė labai geras difuzijos savybes, lyginant su kitų rinkoje esančių inhibitorių savybėmis. Inhibitoriai DME ir KCR turi savybę greitai ir giliai įsiskverbti į apsauginį betono sluoksnį. Santrauka Straipsnyje pateikti eksperimentiniai difuzijos savybių rezultatai naudojant DME ir KCR inhibitorius. Atliekant bandymus buvo nustatytas inhibitorių koncentracijos pasiskirstymas betone ir patikimos difuzijos koeficiento vertės buvo apskaičiuotos sprendžiant atvirkštinį difuzijos lygties uždavinį. Inhibitoriai parodė labai geras difuzijos savybes, lyginant su kitų rinkoje esančių inhibitorių savybėmis. Inhibitoriai DME ir KCR turi savybę greitai ir giliai įsiskverbti į apsauginį betono sluoksnį. First Published Online: 16 May 2013 Reikšminiai žodžiai: betonas, inhibitorius, korozija, difuzija, apsauga, armatūra, gelžbetonis

Modelling the carbonated concrete realkalization

The presented model of carbonated concrete realkalization is compiled on the basis of the multi‐component medium theory equations. The process equations have been obtained from an analysis of the partial equations of mass, electric charge, momentum, energy, and entropy inequality. The experimental testing reported is related to a theoretical model which determines changes of ion concentrations in the pore solution of the cover, as a result of the realkalization. On the basis of the test results, the process equations have been simplified and formally transformed into the form of an equation for the OH– ions flow, coupled with the Na+ions transport. By solving the converse problem of this equation, the determinant OH– ions electro‐diffusion coefficient is calculated and then, after taking the experimental test results into account, its numerical values, the range of stable solutions and the influence of the process non‐stationariness are determined. Santrauka Karbonatizavusio betono šarminės terpės atkūrimo modelis sudarytas remiantis daugiakomponentės aplinkos teorijos lygtimis. Procesą aprašančios lygtys sudarytos atlikus masės balanso, elektros krūvio, judesio kiekio, energijos, taip pat entropijos nevienodumo parcialinių lygčių analizę. Eksperimentiniai tyrimai susieti su teoriniu modeliu apibrėžiant jonų koncentracijos pokytį tirpale apsauginio sluoksnio porose atkuriant šarminę terpę. Remiantis bandymų rezultatų analize, procesą aprašančios lygtys supaprastintos ir formaliai pertvarkytos į lygtis, aprašančias OH¯ jonų, susietų su Na+ jonais, pernešimu. Išsprendus šį uždavinį atvirkštiniu keliu, išreikštas OH¯ jonų elektrodifuzijos koeficientas ir, remiantis eksperimentinių tyrimų rezultatais, nustatyta jo skaitinė reikšmė, sunkiai skaidomų tirpalų sritis, taip pat proceso nepastovumo įtaka. First Published Online: 14 Oct 2010 Reikšminiai žodžiai: betonas, armatūros korozija, elektrocheminis šarminės terpės atkūrimas, eksperimentiniai tyrimai, proceso modeliavimas

The emergence of the Digital Fabrication industry: Domains, applications, and key technology challenges

Novelties created by newly emerging sciences and technologies also capture a substantial amount of promises around their transformative character. Promises and resulting expectations concerning performance and applications but also regarding the impact of new technology on society arise. Key features of emerging industries are high uncertainty, different stakeholder groups that are involved in different phases of development and a strong need for management through these phases. In the context of this innovation ecology, interaction between science and industry is an important aspect to consider. This is usually easier conceptualized as put into practice. Decisions about which technological areas to focus on and to invest in have to be made before marketable technologies or products emerge. Prioritizing a key application field relevant to a disruptive technological domain thus poses significant challenges. In this paper, we first describe how consensus on the most pressing and high potential domains and applications in digital fabrication was reached in a consortium-based approach. What is more, we can show at hand of stakeholder survey results what the future expectations are regarding the maturity of the respective applications. In a next step, we bring key technology challenges (KTCs) into the picture and argue for varying pressures to overcome them along the industry emergence process. This allows both practitioners and researchers to see how the challenges of an emerging field can be addressed with context-driven strategic intelligence

Operacja plastyczna przepukliny pachwinowej i resekcja wola guzowatego powikłane zespołem paciorkowcowego wstrząsu toksycznego (STSS) wywołanym przez Streptococcus pyogenes - opis dwóch przypadków

W niniejszej pracy przedstawiono dwa przypadki zespołu paciorkowcowego wstrząsu toksycznego (STSS) po zabiegach plastyki przepukliny pachwinowej i subtotalnej resekcji wola guzowatego obojętnego. Oba poważne powikłania leczenia chirurgicznego leczono na oddziale intensywnej terapii. W dochodzeniu epidemiologicznym nie wykazano źródła zakażenia. Wdrożenie szeregu procedur profilaktycznych doprowadziło do eliminacji tego typu zakażeń.This paper presents two cases of streptococcal toxic shock syndrome (STSS) after an inguinal hernioplasty and a goiter subtotal resection. These serious complications of surgery were treated in our Intensive Care Ward. An epidemiological investigation did not reveal the source of infection. STSS elimination was achieved by antimicrobial procedures and prophylaxis

A Model for Isotropic Crystal Growth from Vapor on a Patterned Substrate

We developed a consistent mathematical model for isotropic crystal growth on a substrate covered by the mask material with a periodic series of parallel long trenches where the substrate is exposed to the vapor phase. Surface diffusion and the flux of particles from vapor are assumed to be the main mechanisms of growth. A geometrical approach to the motion of crystal surface in two dimensions is adopted and nonlinear evolution equations are solved by a finite-difference method. The model allows the direct computation of the crystal surface shape, as well as the study of the effects due to mask regions of effectively nonzero thickness. As in experiments, lateral overgrowth of crystal onto the mask and enhanced growth in the region near the contact of the crystal and the mask is found, as well as the comparable crystal shapes. The growth rates in vertical and lateral directions are investigated.Comment: 21 pages; submitted to the Journal of Crystal Growt

Constitutive regulation of the glutamate/aspartate transporter EAAT1 by Calcium-Calmodulin-Dependent Protein Kinase II

Glutamate clearance by astrocytes is an essential part of normal excitatory neurotransmission. Failure to adapt or maintain low levels of glutamate in the central nervous system is associated with multiple acute and chronic neurodegenerative diseases. The primary excitatory amino acid transporters in human astrocytes are EAAT1 and EAAT2 (GLAST and GLT-1, respectively, in rodents). While the inhibition of calcium/calmodulin-dependent kinase (CaMKII), a ubiquitously expressed serine/threonine protein kinase, results in diminished glutamate uptake in cultured primary rodent astrocytes (Ashpole et al. 2013), the molecular mechanism underlying this regulation is unknown. Here, we use a heterologous expression model to explore CaMKII regulation of EAAT1 and EAAT2. In transiently transfected HEK293T cells, pharmacological inhibition of CaMKII (using KN-93 or tat-CN21) reduces [3 H]-glutamate uptake in EAAT1 without altering EAAT2-mediated glutamate uptake. While over-expressing the Thr287Asp mutant to enhance autonomous CaMKII activity had no effect on either EAAT1 or EAAT2-mediated glutamate uptake, over-expressing a dominant-negative version of CaMKII (Asp136Asn) diminished EAAT1 glutamate uptake. SPOTS peptide arrays and recombinant glutathione S-transferase-fusion proteins of the intracellular N- and C-termini of EAAT1 identified two potential phosphorylation sites at residues Thr26 and Thr37 in the N-terminus. Introducing an Ala (a non-phospho mimetic) at Thr37 diminished EAAT1-mediated glutamate uptake, suggesting that the phosphorylation state of this residue is important for constitutive EAAT1 function. Our study is the first to identify a glutamate transporter as a direct CaMKII substrate and suggests that CaMKII signaling is a critical driver of constitutive glutamate uptake by EAAT1