bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of Varying Concentrations of Subgingivally Delivered Metformin in the Treatment of Chronic Periodontitis: A Randomized Controlled Clinical Trial
Authors: Pradeep A.R. , Rao Nishanth S. , Naik Savitha B. , Kumari Minal
Published: April 2012

Background: Metformin (MF), a second‐generation biguanide, is a commonly used oral antidiabetic drug that has been shown recently to stimulate osteoblasts and reduce alveolar bone loss. The present study aims to explore the efficacy of 0.5%, 1%, and 1.5% MF gel as a local drug delivery system in adjunct to scaling and root planing (SRP) for treatment of intrabony defects (IBDs) in patients with chronic periodontitis.

Methods: A total of 118 IBDs were treated with 0.5%, 1%, or 1.5% MF gel or placebo gel. Clinical parameters (modified sulcus bleeding index, plaque index, probing depth [PD], and clinical attachment level [CAL]) were recorded at baseline, 3 months, and 6 months, whereas radiographic parameters were recorded at baseline and 6 months. IBD depth at baseline and 6 months was calculated on standardized radiographs by using the image analysis software. The mean concentration of MF in gingival crevicular fluid was estimated by reverse‐phase high‐performance liquid chromatography.

Results: Mean PD reduction and mean CAL gain was found to be greater in MF groups than the placebo group at both 3 and 6 months. Furthermore, significantly greater reduction of IBD depth was found in the MF groups compared to the placebo group, with greatest reduction in 1% MF.

Conclusions: The results of the present study show that local delivery of MF into the periodontal pocket stimulated significant increase in the PD reduction, CAL gain, and improved IBD depth reduction compared to placebo in adjunct to SRP. This can provide a new direction in the field of periodontal healing.
Mast Cell Degranulation in Human Periodontitis
Authors: Huang Shiguang , Lu Fangli , Chen Ying , Huang Bo , Liu Man
Published: April 2012

Background: Mast cells are tissue‐resident immune cells that participate in a variety of allergic and inflammatory conditions. Limited attention has been given to the role of mast cells in periodontal diseases, and the effects of mast cell degranulation on the chronic stages of non‐allergic inflammation, particularly in periodontitis, are not known. The present study analyzes the relationship between the mast cell degranulation and human periodontal disease progression.

Methods: A total of 50 clinical specimens including moderate periodontitis (n = 17), advanced periodontitis (n = 18), and healthy control tissues (n = 15) were used in this study. All specimens were fixed in 10% buffered formalin and stained with hematoxylin and eosin for histopathology, with toluidine blue for identifying mast cells, and by immunohistochemistry for the expressions of mast cell tryptase in periodontal tissues. The total and degranulated mast cell densities (per high‐power field) were quantified in the specimens.

Results: Compared with healthy controls, there were significantly increased both total and degranulated mast cell densities in human moderate (P <0.01) and advanced (P <0.01) periodontitis groups by toluidine blue staining, and there were significantly higher densities of both total and degranulated tryptase‐positive mast cell subpopulation in the moderate periodontitis group (P <0.01) and even significantly higher subpopulation densities in the advanced periodontitis group by immunohistochemical staining, in which both total and degranulated mast cell densities were significantly higher in the advanced periodontitis group than those in the moderate periodontitis group (P <0.01) by both toluidine blue staining and immunohistochemical staining. There was significantly more severe periodontal inflammatory pathology in the advanced periodontitis group than in the moderate periodontitis group (P <0.01).

Conclusion: These findings indicate a significant correlation among tryptase‐positive mast cell density, the degree of their degranulation, and the human periodontitis severity, and the results of this study further indicate that mast cell degranulation appears to be associated with human periodontal disease.
Severe Preeclampsia and Maternal Self‐Report of Oral Health, Hygiene, and Dental Care
Authors: Boggess Kim A. , Berggren Erica K. , Koskenoja Viktoria , Urlaub Diana , Lorenz Carol
Published: April 2012

Background: Maternal periodontal disease diagnosed by a detailed oral health examination is associated with preeclampsia. Our objective was to measure the association between maternal self‐report of oral symptoms/problems, oral hygiene practices, and/or dental service use before or during pregnancy and severe preeclampsia.

Methods: A written questionnaire was administered to pregnant females at the time of prenatal ultrasound and outcomes were ascertained by chart abstraction. The χ2 test compared maternal oral symptoms/problems, hygiene practices, and dental service use between females with severe preeclampsia versus normotensive females. Multivariable logistic regression was used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for severe preeclampsia.

Results: A total of 48 (10%) of 470 females reported ≥2 oral symptoms/problems in the 6 months before pregnancy and 77 (16%) since pregnancy. Fifty‐one (11%) reported previous periodontal treatment. Twenty‐eight (6%) of 470 developed severe preeclampsia. Females with a history of periodontal treatment were more likely to develop severe preeclampsia (aOR = 3.71; 95% CI = 1.40 to 9.83) than females without a history of periodontal treatment. Self‐reported oral health symptoms/problems, oral hygiene practices, or dental service use before or during pregnancy were not associated with severe preeclampsia when considered in the context of other maternal risk factors.

Conclusion: Maternal self‐report of previous periodontal treatment before pregnancy is associated with severe preeclampsia.
Use of submerged anaerobic membrane bioreactor (SAMBR) containing powdered activated carbon (PAC) for the treatment of textile effluents
Authors: Baêta B. E. L. , Ramos R. L. , Lima D. R. S. , Aquino S. F.
Published: April 2012

This work investigated the use of submerged anaerobic membrane bioreactors (SAMBRs) in the presence and absence of powdered activated carbon (PAC) for the treatment of genuine textile wastewater. The reactors were operated at 35 °C with an HRT of 24 h and the textile effluent was diluted (1:10) with nutrient solution containing yeast extract as the source of the redox mediation riboflavin. The results showed that although both SAMBRs exhibited an excellent performance, the presence of PAC inside SAMBR-1 enhanced reactor stability and removal efficiency of chemical oxygen demand (COD), volatile fatty acids (VFA), turbidity and color. The median removal efficiencies of COD and color in SAMBR-1 were, 90 and 94% respectively; whereas for SAMBR-2 (without PAC) these values were 79 and 86%, In addition, the median values of turbidity and VFA were 8 NTU and 8 mg/L for SAMBR-1 and 14 NTU and 26 mg/L for SAMBR-2, indicating that the presence of PAC inside SAMBR-1 led to the production of an anaerobic effluent of high quality regarding such parameters.
HBMO algorithm for calibrating water distribution network of Langarud city
Authors: Sabbaghpour Saman , Naghashzadehgan Mohammad , Javaherdeh Kourosh , Haddad Omid Bozorg
Published: April 2012

In this paper a new meta-heuristic approach based on the nature of honey bees mating has been used for the calibration of a real city in the north of Iran named Langarud. This city has a population of nearly 68,000 people and about 43,000 water consumers. Langarud's area is about 900 km2. The method was used to determine the Hazen–Williams roughness factor of the main pipes of the town and a correction factor for the nodal demands in the main nodes of the network.
Application of cuprous oxide synthesized from copper-containing waste liquid to treat aqueous reactive dye
Authors: Kuo Chao-Yin , Pai Chueh-Ying
Published: April 2012

Cuprous oxide that was prepared from Cu-containing waste liquid from a printed circuit board manufacturer was used to carry out Fenton-like and photo-Fenton-like oxidation reactions to decolorize a reactive dye (RB19). A microwave hydrothermal method was applied in the synthesis. The highest recovery rate of Cu from wastewater was 87% and was obtained when the synthesis was performed at a power of 200 W for 15 min. An RB19 decolorization efficiency of 99.9% was achieved when the Fenton-like reaction was conducted with 50 mmol/L H2O2 and 0.9 g/L of Cu2O. The decolorization of RB19 was more effective when the system was irradiated with visible light than with UV light. Under irradiation, the decolorization rate was the highest when the decolorization was performed in the RB19 solution that contained 50 mmol/L H2O2 and 0.9 g/L CuO2 in the Fenton-like and the 365 nm-irradiated photo-Fenton-like reactions. In the case of irradiation under 410 nm visible light, the system was operated with lower H2O2 (30 mmol/L) and Cu2O (0.5 g/L) to achieve a decolorization rate higher than 365 nm-irradiated photo-Fenton-like reactions.
Heavy metal adsorption changes of EAF steel slag after phosphorus adsorption
Authors: Song Guanling , Cao Lijing , Chen Xiao , Hou Wenhua , Wang Qunhui
Published: April 2012

A kind of electric arc furnace (EAF) steel slag was phosphated, and its isothermal and dynamic adsorptions of copper, cadmium, and lead ions were measured to determine if heavy metal adsorption changes after phosphorus adsorption. The surface area increased greatly after the slag was phosphated. Isothermal adsorption experiments showed that the theoretical Qmax of the EAF steel slag on Cu2+, Cd2+, and Pb2+ improved 59, 50, and 89% respectively after it was phosphated. Dynamic adsorption results showed that the greatest adsorption capacities of unit volume of Cu2+, Cd2+, and Pb2+ were 2.2, 1.8, and 1.8 times that of the column packed with original EAF steel slag when the column was packed with phosphate EAF steel slag at the same heavy metal ion concentration. The breakthrough time, the exhaustion time and elution efficiency of the column also increased when the column was packed with phosphated EAF steel slag compared with that packed with original EAF steel slag. Phosphorus adsorption could further improve the heavy metal ion adsorption of the EAF steel slag.
Distillery wastes as external carbon sources for denitrification in municipal wastewater treatment plants
Authors: Czerwionka K. , Makinia J. , Kaszubowska M. , Majtacz J. , Angowski M.
Published: April 2012

In this study, by-products from alcohol production were examined in terms of their potential application as external carbon sources for enhancing denitrification in biological nutrient removal systems. Three types of batch tests were used to compare the effects of the distillery by-products, such as fusel oil, syrup and reject water, on the non-acclimated activated sludge. Much higher nitrate utilization rates (NURs) were observed for the latter two carbon sources. In the conventional NUR measurements (one-phase experiments), the observed NURs with syrup and reject water were 3.2–3.3 g N/(kg VSS h) compared with 1.0 g N/(kg VSS h) obtained for fusel oils from two different distilleries. When the carbon sources were added at the beginning of the anoxic phase preceded by an anaerobic phase (two-phase experiments), the NURs were 4.2 g N/(kg VSS h) (syrup and reject water) and 2.4–2.7 g N/(kg VSS h) (fusel oils). The heterotrophic yield coefficient, determined based on the conventional OUR measurements, varied in a relatively narrow range (0.72–0.79 g COD/g COD) for all the examined carbon sources. Due to advantageous composition (much higher COD concentrations and COD/N ratios), fusel is a preferred carbon source for practical handling in full-scale wastewater treatment plants.
Integrated coagulation-trickling filter–ultrafiltration processes for domestic wastewater treatment and reclamation
Authors: Zhao Qing-Liang , Zhong Hui-Yuan , Liu Jin-Li , Liu Yu
Published: April 2012

More and more research effort has been put into the development of affordable and high-efficiency wastewater reclamation technology for small communities. In this study, an integrated chemically enhanced primary treatment (CEPT), trickling filter (TF) and ultrafiltration (UF) process was developed with success. Coagulant produced from fly ash was used to enhance primary treatment, while trickling filter packed with coal cinder through four-layer structure without aeration was employed for further removal of COD and ammonium-nitrogen from the CEPT effluent. 95 and 88% removal of COD and ammonium were achieved, while total phosphorus (TP) and suspended solid (SS) were found to be removed completely at a coagulant dosage of 2.5 mL/L in the CEPT–TF–UF system. The product water can meet the standard of Reuse of Recycling Water for Urban Water Quality Standard for Urban Miscellaneous Water Consumption (GB/T 18920-2002, China).
GRACE, GLDAS and measured groundwater data products show water storage loss in Western Jilin, China
Authors: Moiwo Juana Paul , Lu Wenxi , Tao Fulu
Published: April 2012

Water storage depletion is a worsening hydrological problem that limits agricultural production in especially arid/semi-arid regions across the globe. Quantifying water storage dynamics is critical for developing water resources management strategies that are sustainable and protective of the environment. This study uses GRACE (Gravity Recovery and Climate Experiment), GLDAS (Global Land Data Assimilation System) and measured groundwater data products to quantify water storage in Western Jilin (a proxy for semi-arid wetland ecosystems) for the period from January 2002 to December 2009. Uncertainty/bias analysis shows that the data products have an average error <10% (p < 0.05). Comparisons of the storage variables show favorable agreements at various temporal cycles, with R2 = 0.92 and RMSE = 7.43 mm at the average seasonal cycle. There is a narrowing soil moisture storage change, a widening groundwater storage loss, and an overall storage depletion of 0.85 mm/month in the region. There is possible soil-pore collapse, and land subsidence due to storage depletion in the study area. Invariably, storage depletion in this semi-arid region could have negative implications for agriculture, valuable/fragile wetland ecosystems and people's livelihoods. For sustainable restoration and preservation of wetland ecosystems in the region, it is critical to develop water resources management strategies that limit groundwater extraction rate to that of recharge rate.
Estimation and modeling of direct rapid sand filtration for total fecal coliform removal from secondary clarifier effluents
Authors: Li Yi , Yu Jingjing , Liu Zhigang , Ma Tian
Published: April 2012

The filtration of fecal coliform from a secondary clarifier effluent was investigated using direct rapid sand filters as tertiary wastewater treatment on a pilot scale. The effect of the flocculation dose, flow loading rate, and grain size on fecal coliform removal was determined. Direct rapid sand filters can remove 0.6–1.5 log-units of fecal coliform, depending on the loading rate and grain size distribution. Meanwhile, the flocculation dose has little effect on coliform removal, and increasing the loading rate and/or grain size decreases the bacteria removal efficiency. A model was then developed for the removal process. Bacteria elimination and inactivation both in the water phase and the sand bed can be described by first-order kinetics. Removal was successfully simulated at different loading rates and grain size distributions and compared with the data obtained using pilot-scale filters.
Removal of alkylphenols and polybromodiphenylethers by a biofiltration treatment plant during dry and wet-weather periods
Authors: Gilbert S. , Gasperi J. , Rocher V. , Lorgeoux C. , Chebbo G.
Published: April 2012

This paper investigates the occurrence of alkylphenols (APs) and polybromodiphenylethers (PBDEs) in raw wastewater during dry and wet-weather periods, and their removal by physico-chemical lamellar settling and biofiltration techniques. Due to in-sewer deposit erosion and, to a lesser extent, to external inputs, raw effluents exhibit from 1.5 to 5 times higher AP and PBDE concentrations during wet periods compared with dry ones. The lamellar settler obtains high removal of APs and PBDEs under both dry and wet-weather flows (>53% for Σ6AP and >89% for Σ4PBDE), confirming the insensitivity of this technique to varying influent conditions. Indeed, despite the higher pollutant concentrations observed in raw effluents under wet-weather flows, adjusting the addition of coagulant–flocculent allows for efficient removal. By combining physical and biological processes, the biofiltration unit treats nutrient pollution, as well as Σ6AP and Σ4PBDE contamination (58 ± 5% and 75 ± 6% respectively). Although the operating conditions of the biofiltration unit are modified during wet periods, the performance in nutrient pollution, APs and light PBDE congeners remains high. Nevertheless, lower efficiency has been noted in nitrogen pollution, i.e. no denitrification occurs, and BDE-209 (not removed during wet-weather periods). In conclusion, this study demonstrates that the combination of both techniques treats AP and PBDE pollution efficiently during dry periods, but that they are also suitable for stormwater treatment.
Net environmental benefit: introducing a new LCA approach on wastewater treatment systems
Authors: Godin D. , Bouchard C. , Vanrolleghem P. A.
Published: April 2012

Life cycle assessment (LCA) allows evaluating the potential environmental impacts of a product or a service in relation to its function and over its life cycle. In past LCAs applied to wastewater treatment plants (WWTPs), the system function definition has received little attention despite its great importance. This has led to some limitations in LCA results interpretation. A new methodology to perform LCA on WWTPs is proposed to avoid those limitations. It is based on net environmental benefit (NEB) evaluation and requires assessing the potential impact of releasing wastewater without and with treatment besides assessing the impact of the WWTP's life cycle. The NEB allows showing the environmental trade-offs between avoided impact due to wastewater treatment and induced impact by the WWTP's life cycle. NEB is compared with a standard LCA through the case study of a small municipal WWTP consisting of facultative aerated lagoons. The NEB and standard LCA show similar results for impact categories solely related to the WWTP's life cycle but differ in categories where wastewater treatment environmental benefit is accounted for as NEB considers influent wastewater quality whereas standard LCA does not.
Adsorptive performance of penta-bismuth hepta-oxide nitrate, Bi5O7NO3, for removal of methyl orange dye
Authors: Abdullah Abdul Halim , Abdullah Eshraq Ahmed , Zainal Zulkarnain , Hussein Mohd Zobir , Ban Tan Kar
Published: April 2012

The adsorption of methyl orange dye from aqueous solution onto penta-bismuth hepta-oxide nitrate, Bi5O7NO3, synthesized by precipitation method, was studied in a batch adsorption system. The effects of operation parameters such as adsorbent dose, initial dye concentration, pH and temperature were investigated. The adsorption equilibrium and mechanism of adsorption was evaluated by Langmuir and Freundlich isotherm and different kinetic models, respectively. The results indicate that adsorption is highly dependent on all operation parameters. At optimum conditions, the adsorption capacity was found to be 18.9 mg/g. The adsorption data fits well with the Langmuir isotherm model indicating monolayer coverage of adsorbate molecules on the surface of Bi5O7NO3. The kinetic studies show that the adsorption process is a second-order kinetic reaction. Although intra-particle diffusion limits the rate of adsorption, the multi-linearity plot of intra-particle model shows the importance of both film and intra-particle diffusion as the rate-limiting steps of the dye removal. Thermodynamic parameters show that the adsorption process is endothermic, spontaneous and favourable at high temperature.
Lipid peroxidation in the freshwater shrimp Caridina nilotica as a biomarker of Roundup® herbicide pollution of freshwater systems in South Africa
Authors: Mensah P. K. , Palmer C. G. , Muller W. J.
Published: April 2012

Glyphosate-based herbicides used to control weeds and invading alien plant species in South Africa ultimately end up in freshwater ecosystems, but no South African environmental water quality guideline exists to regulate these bio-active chemicals. Ecotoxicological tests to assess the possibility of using lipid peroxidation (LPx) in Caridina nilotica as a potential biomarker of Roundup®, a glyphosate-based herbicide, pollution were conducted. In two separate tests, 40 days post hatch shrimps were exposed to different concentrations of 4.3, 6.7, 10.5, 16.4, 25.6 and 40.0 mg/L in a 96 h acute toxicity test; and 2.2, 2.8, 3.4, 4.3 and 5.4 mg/L in a 21 d chronic toxicity test, using static-non renewal and static-renewal methods, respectively. Shrimp whole body LPx was estimated by thiobarbituric acid reactive species (TBARS) assay, performed by a malondialdehyde (MDA) reaction with 2-thiobarbituric acid (TBA) measured spectrophotometrically. Final MDA concentrations were expressed as nmol MDA produced/mg protein. Results showed that LPx was significantly lower in control animals than in animals exposed to different Roundup® concentrations, (p < 0.05). The present work provides an ecotoxicological basis for the possible use of LPx in Caridina nilotica as a biomarker for monitoring Roundup® pollution in freshwater ecosystems.
Conditions and technologies of biological wastewater treatment in Hungary
Authors: Tardy G. M. , Bakos V. , Jobbágy A.
Published: April 2012

A survey has been carried out involving 55 Hungarian wastewater treatment plants in order to evaluate the wastewater quality, the applied technologies and the resultant problems. Characteristically the treatment temperature is very wide-ranging from less than 10 °C to higher than 26 °C. Influent quality proved to be very variable regarding both the organic matter (typical COD concentration range 600–1,200 mg l−1) and the nitrogen content (typical NH4-N concentration range 40–80 mg l−1). As a consequence, significant differences have been found in the carbon availability for denitrification from site to site. Forty two percent of the influents proved to lack an appropriate carbon source. As a consequence of carbon deficiency as well as technologies designed and/or operated with non-efficient denitrification, rising sludge in the secondary clarifiers typically occurs especially in summer. In case studies, application of intermittent aeration, low DO reactors, biofilters and anammox processes have been evaluated, as different biological nitrogen removal technologies. With low carbon source availability, favoring denitrification over enhanced biological phosphorus removal has led to an improved nitrogen removal.
Microbiological risks of recycling urban stormwater via aquifers
Authors: Page D. , Gonzalez D. , Dillon P.
Published: April 2012

With the release of the Australian Guidelines for Water Recycling: Managed Aquifer Recharge (MAR), aquifers are now being included as a treatment barrier when assessing risk of recycled water systems. A MAR research site recharging urban stormwater in a confined aquifer was used in conjunction with a Quantitative Microbial Risk Assessment to assess the microbial pathogen risk in the recovered water for different end uses. The assessment involved undertaking a detailed assessment of the treatment steps and exposure controls, including the aquifer, to achieve the microbial health-based targets.
Municipal wastewater treatment by biofiltration: comparisons of various treatment layouts. Part 1: assessment of carbon and nitrogen removal
Authors: Rocher Vincent , Paffoni Catherine , Gonçalves Alexandre , Guérin Sabrina , Azimi Sam , Gasperi Johnny , Moilleron Régis , Pauss André
Published: April 2012

One of the largest wastewater treatment plants in the Paris conurbation (240,000 m3/d) has been studied over several years in order to provide technical and economical information about biological treatment by biofiltration. Biofiltration systems are processes in which carbon and nitrogen pollution of wastewater are treated by ascendant flow through immersed fixed cultures. This paper, focused on technical information, aims: (1) to compare performances of the three biological treatment layouts currently used in biofiltration systems: upstream denitrification (UD), downstream denitrification (DD) and combined upstream-downstream denitrification (U-DD) layouts; and (2) to describe in detail each treatment step. Our study has shown that more than 90% of the carbon and ammoniacal pollution is removed during biological treatment, whatever the layout used. Nitrate, produced during nitrification, is then reduced to atmospheric nitrogen. This reduction is more extensive when the denitrification stage occurs downstream from the treatment (DD layout with methanol addition), whereas it is only partial when it is inserted upstream from the treatment (UD layout – use of endogenous carbonaceous substrate). So, the UD layout leads to a nitrate concentration that exceeds the regulatory threshold in the effluent, and the treatment must be supplemented with a post-denitrification step (U-DD layout). Our work has also shown that the optimal ammonium-loading rate is about 1.1–1.2 kg N-NH4+ per m3 media (polystyrene) and day. For denitrification, the optimal nitrate-loading rate is about 2.5 kg N per m3 media (expanded clay) and day in the case of DD with methanol, and is about 0.25 kg N-NO3− per m3 media and day in the case of UD with exogenous carbonaceous substrate.
Integration of the ASG-EUPOS Permanent Stations with First Order National Geodetic Networks - Measurements and Results
Authors: Jaworski Leszek , Swiatek Anna , Zdunek Ryszard , Zielinski Janusz
Published: April 2012

Integration of the ASG-EUPOS Permanent Stations with First Order National Geodetic Networks - Measurements and Results

The ASG-EUPOS network - the active geodetic network was established in Poland in 2008. The 2010/2011 campaign was the second one managed to integrate the ASG-EUPOS network with the first order national geodetic networks in Poland. As the result the station coordinates were determined in the uniform coordinate frame. The paper describes the measurements carried out for data acquisition as well as the data processing method. The results present analyses of differences between selected variants of solutions and show some problems encountered during the calculation.
Reliable and Redundant RTK Positioning for Applications in Hard Observational Conditions
Authors: Bakuła M. , Pelc-Mieczkowska R. , Walawski M.
Published: April 2012

Reliable and Redundant RTK Positioning for Applications in Hard Observational Conditions

It is well known that RTK (Real Time Kinematic) positioning is a very efficient technique for determination of coordinates in real time, directly on location. Although this technique has been well known since the mid-nineties of the last century, the common use of this technique developed since permanent reference GNSS (Global Navigation Satellite Systems) stations started operating as the national reference systems. Positioning in real time is very convenient for users who do not need to know any advanced technique of post-processing, especially in cases when no obstructions exist around the measured point exist. However, in practice, there are some situations when the use of RTK technique makes some difficulties, especially if the GNSS receiver has no full availability of satellites. Obstructions caused by trees, buildings, power lines etc. limit satellite availability and in consequence decrease the reliability of determined coordinates significantly. In those situations gross errors of even meters can appear in RTK positioning. In order to avoid misleading coordinates occurring we can use more than one RTK receiver simultaneously. The paper presents an approach to the RTK technology based on the simultaneous use of three different RTK receivers. Three different GNSS/RTK receivers can be set on a special mounting beam and additionally RTK positions are sent in real time to a computer. The computer software analyses not only the precision but also checks the accuracy and reliability of the RTK positions determined. Consequently, the new approach to RTK survey presented can allow obtaining reliable coordinates of centimeter accuracy even under very severe forest conditions.
On dynamical identification of control in a system with time delay
Authors: Maksimov Vyacheslav
Published: April 2012

On dynamical identification of control in a system with time delay

The problem of identification of a control through results of observations of phase states of dynamical systems described by differential equations with time delay is discussed. The paper presents an algorithm based on the method of feedback control with a model. The algorithm is stable with respect to informational noises and computational errors.
On a continuity of characteristic exponents of linear discrete time-varying systems
Authors: Czornik Adam , Mokry Piotr , Niezabitowski Michał
Published: April 2012

On a continuity of characteristic exponents of linear discrete time-varying systems

In this paper we present a sufficient condition for continuity of Lyapunov exponents of discrete time-varying linear system. Basing on this result we show that Lyapunov exponents of time-invariant systems depend continuously on the time-varying perturbations.
Generalized semi-opened axial dispersion model
Authors: Bártová Darina , Jakeš Bohumil , Kukal Jaromír
Published: April 2012

Generalized semi-opened axial dispersion model

The axial dispersion model (ADM) is studied and then generalized by a new form of the left boundary condition of semi-open flow system. The resulting parameter driven model covers the traditional axial models: axial closed-opened dispersion model with enforced input concentration (AEO), axial closed-opened dispersion model with input Danckwerts' condition (ACO), and axial opened-opened model (AOO). It also enables development of the degraded axial model (ADO). The research is concerned with both modeling and mathematical solution. Also, many numerical aspects of computer realization are discussed.
Checking of the positivity of descriptor linear systems with singular pencils
Authors: Kaczorek Tadeusz
Published: April 2012

Checking of the positivity of descriptor linear systems with singular pencils

A method for checking of the positivity of descriptor continuous-time and discrete-time linear systems with singular pencil is proposed. The method is based on elementary row and column operations on the matrices of descriptor systems. Necessary and sufficient conditions for the positivity of the descriptor systems are established.
Stabilization of multi DC bus link voltages of multilevel NPC VSI. Application to double stator induction motors
Authors: Beriber D. , Talha A. , Boucherit M.
Published: April 2012

Stabilization of multi DC bus link voltages of multilevel NPC VSI. Application to double stator induction motors

Voltage source multilevel inverters have become very attractive for power industries in power electronics applications during last years. The main purposes of studying multilevel inverters are the generation of output voltage signals with low harmonic distortion and reduction of switching frequency. An important issue of the multilevel inverter is the capacitor voltage-balancing problem. The unbalance of different DC voltage sources of multilevel neutral point clamped (NPC) voltage source inverter (VSI) constitutes the major limitation for the use of this new power converter. In this paper, we present study on the stability problem of the input DC voltages of the three-level Neutral Point Clamping (NPC) voltage source inverter (VSI). This inverter is useful for application in high voltage and high power area. In the first part, we remind the model of double stator induction motors (DSIM). Then, we develop control models of this inverter using the connection functions of the semi-conductors. We propose a Pulse Width Modulation (PWM) strategy to control this converter. The inverter is fed by constant input DC voltages. In the last part, we study the stability problem of the input DC voltages of the inverter. A cascade constituted by two three-level PWM rectifiers - two three-level NPC VSI - DSIM is discussed. The results obtained show that the input DC voltages of the inverters are not stable. To solve this problem, we propose to use a half clamping bridge. This solution is very promising in order to stabilize the input DC voltages of this converters.
Pregnancy and substance use – the Norwegian z 10–3 solution.1 Ethical and clinical reflections related to incarceration of pregnant women to protect the foetus from harmful substances
Authors: Söderström Kerstin , Skolbekken John-Arne
Published: April 2012

Aims

This article highlights ethical and clinical dilemmas of incarceration of pregnant drug addicts mandated by z 10–3 of the Norwegian Municipal Health and Care Services act.

Material

The material consists of two cases, Siri and Anna, and the ethical dilemmas posed by the use of z 10–3 in these cases.

Methods

Semi-structured in-depth individual interviews were conducted, audio-recorded and transcribed word for word. Transcripts were coded according to converging interests and possible ethical dilemmas and described in a case format. The practical and experiential consequences of the law are discussed in relation to the four main bioethical principles: respect for autonomy, non-maleficence, beneficence and social justice. These are supplemented by the principles of relational ethics.

Results

The application of z 10–3 may lead to situations which distort the psychological preparation for parenthood and strains the helping relationship. The four principles approach seems to be an insufficient tool in grasping the complexity of the situation.

Conclusions

Interventions to protect the foetus from the pregnant woman's use of substances demand elevated professional awareness of ethical and relational challenges and dilemmas. Relational ethics provides a framework to enhance reflexivity and a trusting therapeutic alliance. The potential for psychological change during pregnancy should be invested in. Hence, we suggest that during incarceration according to z 10–3, foetal protection and the promotion of parental competences should be given equal priority.
Research report
Authors: Greiff Ninive Von , Skogens Lisa
Published: April 2012

Processes of change during and after drug treatment, What factors are described by clients as important to initiate and maintain positive changes?

Aims

The aim is to describe and analyze how clients recovered from alcohol or drug abuse perceive change in connection with treatment interventions. The specific questions are: What factors are described as important to 1) initiate a process of change? 2) avoid returning to abuse?

Design

40 clients were interviewed according to a brief interview guide. The analysis resulted in models with factors that the clients considered important for initiating and maintaining positive changes.

Results

The result suggests that a pattern is emerging in the process of change. Although the clients often describe common factors as important, the variation of timing and severity for different factors makes the individual story unique.

Conclusions

The variation of timing and severity for different factors implies that it is very difficult to predict when a factor is important or not. This underlines the importance of treatment systems with a structure and a flexibility that enables supporting factors to be used when they are of importance for the individual client.
When and Why of Mother Tongue Use in English Classrooms
Authors: Khati Ashok Raj
Published: April 2012

It is often felt that teachers and students overuse their mother tongue, in this case, most probably the Nepali in English as a foreign language (EFL) classroom particularly in government-aided (Nepali medium) schools of Nepal. This, in result, minimizes the students' exposure to English. This article starts with defining mother tongue. Then, it presents the use of mother tongue in EFL classroom in the global and Nepalese contexts followed by summary of three classroom observations and two focused group discussions among teachers and students studying at the secondary level. The final part of the paper presents some simple and applicable strategies and ways of enhancing English language use in the classroom on the part of students provided by three teachers' trainers based on their experience. DOI: http://dx.doi.org/10.3126/nelta.v16i1-2.6128 NELTA 2011; 16(1-2): 42-51
Quality Journey of Turkey from the Perspective of Language Teachers
Authors: Köksal Hayal
Published: April 2012

Interest in quality improvement efforts has boomed during the past decade. Total Quality Management (TQM) based upon “PDCA (Plan-Do-Check-Act) Mindset” originated in the business world but it has gained tremendous popularity in educational institutions in recent years. The philosophy and practice of Quality education have become the center of discussions in academe across the world, especially in universities. This article focuses on the launching of the Quality Campaign in Turkey where all state schools under the Ministry of Education first adopted the campaign in 1999, but then largely resisted its implementation because it was perceived and often practiced as a top-down process. More recently, one of the most fundamental changes occurred in ELT (English Language Teaching) classes through the leadership of ELT teachers in a bottom-up approach. The aim of this paper is to provide a historical review of Quality Education in Turkey and share some insights with readers about its implementation. DOI: http://dx.doi.org/10.3126/nelta.v16i1-2.6129 NELTA 2011; 16(1-2): 52-58
The Effectiveness of Activities for Teaching EFL Writing in a Context of Vietnam
Authors: Nguyen Duy Khang , Tuyet Van Phan Thi , Anh Nguyet Ly Thi
Published: April 2012

The article aims at pointing out what kinds of activities designed to improve the learners’ writing proficiency are effective in a Vietnamese context. With a two-group pretest and posttest design of an empirical research, the authors implemented a series of teaching activities in the classroom. The data were collected by means of pre-tests, post-tests, and interviews. The results indicated that the participants in the experimental condition significantly gained in their writing performance. Qualitative analysis of the data shows that the majority of participants positively evaluated the effectiveness of the activities. However, a consideration for contextual adjustment should be taken when several activities together might be overload to the learners. DOI: http://dx.doi.org/10.3126/nelta.v16i1-2.6132 NELTA 2011; 16(1-2): 82-96
Adequacy Of Haemodialysis
Authors: Hoque MF , Fakir MAH
Published: April 2012

DOI: http://dx.doi.org/10.3329/jafmc.v7i2.10375 JAFMC 2011; 7(2): 3
Effect Of Surface Area Of Dialyzer Membrane On The Adequacy Of Haemodialysis
Authors: Chowdhury NS , Islam FMM , Zafreen F , Begum BA , Sultana N , Perveen S , Mahal M
Published: April 2012

Introduction: Patients with end stage renal disease require 12 hours of haemodialysis per week in three equal sessions (4 hours/day for 3 days/week). But the duration and frequency of treatment can be reduced by increasing the surface area of the dialyzer membrane. Methods: In this prospective study 40 patients of end stage renal disease receiving haemodialysis for more than six months were included to observe the effects of increment in the surface area of the dialyzer membrane on the adequacy of haemodialysis. Result: It was observed that 20 patients receiving haemodialysis on a dialyzer with membrane surface area of 1.2 m² did not have satisfactory solute clearance index. Urea reduction ratio was 45.9 ± 3.03 and fractional urea clearance (Kt/V) was 0.76 ± 0.09. On the other hand patients (20 cases) receiving haemodialysis on a dialyzer with membrane surface area of 1.3 m² had a urea reduction ratio 50.76± 5.16 and fractional urea clearance (Kt/V) 0.91 ± 0.16. All the patients of both groups received dialysis for 8 hours/week in two equal sessions (4 hours/day for 2 days/week). Statistically the increment was significant (p<0.001). Conclusion: This study reveals, adequacy of dialysis can be increased by increasing the surface area of the dialyzer membrane. So, considering the poor socioeconomic condition of Bangladesh and patients' convenience, a short duration, low cost dialysis regime can be tried by increasing the surface area of dialyzer membrane. DOI: http://dx.doi.org/10.3329/jafmc.v7i2.10387 JAFMC 2011; 7(2): 9-11
Comparative Study Of External And Endoscopic Endonasal Dacryocystorhinostomy For The Treatment Of Chronic Dacryocystitis
Authors: Khan MKH , Hossain MA , Hossain MJ , Al-Masud A , Rahman MZ
Published: April 2012

Introduction: Dacryocystorhinostomy (DCR) is the treatment of choice for Chronic Dacryocystitis. Although external DCR is still regarded as gold standard for acquired naso-lacrimal duct obstruction, endoscopic DCR is evolving as an equally effective alternative in the recent past. Objective: The study was carried out to compare the surgical outcome of external DCR and endoscopic endonasal DCR for the treatment of Chronic Dacryocystitis. Method: This observational study was carried out in the Department of Ophthalmology, Combined Military Hospital, Dhaka from November 2008 to May 2009. A total of 30 consecutive patients were selected for DCR surgery. Among those 15 patients underwent endoscopic endonasal DCR and 15 under went patients external DCR. Data regarding ocular examination, lacrimal drainage system, per-operative and postoperative complications and ultimate surgical outcome were collected and analyzed. Surgical success was defined by patient's resolution of symptoms with patency of lacrimal drainage system. Failure was defined as no symptomatic reduction in epiphora and/or inability to irrigate the lacrimal drainage system postoperatively. Results: Mean age of the patients was 35.0±11.3 years. Fifty three percent of the study subject was male and 43% of the study subject was female. Accumulated result showed that both surgical approaches had almost similar success rate (endoscopic DCR 73.3% versus external DCR 80%; p=0.666). Complication rate was low and no appreciable difference in complication was marked in both types of surgery. Twenty percent in endoscopic DCR group and 13.3% in external DCR group had moderate bleeding. Two patients (13.3%) of endoscopic surgery required septoplasty. All the complications were managed by conservative treatment. Post operative complication particularly nonpatent lacrimal drainage system occurred to 26.7% of endoscopic group and 20% of those with external DCR surgery. Silicon tube was in situ up to 3 months in all the cases. Ultimate failure occurred in 26.7% for endoscopic DCR and 20% for external DCR. Conclusions: Surgical outcome of both endoscopic and external DCR for Chronic Dacryocystitis was quite satisfactory. Overall complication rate was low. Endoscopic surgery might have an advantage of not having any external scar but it requires high equipment cost and long learning curve. DOI: http://dx.doi.org/10.3329/jafmc.v7i2.10389 JAFMC 2011; 7(2): 15-17
Haemoglobin Status Of Pregnant Women An Analysis Of 1804 Cases
Authors: Quadrat-E-Elahi M , Rahman MM , Momtaz S , Ferdousi MA , Bhuyan FA
Published: April 2012

Introduction: Anaemia is a very common finding in Bangladeshi women. This is more common in pregnant women. Timely meet up of nutritional need successfully prevents the development of anaemia during pregnancy. Method: A cross-sectional and multi-centre study was carried out among 1804 pregnant cases at Child Welfare Centre (CWC) of Combined Military Hospitals (CMH) of Comilla, Savar and Bogra cantonments over a period of 19 months. Irrespective of ages all pregnant women who attended CWCs for routine ante-natal check up and whose blood haemoglobin level was known at the time of first visit were included in this study. Pregnant women with diabetes mellitus, hypertension and any congenital haemoglobin disorders were excluded from this study. Objectives: The aim of the study was to find out the haemoglobin levels in pregnant women in defence community from different parts of Bangladesh. Result: Total 1804 women were included as per inclusion criteria. Their mean (±SD) age was 28.1±13 years and the range was 19-41 years. Haemoglobin level during pregnancy was estimated and 229 (12.7%) of the pregnant women were observed anaemic. Most of the women had reported in the third trimester (40.8%) followed by second trimester (33.4%) and then first trimester (25.8%). Iron supplement was given to both normal and anaemic pregnant women. Conclusion: The study showed that prevalence and severity of anaemia in pregnant subjects attended CWCs for antenatal check up were exceptionally low. This indicates that consciousness regarding taking care of pregnant women of the community studied was satisfactory. DOI: http://dx.doi.org/10.3329/jafmc.v7i2.10390 JAFMC 2011; 7(2): 18-20
Socio-Demographic Characterstics Of Alleged Sexual Assault (Rape) Cases In Dhaka City
Authors: Al-Azad MAS , Raman Z , Ahmad M , Wahab MA , Ali M , Khalil MI
Published: April 2012

Introduction: Offence means any act of omission made punishable by law for the time being in force. Sexual assault is defined as sexual intercourse performed in a way which is against the provision of the law of the land. Of all the crimes sex related crimes are the most barbarous and humiliating. Rape is the most serious sexual offence, still carrying the death penalty in some parts of the world. Rape is said when 'unlawful sexual intercourse by a man with a woman, by force, fear or fraud'. Young girls and children remain the most vulnerable group to this crime. The alarming rise in the rate of sexual assault worldwide represents a major public health problem. Objectives: To determine socio-demographic characteristics of alleged sexual assault cases in Dhaka city and to create public awareness of furious crime. Methods: The study was conducted on 230 female sexually assaulted victims who reported Dhaka Medical College (DMC) for medical examination during the period between January 2006 and December 2006. Details pertaining to age, sex, religion, literacy, socioeconomic status, site of incidence, time interval between incidence and medical examination, number of assailants, relationship with assailants, findings of physical or genital examination and results of evidence collected during examination were noted. Results: It was revealed from the findings that among 230 female sexually assaulted victims 69.57% were in 11-20 years age group and 11.30% in 21-30 years of age group. Over three-fourths (76.08%) of the victims were Muslims, 78.69% were unmarried, 32.18% were less educated and 77.89 % were with poor socioeconomic background. The majority of the victims (43.91%) knew the assailants and in 30.43% cases they were close friends. Most of the incidents (36.95%) occurred in victim's house followed by Boys' hostel (31.30%). A total 89 victims (38.69%) were examined on the day of the incident. Ninety one (39.57%) victims were found with genital injuries and 83 victims (36.09%) had extra genital injuries and rupture of hymen was found in 78 (33.91%) victims at 6 o'clock position. Conclusion: The study findings may be helpful for baseline information and would be beneficial to the policymakers and programme planners to make awareness among the people. DOI: http://dx.doi.org/10.3329/jafmc.v7i2.10391 JAFMC 2011; 7(2): 21-24