Spectrophotometric determination of nickel using a new chromogenic reagent in plant leaves

A Spectrophotometric method for the determination of nickel in plant leaves with new chromogenic reagent is presented. A new highly sensitive and selective chromogenic reagent dibromo‐p‐methyl‐carboxyazo was synthesized; in 0.25 M phosphoric acid medium, which greatly increases the selectivity. Nickel reacts with DBMCA to form a 1:2 mole‐ratio bluish red complex, having a sensitive absorption peak at 625 nm under optimal conditions. Beer's law is obeyed over the range from 0.01 to 0.79 µ mL^? Ni (II) and the apparent molar absorptivity is 1.038?×?10^??4 mol^??1 cm^??1. The detection limit and variation coefficient were found to be 2.12 ng mL^??1 and 1.0% respectively. It is found that, except for Ca (II) and Ba (II), all foreign ions studied do not interfere with determination. The interference caused by Ca(ll) and Ba(ll) can be easily eliminated by prior extraction with potassium iodide methyl isobutyl ketone. The method has been applied to the determination of nickel in plant leaves with good accuracy.     

Variations in isotopic composition of desalinated water

Variations in isotopic ratios of water samples collected from three plants functioning on two different desalination processes were evaluated by comparing their measured δ¹⁸O, δ¹⁷O and the δ²H isotopic ratios before and after desalination using a system based on tunable off‐axis integrated‐cavity‐output diode laser spectroscopy (OA‐ICOS). The δ¹⁸O, δ¹⁷O and the δ²H isotopic ratio measurements for water samples collected before desalination are compared against their peers of desalinated water from two desalination plants on the Arabian Gulf that are operating under the Multistage Flash (MSF) process. Also, variations in the δ¹⁸O, δ¹⁷O and the δ²H isotopic ratio measurements due to desalination from a Reversal Osmosis (RO) facility in Dhahran, Saudi Arabia were also reported and compared against variations in isotopic composition of water desalinated in two MSF plants.     

Kontinuumsmechanik in der Stahlbeton‐Praxis

Continuum Mechanics in Reinforced Concrete Engineering. Proof of Bearing reserves at three Examples The relevance of nonlinear analysis tools is shown by means of case studies from engineering practice. A brief introduction into the theory of the developed finite element program is supposed to illustrate the basic mechanical principals, the employed constitutive relations and the input data required. The bond behaviour of a concrete overlay is discussed in the first example. Especially the interface stresses due to creep and shrinkage because of the different ages of the two concrete layers are highlighted. The second example investigates a bridge deck cantilever in the case of heavy vehicle impact into a restraint system of a very high containment level. The performance of such a bridge deck cantilever, which was originally not designed for such a high impact, is investigated. The third example shows a frame corner with a simple reinforcement layout, where the anchorage of the reinforcement limits the ultimate load.     

Moving out: Aged migration in Western Australia 1991–96

Abstract

This paper explores aged migration in Western Australia between 1991 and 1996, focusing on net movement outcomes. Migration is considered in three age cohorts: ‘pre‐retirees’ aged 55 to 64; the ‘young old’ aged 65 to 74; and the ‘old old’ aged 75 and over. Senior Western Australians aged between 55 and 74 are, in significant net terms, leaving the established inner and middle suburbs of Perth. This net outward movement is focused on outer coastal suburbs both to the north and south of the city, on peri‐urban areas to the east of the city, and on the coastal strip running from Mandurah to Margaret River. Though much smaller in volume, the net migration of the ‘old old’ is in the opposite direction: towards the city centre or larger regional towns. As the general woe of rural Australia suggests, the net movement of younger Western Australians (aged 5 to 54) also very strongly favours the city.     

Highways and industrial development in the peripheral regions of China

This study estimates how highways affected industrial development in China's peripheral regions between 1998 and 2007, a period during which China experienced rapid growth in highway mileage. Highways between major cities pass through some counties but not others. Based on this difference in counties’ access to highways, we conduct a difference‐in‐difference propensity score matching estimation, with the treatment variables being counties’ highway connection status and their industrial performance before and after being connected to a highway. We find that highways promote industrial development in counties with higher output and greater investment levels. Moreover, highways have differential impacts across industries and regions.     

Indoor air pollution by alkylphenols in Tokyo

The purposes of this study were to develop an analytical method for airborne alkylphenols (APs) using the gas chromatography/mass spectrometry (GC/MS)-SIM method and to investigate airborne C4-C9 APs pollution in houses, offices, and outdoor points in Tokyo. In addition, to identify APs emission sources in a newly built house, migration tests of APs from interior surfaces to solid extraction disks were performed. Air samples were collected from houses, offices, and outdoor points. The recovery of APs from air samples was increased by addition of ascorbic acid to the filters. 4-tert-butylphenol (4-t-BP), 4-tert-octylphenol (4-t-OP), and 4-nonylphenol (4-NP) were detected in both indoor and outdoor air. Their concentrations and detection frequencies were higher in indoor air than outdoor air. The maximum levels of 4-t-BP, 4-t-OP, and 4-NP in indoor were 387, 45.7, and 680 ng/m(3), respectively. 4-t-BP and 4-NP were detected with high frequencies (more than 97%) in indoor air samples. The concentrations of 4-t-BP, 4-t-OP, and 4-NP in indoor air were significantly correlated with room temperature (P < 0.01), and tended to be higher in newly built houses. The migration rates of APs from the floor, wall, and ceiling in the newly built house were higher in polyvinyl chloride coverings than in other materials. Practical Implications Alkylphenol ethoxylate (APE) are widely used surfactants in both industrial and domestic detergents. When these detergents are released into the environment, APE are biodegraded to the smaller chain ethoxylates and alkylphenols (APs). There are many reports about APs in aquatic environments because of their estrogenic effect on wildlife. In building materials, APs are used as antioxidant for polymer resins such as wall or floor coverings. Although APs has a lower vapor pressure, these agents are released into indoor air from the surface of polymer resins. This study surveyed concentrations of airborne AP in indoor air and outdoor air in Tokyo. In addition, to identify APs emission sources in a newly built house, migration tests of APs from interior surfaces to solid extraction disks were performed. PRACTICAL IMPLICATIONS: Alkylphenol ethoxylate (APE) are widely used surfactants in both industrial and domestic detergents. When these detergents are released into the environment, APE are biodegraded to the smaller chain ethoxylates and alkylphenols (APs). There are many reports about APs in aquatic environments because of their estrogenic effect on wildlife. In building materials, APs are used as antioxidant for polymer resins such as wall or floor coverings. Although APs has a lower vapor pressure, these agents are released into indoor air from the surface of polymer resins. This study surveyed concentrations of airborne AP in indoor air and outdoor air in Tokyo. In addition, to identify APs emission sources in a newly built house, migration tests of APs from interior surfaces to solid extraction disks were performed.     

Use of (1-3)-beta-d-glucan concentrations in dust as a surrogate method for estimating specific fungal exposures

Indoor exposure to fungi has been associated with respiratory symptoms,often attributed to their cell wall component, (1-3)-beta-D-glucan. Performing(1-3)-beta-D-glucan analysis is less time consuming and labor intensive than cultivation or microscopic counting of fungal spores. This has prompted many to use(1-3)-beta-D-glucan as a surrogate for fungal exposure. The aim of this study was to examine which indoor fungal species are major contributors to the (1-3)-beta-D-glucan concentration in field dust samples. We used the quantitative polymerase chain reaction (QPCR) method to analyze 36 indoor fungal species in 297 indoor dust samples. These samples were also simultaneously analyzed for (1-3)-beta-D-glucan concentration using the endpoint chromogenic Limulus Amebocyte lysate assay. Linear regression analysis, followed by factor analysis and structural equation modeling, were utilized in order to identify fungal species that mostly contribute to the (1-3)-beta-D-glucan concentration in field dust samples. The study revealed that Cladosporium and Aspergillus genera, as well as Epicoccum nigrum, Penicillium brevicompactum and Wallemia sebi were the most important contributors to the (1-3)-beta-D-glucan content of these home dust samples. The species that contributed most to the (1-3)-beta-D-glucan concentration were also the most prevalent in indoor environments. However, Alternaria alternata, a common fungal species in indoor dust, did not seem to be a significant source of (1-3)-beta-D-glucan. PRACTICAL IMPLICATIONS: This study revealed that the (1-3)-beta-D-glucan content of different fungal species varies widely. (1-3)-beta-D-glucan inhouse dust from the Greater Cincinnati area may be a good marker for some fungal species of the Cladosporium and Aspergillus genera. In contrast, Alternaria alternata did not contribute much to the (1-3)-beta-D-glucan load. Therefore, (1-3)-beta-D-glucan concentration in field samples as a surrogate for total fungal exposure should be used with caution.     

Challenges to surface water quality in mid‐sized African cities: conclusions from Awetu‐Kito Rivers in Jimma,south‐west Ethiopia

Rapid urbanization and industrialization, uncontrolled population growth, indiscriminate waste discharge and poor infrastructure are problems that African cities are facing. This paper describes an exemplary case study from Jimma, south‐west Ethiopia. A cross‐sectional study was conducted along the Awetu‐Kito drainage system in Jimma town to assess the level of pollution from urban dwellers and related activities. The study indicates that the Environmental Protection Agency (EPA) norms for biochemical oxygen demand (BOD), dissolved oxygen (DO) and orthophosphates are not met downstream of the major industrial and institutional activities. Small‐scale industries, Jimma University and residential areas contributed 50, 15 and 23% pollution load on the river, respectively. It can be concluded that the pollution effect in Jimma town is mainly as a result of the growing (uncontrolled) industrial activities and not to discharge of household wastewater. Given the same trends of urbanization and population growth, similar development (socio‐economic) indicators and similar climatic conditions, the key findings for Jimma are transferable to other mid‐sized African cities.     

Biodegradation of chlorpyrifos and 3, 5, 6‐trichloro‐2‐pyridinol by a novel rhizobial strain Mesorhizobium sp. HN3

A chlorpyrifos (CP) and 3,5,6‐trichloro‐2‐pyridinol (TCP) degrading bacterial strain, Mesorhizobium sp. HN3, was isolated and characterized. Mesorhizobium sp. HN3 degraded CP efficiently up to 400 mg/L initial concentration at wide range of temperatures (30–40°C) and pH (6.0–8.0). However, optimal degradation of CP was achieved at 37°C and neutral pH (7.0) at an initial inoculum density 2 × 10⁷ colony forming unit/mL of culture medium. Kinetic parameters for CP degradation by Mesorhizobium sp. HN3 were estimated at different initial concentrations. Cultures exhibited significant variation (P ≤ 0.05) in the specific growth rate (μ), cell mass formation rate (Q_X) and the substrate uptake rate (Q_S) during degradation of CP. The values of kinetic parameters increased up to 100 mg/L CP and decreased at higher concentration. Investigation of degradation metabolites indicated that CP is converted to diethylthiophosphate and TCP that leads to the formation of 3,5,6‐trichloro‐2‐methoxypyridine.     

Strategies in environmental education

The causes of environmental changes, including climate, are neither fully understood nor identified, nor do scientists agree about their nature. Yet, their impact is such that action cannot be delayed. This involves spreading public awareness through environmental education and sensitization. Hence a need to reach, to educate the poorly informed public at large. With the classroom as the base, “town meetings” and eco‐tourism may constitute potentially useful approaches towards that goal.     

The JIT materials management system in developing countries

The just‐in‐time (JIT) approach to materials management appears to be superior to a just‐in‐case (JIC) approach in terms of reducing cost and improving productivity under most circumstances encountered in industrialized countries. However, is it truly more advantageous than the more commonly used approaches in developing countries? Contractors in developing countries may be compelled to keep excessive inventory under some circumstances to help manage uncertainty in the supply chain and production process, high inflation rates, available discounts on prices of large amounts of materials, and price cuts in case of early purchasing. This study presents a comparison of the JIT and JIC materials management systems in terms of total cost of inventory by means of a simulation model that makes use of actual data obtained from an ongoing trade centre project in Istanbul, Turkey. The study suggests that had the JIT system been used in the project in Istanbul the total cost of inventory would have been 4.4% higher than the total cost of inventory in the JIC system currently used.     

Evaluation of ground motion scaling methods in soil–structure interaction analysis

Dynamic analysis of structures deals with scaling of ground motions, which is vital for estimation of seismic responses. A major source of variability in seismic responses of structures arises from scaling of ground motions. In this paper, the accuracy of six conventional scaling methods on estimation of engineering demand parameters of soil–structure interacting systems is investigated. Two‐dimensional structural models of 5, 10, and 20 stories shear buildings are studied by using stick models, whereas the underlying soil is modeled using the cone model concept. This research attempts to elucidate the accuracy of considered methods for the evaluation of responses. The results show that a suitable scaling method for a response may differ from one to another in terms of accuracy and efficiency. Copyright © 2012 John Wiley & Sons, Ltd.     

Model framework for integrating multiple exposure pathways to chemicals in household cleaning products

We present a screening‐level exposure‐assessment method which integrates exposure from all plausible exposure pathways as a result of indoor residential use of cleaning products. The exposure pathways we considered are (i) exposure to a user during product use via inhalation and dermal, (ii) exposure to chemical residues left on clothing, (iii) exposure to all occupants from the portion released indoors during use via inhalation and dermal, and (iv) exposure to the general population due to down‐the‐drain disposal via inhalation and ingestion. We use consumer product volatilization models to account for the chemical fractions volatilized to air (f_volatilized) and disposed down the drain (f_{down‐the‐drain}) during product use. For each exposure pathway, we use a fate and exposure model to estimate intake rates (iR) in mg/kg/d. Overall, the contribution of the four exposure pathways to the total exposure varies by the type of cleaning activities and with chemical properties. By providing a more comprehensive exposure model and by capturing additional exposures from often‐overlooked exposure pathways, our method allows us to compare the relative contribution of various exposure routes and could improve high‐throughput exposure assessment for chemicals in cleaning products.     

Chlorinated ethyl and isopropyl phosphoric acid triesters in the indoor environment--an inter-laboratory exposure study

The chlorinated organo-phosphate triesters, tris(2-chloroethyl)-phosphate (TCEP) and tris(monochloroisopropyl)-phosphate (TCPP), are employed in consumer articles for indoor usage, e.g. flame retardants and plasticizers in foam material as well as in paints, varnishes and wallpapers. As a result of this widespread usage, employing domestic dust as a matrix, both chemicals have been detected in the indoor environment. TCEP was present in 85% of a total of 983 samples, whereas TCPP was found in 60-90% of 436 cases (with levels ranging from 0.1 to 375 mg/kg). Since TCEP and TCPP residues in domestic dust are assumed to be condensates arising from primary sources, spot check analysis of various indoor materials was performed. The results show that soft foams, paints and wallpapers contained mainly TCEP, whereas in insulation and sealant foams high levels of TCPP were found. Moreover, TCEP can also be detected in indoor air in concentrations up to 6,000 ng/m3. On the basis of this data, we estimated the levels of indoor exposure via oral and inhalative ingestion.     

Effects of run‐of‐the‐river hydropower plants on the surface water quality in the Solakli stream watershed,Northeastern Turkey

In recent years, Turkey has turned its attention to alternative energy sources rather than fossil fuels. The Eastern Black Sea Region of Turkey has steep mountains with hilly topography and has large potential in terms of energy production with run‐of‐the‐river hydropower plants (RHPPs). In this study, the effects of two RHPPs on some water quality parameters were examined in the Solakl? stream watershed. This research was conducted over the course of 12 months (January–December 2014). In total, 12 sampling points were selected and various water quality parameters, such as temperature, pH, dissolved oxygen, total suspended solids, electrical conductivity, total dissolved solid, chloride and salinity, were monitered at each point. Statistically, significant changes occured in water quality parameters such as total suspended solids, pH and temperature. In particular, total suspended solids ranged from 10 to 440 mg/L.These results suggest that the RHPP negatively effect water quality and quantity in the main stream in both the operational and constructional phases.