Application of infrared analysis for the detection of organic substances in the building structures

Artykuł dotyczy wykorzystania metody analizy w podczerwieni do stwierdzenia obecności substancji organicznych w elementach obiektów budowlanych. Substancje takie mogą być celowo wprowadzane do wyrobów budowlanych jako dodatki i domieszki, składniki klejów czy uszczelniacze, lub na ich powierzchnie - jako ochrona powierzchniowa: hydrofobizacja, impregnacja, powłoki. Substancje organiczne mogą również wnikać do elementów obiektu budowlanego ze środowiska użytkowania jako ciecze czy opary technologiczne i wówczas stanowią niepożądane zanieczyszczenia.The paper refers to the application of infrared analysis method to identify the organic substances in the elements of building structures. Such substances, as additives and admixtures, as the adhesives and sealants components, may be intentionally introduced into the building products or, on their surfaces, as the surface protection: hydrophobization, impregnation, coatings. Organic substances as a liquid or fumes can also penetrate into structure and contaminate the concret

Testing and estimation of changes in selected characteristics of products for the repair of reinforced concrete structures

Przedstawiono wyniki badań trzech zapraw przeznaczonych do wykonywania napraw otuliny zbrojenia w konstrukcjach żelbetowych. Określono wpływ warunków atmosferycznych, symulowanych w laboratoryjnych badaniach starzeniowych, na właściwości utwardzonych zapraw, istotne dla trwałości otuliny zbrojenia: odporność na karbonatyzację, wytrzymałość i nasiąkliwość. Oceniono wyniki uzyskanych badań w aspekcie trwałości naprawy otuliny zbrojenia.The laboratory tests of three mortars for the repair of concrete structures were presented. Report contains description of changes in characteristics of tested products caused by accelerated weathering. During accelerated weathering the strength, water absorption and resistance to carbonation were determined. Results of tests were discussed

A maintenance programme taking account of the durability of hyperboloid cooling towers after 30 years of use

W artykule przedstawiono kompleksowe badania diagnostyczne dwóch użytkowanych chłodni kominowych po 30 latach eksploatacji wraz z analizą statyczno-wytrzymałościową ich konstrukcji.This article describes comprehensive diagnostic tests carried out on two operational cooling towers after 30 years of use, as well as a static and strength analysis of their structure

Test of changes of dynamic contact angle of the concrete hydrophobic impregnation

Impregnacja hydrofobizująca jest metodą obróbki powierzchniowej betonu, zabezpieczającej go przed zawilgoceniem oraz wnikaniem substancji agresywnych. Stosowana jest głównie jako zabezpieczenie przed czynnikami agresywnymi obecnymi w warunkach atmosferycznych. Impregnacja hydrofobizująca, odpowiednio dobrana do warunków użytkowania i właściwie wykonana, korzystnie wpływa na trwałość obiektów betonowych i żelbetowych. Opisane w artykule badania stanowią próbę wykorzystania pomiarów zmian dynamicznego kąta zwilżania do określenia skuteczności impregnacji hydrofobizującej betonu.Hydrophobic impregnation is a method of concrete surface protection against the ingress of moisture and aggressive substances. It is used mainly as a protection against corrosive agents present in the atmospheric conditions. Hydrophobic impregnations, chosen according to the conditions of use and properly executed, have a beneficial effect on the durability of concrete and reinforced concrete. Research works described in this paper constitute the attempt to recognize the possibility of using measurements of dynamic contact angle to determine the effectiveness of the hydrophobic impregnation

Potassium phosphonate alters the defence response of Xanthorrhoea australis following infection by Phytophthora cinnamomi

Potassium phosphonate (phosphite) is widely used in the management of Phytophthora diseases in agriculture, horticulture and natural environments. The Austral grass tree, Xanthorrhoea australis, a keystone species in the dry sclerophyll forests of southern Australia, is susceptible to Phytophthora cinnamomi, but is protected by applications of phosphite. We examined the effect of phosphite application on the infection of X. australis seedlings and cell suspension cultures by zoospores of P. cinnamomi. Phosphite induced more intense cellular responses to pathogen challenge and suppressed pathogen ingress in both seedlings and cell cultures. In untreated X. australis seedlings, hyphal growth was initially intercellular, became intracellular 24 h after inoculation, and by 48 h had progressed into the vascular tissue. In phosphite-treated seedlings, growth of P. cinnamomi remained intercellular and was limited to the cortex, even at 72 h after inoculation. The cell membrane retracted from the cell wall and phenolic compounds and electron dense substances were deposited around the wall of infected and neighbouring cells. Suspension cells were infected within 6 h of inoculation. Within 24 h of inoculation, untreated cells were fully colonised, had collapsed cytoplasm and died. The protoplast of phosphite-treated suspension cells collapsed within 12 h of inoculation, and phenolic material accumulated in adjacent, uninfected cells. No anatomical response to phosphite treatment was observed before infection of plant tissues, suggesting that the phosphite-associated host defence response is induced following pathogen challenge. Anatomical changes provide evidence that phosphite stimulates the host defence system to respond more effectively to pathogen invasion.<br /

Inhibition of human immunodeficiency virus (HIV-1) infection in human peripheral blood leucocytes-SCID reconstituted mice by rapamycin

The capacity of the immunomodulatory drug rapamycin (RAPA) to inhibit replication of the CCR5 strain of human immunodeficiency virus (HIV) in vitro prompted us to test its effects in a murine preclinical model of HIV infection. RAPA (0.6 or 6 mg/kg body weight) or its vehicle were administered daily, per os, to SCID mice reconstituted with human peripheral blood leucocytes (hu-PBL) starting 2 days before the intraperitoneal challenge with the R5 tropic SF162 strain of HIV-1 (1000 50% tissue culture infective dose/ml). Relative to hu-PBL-SCID mice that received no treatment, HIV-infected hu-PBL-SCID mice treated with the vehicle control for 3 weeks exhibited a severe depletion of CD4(+) cells (90%), an increase in CD8(+) cells and an inversion of the CD4(+)/CD8(+) cell ratio. In contrast, treatment of HIV-infected mice with RAPA prevented a decrease in CD4(+) cells and the increase of CD8(+) cells, thereby preserving the original CD4(+) : CD8(+) cell ratio. Viral infection also resulted in the detection of HIV-DNA within peritoneal cells and spleen, and lymph node tissues of the vehicle-treated mice within 3 weeks of the viral challenge. In contrast, treatment with RAPA decreased cellular provirus integration and reduced HIV-RNA levels in the blood. Furthermore, in co-cultivation assays, spleens from RAPA-treated mice exhibited a reduced capacity for infecting allogeneic T cells which was dose-dependent. These data show that RAPA possesses powerful anti-viral activity against R5 strains of HIV in vivo and support the use of additional studies to evaluate the potential application of this drug in the management of HIV patients