Effects of different drying processes on the concentrations of metals and metalloids in plant materials.

6 p.The drying process of fresh plant materials may affect the porous structure, dehydration and a number of quality characteristics of these materials. Therefore, this study has investigated the effect of different drying processes on the variation of metal and metalloid concentrations in the dried plant materials. Seven varieties of native plant species collected from Sa˜o Domingos mine were analyzed by instrumental neutron activation analysis(INAA) to investigate the effects of freeze-drying (FD),ambient air-drying (AAD) and oven-drying (OD) process on the concentrations of metals and metalloids in the plant biomass. Comparison of ambient air-dried, oven-dried and freeze-dried preparations allows a phenomenological description of the dehydration artefacts. In the quantitative analysis of metals and metalloids, FD and OD plant samples show the higher concentrations of metals and metalloids when compared to those in the AAD plant biomass. The freeze-drying process is comparatively reliable for determination of metals and metalloids concentrations in plant materials.This research work was supported by the Fun- 242 dac¸a˜o para Cieˆncia e Tecnologia (FCT, Portugal) through research 243 contract PTDC/AMB/65462/2006—HYPERAS. The principal author 244 (H.M.A) thanks FCT for his post-doctoral grant.Peer reviewe

Determination of phytoextraction potential of plant speciesfor toxic elements in soils of abandoned sulphide-mining areas

This study has determined contamination levels in soils and plants from the Sa˜o Domingos mining area, Portugal, by k0-INAA. Total concentrations of As, Sb, Cr, Hg, Cu, Zn and Fe in soils were very high, exceeding the maximum limits in Portuguese legislation. Concentrations of toxic elements like As, Sb and Zn were highest in roots of Erica andevalensis, Juncus acutus, Agrostis castellana and Nicotiana glauca. Additionally, As, Br, Cr, Fe, Sb and Zn in all organs of most plants were above toxicity levels. Those species that accumulated relatively high concentrations of toxic elements in roots (and tops) may be cultivated for phytostabilisation of similar areas

Optimization of Flame Atomic Absorption Spectrometry for Measurement of High Concentrations of Arsenic and Selenium

High concentrations of As and Se in mining wastes covering a large area in the mine operating countries present a threat to public health, environment and ecological diversity in different countries. Therefore, a rapid, cost-effective, affordable and routine analysis is needed to monitor the preliminary contamination levels in these countries. In order to achieve this goal, this study has optimised the flame atomic absorption spectrometry (FAAS) to determine the high concentrations of As and Se using standard samples. The best result of the calibration curve fit (R2 = 0.959) was found for the standard As concentrations of 0, 5.61, 11.22, 16.83 and 22.45 mg/L; and indicated the very strong linearity of calibration. This procedure allowed a rapid determination of As from minimum 4.462 mg/L to higher concentrations without sample pretreatment. Besides As, this method successfully measured Se concentrations from minimum 1.0 mg/L to higher concentrations. The results showed that FAAS can measure lower concentrations of Se than As. Therefore, this method can be widely applied in different countries for determination of As and Se in environmental samples with high concentrations for the rapid, cost-effective and routine analysis, who can not afford the expensive methods such as ICP-MS, ICP-AES, ICP-OES etc. The study finally suggests the implications of the findings to chemical education

Remediation of Polluted River Water by Biological, Chemical, Ecological and Engineering Processes

Selection of appropriate river water treatment methods is important for the restoration of river ecosystems. An in-depth review of different river water treatment technologies has been carried out in this study. Among the physical-engineering processes, aeration is an effective, sustainable and popular technique which increases microbial activity and degrades organic pollutants. Other engineering techniques (water diversion, mechanical algae removal, hydraulic structures and dredging) are effective as well, but they are cost intensive and detrimental to river ecosystems. Riverbank filtration is a natural, slow and self-sustainable process which does not pose any adverse effects. Chemical treatments are criticised for their short-term solution, high cost and potential for secondary pollution. Ecological engineering-based techniques are preferable due to their high economic, environmental and ecological benefits, their ease of maintenance and the fact that they are free from secondary pollution. Constructed wetlands, microbial dosing, ecological floating beds and biofilms technologies are the most widely applicable ecological techniques, although some variabilities are observed in their performances. Constructed wetlands perform well under low hydraulic and pollutant loads. Sequential constructed wetland floating bed systems can overcome this limitation. Ecological floating beds are highly recommended for their low cost, high effectiveness and optimum plant growth facilities

Arsenic-phosphorus interactions in the soil-plant-microbe system: dynamics of uptake, suppression and toxicity to plants

High arsenic (As) concentrations in the soil, water and plant systems can pose a direct health risk to humans and ecosystems. Phosphate (Pi) ions strongly influence As availability in soil, its uptake and toxicity to plants. Better understanding of As(V)-Pi interactions in soils and plants will facilitate a potential remediation strategy for As contaminated soils, reducing As uptake by crop plants and toxicity to human populations via manipulation of soil Pi content. However, the As(V)-Pi interactions in soil-plant systems are complex, leading to contradictory findings among different studies. Therefore, this review investigates the role of soil type, soil properties, minerals, Pi levels in soil and plant, Pi transporters, mycorrhizal association and microbial activities on As-Pi interactions in soils and hydroponics, and uptake by plants, elucidate the key mechanisms, identify key knowledge gaps and recommend new research directions. Although Pi suppresses As uptake by plants in hydroponic systems, in soils it could either increase or decrease As availability and toxicity to plants depending on the soil types, properties and charge characteristics. In soil, As(V) availability is typically increased by the addition of Pi. At the root surface, the Pi transport system has high affinity for Pi over As(V). However, Pi concentration in plant influences the As transport from roots to shoots. Mycorrhizal association may reduce As uptake via a physiological shift to the mycorrhizal uptake pathway, which has a greater affinity for Pi over As(V) than the root epidermal uptake pathway

Non-monetary incentives in participatory sensing framework: a case of mobile health / Syarulnaziah Anawar

Non-communicable diseases (NCD), which are related to unhealthy lifestyles, cause a high proportion of deaths across the globe. This calls for a participatory sensing solution that may significantly expand access to healthcare to more people. Participatory sensing allows citizens to monitor activities, while enabling researchers and stakeholders to collect, analyse, and share local knowledge. However, in the absence of adequate participation, the participatory sensing system will fail to collect meaningful findings for decision making. Recent developments in the field of incentives have led to a renewed interest in non-monetary strategies to improve participants’ performance. Nevertheless, most of the studies typically addressed the extrinsic incentives and largely overlooked the intrinsic aspect of the non-monetary incentives, thus losing the potency to fulfil the needs of the data contributor holistically

IRIS RECOGNITION FAILURE IN BIOMETRICS: A REVIEW

More than twenty years iris has been claimed to be the most stable modality in human lifetime. However, the iris recognition produces ‘failure to match’ problem which made the known is unknown user or the genuine is recognized as imposter in the biometric systems. Apparently, failure to recognize the real user as in the database is due to a few assumptions: aging of the sensor, changes in how a person uses the system such as the threshold settings and template aging effect. This paper focuses on template aging effect since it is on ongoing problem faced in iris recognition. Many studies attempted several techniques to overcome the problem in every phase which consists of three general phases: the pre-processing, feature extraction and feature matching. Therefore, the purpose of this paper is to study and identify the problems in iris recognition that lead to failure-to-match in biometrics

Screening risk assessment tools for assessing the environmental impact in an abandoned pyritic mine in Spain

This is the author’s version of a work that was accepted for publication in Science of the Total Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Science of the Total Environment 409.4 (2011): 692-703 http://dx.doi.org/10.1016/j.scitotenv.2010.10.056This paper describes a new methodology for assessing site-specific environmental impact of contaminants. The proposed method integrates traditional risk assessment approaches with real and variable environmental characteristics at a local scale. Environmental impact on selected receptors was classified for each environmental compartment into 5 categories derived from the whole (chronic and acute) risk assessment using 8 risk levels. Risk levels were established according to three hazard quotients (HQs) which represented the ratio of exposure to acute and chronic toxicity values. This tool allowed integrating in only one impact category all the elements involved in the standard risk assessment. The methodology was applied to an abandoned metal mine in Spain, where high levels of As, Cd, Zn and Cu were detected. Risk affecting potential receptors such as aquatic and soil organisms and terrestrial vertebrates were assessed. Whole results showed that impact to the ecosystem is likely high and further investigation or remedial actions are necessary. Some proposals to refine the risk assessment for a more realistic diagnostic are included.This work has been financed by Madrid Community through EIADES Project S-505/AMB/0296, and by Spanish MinistryfEducation and Science, project CTM-2007-66401-CO2/TECN

The new services in nagios: network bandwidth utility, email notification and sms alert in improving the network performance

a new feature of services in Nagios has been added to the existing system which has no such services. The bandwidth monitoring and notification system are configured for alerting the network administrators when the bandwidth of the network in an organization hits a certain threshold settings. The system sent an email alert and sms notification to the network administrator for taking further action in order to maintain the Quality of Service (QoS) in the network. All the logs file of the Nagios actions is saved in the Nagios File Logs. The analysis was conducted from the case study and problem statements. Network Development Life Cycle (NDLC) was chosen as a methodology for implementing this system in the network. Nagios is installed inside Ubuntu 10 Operating System along with Multi-Router Traffic Grapher (MRTG) and Mail Postfix. MRTG and Mail Postfix were configured to be integrated with the Nagios System. On the client side, NSClient++ has been installed, for monitoring the bandwidth and performance of windows based on operating system. The Nagios services have been improved with the implementation of sms and emails notifications since the existing services have no such utilities. With the implementation of these services to Nagios, the performance could be even better for the future

Pengembangan Model Kepemimpinan Kepala Sekolah yang Efektif

The aim of this study are: 1). To find an appropriate model of principal leadership conducting a pilot in public junior high schools in Konda sub-District; 2). To find out the description of the NEM paradigm of principal leadership concept; which include entrepreneurship skill, good role model, capable and democratic in implementing the leadership skill as a principal. The result of this study describes; 1). The model of principal leadership skill besed on the public junior high school in Konda, which include entrepreneur skill, good role model, capable and democratic, and 2) the description of the result of the head master leadership skill including; a) entrepreneur skill is moderate; b) good role model is moderate; c) capability is effective; d) democracy is very effective. ABSTRAK Penelitian ini bertujuan untuk: 1) untuk mendapatkan sebuah model kepemimpinan kepala sekolah yang efektif sesuai dengan kondisi SMP Negeri di Kecamatan Konda dan 2) untuk mendapatkan gambaran keefektifan pilar entrepreneur, teladan, cerdas dan demokratis dalam implementasi kepemimpinan kepala sekolah efektif di SMP Negeri Kecamatan Konda. Hasil penelitian dan pengembangan menunjukkan bahwa: 1) model kepemimpinan kepala sekolah yang efektif sesuai dengan kondisi di SMP Negeri se-Kecamatan Konda adalah kepemimpinan entrepreneur, teladan, cerdas dan demokratis (ENTELCERDS) dan 2) efektivitas implementasi kepemimpinan kepala sekolah efektif di SMP Negeri se-Kecamatan Konda terkait dengan: (a) Entrepreneur secara rerata berkualifikasi cukup efektif, (b) Keteladanan secara rerata berkualifikasi cukup efektif; (c) kecerdasan secara rerata berkualifikasi efektif, dan (d) demokratis secara rerata berkualifikasi sangat efektif.</p