Future of clay-based construction materials – A review

Sustainability in the manufacture of different construction materials raises many important issues. Nowadays, there is increasing demand for such materials to be produced using environmentally friendly, low energy consuming production methods. This paper presents a review of the current research relating to the use of various production techniques for clay-based construction materials. The techniques which will be reviewed are: blending and stabilising, alkali activation (geopolymerisation) and the use of microwave heating as an innovative sintering, curing and drying method. The advantages and disadvantages of each technique will be discussed. Additionally, a comparison between the environmental and economic aspects of the studied production techniques along with some suggestions to improve the sustainability of different production techniques will be discussed

microRNA-141 as a diagnostic and prognos- tic biomarker for prostate cancer in Egyptian population: Pilot study

Introduction: microRNAs are a family of small non protein-coding RNAs. They are involved in posttranscriptional gene regulation of their target genes. The deregulation of microRNAs has been linked to cancer development and tumor progression. The aim of out study was to look for microRNA-141 as a diagnostic and prognostic biomarker for prostate cancer.Patients and methods: The study prospectively recruited 30 patients newly diagnosed with prostate cancer; including 13 and 17 patients without and with metastases, respectively. Another 30 patients without prostate cancer diagnosis were included as a control group. Real-time polymerase chain reaction analysis was done for relative quantification of microRNA-141.Results: The present study showed that microRNA-141 was significantly upregulated in cancerous patients compared to control group. Also it was significantly upregulated in patients with metastatic disease compared to non-metastatic patients. Moreover, it was significantly correlating with serum PSA and Gleason score.Conclusion: Serum microRNA-141 could be a promising diagnostic and prognostic biomarker for prostate cancer and a good indicative of disease aggressiveness

Mechanical and Tribological Properties of Carbon-Based Graded Coatings

The paper presents research on coatings with advanced architecture, composed of a Cr/Cr2N ceramic/metal multilayer and graded carbon layers with varying properties from Cr/a-C:H to a-C:N. The microstructure of the coatings was analysed using transmission electron microscopy and Energy Dispersive Spectroscopy, the mechanical properties were tested by nanoindentation, spherical indentation, and scratch testing, and tribological tests were also conducted. The proper selection of subsequent layers in graded coatings allowed high hardness and fracture resistance to be obtained as well as good adhesion to multilayers. Moreover, these coatings have higher wear resistance than single coatings and a friction coefficient equal to 0.25

Final Report - Glass Formulation Development and Testing for DWPF High AI2O3 HLW Sludges, VSL-10R1670-1, Rev. 0, dated 12/20/10

The principal objective of the work described in this Final Report is to develop and identify glass frit compositions for a specified DWPF high-aluminum based sludge waste stream that maximizes waste loading while maintaining high production rate for the waste composition provided by ORP/SRS. This was accomplished through a combination of crucible-scale, vertical gradient furnace, and confirmation tests on the DM100 melter system. The DM100-BL unit was selected for these tests. The DM100-BL was used for previous tests on HLW glass compositions that were used to support subsequent tests on the HLW Pilot Melter. It was also used to process compositions with waste loadings limited by aluminum, bismuth, and chromium, to investigate the volatility of cesium and technetium during the vitrification of an HLW AZ-102 composition, to process glass formulations at compositional and property extremes, and to investigate crystal settling on a composition that exhibited one percent crystals at 963{degrees}C (i.e., close to the WTP limit). The same melter was selected for the present tests in order to maintain comparisons between the previously collected data. The tests provide information on melter processing characteristics and off-gas data, including formation of secondary phases and partitioning. Specific objectives for the melter tests are as follows: Determine maximum glass production rates without bubbling for a simulated SRS Sludge Batch 19 (SB19). Demonstrate a feed rate equivalent to 1125 kg/m{sup 2}/day glass production using melt pool bubbling. Process a high waste loading glass composition with the simulated SRS SB19 waste and measure the quality of the glass product. Determine the effect of argon as a bubbling gas on waste processing and the glass product including feed processing rate, glass redox, melter emissions, etc.. Determine differences in feed processing and glass characteristics for SRS SB19 waste simulated by the co-precipitated and direct-hydroxide methods. The above tests were proposed based on previous tests for WTP in which there were few differences in the melter processing characteristics, such as processing rate and melter emissions, between precipitated and direct hydroxide simulants, even though there were differences in rheological properties. To the extent this similarity is found also for simulants for SRS HLW, the direct hydroxide methods may offer the potential for faster, simpler, and cheaper simulant production. There was no plan to match the yield stress and particle size of the direct hydroxide simulant to that of the precipitated simulant because that would have increased the preparation cost and complexity and defeated the purpose of the tests. These objectives were addressed by first developing a series of glass frits and then conducting a crucible scale study to determine the waste loading achievable for the waste composition and to select the preferred frit. Waste loadings were increased until the limits of a glass property were exceeded experimentally. Glass properties for evaluation included: viscosity, electrical conductivity, crystallinity (including liquidus temperature and nepheline formation after canister centerline cooling (CCC) heat-treatment), gross glass phase separation, and the 7- day Product Consistency Test (PCT, ASTM-1285) response. Glass property limits were based upon the constraints used for DWPF process control

Chaos induced coherence in two independent food chains

Coherence evolution of two food web models can be obtained under the stirring effect of chaotic advection. Each food web model sustains a three--level trophic system composed of interacting predators, consumers and vegetation. These populations compete for a common limiting resource in open flows with chaotic advection dynamics. Here we show that two species (the top--predators) of different colonies chaotically advected by a jet--like flow can synchronize their evolution even without migration interaction. The evolution is charaterized as a phase synchronization. The phase differences (determined through the Hilbert transform) of the variables representing those species show a coherent evolution.Comment: 5 pages, 5 eps figures. Accepted for publication in Phys. Rev.

Novel Mode of Trisiloxane Application Reduces Spider Mite and Aphid Infestation of Fruiting Shrub and Tree Crops

Application of pesticides leads to contamination of the natural environment, which entails the necessity to seek solutions that use substances which do not pose ecological hazards. The presented investigations tested the efficacy of a preparation containing organomodified trisiloxane and a cross-linking agent (Siltac EC) to limit the number of two-spotted spider mite (Tetranychus urticae) on the leaves of raspberry (Rubus idaeus) and blackcurrant (Ribes nigrum), as well as the numbers of green apple aphid (Aphis pomi) on apple trees (Malus domestica). The high effectiveness (more than 90%) of Siltac against spider mite on raspberry and blackcurrant leaves was rapid and persisted at least by two- three weeks after spraying. There was observed an inhibition of pest developing (i.e. significant decrease of eggs and larvae). Similar effect occurred per an apple tree shoot and the number of living apple aphids was reduced by more than 93% in comparison to untreated trees. In all experiments, the effectiveness of Siltac was similar and usually longer lasting than control pesticides. Moreover, no phytotoxicity of the tested preparation was observed during the investigations. In conclusion, on the basis of the presented results it was found that Siltac EC could be a good alternative to the currently used plant protection chemicals

The role of nω-nitro-L-arginine in modulation of pulmonary vascular tone in the maturing newborn pig

AbstractCurrent therapeutic modalities for treatment of newborn pulmonary hypertensive crisis include but are not limited to the administration of nitric oxide (endothelium-derived relaxing factor). However, few data are available on the role of endogenously produced endothelium-derived relaxing factor in the modulation of pulmonary vascular tone in the neonate. In the current study, we investigated the acute effects of Nω-nitro- L -arginine (a potent competitive inhibitor of endothelium-derived relaxing factor synthase) on the pulmonary vasculature of anesthetized open-chest 48-hour-old ( n = 8) and 2-week-old ( n = 7) Yorkshire pigs. After baseline data were acquired, all animals received a 10 mg/kg per minute infusion of Nω-nitro- L -arginine for 10 minutes. To discern distal and proximal pulmonary arterial vessel changes, input mean and characteristic impedance were respectively determined. Pulmonary vascular resistance was also calculated (units determined in dyne • sec • cm -5 plus or minus the standard errorof the mean). Results showed Nω-nitro- L -arginine infusion did not significantly alter baseline pulmonary arterial pressure (22,370 ±1473 dyne/cm2 ), pulmonary vascular resistance (5171 ±805 dyne • sec • cm -5 ), input impedance (6343 ±806 dyne • sec • cm -5 ), or characteristic impedance (2073 ±418 dyne • sec • cm -5 ) in 48-hour-old pigs. In 2-week-old pigs, infusion of Nω-nitro- L -arginine elevated pulmonary arterial pressure (18,162 ±1415 dyne/cm 2 versus 23,838 ±1810 dyne/cm 2 , p = 0.015), pulmonary vascular resistance (810 ±137 dyne • sec • cm -5 versus 1519 dyne • sec • cm -5 , p = 0.030), and input impedance (2302 ±251 dyne • sec • cm -5 versus 2900 ±255 dyne • sec • cm -5 , p = 0.018). Characteristic impedance was not altered in 2-week-old pigs. These data indicate that Nω-nitro- L -arginine infusion resulted in pulmonary arteriolar vasoconstriction in 2-week-old pigs, but not in 48-hour-old pigs. This finding suggests that endothelium-derived relaxing factor does not modulate basal pulmonary arteriolar tone during the early newborn period, but does play a significant role in 2-week-old pigs. These data also suggest that the functional role for endothelium-derived relaxing factor is confined to the distal arteriolar pulmonary bed and does not extend to the larger proximal arterial vessels. (J THORAC CARDIOVASC SURG 1995;110:1486-92

Maternal stress during pregnancy and neurodevelopmental outcomes of children during the first 2 years of life

AIM: A growing body of literature documents associations between maternal stress in pregnancy and child development, but findings across studies are often inconsistent. The aim of this study was to estimate the association between exposure to different kinds of prenatal stress and child psychomotor development. METHODS: The study population consisted of 372 mother-child pairs from Polish Mother and Child Cohort. The analysis was restricted to the women who worked at least 1 month during pregnancy period. Maternal psychological stress during pregnancy was assessed based on: the Subjective Work Characteristics Questionnaire, Perceived Stress Scale and Social Readjustment Rating Scale. The level of satisfaction with family functioning and support was evaluated by APGAR Family Scale. Child psychomotor development was assessed at the 12th and 24th months of age by Bayley Scales of Infant and Toddler Development. RESULTS: Negative impact on child cognitive development at the age of two was observed for the Perceived Stress Scale (β = -0.8; P = 0.01) and the Social Readjustment Rating Scale (β = -0.4; P = 0.03) after adjusting for the variety of confounders. Occupational stress, as well as satisfaction with family functioning, was not significantly associated with child psychomotor development (P > 0.05). CONCLUSIONS: The study supports the findings that prenatal exposure to maternal stress is significantly associated with decreased child cognitive functions. In order to further understand and quantify the effects of prenatal stress on child neurodevelopment further studies are needed. This will be important for developing interventions that provide more assistance to pregnant women, including emotional support or help to manage psychological stress

Development of New Precursors for One-Part Alkali-Activated Geopolymer Using IndustrialWastes

Conventional two-part alkali activation has many drawbacks: the hazardous activating solution, which makes it less friendly to handle and the absence in long-term availability of its main precursors such as fly ash and ground granulated furnace slag. This research aimed to develop a one-part alkali-activated cement, which is free of chemical solutions. A blend of alumina-silicate rich materials with adequate alkaline content to minimise the limitations associated with the current (AAC) relating to source materials was utilised. At the same time, applying alternative activation methods such as thermo-mechanical activation, alkali-thermal activation or thermo-chemical activation of new (AAC) precursors were investigated. Materials were analysed in terms of their physical, chemical and metallurgical properties to understand the changes after thermal activation. Enhanced compressive strength was recorded from individual thermal activation of the materials at 450 °C and 950 °C

An analyses of the status of landfill classification systems in developing countries: Sub Saharan Africa landfill experiences

Municipal solid waste (MSW) management remains a challenge in developing countries due to increasing waste generation, high costs associated with waste management and the structure of the containment systems implemented. This study analyses the classification of landfilling systems by using documented cases reported mainly in publications in waste management in relation to non-engineered landfilling systems/approved dumpsites in Sub Saharan African (SSA) countries from 2000 to 2018. The work identifies an existing system for the classification of landfill sites and utilises this system to determine the situation of landfill sites in SSA countries. Each article was categorised according to the main landfilling management practice reported: Uncontrolled dumping, semi controlled facility, medium controlled facility, medium/high-engineered facility or high state-of the-art facility. Findings suggested that 80% of the documented cases of landfill sites assessed in SSA countries were classified as level 0 or 1. The structure of the containment and controlled regime were identified by the focus group discussion participants as important predictors of possible strengths, weaknesses, opportunities and threats for the landfill sites considered. The study represents the first identifiable and comprehensive academic evaluation of landfill site classification based on site operations reported in the available peer reviewed literature. The information provides insight on the status of landfill sites in SSA countries with respect to the landfilling management practice and a baseline for alternative corrective measures