Role of DeNOx Catalyst in PCDD/F Emission Reduction in Hazardous Waste Incineration (HWI) Plant

On the basis of nine periodical measurements, emissions of PCDD/F have been analysed. As a result, a correlation was detected between elevated PCDD/F emissions and operational problems with selective catalytic reduction (SCR) system. The air pollution control system (APCS) consisted of dry scrubbing system (mixture of active carbon and NaHCO3), fabric filter, DeNOx catalyst and wet scrubber. It was assumed that such a state-of-the-art system should be able to achieve dioxin emission limit of 0.1 ng Nm–3 I-TEQ, even without DeNOx catalyst. However, this expectation proved to be wrong. The presence of memory effect was recognized as the possible cause of elevated PCDD/F emissions. During normal operational periods presence of memory effect was not noticed, due to selective catalytic reduction system. With malfunction of DeNOx catalyst, this effect escalated, causing elevated PCDD/F emissions

On the number of contacts of a floating polymer chain cross-linked with a surface adsorbed chain on fractal structures

We study the interaction problem of a linear polymer chain, floating in fractal containers that belong to the three-dimensional Sierpinski gasket (3D SG) family of fractals, with a surface-adsorbed linear polymer chain. Each member of the 3D SG fractal family has a fractal impenetrable 2D adsorbing surface, which appears to be 2D SG fractal. The two-polymer system is modelled by two mutually crossing self-avoiding walks. By applying the Monte Carlo Renormalization Group (MCRG) method, we calculate the critical exponents $\phi$, associated with the number of contacts of the 3D SG floating polymer chain, and the 2D SG adsorbed polymer chain, for a sequence of SG fractals with $2\le b\le 40$. Besides, we propose the codimension additivity (CA) argument formula for $\phi$, and compare its predictions with our reliable set of the MCRG data. We find that $\phi$ monotonically decreases with increasing $b$, that is, with increase of the container fractal dimension. Finally, we discuss the relations between different contact exponents, and analyze their possible behaviour in the fractal-to-Euclidean crossover region $b\to\infty$.Comment: 15 pages, 3 figure

Dental Hypersensitivity as a Consequence of the Initial Course of Periodontal Treatment

Preosjetljivost dentina često je i bolno patološko stanje koje se javlja kao posljedica različitih provokacijskih čimbenika. Dentinska preosjetljivost očituje se kratkom i jakom boli koja se javlja u području ogoljela dentina kao odgovor na tipične stimuluse, kao što su: toplotni, evaporativni, taktilni, osmotski, ili kemijski, a koji se ne mogu pripisati ni jednom drugom obliku dentalnoga defekta ili dentalne patologije. (Addy M, 2002). To patološko stanje još uvijek nije potpuno razjašnjeno, ali ga treba razlikovati od boli kod zubnoga karijesa, boli kod oštećenih zuba, frakturiranih restauracija, nedovoljnoga zubnog zatvora te palatogingivnih fisura i udubina. Jedina sličnost s dentinskom preosjetljivošću jest osjetljivost zuba koja se javlja nakon profesionalne inicijalne parodontalne terapije. Čestoća dentinske preosjetljivosti varira od 3 - 57% (Verzak Ž et al. 1998, Ress JS 2000), a preosjetljivost u sklopu parodontalnih bolesti može doseći znantno veći postotak (72 - 98% (Chabanski MB et al 1996). U studiju je bilo uključeno 60 slučajno odabranih pacijenata, liječenih na klinikama našega fakulteta. Pacijenti su podijeljeni u 4 skupine prema stanju parodontalnog zdravlja. Dentalna preosjetljivost bila je ispitana s pomoću taktilne osjetljivosti, osjetljivosti na hladan zrak i vodu, prije i poslije inicijalnog parodontalnog tretmana, koji je obavljen ultrazvukom. Stupanj boli izražavan je vrijednošću od 0 - 3 (0- nema boli, 1 - blaga osjetljivost, 2 - umjerena osjetljivost, 3 - jaka bol. Preosjetljivost zuba bila je najizražene bez obzira na vrstu provokacijskoga čimbenika bol postupno smanjivala krajem prvoga tjedna. Upotreba ultrazvuka u terapiji parodontalnih bolesti može izazvti preosjetljivost zuba. Služeći se različitim provokacijskim čimbenicima utija ako se kao provokacijski čimbenik upotrebljavao hladan zrak. Također je ustanovljeno da svrdili smo da je hladan zrak izazivao naj jaču osjetljivost. Bol se obično javljala neposredno nakon uporabe ultrazvuka, ali je trajanje boli bilo razmjerno kratko.Dentin hypersensitivity is a common and painful condition, wich can occur on different kinds of provocation factors. Dental hypersensitivitiy is characterized by short sharp pain arising from exposed dentine in response to stimuli typically thermal, evaporative, tactile, osmotic or chemical and wich cannot be ascribed to any other form of dental defect or pathology (Addy M, 2002). Until today this pathological condition is still unclear but should be deffered from dental caries, chipped teeth, fractured restorations, marginal leakage around restoration, palatogingival fissures and grooves. The only similarity to the dentin hypersensitivity is teeth sensitivity, wich follows the professional initial course of periodontal therapy. The frequency of dentin hypersensitivity varies from 3 - 57% (Verzak Ž et al, 1998, Ress JS 2000), while sensitivity in periodontal diseases could reach a higher percentage: 72-98% (Chabanski MB et al 1996). 60 randomly selected patients from our Clinic were included in the study. All patients were divided into 4 groups according to the grade of pathological periodontal condition. Dental hypersensitivity was investigated by tactile and by cold air/water provocation factors before and after initial periodontal treatment using ultrsound scaling. Pain was scored by 0 - 3 scoring system ( 0 - no pain, 1 - mild pain, 2 - moderate pain, 3 - severe pain). Teeth hypersensitivity was most pronounced if cold air was used as the provocative factor. Regardless of the sort of provocative factor the pain subsided gradually within one week. Ultrasound usage in periodontal treatment may cause teeth hypersensitivity. The hypersensitivity was provoked by mechanical od psysical provocative factors. The most painful sensation was related to cold air. The pain started early after treatment and lasted for a relatively short period of time

On the steady states of the spherically symmetric Einstein-Vlasov system

Using both numerical and analytical tools we study various features of static, spherically symmetric solutions of the Einstein-Vlasov system. In particular, we investigate the possible shapes of their mass-energy density and find that they can be multi-peaked, we give numerical evidence and a partial proof for the conjecture that the Buchdahl inequality $\sup_{r > 0} 2 m(r)/r < 8/9$, $m(r)$ the quasi-local mass, holds for all such steady states--both isotropic {\em and} anisotropic--, and we give numerical evidence and a partial proof for the conjecture that for any given microscopic equation of state--both isotropic {\em and} anisotropic--the resulting one-parameter family of static solutions generates a spiral in the radius-mass diagram.Comment: 34 pages, 18 figures, LaTe

Preliminary geosite assessment model (gam) and its application on Fruška gora mountain, potential geotourism destination of Serbia

This paper presents a preliminary geosite physical assessment model which has the potential to assist in the sustainable planning and management of natural heritage locations and their transformation into tourism destination. The methodology is based on several existing models and presented through two groups of values – main and additional, which are further divided into indicators and subindicators respectively. The resultant model is a graph that consists of nine fields, into which geosites can be classified as fitting into nine general areas of suitability for tourism in terms of their main (scientific/educational, aesthetic/scenic and protection as market appeal and conservation) and additional values (functional and tourism use as current stage of development). This could prove to be of great help to natural heritage protection and tourism managers, as they could assess the current state of a geosite and thence propose a future path for it

Orthogonality conditions and asymptotic stability in the Stefan problem with surface tension

We prove nonlinear asymptotic stability of steady spheres in the two-phase Stefan problem with surface tension. Our method relies on the introduction of appropriate orthogonality conditions in conjunction with a high-order energy method.Comment: 25 pages, important references added, two remarks added, typos correcte

Hamiltonian walks on Sierpinski and n-simplex fractals

We study Hamiltonian walks (HWs) on Sierpinski and $n$--simplex fractals. Via numerical analysis of exact recursion relations for the number of HWs we calculate the connectivity constant $\omega$ and find the asymptotic behaviour of the number of HWs. Depending on whether or not the polymer collapse transition is possible on a studied lattice, different scaling relations for the number of HWs are obtained. These relations are in general different from the well-known form characteristic of homogeneous lattices which has thus far been assumed to hold for fractal lattices too.Comment: 22 pages, 6 figures; final versio