bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding the Mechanism of Nanoparticles Applications in Enhanced Oil Recovery
Authors: El-Diasty Abdelrahman Ibrahim , Aly Ahmed M.
Published: September 2015

Innovative techniques are highly required in the O&G industry to meet the future demand of the hydrocarbon fuels, significant efforts have been exerted on the development of new innovative technologies to increase the oil recovery. Nanotechnology has provided new promising approaches to enhanced oil recovery (EOR) techniques in old and marginal fields.

Nanoparticles have been developed for various applications in reservoir engineering and EOR fields. Using nanoparticles for EOR applications refers to their small size compared to the pore throat sizes; therefore, they could easily move into porous rocks without severe influence on permeability.

The applications of nanoparticles to enhance the oil recovery can be summarized in three approaches; Nanocatalysts, Nanoemulsions, and Nanofluids. In this paper, the different possible displacement mechanisms of the nanofluids are discussed.
Integrated Petrophysical Approach on the Reservoir Characterization of Shaly-Sand Thin bedded Formation. A Case Study of Upper. BAHARIYA Formation in Misaada Field, Abu Gharadig basin, Egypt
Authors: Shokry I. M. , Elyazid K. A. , Clerk C.. , ElAnbaawy M. I.
Published: September 2015

An integration work flow between detailed log data analysis, characterization methodology, and core data { petrophysical, XRD, thin sections, petrological and sedimentological description } is very important to detect the diagenetic constraints for reservoir quality in shaly-sand reservoirs in order to build a more robust petrophysical model.

The work flow enables the identification of the types of clay minerals which detected during this study that affect porosity/permeability relationship. The dispersed distribution of clay minerals complicate the petrophysical analysis when using conventional tools to identify the different reservoirs zones, hence we resorted to another Petrophysical approach in reservoir characterization such as probabilistic petrophysical approach corrected to core data and thin sections analysis which have a significant clarification of the clay minerals that help in porosity preservation.

This study will allow the understanding of the factors which have a direct effect on the petophysical parameters and properties (porosity, permeability, fluid identification and characterization, fluid saturations) as well as tracking the influence of clay minerals typing (Chlorite, Kaolinite, Illite) that will lead to better detection of reservoir characterization to improve enhanced oil recovery (EOR). However, the dissolution of initial carbonate cement and the unstable feldspar grains may be the most diagenetic factor that enhanced the Bahariya reservoir quality.

The proposal of this workflow is to build a petrophysical model of this field and can provide with better porosity and fluid saturation, hence these parameters will affecting the calculations of net pay in the reservoirs.
An Innovative Technique to Grade and Scale Shale Sweetspots
Authors: Algarhy A.A.. A. , Bateman R.M.. M. , Soliman M.Y.. Y. , Afify Walid
Published: September 2015

The Sweetspot Quality Index (SSQI) is a single index that represents the quality of a shale sweetspot. Four indices are used to calculate the SSQI: the Reservoir Quality Index (RQI), Completion Quality Index (CQI), Conventional Behavior Index (CBI), and Operation Index (OI). The RQI is calculated from porosities (rock porosity, organic porosity, and natural fractures), saturation, TOC, Ro, and reservoir pressure, and the CQI is calculated from shale brittleness, and the existence of micro fractures and laminations. The CBI is calculated from porosity, permeability, saturations, reservoir pressure, viscosity, and residual oil, and the OI is estimated from hydrocarbon market price, source rock depth, and cost of operations. These four indices include all the approaches that compare and evaluate shale plays and together offer a more complete view of grading and scaling shale sweetspots.

The proposed technique has been applied to different data sets from North American shale plays, and the final results are very consistent with best practices. Due to this consistency, this approach has the potential to become a standard evaluation technique for E&P and service companies.
Feasibility of Gas Lift to Increase Oil Production in an Iraqi Giant Oil Field
Authors: Al-Fatlawi O. F. , Al-Jawad M.. , Alwan K. A. , Essa A. A. , Sadeq D.. , Mousa A. J.
Published: September 2015

Gas lift is one of the artificial lift techniques which it is frequently implemented to raise oil production. Conventionally, the oil wells produce depending on the energy of reservoir pressure and solution gas which declines due to continuous production. Therefore, many oil wells after a certain production time become unable to lift oil to the surface. Thus, the continuity of production requires implementation of gas lift which works to decrease the average fluid density in the tubing by injection gas through the annulus into the tubing. This paper aims to get maximum oil production of an Iraqi giant oil field at optimum injected gas rate. The field is located in south of Iraq and includes 67 wells.

In this paper, new model is designed to matching PVT data, matching vertical pressure drop calculations, making sensitivity analysis of wellhead temperature variation, making sensitivity analysis of productivity index variation, achievement of optimum design of gas lift and finding optimum values of oil production and injected gas rate.

The gas lift design is implemented within two cases. The first case aims to get the maximum oil production using flowing bottom hole pressure cut off as 50 psi above the bubble point pressure at certain depth. Whereas in the second plan, the same cut off value is maintained while keeping the injected gas oil ratio below or equals 350 SCF/STB. The two constraints are applied according to the policy of the operating company for the field under study.

This results show the implementation of the gas lift technique can increase oil production from 64379 STB/D to 302712 STB/D in the first case and to 272359 STB/D in the second case. In addition, 45 ceased wells were brought to production by implementation of the gas lift. The model predicts that the required injected gas rates to produce the new production are 186.3 MMSCF/D and 74.606 MMSCF/D in the first and second cases respectively. The main conclusions lead to the application of gas lift technique for this reservoir can increase the oil production volume significantly.
Pressure Transient Analysis for Composite Tight Oil Reservoirs after Fracturing
Authors: Xu Jianchun , Han Guangwei , Jiang Ruizhong , Deng Qi , Zhao Yulong
Published: September 2015

In this paper, a new mathematical model of multistage fractured horizontal well (MsFHW) considering stimulated reservoir volume (SRV) was proposed for tight oil reservoir considering different regions and formation properties. In this model, two regions with different formation parameters were distinguished. Non-steady state flow in matrix was considered which is reasonable for tight oil/gas formations. The SRV is characterized by the inner region. Both inner and outer regions were assumed as dual porosity medium. Then, the solution of multistage fractured horizontal well performance analysis model is obtained by the point source function method and the source function superposition principle. The pressure transient analysis (PTA) for well producing at a constant production rate was obtained and discussed. At last, different flow regimes were divided based on PTA curves. The effects of related parameters such as SRV radius, inner-porosity coefficient, mobility ratio, fracture number, fracture half-length and fracture spacing were analyzed.
An Integrated Approach to Improve Safety Margins While Drilling – A Case Study from Ha'py Field, Offshore Nile Delta
Authors: El Waseef Mohamed , Bentham Peter , Wild Lorraine , Mansour Mohamed , Ismail Saher , El Kasrawy Gamal , Raslan Samir , Mahmoud Moustafa
Published: September 2015

This study has been focusing on planning wells, which target lower Pleistocene reservoirs below a depleted Ha'py gas field. Many Non Productive time events (NPT) have been anticipated, and the challenges of losing wells and running over budget have been considered as major risks in targeting the deeper prospects.

Years of production from the main Pleistocene A20 reservoir has resulted in significant pressure depletion, while underlying largely-undeveloped Pleistocene reservoirs appear to be very promising they remain at or close to virgin conditions. In addition, the position of the platform at the centre of the field has made it necessary to drill highly-deviated wells to access remaining reserves at the crest of the field.

Detailed planning and close collaboration between the PhPC (Pharaonic Petroleum Company) subsurface and drilling teams has been necessary to understand the geological and geomechanical properties of the key formations. This has helped in selecting appropriate mud rheology and mud additives in addition to ensuring good drilling practices that maximise safety and success. The combined effects of depletion and low rock strength make it effectively impossible to drill the A20 interval with the mud weights required to minimize well bore instability. As a result, stress cage additives were employed in the drilling mud in order to reduce the potential for losses due to the large overbalance against the depleted sand. Modeling prior to drilling suggested this application lay close to the technical limit of the stress cage methodology, and was beyond anything previously attempted within the Pleistocene reservoirs in the offshore Nile Delta.

Careful execution meant we were able to successfully drill through the depleted zone, and as a result of this work, we have been able to deepen recent wells to access underlying gas resources. This success has allowed us to reduce NPT while ensuring safe well operations.
Eliminate Pre-Flush and/or Post-Flush Acid Stages During Hydrofluoric Acid Treatments: Experimental and Field Cases
Authors: Gomaa Ahmed M. , Stolyarov Sergey , Cutler Jennifer
Published: September 2015

The goal of sandstone matrix acidizing is to remove siliceous particles such as formation clay, feldspar, and quartz fines that are blocking or bridging pore throats. This is accomplished by injecting acid formulations containing hydrofluoric (HF) acid or its precursors, as HF is the only common acid that dissolves siliceous particles sufficiently. Standard treatments include pre-flush and/or post-flush stages of HCl acid to minimize the potential for calcium fluoride and other secondary precipitation. However, there is no guarantee that the HF acid stage will follow the path of the preflush stage; therefore, precipitation could still occur. In addition, the fast reaction of HF acid with clay minerals presents another challenge to effectively stimulating deep sandstone formations.

This paper presents experimental and field case studies with a sandstone acidizing treatment designed to retard the HF reaction rate and enable single-stage treatment -- eliminating the pre- and post-flush HCl acid stages and thereby reducing treatment complexity and treatment/rig time.

Extensive laboratory testing was performed using a variety of quarried sandstone cores with varying amounts of clay minerals, feldspar, and carbonate to confirm the ability to stimulate a wide range of sandstone formations. Also, formation core material was evaluated to confirm the results. Static solubility tests indicated that around 80% of the treated formation was soluble in the new acid system formulation. Coreflood testing noted an improvement in permeability of as much as 326%. Also, corrosion tests conducted using different metallurgy showed a very low corrosion rate (less than 0.005 lb/ft2 for N–80 and less than 0.02 lb/ft2 for Cr–13). Using coiled tubing, the new design was injected into three deep offshore wells, resulting in injectivity increases of 227%, 236%, and 256%. This paper will describe in detail the experimental result and the successful field treatments.
Diabetes and the Female Disadvantage
Authors: Woodward Mark , Peters Sanne AE , Huxley Rachel R
Published: September 2015

We have produced compelling evidence that women are subject to a higher relative increase in their risk of coronary heart disease and stroke following a diagnosis of Type 2 diabetes. Thus, in terms of vascular risk, diabetes confers a female disadvantage. This excess risk could be due to three main factors. First, it is conceivable that this is merely a mathematical artifact caused by the relatively low background rate for cardiovascular diseases among women, compared with men. Second, it could be due to women receiving poorer care following their diagnosis of diabetes than men; for instance, due to physician bias. Third, certain underlying biological differences in women and men, most likely related to the distribution of body fat, could explain this female disadvantage.
The Effect of Frequency and Automation of Internal Control Testing on External Auditor Reliance on the Internal Audit Function
Authors: Farkas Maia J. , Hirsch Rina M.
Published: September 2015

Failure of the internal audit function (IAF) to detect a significant deficiency in internal controls is a significant shortcoming in the IAF's work performance. This shortcoming in the IAF's work performance reduces external auditors' willingness to rely on the IAF's work. Using a two-stage experiment, we investigate how the implementation of three different internal control testing remediation strategies (akin to CCM, ACL, and periodic manual testing), which vary in their automation and frequency, affect external auditors' perceptions of IAF strength and planned reliance on the IAF's work. We find that automated remediation strategies fully remediate external auditors' perceptions of poor IAF work performance and low degree of reliance on the IAF, whereas manual remediation strategies result in only partial remediation. Counterintuitively, less frequent remediation strategies are more effective at improving perceptions of poor IAF work performance and low levels of reliance on the IAF, relative to continuous remediation strategies.
Pulmonary Artery Pseudoaneurysm: A Rare Cause of Hemoptysis in a Child
Authors: Vaideeswar Pradeep , Karande Sunil , Yadav Subhash , Pardeshi Kirti
Published: September 2015

Aneurysms and pseudoaneurysms of pulmonary vasculature are uncommon occurrences that contribute to mortality and morbidity, without timely diagnosis and intervention. We report a fatal massive hemoptysis in a child due to a consolidation-related pulmonary arterial pseudoaneurysm, an extremely rare phenomenon.
Characterization of Real-World Particle Number Emissions during Reignition Events from a 2010 Light-Duty Hybrid Electric Vehicle
Authors: Conger Matt , Holmén Britt A.
Published: September 2015

Despite the increasing popularity of hybrid electric vehicles (HEVs), few studies have compared the real-world particle emissions of HEVs from internal combustion engine (ICE) reignition events with that of a conventional vehicle (CV) during real-world driving. Reignition events occur under unstable combustion conditions and frequently result in particle number (PN) emission rates (PNERs) that exceed those for stabilized engine operation. Tailpipe PNERs from a CV and an HEV 2010 Toyota Camry were quantified on a 32-mi route over rural, urban, and freeway roadways in Chittenden County, Vermont, with the total onboard tailpipe emissions measurement system. This study directly compared the CV and HEV PNERs and characterized the operation of the HEV in a new HEV ICE operating mode framework. Mean PNER for reignition events (7.19 pM 11.8 × 1010 particles/s) were on average four times greater than for stabilized HEV operation (1.79 ± 3.99 × 1010 particles/s). Under urban, rural, and freeway driving, HEV reignition event operation accounted for 58.7%, 44.6%, and 5.0%, respectively, of the total PN inventory. Mean HEV PNER was 1.8 times greater than that of the CV in urban driving, while under freeway driving, where the two vehicles operated similarly, average CV PNER was 2.4 times greater than that of the HEV. The data show that the typical fuel consumption benefits of HEVs in urban driving are associated with a trade-off in PN emissions. The HEV ICE operating behavior has implications for the spatial distribution of PN hot spots as well as the associated microscale modeling of alternative vehicle technology emissions.
Empirical evidence in the study of labor markets: Opportunities and challenges for a new household survey
Authors: Black Dan A. , Taylor Lowell J. , Zaber Melanie
Published: September 2015

Many of the key issues confronting modern societies are closely tied to labor market outcomes: What factors contribute to the persistence of poverty and deprivation? Why does long-term unemployment damage re-entry prospects into labor markets? Along which dimensions is economic inequality increasing, and to what extent should we be concerned about these trends? To what degree is inequality transmitted within families across generations? Why does race play such an important role in economic success in the U.S.? How are male-female differences in economic outcomes shifting over time? In this essay we suggest that a well-designed survey that follows individuals within households over a long horizon is crucial for sorting some facets of these questions. We provide some thoughts about how a future household survey should be designed for the purpose facilitating high-value research in empirical labor economics.
Type 2 Diabetes Mellitus is Associated with Lower Serum Adiponectin Level in Bangladeshi Population
Authors: Eva Sohely Nazneen , Zinnat Rahelee , Molla Golam Morshed , Zahir Muneera , Akter Fatema , Rehnuma Behterin , Amin Rukhsana
Published: September 2015

Background: The physiological role of adiponectin is not yet fully clear, but it is now generally accepted that it has a protective role against the development of lifestyle disorders, related to insulin resistance and atherosclerosis. Insulin resistance is one of the basic defects of type 2 diabetes (T2DM) and adiponectin is inversely associated with T2DM. As serum adiponectin level has not yet been investigated in Bangladeshi T2DM subjects,so that the present study has been under taken to find out the association of T2DM with serum adiponectin level in Bangladeshi population.Methodology: In this observational case control study, sixty six (66) T2DM subjects, seventy four (74) healthy control subjects were included. Diabetes was diagnosed and classified as per WHO criteria. Serum Adiponectin was measured by Enzyme Linked Immunosorbent Assay (ELISA) method. Serum glucose was measured by glucose-oxidase method; serum insulin was measured by chemiluminescence-based ELISA technique. The insulin secretory capacity (HOMA%B), insulin sensitivity (HOMA%S) & insulin resistance (HOMA IR) were assayed by homeostasis model assessment method.Results: The study subjects were BMI matched. BMI of the Control subjects and T2DM subjects (Mean±SD) were 25.02±3.55 and 25.85±3.62. Age (year) of the Control subjects and T2DM subjects (Mean±SD) were 42.46±9.24 and 48.49±8.09. Median (range) fasting serum insulin in the control and T2DM was 14.68 (1.86-45.92) and 18.09 (4.10-42.78) respectively which was not statistically significant (p=0.214). Median (range) HOMA%B values in the control and T2DM subjects was 160.10(33.40-493.40) and 100.45(17.70-349.30). Median HOMA%B in the T2DM group was significantly lower compared to the control (p=0.0001). Median (range) HOMA%S values in the control and T2DM subjects was 44.20(9.80- 339.40) and 32.80(14.30-154.70) respectively. Median HOMA%S in the T2DM group was significantly lower compared to the control (p=0.036). Median (range) serum adiponectin (?g/ml) of the control and T2DM subjects was 8.70 (0.76-15.96) and 6.19 (1.13-22.37). Serum adiponectin was significantly lower in T2DM compared to the control (p=0.0001).Conclusions: From this study it may be concluded that, T2DM subjects have both insulin secretory defects and insulin resistance and associated with lower serum adiponectin level in Bangladeshi population.Anwer Khan Modern Medical College Journal Vol. 6, No. 1: January 2015, Pages 10-13
Retinopathy and Neuropathy in Patients with End Stage Renal Disease on Haemodialysis- A Hospital Based Study
Authors: Mahmood Nazneen , Chowdhury Shaila Safia
Published: September 2015

Bacground: Chronic renal failure is irreversible and progressive process that results in end stage renal disease (ESRD) where the patient has to be dependent on renal replacement therapy for survival. Retinopathy and neuropathy are often asymptomatic in their most treatable stage; delay in diagnosis can result in significant increase in the patient's risk of visual loss and disability. Ocular condition is also an indicator of the metabolic control of the disease process. This study is an attempt to access the ocular status/complications as well as neurological manifestation associated with end stage renal disease on haemodialysis.Methodology: This is a cross sectional descriptive type of observational study on patients of end stage renal disease getting haemodialysis in Medical College for Women and Hospital. Duration of study was 3 years from January 2011 to December 2013. This study is an attempt to access the ocular status/complications as well as neurological manifestation associated with end stage renal disease on haemodialysis.Result: Among 81 patients, 42 patients had hypertension (HTN) and 19 had diabetes mellitus (DM) and 20 had other causes of chronic kidney disease(CKD). In our study, out of 19 patients of diabetes mellitus, 73.68%(14) had diabetic retinopathy(DR) and 26.32%(5) had normal fundus. All the 42 patients had hypertensive retinopathy(HR). Regarding fundal examination of patients with hypertensive retinopathy(HR), 32.26% had gradel, and 17.74%, 43.55% and 6.45% were of grade ll, lll, lV respectively. It was found that non-proliferative changes in ocular fundal examination in diabetic patients were the commonest abnormality. On fundal examination of diabetic retinopathy (DR), 26.32% had normal fundus, 26.32% had dot and blot haemorrhages, 21.05% had hard exudates and cotton wool, 21.05% had new vascularization while 5.26% had retinal detachment.The following types of neuropathy were seen among our patients; 48.15% had symmetrical distal sensory motor polyneuropathy, 19.75% had a symmetrical polyneuropathy, 19.75% had mononeuropathy and cranial nerve palsies were detected in 12.35%.Conclusion: Detailed ocular and neurological examination should be undertaken in patients of end stage renal disease(ESRD) on maintenance haemodialysis(HD) for early diagnosis and treatment of the complications. Awareness is needed of the potential ocular and neurological complications of the disease process.Anwer Khan Modern Medical College Journal Vol. 6, No. 1: January 2015, Pages 14-19
Emergence of Ebola Virus Disease (EVD): Key Facts
Authors: Rahman Md Mahfuzar , Mehrin Farnaz , Ahmed Fahim
Published: September 2015

The modern emerging infection Ebola Virus Disease (EVD) is of global threat originates from Africa region. This is zoonotic and identified as human diseases or previously called Ebola hemorrhagic fever which is a highly fatal human illness where case fatality rate is found up to 90%. The virus transmission begins from wild animals to human and then spreads within population through human to human. Fruit bats are found as natural host of Ebola virus. There is no specific treatment or vaccine available in the market so far, intensive supportive care is needed for severely ill patients. This paper highlights background information, problem statement, viral characteristics, mode of transmission, signs and symptoms, prevention & vaccination. It also indicates possible actions towards prevention of transmission & personal protection.Anwer Khan Modern Medical College Journal Vol. 6, No. 1: January 2015, Pages 35-37
Le point sur…
Authors: Madoré Stan
Published: September 2015

Stan Madoré reprend un des concepts incontournables de l’analyse transactionnelle qu’est l’enclos OK. Dans une démarche vivifiante, de son point de vue de PTSTA en Organisation, il ouvre une réflexion critique. N’hésitez pas à envoyer vos commentaires et réactions à la revue ( aatcomitelecture@gmail.com ). Le comité de rédaction se réserve le droit de publier les plus intéressants, avec votre accord bien évidemment. C.F.
Parkinson's Disease Detection with Gait Recognition using Soft Computing Techniques
Authors: Shukla Anupam , Rathore Chandra Prakash , Bhansali Neera
Published: September 2015

Parkinson's disease is a degenerative disorder of the central nervous system which occurs as a result of dopamine loss, a chemical mediator that is responsible for body's ability to control the movements. It's a very common disease among elder population effecting approx 6.3 million people worldwide across all genders, races and cultures. In this chapter, authors have proposed an automated classification system based on Artificial Neural Network using Feed Forward Back-propagation Algorithm for Parkinson's disease diagnosis by analyzing gait of a person. The system is trained, tested and validated by a gait dataset consisting data of Parkinson's disease patients and healthy persons. The system is evaluated based on several measuring parameters like sensitivity, specificity, and classification accuracy. For the proposed system observed classification accuracy is 97.11% using 19 features of gait, and 95.55% using 10 prominent features of gait selected by Genetic Algorithm.
Quantum Computing Based Technique for Cancer Disease Detection System
Authors: Chaturvedi Setu Kumar , Jain Milan
Published: September 2015

Barring any cancer prevention breakthroughs, the expansion of the aged population will likely increase number of older individuals diagnosed for cancer in the coming decades. Dimensions of the cancer burden and its devastating manner of challenge ahead are inferred in the context of with aging populations to underscore the possible increase that demographic factors may have on the magnitude of the cancer problem for older persons in the future years. Presently the detection procedure is very time consuming and not accurate, in this respect there is a need of more accurate, fast and efficient method through computing technologies. The present research work incorporates quantum computing with clustering algorithm i.e. Shor's algorithm of quantum computing with hierarchical clustering technique. Here adaptation of Shor's algorithm helps to increase accuracy, and hierarchical clustering technique helps to detect the stages of cancer.
Possibilities of Using Natural Fibres for Production of Particular Insulation for Use in Civil Engineering
Authors: Reif Martina , Hroudová Jitka , Zach Jiří
Published: September 2015

The paper deals with the development options of particular insulation based on a blend of recycled cellulose fibers and natural (mainly) bast fibers. The paper presents the results of research work in the field of addiction thermal insulation, acoustic and mechanical properties of experimentally produced insulators on density..Keywords: Natural fibers, thermal conductivity, insulation materials, straw, fibreboard, cellulose fibers
Development of Fibre-Cement Composites with Self-Cleaning and de-NOx Ability
Authors: Boháč Martin , Čechmánek René , Staněk Theodor
Published: September 2015

Paper deals with development of face architectural fibre-cement composites based on white Portland cement with addition of photoactive TiO2. Tests were carried on composite binder and then on the composites. The role of TiO2 on performance of materials was monitored. Selected composites were tested on self-cleaning ability, de-NOx activity and resistance to weathering in outdoor conditions. Two series of thin-walled products based on developed composites were prepared with self-cleaning ability and de-NOx activity.
Diffusion Parameters of Basic Diffusion Adhesive Mortars with Silicate or Acrylic Plaster
Authors: Nenadálová Šárka , Balík Lukáš , Rydval Milan , Bittner Tomáš
Published: September 2015

The paper summarizes the results of water vapour resistance factors of three commonly used compositions for wall finishing (basic adhesive diffusion mortar; basic adhesive diffusion mortar + silicate plaster; basic adhesive diffusion mortar + acrylic plaster). The border conditions of the measuring (temperature, relative humidity and barometric air pressure) and their impacts on the results are discussed as well.
Possibilities of Development of Thermal Insulating Materials Based on Waste Textile Fibers
Authors: Sedlmajer Martin , Zach Jiří , Hroudová Jitka
Published: September 2015

The paper describes the possibility of using textile fibers (natural and synthetic) for the production of thermal insulation materials in the form of mats using in construction. The paper deals mainly with soft thermal insulation mats and the factors that affect the thermal insulation properties of the insulating material in its manufacture and subsequent incorporation into the structure.
Hydration of Synthetized Clinker Phases C3S and C3A with Metakaolin in Isothermal Conditions
Authors: Boháč Martin , Novotný Radoslav , Másilko Jiří , Opravil Tomáš , Šoukal František , Yadav Raghvendra Singh , Palou Martin
Published: September 2015

Heat flow development during initial hydration of fresh pastes based on mixtures of pure clinker phases C3S and C3A with metakaolin was investigated by means of isothermal calorimetry. Phase composition development was examined by "in situ" X-ray diffraction technique. Obtained results from calorimetric measurements and X-ray diffraction were correlated with recent studies in field of hydration of cementitious systems. The effect of co-sintering of clinker phases on early hydration was characterized by isothermal calorimetry.
Permeability Measurement of High Performance Concrete at Elevated Temperature Employing a New Test Set-Up
Authors: Fiedlerová Michaela , Kirnbauer Johannes , Bruckner Heinrich
Published: September 2015

This paper is focused on clarifying behaviour of concrete at elevated temperature with employing new test set-up constructed at Institute of Building Construction and Technology, Vienna University of Technology. This unique test set-up allows measuring gas permeability of different building materials such as concrete or ceramic at both high temperature (up to 400°C) and pressure (up to 6 bars). Present paper illustrates a new set up for permeability measurement during the heating and cooling and different testing procedures and evaluation of their influence on results.
Comparison of Modal Analysis Using FEM and Eigenfrequency Measurements
Authors: Martinek Jan , Carbol Ladislav
Published: September 2015

In ultrasonic testing the vibration spectrum must be understood and the measured frequency peaks should match specific sample characteristics. In this paper, the experimental data are compared with results obtained using modal analysis based on Finite Element Method and the vibration was also calculated using classical Euler-Bernoulli approach, which is very simple but somewhat limited. The specimen geometry as well as the material of choice are both very simple to predict, model and measure - i.e. round cross section metal rod. In this case the FEM gives slightly better result that the simplified analytical calculation.
Experimental Verification of Properties of Roller-Compacted Concrete for Pavements
Authors: Bily Petr , Fladr Josef , Haase Michael
Published: September 2015

Increased requirements on environmentally friendly construction process of road structures with emphasis on economical savings and durability of roadways lead to search for new material solutions for pavements. Roller-compacted concrete (RCC) is an ordinary concrete poured and compacted with machines typically used for placement of asphalt pavement layers. Its main advantage is relatively good ratio between mechanical properties and overall costs during construction, operation and maintenance phases. After extensive literature review on the use of RCC in the world, the authors focused themselves on a series of tests of specimens made from RCC mix to verify the main characteristics of the material. Slump, compressive and flexural strength, resistance of concrete to deicing chemicals and resistance to abrasion was tested. The results were assessed from the point of view of exploitation of RCC in pavement structures.
Substitution of Limestone in Raw Mixture for Burning Portland Cement by FBC Ash
Authors: Magrla Radek , Kulísek Karel , Dvořák Karel , Gazdič Dominik
Published: September 2015

This paper describes effort to reduce amount of gypsum in raw mixture for burning of Portland cement. Substitution of this material was realized by FBC ash. From these modified raw mixtures the clinkers were burnt, which were milled into cement then. These cements were subjected to basic technological tests.
Evaluation of Mechanical Properties of Glass/Epoxy Syntactic Foams Containing Carbon Nanotubes and Nanosilica
Authors: Drdlová Martina , Frank Michal , Buchar Jaroslav , Řídký Radek
Published: September 2015

The effect of multi-wall carbon nanotubes and nanoSiO2 content on physico-mechanical properties of glass microspheres-epoxy resin composite, designed for blast energy absorbing applications, was evaluated experimentally. Specific porous lightweight foam with high volume fraction of microspheres (70 vol.%) was prepared and modified by 1 to 5 vol.% of multi-wall carbon nanotubes and nanosilica (nanoSiO2). Two types of microsperes with different wall thickness and strength were used. The quality of dispersion of nanoparticles was evaluated in relation to the mixing procedure using scanning electron microscope observation. The compressive and flexural strength tests were conducted at quasi-static load. The mixtures containing nanosilica exhibited an increasing trend in both flexural and compressive strength with increasing nanoparticle content up to 4 vol.%. The addition of carbon nanotubes also increased flexural strength (again up to 4 vol%, crossing this concentration, the significant drop was observed), whereas the compressive strength was affected at lower level. Nanoparticle modification is more effective in the foams with higher thickness and thus strength. The evaluation of test results showed that the properties of glass/epoxy foams can be tailored by adding nanoscale fillers.
Las edades de la migración boliviana en Argentina: Córdoba y Ushuaia como destino
Authors: Magliano María José , Mallimaci Barral Ana Inés
Published: September 2015

A partir de los resultados de un trabajo de campo cualitativo realizado en dos ciudades argentinas, Córdoba y Ushuaia, el propósito de este trabajo es la comparación socio-histórica de las migraciones de personas nacidas en Bolivia en dichas ciudades de acuerdo al momento de su arribo, las diferentes localizaciones territoriales, las formas que adquiere la migración así como también las principales trayectorias laborales en los lugares dedestino. La categoría edades de la migración, acuñada por Sayad (1977), es recuperada aquí para pensar las complejidades y diferenciaciones de la presencia continua e histórica de migrantes bolivianos en el territorio nacional y sus trayectorias que manifiestan distintos momentos de la migración. El análisis que proponemos parte de la premisa que la historia de la propia migración boliviana hacia Argentina se expresa en un saber hacer migratorio acumulado y naturalizado a través de vastas generaciones de migrantes que condiciona las formas y repertorios migratorios disponibles de varones y mujeres, especialmente cuando la migración resulta una estrategia para la reproducción familiar.
’n Verkenning van die verhouding tussen wetenskap en inheemse kennis: Moontlikhede vir integrasie in Suid-Afrikaanse Lewenswetenskappeklaskamers
Authors: Le Grange Lesley
Published: September 2015

The article is a theoretical exploration of the relationship between science and indigenous knowledge, as well as the implications for integrating the two in Life Sciences classrooms in schools. The theoretical discussion draws on insights from the sociology of scientific knowledge and argues that science should not only be viewed as representation but also as performance. Such a view, it is argued, serves as the basis for integrating indigenous knowledge into the Life Sciences. Practical suggestions are made as to how indigenous knowledge could be infused into Life Sciences classrooms and how teachers can scaffold learners through different types or stages of what Jegede calls, ‘collateral learning’.
Boundary Control Problems in Convective Heat Transfer with Lifting Function Approach and Multigrid Vanka-Type Solvers
Authors: Aulisa Eugenio , Bornia Giorgio , Manservisi Sandro
Published: September 2015

This paper deals with boundary optimal control problems for the heat and Navier-Stokes equations and addresses the issue of defining controls in function spaces which are naturally associated to the volume variables by trace restriction. For this reason we reformulate the boundary optimal control problem into a distributed problem through a lifting function approach. The stronger regularity requirements which are imposed by standard boundary control approaches can then be avoided. Furthermore, we propose a new numerical strategy that allows to solve the coupled optimality system in a robust way for a large number of unknowns. The optimality system resulting from a finite element discretization is solved by a local multigrid algorithm with domain decomposition Vanka-type smoothers. The purpose of these smoothers is to solve the optimality system implicitly over subdomains with a small number of degrees of freedom, in order to achieve robustness with respect to the regularization parameters in the cost functional. We present the results of some test cases where temperature is the observed quantity and the control quantity corresponds to the boundary values of the fluid temperature in a portion of the boundary. The control region for the observed quantity is a part of the domain where it is interesting to match a desired temperature value.
Chemical aging of single and multicomponent biomass burning aerosol surrogate particles by OH: implications for cloud condensation nucleus activity
Authors: Slade J. H. , Thalman R. , Wang J. , Knopf D. A.
Published: September 2015

Abstract. Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low-soluble single-component OA by OH and O3 can increase their water solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate particles exposed to OH and O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH and O3 exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~ 0.1, indicating that chemically aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH-exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions, chemical aging has no significant impact on OA hygroscopicity. The organic compounds exhibiting low solubility behave as if they are infinitely soluble when mixed with a sufficient number of water-soluble compounds. At and beyond this point, the particles' CCN activity is governed entirely by the water-soluble fraction and is not influenced by the oxidized organic fraction. Our results have important implications for heterogeneous oxidation and its impact on cloud formation given that atmospheric aerosol is a complex mixture of organic and inorganic compounds exhibiting a wide range of solubilities.
Accessible television: The new frontier in disability media studies brings together industry innovation, government legislation and online activism
Authors: Ellis Katie , Kent Mike
Published: September 2015

As television moves beyond digital broadcast modes of distribution towards online modes of delivery, this paper considers the opportunities and challenges for people with disabilities. With accessibility relying on a complex mix of regulation, legislation and industry innovation, the paper questions whether predictions of improved accessibility are an automatic outcome of new television technologies. The paper asks ‘where to next?’ for disability and the Internet through an emphasis on the importance of television in an accessible new media environment. The paper draws on government policies, the activist intervention of a number of people with disabilities as documented online, and primary research into Australian television audiences with disabilities that took place in 2013 and 2014.
Virginia Woolf's Cinegraphic Poetics in The Years
Authors: Marie Caroline
Published: September 2015

This article analyzes the cinegraphic quality of The Years by Virginia Woolf. It does not seek to prove direct influences but establishes correspondences between the poetics of Virginia Woolf's novel and films by Serguei Eisenstein, René Clair, Francis Picabia, and German expressionists as well as the theater of its time, which was also under the influence of cinema. Just as these films do, The Years rethinks the relationship between time and space, or “Here & Now,” one of its working titles. Its attempt to render point of view anonymous, its representation of perception as movement, and its use of anamorphosis as transition create moments that overflow their limits so that the present moment is constructed as time in exile. Such time that adheres to space too much or too little is to be read in the light of Gilles Deleuze's concept of aiôn as well as according to his theory of the “dream-image.”
The Stable Trajectory Tracking Control of a Skid-Steered Mobile Platform with Dynamic Uncertainties
Authors: Jeon Seungwoo , Jeong Wootae
Published: September 2015

In order to clean the surfaces of air ducts in underground facilities, recent research has been conducted on driving the control and development of an autonomous mobile duct-cleaning platform. The duct-cleaning robots removes contaminants that are inside a duct using the friction between a rotating cleaning brush and the duct surface. For the effective removal of the contaminants and stable steering control of the autonomous mobile platform, the interaction force between the brush and the duct surface needs to be measured. However, it is not possible to achieve an accurate measurement of the contact force for the duct surface and brush, which has a nonlinear deformation characteristic. Therefore, in this study, a simple and robust controller has been proposed. This controller integrates the backstepping method with an I-PD controller for the robust platform control against irregular external forces on the cleaning brush. In addition, various trajectory tracking simulations have been conducted and the results present stable trajectory tracking of the mobile platform in air duct cleaning.
Debugging the Plant: Managing Reverse Osmosis Biofouling at a Groundwater Treatment Plant
Authors: Walker Troy , Cardenas Myriam , Richinick Gary
Published: September 2015

Commissioned in 2010, the Arcadia Water Treatment Plant treats local groundwater to provide approximately 10 mgd of treated water as part of the City of Santa Monica's (Calif.) drinking water supply. The plant removes iron and manganese and then treats a portion of the water with reverse osmosis (RO) as a softening process to achieve desired levels of hardness. Shortly following the plant's commissioning, biological fouling occurred, first at the pretreatment cartridge filters and then spreading to the RO units. Chloramine dosing, long established as an effective strategy for RO biological fouling control in wastewater reuse, is not as widespread in groundwater treatment. Previous studies of chloramine use in surface water and groundwater RO systems reported an undesirable increase in salt transport, which can adversely affect treated water quality and decrease usable membrane life. Despite this, successful implementation of chloramine dosing was achieved at the Santa Monica facility, which has overcome fouling.
HIV prevention and care services for female sex workers: efficacy of a targeted community‐based intervention in Burkina Faso
Authors: Traore Isidore T , Meda Nicolas , Hema Noelie M , Ouedraogo Djeneba , Some Felicien , Some Roselyne , Niessougou Josiane , Sanon Anselme , Konate Issouf , Van De Perre Philippe , Mayaud Philippe , Nagot Nicolas
Published: September 2015

Introduction

Although interventions to control HIV among high‐risk groups such as female sex workers (FSW) are highly recommended in Africa, the contents and efficacy of these interventions are unclear. We therefore designed a comprehensive dedicated intervention targeting young FSW and assessed its impact on HIV incidence in Burkina Faso.

Methods

Between September 2009 and September 2011 we conducted a prospective, interventional cohort study of FSW aged 18 to 25 years in Ouagadougou, with quarterly follow‐up for a maximum of 21 months. The intervention combined prevention and care within the same setting, consisting of peer‐led education sessions, psychological support, sexually transmitted infections and HIV care, general routine health care and reproductive health services. At each visit, behavioural characteristics were collected and HIV, HSV‐2 and pregnancy were tested. We compared the cohort HIV incidence with a modelled expected incidence in the study population in the absence of intervention, using data collected at the same time from FSW clients.

Results

The 321 HIV‐uninfected FSW enrolled in the cohort completed 409 person‐years of follow‐up. No participant seroconverted for HIV during the study (0/409 person‐years), whereas the expected modelled number of HIV infections were 5.05/409 person‐years (95% CI, 5.01–5.08) or 1.23 infections per 100 person‐years (p=0.005). This null incidence was related to a reduction in the number of regular partners and regular clients, and by an increase in consistent condom use with casual clients (adjusted odds ratio (aOR)=2.19; 95% CI, 1.16–4.14, p=0.01) and with regular clients (aOR=2.18; 95% CI, 1.26–3.76, p=0.005).

Conclusions

Combining peer‐based prevention and care within the same setting markedly reduced the HIV incidence among young FSW in Burkina Faso, through reduced risky behaviours.
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Authors: Capelotti P.J.
Published: September 2015

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Workshop participants
Authors: Capelotti P.J.
Published: September 2015

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