bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of amyloglucosidase from Aspergillus niger NRRL 3122 using ion exchange resin
Authors: Manera Ana Paula , Kamimura Eliana Setsuko , Brites Luciana Machado , Kalil Susana Juliano
Published: October 2008

Amyloglucosidase enzyme was produced by Aspergillus niger NRRL 3122 from solid-state fermentation, using deffated rice bran as substrate. The effects of process parameters (pH, temperature) in the equilibrium partition coefficient for the system amyloglucosidase - resin DEAE-cellulose were investigated, aiming at obtaining the optimum conditions for a subsequent purification process. The highest partition coefficients were obtained using 0.025M Tris-HCl buffer, pH 8.0 and 25ºC. The conditions that supplied the highest partition coefficient were specified, the isotherm that better described the amyloglucosidase process of adsorption obtained. It was observed that the adsorption could be well described by Langmuir equation and the values of Qm and Kd estimated at 133.0 U mL-1 and 15.4 U mL-1, respectively. From the adjustment of the kinetic curves using the fourth-order Runge-Kutta algorithm, the adsorption (k1) and desorption (k2) constants were obtained through optimization by the least square procedure, and the values calculated were 2.4x10-3 mL U-1 min-1 for k1 and 0.037 min-1 for k2 .
Effect of alcoholic fermentation in the content of phenolic compounds in cider processing
Authors: Nogueira Alessandro , Guyot Sylvain , Marnet Nathalie , Lequéré Jean Michel , Drilleau Jean-Francoise , Wosiacki Gilvan
Published: October 2008

The objective of this work was to study the effect of alcoholic fermentation on the content of phenol compounds of five cider apple varieties. The initial content in the apple juice samples, as determined by HPLC, varied from 188.4 to 2776.17 m mg.L-1. In three of them (DC, PJ, GU), the total phenol compounds remained unaffected by fermentation. However, in two (DM, KE), the final values were lower (55 and 313 mg.L-1). In these apple cider, the values of caffeic acid increased from 6.6 mg.L-1 to 41.8 mg.L-1. The catechin content increased during the process, approximately 13 mg.L-1 independent of the variety. The other phenols class did not present any modifications due to the alcoholic fermentation, maintaining the phenolic compounds of original clarified apple juice in the cider.
The occurrence of Aeromonas spp. in the bottled mineral water, well water and tap water from the municipal supplies
Authors: Scoaris Denise de Oliveira , Bizerra Fernando Cezar , Yamada-Ogatta Sueli Fumie , Abreu Filho Benício Alves de , Ueda-Nakamura Tânia , Nakamura Celso Vataru , Dias Filho Benedito Prado
Published: October 2008

The aim of this work was to study the occurrence of Aeromonas sp in the bottled mineral water, well water and tap water from the municipal supplies. Positive samples were found for Aeromonas spp. 12.7% from the mineral water, 8.3% from the artesian water and 6.5% from the tap water. The recovery of Aeromonas spp. was significantly higher in the bottled mineral and artesian water than in the tap water from municipal supplies. The occurrence of the Aeromonas spp. did not correlate significantly with the contamination indicator bacteria (i.e. total coliforms) in the artesian water samples. However, a significant correlation was found between Aeromonas spp. and total coliforms in the both mineral water and tap water samples. The presence or absence of a correlation between the indicator bacteria and Aeromonas could reflect the occasional appearance of the pathogen in the drinking water and the different rates of survival and recovery of these agents compared with those fecal indicators. The finding that 41.6, 14.8 and 9.0 % of the artesian water, bottled mineral water and tap water, respectively, sampled in the current study failed to meet the Brazilian standard for total coliforms in the drinking water should therefore be of concern.
Imposex in endemic volutid from Northeast Brazil (Mollusca: Gastropoda)
Authors: Castro Ítalo Braga de , Meirelles Carlos Augusto Oliveira de , Matthews-Cascon Helena , Rocha-Barreira Cristina de Almeida , Penchaszadeh Pablo , Bigatti Gregório
Published: October 2008

Imposex is characterized by the development of masculine sexual organs in neogastropod females. Almost 120 mollusk species are known to present imposex when exposed to organic tin compounds as tributyltin (TBT) and triphenyltin (TPT). These compounds are used as biocide agents in antifouling paints to prevent the incrustations on boats. Five gastropod species are known to present imposex in Brazil: Stramonita haemastoma, Stramonita rustica, Leucozonia nassa, Cymathium parthenopeum and Olivancillaria vesica. This paper reports the first record of imposex observed in the endemic gastropod Voluta ebraea from Pacheco Beach, Northeast Brazil. Animals presenting imposex had regular female reproductive organs (capsule gland, oviduct and sperm-ingesting gland) and an abnormal penis. As imposex occurs in mollusks exposed to organotin compounds typically found at harbors, marinas, shipyards and areas with high shipping activities, probably contamination of Pacheco Beach is a consequence of a shipyard activity located in the nearest areas.
Coaching Reading Buddies for Success
Authors: Theurer Joan Leikam , Schmidt Kathy Burson
Published: October 2008

Reading buddies have been used by teachers for many years. The practice and benefits of having older students reading with younger students on a regular basis has been well documented. This article provides suggestions for teachers as they begin a reading buddy program and includes ideas for meaningful follow‐up activities that will help keep students on task, reinforce the purpose of their time together, and improve the comprehension of both reading buddies.

لقد استخدم المدرّسون زملاء القراءة لسنوات كثيرة وقد تم توثيق فوائد القراءة التي يوجد فيها طلاّب أكبر سناً يقرؤون مع طلاّب أصغر سناً بشكل منتظم. وتوفّر هذه المقالة اقتراحات للمدرّسين الذين ينشؤون برنامج زميل القراءة وتشتمل على أفكار لأنشطة متابعة معنوية تجعل الطلاّب منتبهين مركزين على الواجب وتعزّز غرض قضاء وقتهم معاً وتحسّن استيعاب كلا زميلي القراءة.

阅读同伴这种教学实践已被教师采用多年。这种教学实践让年纪较大和年纪教小的学生经常一起阅读。在文献上亦有充分证据证明阅读同伴这种教学实践对学生的效益。本文为刚开始采用阅读同伴教学计划的教师提供建议并说明：如何进行有意义的后续活动以帮助学生专心阅读，如何增强与同伴一起阅读的目的，及如何改进阅读同伴两者的阅读理解能力。

Les enseignants font appel depuis longtemps à des camarades de lecture. On dispose de nombreuses informations sur la pratique et les avantages qu'il y a à ce que des élèves plus âgés lisent de façon régulière avec de jeunes lecteurs. Cet article fournit des suggestions aux enseignants qui démarrent un programme de lecture avec des camarades. Il donne des idées pour assurer un suivi significatif des activités qui aideront à maintenir l'élève au travail, renforcera la raison d'être du temps passé ensemble, et améliorera la compréhension des deux copains qui lisent ensemble.

Для развития навыков чтения преподаватели уже многие годы практикуют объединение детей в разновозрастные пары. Существует много свидетельств в пользу подобного метода обучения. Учителя, только начинающие работу по такой программе, найдут в этой статье много полезных советов: по какому принципу подбирать пары; какие задания помогут ученикам сознательно выполнять общую задачу; как сделать, чтобы от проведенного ими вместе времени была польза; что будет способствовать более глубокому пониманию прочитанного обоими детьми.

Los maestros han usado amigos lectores por muchos años. La práctica y los beneficios de tener estudiantes mayores leyendo regularmente con estudiantes menores han sido muy bien documentados. Este artículo ofrece sugerencias para maestros que van a empezar programas de amigos lectores, e incluye ideas para actividades de poslectura que hacen sentido y que ayudarán a mantener a los estudiantes enfocados en la tarea, reforzarán el propósito del tiempo que están juntos, y mejorarán la comprensión de ambos amigos lectores.
Adiponectin receptors are expressed in hypothalamus and colocalized with proopiomelanocortin and neuropeptide Y in rodent arcuate neurons
Authors: Guillod-Maximin E , Roy A F , Vacher C M , Aubourg A , Bailleux V , Lorsignol A , Pénicaud L , Parquet M , Taouis M
Published: October 2008

Adiponectin is involved in the control of energy homeostasis in peripheral tissues through Adipor1 and Adipor2 receptors. An increasing amount of evidence suggests that this adipocyte-secreted hormone may also act at the hypothalamic level to control energy homeostasis. In the present study, we observed the gene and protein expressions of Adipor1 and Adipor2 in rat hypothalamus using different approaches. By immunohistochemistry, Adipor1 expression was ubiquitous in the rat brain. By contrast, Adipor2 expression was more limited to specific brain areas such as hypothalamus, cortex, and hippocampus. In arcuate and paraventricular hypothalamic nuclei, Adipor1, and Adipor2 were expressed by neurons and astrocytes. Furthermore, using transgenic green fluorescent protein mice, we showed that Adipor1 and Adipor2 were present in pro–opiomelanocortin (POMC) and neuropeptide Y (NPY) neurons in the arcuate nucleus. Finally, adiponectin treatment by intracerebroventricular injection induced AMP-activated protein kinase (AMPK) phosphorylation in the rat hypothalamus. This was confirmed byin vitrostudies using hypothalamic membrane fractions. In conclusion, Adipor1 and Adipor2 are both expressed by neurons (including POMC and NPY neurons) and astrocytes in the rat hypothalamic nuclei. Adiponectin is able to increase AMPK phosphorylation in the rat hypothalamus. These data reinforced a potential role of adiponectin and its hypothalamic receptors in the control of energy homeostasis.
Creep and shrinkage of HPC in prebended composite structures. Part I: modelling
Authors: Staquet S. , Tailhan J.-L. , Espion B.
Published: October 2008

This paper presents a comprehensive modelling of the time-dependent deformations of high-performance concretes (HPCs) based on chemo-physical phenomena. For each component of the concrete delayed effects (autogenous shrinkage, thermal strain, desiccation shrinkage, basic creep, intrinsic desiccation creep, structural desiccation creep), a modelling based on the local evolution in time of the temperature, the degree of advancement of the hydration reaction and the water content of concrete is proposed. These variables are computed with the CESAR–LCPC finite-element code. The model is applied in this paper to predict the time-dependent strain evolution of concrete cylindrical specimens undergoing shrinkage and creep tests in laboratory conditions.
Prediction Hydrate Formation Temperature And Comparison Between Different Types Of Hydrate Inhibitors In The South Pars Gas Complex-Phases 4&5
Authors: Karimkhani Behrooz , Khorrami Zahra
Published: October 2008

Formation of gas hydrates is one of the most commonly encountered operating difficulties in the transmission of natural gas.

There are two 32" sealines originating from the wellhead platforms (SPD5 and SPD6) which are located at Assaluyeh in Persian Gulf, Iran, and route multi-phase flow (gas/ condensate and glycolated water) to reception facilities in onshore. The purpose of this paper is calculating the hydrate formation temperature and the required MEG injection flow rate to keep the sea line in safe margin and inhibit hydrate formation. According to results, average formation temperature at sealine inlet and outlet is 19.6ºC and 17ºC respectively while corresponding pressures are 116 and 77.3 barg. As associated and condensed water are present, MEG should be injected to prevent hydrate formation.

Impact of different parameters such as depression temperature, lean MEG concentration and amount of water on injection rate has been checked.

Introduction to South Pars Gas Complex

South Pars Gas Complex (S.P.G.C) was established as a subsidiary of the National Iranian Gas Company on 19th Oct 1998 in order to explore & develop multiple phases of South Pars Gas Field. Each phase consists of offshore production platforms, under sea pipe lines and onshore gas refinery installations. Phases 4 & 5 gas plant was designed in a base of 2000 MMSCFD of reservoir fluid. This reservoir fluid mixed with MEG in order to avoid risk of hydrate formation in the presence of free water [2].

Hydrate formation Prediction

Hydrate is a physical combination of water and other small molecules to produce a solid which has an "ice-like" appearance but possesses a different structure than ice. Their formation in gas and/or NGL systems can plug pipelines, equipment, and instruments, restricting or interrupting flow. There are three recognized crystalline structures for such hydrates. In all three, water molecules build the lattice and hydrocarbons, nitrogen, CO2 and H2S occupy the cavities. Smaller molecules (CH4,

C2H6, CO2, and H2S) stabilize a body-centered cubic called structure I. Larger molecules (C3H8, i-C4H10, n-C4H10) form a diamond-lattice called structure II. Normal paraffin molecules larger than n-C4H10 do not form structure I or II hydrates as they are too large to stabilize the lattice. However, some isoparaffins and cycloalkanes larger than pentane are known to form structure H hydrates [4].
Drilling Optimization Technique – Using Real Time Parameters
Authors: Iqbal Fauzan
Published: October 2008

Once a drilling system is established, there are only few parameters that can be altered or changed due to the system constraints and limitations. However; with the variation in encountered formation characteristics the optimum value of drilling parameters changes and during drilling only few operational parameters can be changed to their optimum values. The real time data is used to re-evaluate the optimum values of such parameters (RPM, WOB etc) by using simple analysis technique. With the help of this simple program the operator can change the characteristics to their respective optimum values and get maximum rate of penetration within allowable constraints. Thus, an increase in rate of penetration will ultimately reduce the drilling cost. These result in an economic, cost effective and efficient drilling operation.

The paper elaborates the above discussion, shows how simple program can analyze the on going drilling process and suggests recommendations to acquire better results.
Synergies of Underground Gas Storage and Enhanced Oil Recovery in a Fractured Reservoir
Authors: De Kok Joop , Ali Abduladim , Clemens Torsten
Published: October 2008

The Schönkirchen Tief reservoir is located in the Vienna Basin. The reservoir contained 19 mn m3 oil originally in place. The current recovery factor after 45 years of production is 59 %. The field was produced by water injection. The wells, located at the crest of the high relief structure are exhibiting a high water cut. In 2006-2007, a comprehensive study was performed to optimise the future development of the field.

The field is made up of different types of dolostones. The lower part of the field consists of fractured dolomite, the upper part of weathered dolomite and dolomite debris. A dual-permeability model was used to simulate the flow in the dolomite and the weathered zone, whereas a single-permeability model was sufficient for the debris.

The main recovery mechanisms for this reservoir are imbibition and water/oil gravity drainage. Laboratory experiments indicated that the dolomite is water-wet to mixed-wet at reservoir conditions of 100 degrees centigrade.

The results of the study show that an economically attractive option for the field development is a combination of Underground Gas Storage and EOR. Due to the fact that the current reservoir pressure is below initial pressure, within half a year, about 1 bn m3 can be injected. Only about one third of this gas has to remain as cushion gas during the first cycle. To further increase the amount of gas which can be used for UGS, fluids have to be withdrawn from the reservoir. Drilling horizontal wells close to the original oil/water contact enable injection of additional 2 bn m3 gas.

The gas injection leads to gas/oil gravity drainage of the oil and water present in the matrix of the fractured reservoir. The oil is collected by the horizontal wells, resulting in incremental oil recovery of up to 5 % of oil originally in place.
Lightweight Cement Slurry Design Optimization for Cementing High Flow-Rate Wells in Low-Temperature Ranges
Authors: Radojevic Dean , Palitsyn Andrey , Krasovsky Alexander
Published: October 2008

It is important for wells in the Yuzhno-Khylchuyu field (Russian Arctic region) to have sufficient zonal isolation and thermal protection between production casings and the permafrost media because they will initially be produced with high flow-rates. High cement integrity helps prevent the permafrost from thawing therefore alleviating problems associated with the creation of unwanted cross-flows and eventual casing deterioration.

Low-density cement slurry has been used as an alternative to foam cementing because it contains hollow microspheres which help decrease cement thermal conductivity. The use of hollow microspheres in cement blends creates further challenges for engineers with regards to slurry optimization. Special attention is given to slurry properties because the presence of hollow microspheres can influence slurry rheology, increase cement setting time, and act negatively on compressive strength development.

The optimization of slurry design takes all of these parameters into consideration while resolving the problem of heat insulation, thus helping reduce the chance of primary cementing failure over the life cycle of the well.

The optimization of the cement slurry design makes it possible to significantly decrease the initial cement setting time, provide high compressive strength, and resolve the problem of heat insulation.
Air Permeability in Repacked Porous Media with Variable Structure‐Forming Potential
Authors: Poulsen Tjalfe G. , Blendstrup Helle , Schjønning Per
Published: October 2008

Air permeability was measured as a function of gravimetric water content and dry bulk density for six sieved, repacked porous materials with organic matter contents ranging from 0 to 88%. The six media used were two relatively fine sandy soils, a filter sand, a peat soil, and two commercial composts made from sewage sludge and yard waste, respectively. The materials were initially wetted from air dry to the desired water content, after which measurements were done. Selected combinations of material gravimetric water content and dry bulk density were used in the permeability measurements. The combinations were selected to cover the entire possible ranges of water content and dry bulk density for each material. The six materials exhibited very different relationships between air permeability, water content, and dry bulk density, exhibiting both increasing and decreasing air permeability with water content depending on their structural behavior. All six materials had regions in their water content–dry bulk density domains where air permeability tended to increase with increasing water content, indicative of increasing structure formation in these regions. This tendency was strongest for the two sandy soils and weakest for the filter sand, which exhibited almost no structure formation. Increased structure, as indicated by increasing air permeability with increasing water content, was strongest for low values of dry bulk density in all six materials.
Gravity‐Driven and Viscosity‐Dominated Infiltration into a Full‐Scale Sand Model
Authors: Germann Peter F. , al Hagrey Said Attia
Published: October 2008

Data from an infiltration and drainage experiment into and from a sand tank model of 5 by 3 m and 2 m deep were reevaluated. The uniform sand overlaid a 0.2‐m‐thick gravel layer from which five perforated pipes collected drainage flow. The data include time series of capillary potentials, ψ, volumetric water contents, θ, both from nine levels, and drainage flow, q, that resulted from sprinkler infiltration with a constant rate of 15.6 mm h−1 that lasted >16 h. The wetting and the pressure fronts (i.e., the increases of water content and of capillary potential) moved with the same constant velocity of 3.25 × 10−5 m s−1 The capillary potentials about 0.2 to 0.4 m behind the wetting front remained constant at about −2.5 kPa. The maximum degree of saturation during infiltration was <0.6 and the mobile water content involved in flow was about 0.15 m3 m−3 The constant velocity indicates a continuous and dynamic balance of forces acting on the mobile water. Thus, viscosity is considered to have balanced gravity as the driving force, and a momentum dissipation approach to infiltration evolved. Capillary and Bond numbers indicate that flow was subjected to considerable capillary potential, yet its gradient was only active throughout a depth range of 0.2 to 0.4 m behind the wetting front. The constant velocity prevailed despite local variations in the mobile water content. Constant velocity of wetting is proposed as the global key parameter during infiltration on which local features, like volume flux density and variation of water content, may depend.
A Study on the Operating Condition for Carbon-Nitrogen Removal in Wastewater and Sludge Reduction Using PVA-GEL Immobilized Microorganism
Authors: Chul-Hwi Park , Jin-Sook Lee , Duck-Hyun Nam , Yoon-sun Bae , In-Ho Jung
Published: October 2008

The carbon and nitrogen removal process using PVA-gel (Polyvinyl Alcohol) immobilized microorganisms was studied. The process has been operated under diverse process conditions for 12 months. The process consists of denitrification with internal recycle of 300%, nitrification, aerobic digestion reactors and settling tank. Nitrification and nitrogen removal efficiency according to gel packing ratio, temperature were studied. Yield for heterotrophs (YH), decay coefficient for heterotrophs (bH) in aerobic digestion reactor were determined to characterize the sludge reduction mechanism and compared with typical data of activated sludge process. Then SRT in aerobic digestion reactor was determined on an experimental basis and sludge reduction efficiency was calculated. The process was implemented successfully with sludge reduction efficiency of 92.0~98.5% on a basis of biomass.
Leakage – The Key to Improving the Efficiency of Water Networks
Authors: Rogers Dewi , Ruta Mario
Published: October 2008

Abstract: Leakage is one of the most important drivers for rehabilitation. Excess flow leads to low pressures, poor reliability and high operating costs. The project undertaken in the city of Lucca in central Italy demonstrates how it is possible to design and create a permanent leakage and pressure control system in an old and complex water network. It is estimated that when the project is completed, the saving will be in excess of 2 million m3/ year. This will allow the closure of 75% of the boreholes which will significantly reduce the environmental impact resulting from the over exploitation of the aquifer. The projected annual economic saving is estimated to be €250,000.
Counting Fish: Environmental Benefits Calculation for Avoided Costs Analysis in Urban Water Use Efficiency Planning
Authors: Joung Katie Shulte , Dickinson Mary Ann
Published: October 2008

This report documents a project undertaken for the California Urban Water Conservation Council to create a method to calculate water utility avoided costs and assign economic value to the environmental benefits of raw water savings as a result of implementing urban water conservation programs.

It is assumed that water savings associated with implementation of conservation programs can be quantified and represented as a reduction in the demand for water from a particular set of supply sources. This demand reduction may in turn result in a change to the availability of an environmental benefit provided by that source. Environmental valuation, as it is applied here, is relatively new and there are numerous complications, ambiguities, data gaps and differences of opinion in the application of the methodology. For that reason, this report should be considered a pioneering effort to put together all the required elements in a single coherent framework.
The Effect Analysis of the Decentralized Rainwater Management System in Korea Apartment Complex
Authors: Hyun Kyung-Hak , Ahn Sung-Sick , Choi Joung-Joo , Park Soon-Young
Published: October 2008

In this study, the effect of the decentralized rainwater management facility in Korean apartment complexes is analyzed. The experimental site is Singal 1 tenant apartment complex in Yongin, Korea. An underground rainwater storage tank, an infiltration barrel and an infiltration trench are applied. Rainwater flows through rainwater management facility and then it is stored or infiltrated into the underground. Experiment is run with the natural rainfall and artificial rainfall. Rainwater runoff reduction and pollution load reduction effect are analyzed. The rate of runoff reduction is compared with runoff discharge. The rate of pollution load reduction is analyzed with the water quality test on the inflow and the outflow.
Adapting to climate change with water savings and water reuse
Authors: Anderson J.M.
Published: October 2008

Climate change due to global warming will reduce river flows across much of Australia and reduce the yield of existing urban and rural water systems. These reductions are additional to yield reductions that have flowed from the allocation of more water for environmental flows under national water reforms, and the severity of the 2001-2007 drought in southern Australia. Australian water authorities are adapting to these changes by implementing extensive water savings programs and by developing new water sources including water reuse, stormwater and desalination as well as traditional river and groundwater sources. The paper describes two case studies and discusses how stochastic analysis of system scenarios can help identify drought and climate change risks and the economic benefits of water reuse.
Potential of innovative Dual CAS-MBR configurations in two very diverse market situations: Bulgaria and Cyprus
Authors: Bixio D. , De Wilde W. , Nenov V. , Eliades P. , Lesjean B. , Thoeye C.
Published: October 2008

This paper reports on the first-order Aquafin analysis on the market potential of conventional and innovative MBR concepts for upgrading STPs which are non-compliant with European standards on urban wastewater treatment. The analysis looked at the feasibility of two innovative hybrid solutions comprising both an activated sludge plant with existing clarifiers and an MBR unit (the so-called “Dual” concepts). The upgrading potential will be illustrated throughout the description and analysis of two market situations lying at the extremes of the application spectrum, namely: Bulgaria, which is representative of compliance with the Urban Waste Water Treatment Directive standards, and Cyprus, which is iconic of strict, mandatory effluent standards for water reuse.
Use of reclaimed water in the recreation and restoration of aquatic ecosystems: practical experience in the Costa Brava region (Girona, Spain)
Authors: Sala L. , de Tejada S. Romero
Published: October 2008

Where there is water scarcity, the situation is dramatic for aquatic ecosystems. In many Mediterranean basins the exploitation of water resources has gone clearly beyond renewable level and affects aquatic ecosystems. Thus, they may benefit from the recycling of high-quality effluents that can be used to cope with environmental water demands instead of being discharged. Their reclamation with natural technologies produces an improvement in quality based on the development of trophic webs built upon nutrients still dissolved in the reclaimed water. The main project in the Costa Brava area is that of the Empuriabrava constructed wetland system, where nitrified effluent is further treated to reduce the concentration of nutrients in the water and is reused for environmental enhancement. This facility is also an interesting site for bird-watching. Other projects where water recycling produces indirect benefits on the aquatic ecosystems are those in Tossa de Mar, affecting the “temporary” Tossa Creek (a watercourse which flows on temporary basis according to rainfall patterns), and in the Aro Valley, affecting the also “temporary”, but slightly bigger, Ridaura River. This document summarizes these projects and proposes practical recommendations for the use of treated effluents in the recreation and restoration of aquatic ecosystems.
Sustainable Reclaimed Water Management by Subsurface Drip Irrigation System: a study case for forage production
Authors: Palacios M.P. , Mendoza-Grimón V. , Fernández F. , Fernandez-Vera J.R. , Hernandez-Moreno J.M.
Published: October 2008

In the Canary Islands the price fluctuation of groundwater (0.3 to 0.7 €/m3), which is a private resource, often limits the recovery of the agricultural investments. Availability of alternative resources (reclaimed water: RW, desalinized seawater: DW and desalinized reclaimed water: DRW) at a foreseeable price will allow people to design the optimal infrastructures adapted to their needs The pumping cost is included in the “public” water price of DW (0.6 €/m3), RW (0.2 €/m3) and DRW (0.42 €/m3), but only if it is under 300 m of altitude. As a subsurface irrigation system (SDI), uses the soil as a natural advanced (but not high cost) water treatment, the in situ reuse of RW produced by lower tech wastewater plants would provide a valuable resource for the small villages.

A successful study case is presented here. A 2-year SDI experiment was performed using RW, cultivating alfalfa (Medicago sativa) and Sudan grass hybrid (Sorghum bicolor ssp sudanense). Although a saline (EC: 2.24 dS/m) and sodic (SAR: 6.9) water was used, irrigation with SDI led to high forage yields (between 8.4 and 11.9 kg of fresh matter/m2 obtained by 8 harvests per year). However, sand filter and drip lines have to be cleaned weakly and every 6 months respectively. As a conclusion of this study, adequate plant germination and yields, and feasibility of SDI using a secondary effluent was demonstrated. Besides, water cost represents only 24 to 17 % from the gross income.
Enhanced pathogen removal in on-site biofiltration systems over organic filtration materials
Authors: Garzón-Zúñiga Marco A. , Tomasini-Ortíz Ana C. , Moeller-Chavez Gabriela , Hornelas-Uribe Yolanda , Buelna Gerardo , Mijaylova-Nacheva Petia
Published: October 2008

Municipal wastewater was treated in 4 biofilters packed with a mix of endemic tropical woodchips and natural fibers to evaluate the removal efficiency of organic matter and pathogen microorganisms under tropical conditions. Biofilters were operated during 400 days, with a hydraulic rate of 0.3 m3/m2.d and an aeration rate of 0.68 m3air/m2 h-1. Raw municipal wastewater presented higher concentrations, of organic matter and pathogens, than those reported for municipal wastewaters in temperate countries. However, pollutants were successfully removed: <98.5% of the organic matter as BOD5 < 99.99% of Faecal Coliforms (FC) and Total Colony Forming Units (TCFU), and < 96.93% Helminth eggs (HE) were removed remaining only very low concentrations in the treated effluent (≤2.5 mg DBO5/L; ≤ 240 FC/100 mL; ≤ 240 TCFU /100 mL and < 1.0 HE/5L). According with Mexican regulations (Nom 001-SEMARNAT, 1996) and with the EPA suggested guidelines for water reuse (U.S. EPA, 1992a) treated effluents with this quality can be safely reused for three main activities: Nonfood crop irrigation, landscape impoundments and for construction activities. The high removal efficiency of TCFU and FC may be related with a predatory activity of testate amoebas which were detected growing into the biofilters and, the most plausible hypothesis concerning HE removal is that they are retained by filtration over the organic materials.
Integration of biomass drying with combustion/gasification technologies and minimization of emissions of organic compounds
Authors: Svoboda Karel , Martinec Jiří , Pohořelý Michael , Baxter David
Published: October 2008

Moisture content (MC) of green biomass or raw biomass materials (wood, bark, plants, etc.) commonly exceeds 50 mass % (wet basis). The maximum possible MC of biomass fuel for big scale combustion (e.g. fluidized bed combustion with low external heat losses) is approximately 60–65 mass %. Higher biomass MC generally causes operational problems of biomass combustors, lower stability of burning and higher CO and VOC emissions. Gasification of biomass with higher MC produces fuel gas of lower effective heating values and higher tar concentrations. In this review, various technological schemes for wood drying in combination with combustion/gasification with the assessment of factors for possible minimization of emissions of organics from the drying processes are compared. The simple direct flue gas biomass drying technologies lead to exhaust drying gases containing high VOC emissions (terpenes, alcohols, organic acids, etc.). VOC emissions depend on the drying temperature, residence time and final MC of the dried biomass. Indirect biomass drying has an advantage in the possibility of reaching very low emissions of organic compounds from the drying process. Exhaust drying gases can be simply destroyed as a part of the total combustion air (gas) in a combustion chamber or a gasifier. Liquid, condensed effluents have to be treated properly because they have relatively high content of organic compounds, some of them accompanied by odor. Drying of biomass with superheated steam offers more uniform drying of both small and bigger particles and shorter periods of higher temperatures of the dried biomass, particularly if drying to the final MC below 15 mass % is required. In practical modern drying technologies, biomass (mainly wood) is dried in recirculated gas of relatively high humidity (approaching saturation) and the period of constant rate drying is longer. Drying of moist wood material (saw dust, chips, etc.) is required in wood pellet production. Emissions of organics in drying depend on biomass properties, content of resins, storing time and on operational aspects of the drying process: drying temperature, drying medium, final MC, residence time, and particle size distribution of the dried biomass (wood). Integration of biomass drying with combustion/gasification processes includes the choice of the drying medium (flue gas, air, superheated steam). Properties of the drying media and operational parameters are strongly dependent on local conditions, fuel input of the combustion/gasification unit, cleaning of the exhaust drying media (gas, steam, wastewater), and on environmental factors and requirements.
Polymer interfaces used in electrochemical DNA-based biosensors
Authors: Galandová Júlia , Labuda Ján
Published: October 2008

Nowadays DNA-based biosensors represent powerful tools for the study of DNA sequence, DNA chemical interactions and damage. Among them, biosensors with an electrochemical signal transducer play the most important role. The performance of a biosensor strongly depends on the method of a biorecognition element being attached to the electrode. This review refers to polymer materials being used to create a DNA-electrode interface. The main terminology is given in Introduction followed by a description of polymers and polymer-based nanocomposites and their electrochemical properties. A comprehensive table reports examples of the electrochemical detection of DNA immobilized on the polymer matrix. Finally, a short survey is given.
Application of hydrocolloids as baking improvers
Authors: Kohajdová Zlatica , Karovičová Jolana
Published: October 2008

Hydrocolloids (or gums) belong to a group of biopolymers widely used in food technology. In the bakery industry, these compounds help to improve food texture and moisture retention, to retard starch retrogradation, and, finally, to enlarge the overall quality of the products during storage. Since recently, some hydrocolloids are being used due to their polymeric structure as fat replacers to obtain low calorie products and to substitute gluten in the formulation of gluten-free breads. This study describes the applications of some hydrocolloids in the bakery industry. Technological effects of these substances for different types of bakery products are also discussed.
Micromorphology and anatomy of three Symphytum (Boraginaceae) taxa from Turkey
Authors: Akcin Oznur Ergen , Baki Hilal
Published: October 2008

Symphytum asperum Lepechin, S. ibericum Steven and S. sylvaticum Boiss. were examined morphologically, micromorphologically and anatomically. Scanning electron microscopy was used to examine leaf surface and trichomes of these species. These species had bifacial and hypostomatous leaf types. Epidermal cells of leaves were usually polygonal or irregular in form. The pattern of anticlinical cells may vary in different species and between the upper and lower epidermis of the same species. Stomata are anisocytic and anomocytic in three species. Stomata index is 27.5 for S. sylvaticum, 24.65 for S. ibericum and 21.86 for S. asperum glandular trichomes are capitate in forms and more dense on the lower epidermis than upper epidermis. Eglandular trichomes are simple, short or long, unicellular or multicellular and thin or thick. Key words: Micromorphology, Anatomy, Symphytum DOI = 10.3329/bjb.v36i2.1496 Bangladesh J. Bot. 36(2): 93-103, 2007 (December) Â Â
Comparison of pollen morphological structures of some taxa belonging to Asparagus L. and Fritillaria L. (Liliaceae) from Turkey
Authors: Ozler H , Pehlivan S
Published: October 2008

Pollen grains of 20 taxa from two genera of the Liliaceae were examined and compared by LM (light microscope), SEM (scanning electron microscope) and pollens of four taxa were also examined with TEM (transmission electron microscope). Pollen grains shed as monads. They are monosulcate and ellipsoidal. Fritillaria crassifolia subsp. crassifolia Freyn & Smt. sometimes sheds the pollen as dyads. Exine is semitectate and the tectum is perforate. Columellae are simplicolumellate. Ectexine is thicker than endexine. Exine sculpture (ornamentation) is reticulate, reticulate-rugulate, rugulate and retipilate in Asparagus pollens and reticulate, suprareticulate, rugulate-reticulate and striate-reticulate in Fritillaria pollens. Sulcus extends from distal to proximal in some pollens of Asparagus and Fritillaria. Â  Key words: Asparagus, Fritillaria, Liliaceae, Pollen morphology DOI = 10.3329/bjb.v36i2.1498 Bangladesh J. Bot. 36(2): 111-120, 2007 (December)
Genetic diversity in potato (Solanum tuberosum L.)
Authors: Mondal MAA , Hossain MM , Rasul MG , Uddin M Shalim
Published: October 2008

Genetic diversity in 31 potato genotypes (parents and their hybrid progenies) was determined using multivariate analysis. Cluster analysis revealed that the parents and their hybrid progenies could be grouped into five different clusters. The maximum number of genotypes were included in clusters II and V. Cluster V had maximum and cluster I had minimum intra-cluster distance. Cluster mean showed wide range of variation for several characters among single as well as multi-genotypic clusters. Considering diversity pattern, parents should be selected from clusters I, III and V for the improvement of potato. Â  Key words: Genetic diversity, Cluster analysis, Potato DOI = 10.3329/bjb.v36i2.1499 Bangladesh J. Bot. 36(2): 121-125, 2007 (December)
Response of chickpea (Cicer arietinum L.) to zinc and molybdenum fertilization
Authors: Bozoglu Hatice , Ozcelik Huseyin , Mut Zeki , Pesken Erkut
Published: October 2008

A field experiment was conducted in Amasya conditions in northern Turkey for two years in order to determine the effect of zinc and molybdenum fertilization on chickpea following a completely randomized block design with three replications. Doses of zinc (Zn0 : 0, Zn1 : 1 ppm, Zn2 : 2 ppm) and molybdenum (Mo0 : 0, Mo1 : 0.05 ppm, Mo2 : 0.1 ppm) were applied on leaf when the plants were in vegetative stage. Variation of years on all investigated characters was statistically significant. Applied zinc or molybdenum failed to show any significant effect on any parameter. It was found that effect of Zn Ã Mo interaction was statistically significant (p < 0.01) on the seed yield. The highest seed yield resulted from Zn2 (2 ppm) Ã Mo0 interaction. This was followed by Zn1 (1 ppm) Ã Mo1 (0.05 ppm) and Zn1 Ã Mo2 doses showing no statistical differences from each other. Â  Key words: Chickpea, Seed yield, Zinc, Molybdenum, Response DOI = 10.3329/bjb.v36i2.1503 Bangladesh J. Bot. 36(2): 145-149, 2007 (December)
An Electrochemical DNA Biosensor Developed on a Nanocomposite Platform of Gold and Poly(propyleneimine) Dendrimer
Authors: Arotiba Omotayo , Owino Joseph , Songa Everlyne , Hendricks Nicolette , Waryo Tesfaye , Jahed Nazeem , Baker Priscilla , Iwuoha Emmanuel
Published: October 2008

An electrochemical DNA nanobiosensor was prepared by immobilization of a 20mer thiolated probe DNA on electro-deposited generation 4 (G4) poly(propyleneimine) dendrimer (PPI) doped with gold nanoparticles (AuNP) as platform, on a glassy carbon electrode (GCE). Field emission scanning electron microscopy results confirmed the codeposition of PPI (which was linked to the carbon electrode surface by C-N covalent bonds) and AuNP ca 60 nm. Voltammetric interrogations showed that the platform (GCE/PPI-AuNP) was conducting and exhibited reversible electrochemistry (E°′ = 235 mV) in pH 7.2 phosphate buffer saline solution (PBS) due to the PPI component. The redox chemistry of PPI was pH dependent and involves a two electron, one proton process, as interpreted from a 28 mV/pH value obtained from pH studies. The charge transfer resistance (Rct) from the electrochemical impedance spectroscopy (EIS) profiles of GCE/PPI-AuNP monitored with ferro/ferricyanide (Fe(CN)63-/4-) redox probe, decreased by 81% compared to bare GCE. The conductivity (in PBS) and reduced Rct (in Fe(CN)63-/4-) values confirmed PPI-AuNP as a suitable electron transfer mediator platform for voltammetric and impedimetric DNA biosensor. The DNA probe was effectively wired onto the GCE/PPI-AuNP via Au-S linkage and electrostatic interactions. The nanobiosensor responses to target DNA which gave a dynamic linear range of 0.01 - 5 nM in PBS was based on the changes in Rct values using Fe(CN)63-/4- redox probe.
Do bryophyte shoot systems function like vascular plant leaves or canopies? Functional trait relationships in Sphagnum mosses (Sphagnaceae)
Authors: Rice Steven K. , Aclander Lynn , Hanson David T.
Published: October 2008

Vascular plant leaf traits that influence photosynthetic function form the basis of mechanistic models of carbon exchange. Given their unique tissue organization, bryophytes may not express similar patterns. We investigated relationships among tissue, shoot, and canopy traits, and their associations with photosynthetic characteristics in 10 Sphagnum species. Trait relationships were organized around a primary dimension accounting for 43% of variation in 12 traits. There was no significant relationship between nitrogen content of shoot systems and maximum photosynthesis expressed on mass (Amass) or area (Aarea) bases due to nitrogen sequestration and storage within the canopy interior. This pattern differs from the distribution of nitrogen in vascular plant canopies. Thus, nitrogen and its relationship to carbon uptake in Sphagnum shoots does not conform to patterns of either vascular plant leaves or canopies. Species that concentrate biomass and nitrogen in the capitulum have enhanced rates of Amass and Aarea. Consequently, Aarea was positively associated with Narea of the capitulum only. Overall, water content and carotenoid concentration were the strongest predictors of both Amass and Aarea and these were expressed as inverse relationships. The relationships of plant traits in Sphagnum defines a principal trade‐off between species that tolerate environmental stress and those that maximize carbon assimilation.
Nei's to Bayes’: comparing computational methods and genetic markers to estimate patterns of genetic variation in Tolpis (Asteraceae)
Authors: Levsen Nicholas D. , Crawford Daniel J. , Archibald Jenny K. , Santos‐Geurra Arnoldo , Mort Mark E.
Published: October 2008

Accurate determination of patterns of genetic variation provides a powerful inferential tool for studies of evolution and conservation. For more than 30 years, enzyme electrophoresis was the preferred method for elucidating these patterns. As a result, evolutionary geneticists have acquired considerable understanding of the relationship between patterns of allozyme variation and aspects of evolutionary process. Myriad molecular markers and statistical analyses have since emerged, enabling improved estimates of patterns of genetic diversity. With these advances, there is a need to evaluate results obtained with different markers and analytical methods. We present a comparative study of gene statistic estimates (FST, GST, FIS, HS, and HT) calculated from an intersimple sequence repeat (ISSR) and an allozyme data set derived from the same populations using both standard and Bayesian statistical approaches. Significant differences were found between estimates, owing to the effects of marker and analysis type. Most notably, FST estimates for codominant data differ between Bayesian and standard approaches. Levels of statistical significance are greatly affected by methodology and, in some cases, are not associated with similar levels of biological significance. Our results suggest that caution should be used in equating or comparing results obtained using different markers and/or methods of analysis.
Phylogenetic comparative analysis of microsporogenesis in angiosperms with a focus on monocots
Authors: Nadot Sophie , Furness Carol A. , Sannier Julie , Penet Laurent , Triki‐Teurtroy Sarah , Albert Beatrice , Ressayre Adrienne
Published: October 2008

This paper presents the first broad overview of three main features of microsporogenesis (male meiosis) in angiosperms: cytokinesis (cell division), intersporal wall formation, and tetrad form. A phylogenetic comparative approach was used to test for correlated evolution among these characters and to make hypotheses about evolutionary trends in microsporogenesis. The link between features of microsporogenesis and pollen aperture type was examined. We show that the pathway associated with successive cytokinesis (cytoplasm is partitioned after each meiotic division) is restricted to wall formation mediated by centrifugally developing cell plates, and tetragonal (or decussate, T‐shaped, linear) tetrads. Conversely, much more flexibility is observed when cytokinesis is simultaneous (two meiotic divisions completed before cytoplasmic partitioning). We suggest that the ancestral type of microsporogenesis for angiosperms, and perhaps for all seed plants, associated simultaneous cytokinesis with centripetal wall formation, resulting in a large diversity in tetrad forms, ranging from regular tetrahedral to tetragonal tetrads, including rhomboidal tetrads. From this ancestral pathway, switches toward successive cytokinesis occurred among basal angiosperms and monocots, generally associated with a switch toward centrifugal intersporal wall formation, whereas eudicots evolved toward an almost exclusive production of regular tetrahedral tetrads. No straightforward link is found between the type of microsporogenesis and pollen aperture type.