82 research outputs found

    Soil and water bioengineering: practice and research needs for reconciling natural hazard control and ecological restoration

    Get PDF
    Soil and water bioengineering is a technology that encourages scientists and practitioners to combine their knowledge and skills in the management of ecosystems with a common goal to maximize benefits to both man and the natural environment. It involves techniques that use plants as living building materials, for: (i) natural hazard control (e.g., soil erosion, torrential floods and landslides) and (ii) ecological restoration or nature-based re-introduction of species on degraded lands, river embankments, and disturbed environments. For a bioengineering project to be successful, engineers are required to highlight all the potential benefits and ecosystem services by documenting the technical, ecological, economic and social values. The novel approaches used by bioengineers raise questions for researchers and necessitate innovation from practitioners to design bioengineering concepts and techniques. Our objective in this paper, therefore, is to highlight the practice and research needs in soil and water bioengineering for reconciling natural hazard control and ecological restoration. Firstly, we review the definition and development of bioengineering technology, while stressing issues concerning the design, implementation, and monitoring of bioengineering actions. Secondly, we highlight the need to reconcile natural hazard control and ecological restoration by posing novel practice and research questions

    Regional patterns of transition at Çadir Höyük in the Byzantine period

    Get PDF
    Byzantine archaeological sites tend to be seen as representative of the empire as a whole, with little concern given to regional context. Within the imperial narrative that shapes Byzantine history, sites—whether urban or rural—are often used to explain and illustrate imperial trends. However, when we remove that overarching narrative, the sites in Anatolia provide the potential to view them as singular examples of local and regional identity. In this article, we have separated out four types of data: fortifications, coins, faunal material, and archaeobotanical evidence to illustrate how a close examination of the data provides new ways of understanding regional identity. In doing so, we posit that the Byzantine empire needs to be seen as a collection of local identities working alongside one another, but always expressing individual needs and resources

    A review of the occurrence and causes for wildfires and their impacts on the geoenvironment

    Get PDF
    Wildfires have short- and long-term impacts on the geoenvironment, including the changes to biogeochemical and mechanical properties of soils, landfill stability, surface- and groundwater, air pollution, and vegetation. Climate change has increased the extent and severity of wildfires across the world. Simultaneously, anthropogenic activities—through the expansion of urban areas into wildlands, abandonment of rural practices, and accidental or intentional fire-inception activities—are also responsible for a majority of fires. This paper provides an overall review and critical appraisal of existing knowledge about processes induced by wildfires and their impact on the geoenvironment. Burning of vegetation leads to loss of root reinforcement and changes in soil hydromechanical properties. Also, depending on the fire temperature, soil can be rendered hydrophobic or hydrophilic and compromise soil nutrition levels, hinder revegetation, and, in turn, increase post-fire erosion and the debris flow susceptibility of hillslopes. In addition to direct hazards, wildfires pollute air and soil with smoke and fire suppression agents releasing toxic, persistent, and relatively mobile contaminants into the geoenvironment. Nevertheless, the mitigation of wildfires’ geoenvironmental impacts does not fit within the scope of this paper. In the end, and in no exhaustive way, some of the areas requiring future research are highlighted

    Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

    Get PDF
    Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

    High surface area Au-SBA-15 and Au-MCM-41 materials synthesis: Tryptophan amino acid mediated confinement of gold nanostructures within the mesoporous silica pore walls

    No full text
    Advantages of confining the gold nanostructures formation within the mesoporous silica pore walls during its silica condensation and consequent improvement in the textural properties such as specific surface area, pore volume, pore diameter have been demonstrated, while retaining gold nanostructures within the silica walls. This has been achieved by tryptophan mediated confinement of gold nanoparticles formation within the condensing silica framework, to obtain Au-SBA-15 (SSA 1247 m(2)/g, V(t) similar to 1.37 cm(3)/g) and Au-MCM-41 (SSA 1287 m(2)/g, V(t) similar to 1.1 cm(3)/g), mesoporous silica materials having the combination of very high surface area from the porous support as well as gold nanoparticles infiltrated silica walls. Choice of tryptophan for this purpose is that it has an indole group, which was known to reduce gold ions to form gold nanoparticles and its amine and carboxylic acid groups, catalyze the hydrolysis of silica precursors in a wide range of pH. These properties have been utilized in restricting the gold nanostructures formation inside the condensing silica phase without affecting the self assembly between the silica precursors and the triblock copolymer (for SBA-15) or cetyltrimethylammonium bromide template (for MCM-41). The polytryptophan and the gold nanostructures, which were encapsulated within the silica framework and upon removal of the template by calcination resulting in the formation mesoporous materials wherein the silica walls become microporous due to the removal of occluded polytryptophan and the resulting microchannels contain very small gold nanostructures. Hence, the resulting materials have very high surface area, high pore volume and narrow pore size distribution as compared to their parent SBA-15, MCM-41 and SBA-15, MCM-41 post functionalized with gold nanoparticles inside the pores

    Design of novel ultrafiltration systems based on robust polyphenylsulfone hollow fiber membranes for treatment of contaminated surface water

    No full text
    This work focuses on development of robust but economical hollow fiber ultrafiltration systems that could be operated with or without electric power to treat polluted surface water. A diverse experimental study was carried out to synthesize novel hollow fiber membranes based on polyphenylsulfone (PPSu) and polyvinylidenefluoride (PVDF) fibers for surface water treatment. A manual hollow fiber spinning machine incorporated with an inexpensive spinneret was designed to fabricate hollow fibers from dope compositions of 20wt% PVDF in DMAc and 20wt% PPSu in NMP by phase inversion technique. Isothermal ternary phase diagrams of PVDF or PPSu/solvent/non-solvent systems were established using three different solvents such as N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidinone (NMP) and N,N-dimethylformamide (DMF) with water being the non-solvent. The indigenous fibers had an approximate outer diameter of 1.5mm and the wall thickness of 0.25mm and were housed in inexpensive PVC and UPVC tubes using epoxy resin and nylon end connectors. PVDF hollow fibers (HF) exhibited 94.8% turbidity rejection, whereas PPSu fibers exhibited 91% rejection with 5 log E-Coliform reduction from surface water at a low hydraulic pressure of 1bar with high flux values of 125Lm-2h-1 and 73Lm-2h-1, respectively at a substantial water recovery of 80%. A water purification device capable of generating 25Lh-1 purified water flow at an overhead tank pressure of 0.5bar was designed and fabricated for households along with a hand pump operated submerged ultrafiltration (UF) system for treatment of surface water in flood prone regions. Detailed economic estimation of the indigenously designed water purification device for household purpose is presented which shows a low operating cost of 0.02 US $ per liter of purified water obtained
    corecore