bluuebunny/crossref_metadata_2025 huggingface dataset:
Islam and the Struggle for Religious Pluralism in Indonesia: A Political Reading of the Religious Thought of Mukti Ali
Authors: Munhanif Ali
Published: June 2014

Problems of inter-religious dialogue is one of the important discourse in the development of religious thought in modern Indonesia. One of the leading Muslim intellectuals seoran put a great interest in the discourse of religious thought is Prof. HA Mukti Ali, former Minister of Religious Affairs of the Republic of Indonesia, which has served as Rector of IAIN Yogyakarta.In the view of many people, known as Mukti Ali Muslim leaders who have diverse Islamic thought. He, set in the traditional students and the cast of revivalist organization, Muhammadiyah is the pioneer of Comparative Studies of Religion in Indonesia. He is also known as the man who chose the problem of inter-religious dialogue in Indonesia as 'immortal work' throughout his life. Equally important, Mukti Ali is an Indonesian Religious Affairs Minister re-orientation is important in the political-religious wisdom in the New Order.DOI: 10.15408/sdi.v3i1.814
‘Alāqat Ḥarakat Nashr al-Islām wa al-Tarbīyah al-Islāmiyyah fī Ṣultanah Aceh
Authors: Rosatria Eri
Published: June 2014

The emergence of such great 'ulama' in the Sultanate of Aceh, north of Sumatra, as Hamzah Fansuri (Hamzah al-Fansuri), Syamsuddin Sumatrani (Shams al-Din al-Sumatrani), Nuruddin Arraniri (Nur al-Din al-Raniri) and Abdurrauf Singkel ('Abd al-Rauf al-Sinkili) could lead one to pose an important questions. Why they emerged in the Sultanate of Aceh and not in other part of Nusantara. This study argues that that their emergence had closely to do with the fact that activity of Islamic learning was strongly supported by the Acehnese sultans.DOI: 10.15408/sdi.v3i1.815
Changing the Image of Islam and Muslim World: Indonesian Exercise
Authors: Taher Tarmizi
Published: June 2014

This paper was originally a public lecture text of former Minister of Religious Affairs. H. Tarmizi Taher, MD, at the Center for the Study of World Religions, Harvard University, USA., On 8 November 1995, discussed the Indonesian Muslim religious discourse in relation to inter-religious relations.DOI: 10.15408/sdi.v3i2.805
The Khittah of 1926 Reexamined: Views of the NU in Post-Cipasung Congress
Authors: Munhanif Ali
Published: June 2014

When established in 1926 in Surabaya, Nahdlatul Ulama (NU) is meant as an organization of scholars engaged in the field of socio-religious. Concentration struggles and activities of the organization was shaped in the development of the Indonesian Muslim community in the socio-cultural field such as education, teaching, health care, and economic development of the people. In this framework, then, the scholars and leaders of this organization to formulate a vision NU known as Khittah 1926. After a long period gait for NU deviate from Khittah as outlined, to enter the world of practical politics - join Masjumi, became NU party, the PPP fuse - at Muktamarnya 27th in Situbondo, 1984, KH duet. And KH Abdurrahman Wahid. Ahmad Siddiq managed to bring NU back to Khittah 1926. Decision was meant to remove themselves from the bondage of practical politics and prioritize the development of the Indonesian Muslim community culturally.DOI: 10.15408/sdi.v3i2.808
Islam di “Negeri Bawah Angin” dalam Masa Perdagangan
Authors: Azra Azyumardi
Published: June 2014

This article is a review of the book Anthony Reid, Southeast Asia in the Age of Commerce 1450-1680, Volume One: The Lands below the Winds, New Haven & London: Yale University Press, 1988; Southeast Asia in the Age of Commerce 1450-1680, Volume Two: Expansion and Crisis, New Haven & London, Yale University Press, 1993.Studies of 'The Lands Below the Winds' - a medical Middle Eastern term reffering to Southeast Asia - especially those related to Islam, remain incomplete. Numerous problems, subject and topics are still hotly debated among schoolars of Southeast Asia. Also, there are many issues which need more adequate and serious research.DOI: 10.15408/sdi.v3i2.811
Measurement of flow diverter hydraulic resistance to model flow modification in and around intracranial aneurysms
Authors: Ugron Ádám , Szikora István , Paál György
Published: June 2014

Flow diverters (FDs) have been successfully applied in the recent decade to the treatment of intracranial aneurysms by impairing the communication between the flows in the parent artery and the aneurysm and, thus, the blood within the aneurysm sac. It would be desirable to have a simple and accurate computational method to follow the changes in the peri- and intraaneurysmal flow caused by the presence of FDs. The detailed flow simulation around the intricate wire structure of the FDs has three disadvantages: need for high amount of computational resources and highly skilled professionals to prepare the computational grid, and also the lack of validation that makes the invested effort questionable. In this paper, we propose a porous layer method to model the hydraulic resistance (HR) of one or several layers of the FDs. The basis of this proposal is twofold: first, from an application point of view, the only interesting parameter regarding the function of the FD is its HR; second, we have developed a method to measure the HR with a simple apparatus. We present the results of these measurements and demonstrate their utility in numerical simulations of patient-specific aneurysm simulations.
Silicon Carbide Junction Transistors and Schottky Rectifiers optimized for 250°C operation
Authors: Sundaresan Siddarth , Grummel Brian , Singh Ranbir
Published: June 2014

Electrical performance and reliability of SiC Junction Transistors (SJTs) and Schottky rectifiers are presented. The 650 V/50 A-rated SiC SJTs feature current gains (β) up to 110 at room-temperature, 70 at 250°C, and stable breakdown characteristics. Single current pulse measurements indicate an almost invariant β up to 800 A/cm2 at 175°C – a measure of the SOA boundary for pulsed current SJT operation. Lower than 5 mA/cm2 leakage currents are measured on the SJTs at the rated blocking voltage and at 250°C. 1200 V Schottky rectifiers designed for high-temperature operation display < 3 mA/cm2 leakage currents up to 250°C. A 10x reduction in leakage current and 23% reduction in junction capacitance are observed when compared to the nearest competitor. The high-temperature Schottky rectifiers and SJTs display stable breakdown voltages and on-state characteristics after long-term HTRB stressing. A significant improvement in current gain stability is achieved by fine-tuning the fabrication process.
Fabrication of Transparent Electrodes with Silver Nanowires and PPT Gel for Organic Optoelectronic Devices
Authors: Tsai Ming-Chih , Chen Yu-Hsuan , Ho Yu-Hsuan , Yang Shang-Jung , Wei Pei-Kuen
Published: June 2014

We have developed a low cost and convenient approach to fabricate ITO-comparable transparent electrodes by using solution process of silver nanowires mixed with poly peroxotitanic acid (PPT) gel. The PPT gel is applied to connect the dispersed silver nanowires to preserve its high conductivity while remaining transparency and reducing surface roughness of the transparent electrode. The silver nanowires were synthesized via a modified polyol method, and the PPT gels were prepared by sol-gel method in appropriate concentrations. After applying the PPT gels, the sheet resistance of the transparent electrodes was improved from 192 Ω/□ to 44.7 Ω/□ with a transmittance of 81 %. And the roughness (RMS) was decreased from 106.3 nm to 48.1 nm. The PPT gel also improved the reliability of the proposed electrodes, which the conductivity was remained after general atmospheric storage of 6 months. We also demonstrate an Alq3 based OLED with the proposed transparent electrodes.
Degradation Mechanisms in Ferroelectric and High-Permittivity Perovskites
Authors: Warren William L. , Dimos Duane , Waser Rainer M.
Published: June 2014

Due to the importance of ferroelectric and high-permittivity perovskite thin films for a wide range of applications, there has been extensive research devoted to understanding the mechanisms responsible for the degradation observed with time, temperature, and/or external field stress. The three most important degradation phenomena for ferroelectric materials such as Pb(Zr, Ti)O3 (PZT) and BaTiO3 are ferroelectric fatigue, ferro-electric aging, and resistance degradation. Ferroelectric fatigue is the loss of switchable polarization by repeated polarization reversals. Ferroelectric aging is characterized by a spontaneous change with time in the polarization-voltage (P-V) response. Resistance degradation is a deterioration of the insulating properties of a dielectric under direct-current (dc) bias and elevated temperature.

These degradation processes ultimately limit the lifetime and reliability of devices that use ferroelectric and high-permittivity perovskite dielectrics. Fatigue and aging lead to reliability concerns for electronic (nonvolatile memories), piezo-electric, electro-optic, and pyroelectric applications. Likewise resistance degradation typically limits the lifetime of ceramic capacitors and high-dielectric constant thin films such as (Ba, Sr)TiO3, which is the principal candidate material for very high-density dynamic random-access memories (DRAMs).

Because of the importance of these degradation processes, it is critical to understand them and to develop methods of eliminating or mitigating their effects. By combining results from studies on thin films with ones on ceramics and single crystals, a consistent picture of the mechanisms involved in these degradation processes is emerging. In this article, we discuss these degradation mechanisms with particular emphasis on the interaction between ferroelectric domains and charge trapping and the role of oxygen vacancies and associated defect dipoles.
Seizure Prognosis in Brain Tumors: New Insights and Evidence-Based Management
Authors: Vecht Charles J. , Kerkhof Melissa , Duran-Pena Alberto
Published: June 2014

Brain tumor-related epilepsy (BTE) is common in low- and high-grade gliomas. The risk of seizures varies between 60% and 100% among low-grade gliomas and between 40% and 60% in glioblastomas. The presence of seizures in patients with brain tumors implies favorable and unfavorable factors. New-onset seizures represent an early warning sign for the presence of a brain tumor and count as a good prognostic factor for survival. Recurrence or worsening of seizures during the course of disease may signal tumor progression. Each of the modalities for tumor control (i.e., surgery, radiotherapy, chemotherapy) contributes to seizure control. Nevertheless, one third of BTE shows pharmacoresistance to antiepileptic drugs (AEDs) and may severely impair the burden of living with a brain tumor. For symptomatic therapy of BTE, seizure type and individual patient factors determine the appropriate AED. Randomized controlled trials in partial epilepsy in adults to which type BTE belongs and additional studies in gliomas indicate that levetiracetam is the agent of choice, followed by valproic acid (VPA). In the case of recurring seizures, combining these two drugs (polytherapy) seems effective and possibly synergistic. If either one is not effective or not well tolerated, lacosamide, lamotrigine, or zonisamide are additional options. A new and exciting insight is the potential contribution of VPA to prolonged survival, particularly in glioblastomas. A practice guideline on symptomatic medical management including dose schedules of AEDs is supplied.
Prediction of stone column ultimate bearing capacity using expansion cavity model
Authors: Frikha Wissem , Bouassida Mounir
Published: June 2014

The ultimate bearing capacity of an isolated column was investigated by combining a state of stress with a failure mechanism of lateral expansion in a cylindrical cavity which reproduces the stone column installation in a purely cohesive soft soil. Some analytical and empirical methods were used to determine the limit pressure of a cylindrical cavity with the assumption of varied behaviour laws of the medium around the cavity. These models permitted the calculation of the limit pressure of an expanded cylindrical cavity from which the ultimate bearing capacity was derived. Using recorded in situ data from load tests performed on 13 isolated column configurations, the model parameters are identified. A comparison between experimental data and predictions generated from several models is presented.
Intelligent Distributed Acoustic Sensing for In-well Monitoring
Authors: Xiao J. J. , Farhadiroushan M. , Clarke A. , Abdalmohsen R. A. , Alyan E. , Parker T. R. , Shawash J. , Milne H. C.
Published: June 2014

Interval Control Valves ICVs and Inflow Control Devices ICDs can enable optimization of the production and injection profile along the wellbore. The ICV devices are operated to increase the hydrocarbon recovery and prevent unwanted fluid production. The ICDs are selected and positioned to optimize the water flood profile. Although the operations of devices are well understood, the optimization of these devices in-situ is complex. The real-time monitoring of fluid flow along the wellbore can provide valuable information to set the position of the inflow devices and optimize the fluid flow in multilateral zones.

The intelligent Distributed Acoustic Sensor (iDAS) uniquely allows the simultaneous recording of acoustic energy along many kilometers of optical fiber deployed along the wellbore. The system uses a novel digital optoelectronics detection technique that captures the amplitude and phase of the acoustic waves generated and propagated along the wellbore over a wide frequency (1mHz – 100kHz) range with a high dynamic range (>120dB). A number of signal processing techniques have been developed for processing a large array of acoustic data that can be recorded along the wellbore for monitoring the inflow at different zones. The iDAS system can be used with single-mode as well as multimode optical fibers.

The iDAS system was retrofitted to existing optical fibers that were already installed along several wells in Saudi Arabia. The acoustic noise energy generated across the inflow devices and propagating along the wellbore tubing was recorded. The acoustic noise spectrum can be used to monitor the fluid flow through the inflow devices. Using array processing, the speed of sound can be determined over several sections of the tubing to identify the fluid composition.

This paper reports on the results of the field trial carried in 2012 in several wells equipped with inflow devices.
Application of Neural Network to Predict Gas Well Performance During Two-Phase Flow in Gas Condensate Reservoirs
Authors: Al-Dhamen Mohammed A.
Published: June 2014

In this study, field data from Saudi Arabian gas condensate reservoirs were used to develop Artificial Neural Network (ANN) model to estimate gas rate from wells having Condensate to Gas Ratio (CGR) ranging from 10 to 400 STB/MMSCF. This model can predict gas rates for both critical and subcritical flow regimes. This paper will discuss the advantages of this new model as well as the limitations of utilizing this model in predicting the gas rate.

Most of the choke correlations estimate gas rates with high accuracy in dry gas environment or in reservoirs with low CGR. There are some correlations built to estimate the rates for multiphase flow; however, there is no unique correlation that works for wide range of CGR values with acceptable accuracy. Also, there are two sets of correlations were built for critical flow regime and for subcritical flow.

The ANN model was developed based on analyzing more than 6,000 data points collected from separator tests. These data were used as follows: 70% for training, 15% for validation, and 15% for testing. The data covers wide range of flow rates, choke sizes, and CGR values. The models were built as function of choke sizes, upstream & downstream pressures, and CGR. Graphical and statistical tools have been used to evaluate and validate the ANN models.

In conclusion, the new ANN model applies novel techniques and wide range of field data and predicts the gas rate for high CGR wells with an average absolute error of 10.2 %. These models will be used to forecast and evaluate performances of gas reservoirs and will minimize utilizing the costly separator tests normally required high CGR wells.
Anisotropy Effect in Geosteering: Anisotropy and D2B Estimate from Directional Resistivity Tool
Authors: Hagiwara Teruhiko , Anguiano-Rojas Pedro
Published: June 2014

We examined the tool response of coaxial tool in a layered isotropic earth model, and provide methods to determine the distance to bed and the resistivity of the bed beyond the boundary from a set of tool responses. We also examined the tool response of a directional resistivity tool with tilted transmitter/receiver antenna(s) in a layered isotropic earth model. The difference between the downward receiver response and upward receiver response can be used as interface indicators. We provide methods using the interface indicators to simultaneously determine the distance to bed and the resistivity of the bed beyond the boundary.

We examined the effect of layer anisotropy in the distance to the boundary (D2B) and resistivity determination by modeling responses of a coaxial tool and a directional resistivity tool in layered anisotropic earth models.

When the tool is in an anisotropic layer such as shale, the anisotropy of the layer significantly affects the tool response and the D2B estimate has to be corrected for the anisotropy. When the tool is in an isotropic layer, the anisotropy of an adjacent layer will affect the tool response less. However, the anisotropy effect gets larger when the adjacent anisotropic layer is less resistive. The effect of anisotropy has to be corrected only at the short distance from the boundary. Based on the modeling results, we propose a method to account for the anisotropy effect and correctly estimate the D2B and resistivity beyond the boundary.
Integrated Modeling for Better Reservoir Management: A Case Study from a Large Carbonate Middle East Reservoir
Authors: Shammari B. A. , Putra S. A. , Nooruddin H. A. , Bellaci I. J. , Shammari A. T.
Published: June 2014

This paper presents a workflow developed to integrate subsurface and surface network models for a huge carbonate oil reservoir overlain by a large gas-cap located in the Middle East region. The integrated model consists of separate standalone models connected through commercial software. The reservoir simulation model is compositional with nine-components and over 60 million-very-refined grid-cells. The reservoir simulation model runs on a state-of-the-art in-house simulator; GigaPOWERS. The surface production network model consists of five production networks in addition to a gas injection network, with detailed network and elevation profiles, to model the desert terrain found in the field. The surface network model implements compositional components — as in the reservoir simulation model to capture compositional variations — to evaluate the NGL recovery processes and lean gas injection options. The detailed elevation profiles of the desert terrain in the surface network model allow for an accurate evaluation of the fluid velocities in the pipelines. It also provides a back pressure profile for each and every well in the network. The integration of the reservoir simulation and surface network models helped in assessing the reservoir and well production strategies and their impact on the production facilities, such as the early detection of low velocity in the pipelines that could eventually reduce the potential of corrosion due to this factor, and avoiding producing at high GOR levels to prevent reaching or exceeding erosional velocity limits. The integrated modeling therefore allows for simultaneous reservoir management and surface production facility planning.
Sweet Spot Identification and Optimum Well Planning: An Integrated Workflow to Improve the Sweep in a Sector of Giant Carbonate Mature Oil Reservoir
Authors: Al-Sada Abdullah I. , Bouaouaja Mohammed T. , Al-Hhuthali Ahmed H. , Al-Safi Abdullah A.
Published: June 2014

This study illustrates a comprehensive-integrated approach to identify the potential locations for future development in a sector area of a giant carbonate mature oil reservoir. The approach uses various data from several sources including reservoir surveillance, production performance, geological interpretation and numerical simulation and cohesively combines them to yield an informed decision to assess field development and management. The study area is under peripheral waterflood for more than fifty years and dominated by heterogeneity related to fracture corridors, high permeable zone, and reservoir zonation. These features leads to a preferential and uneven propagation of water flow which results in un-swept oil bearing spots using the existing wells lay-out and configuration.

The reservoir management team has developed an integrated workflow to address these challenges by using several reservoir engineering methods and models including Water Encroachment, Reservoir Opportunity index, Fractional Flow Calculation, Remaining Volumetric and Water Flow Paths. The designed workflow consists of creating derived attributes that describe these models and filter the sector area to define the sweet spots. The selection and prioritization of the defined sweet spots are supported by available reservoir surveillance and production data. However, the scarcity of reservoir surveillance and production data in some areas of the sector, motivated reservoir management team to stretch the limits by capitalizing on gas wells penetrating the shallower oil reservoirs. The open-hole logs of these wells recorded thicker oil column than the preestimated column using the existing surveillance data.

As a result of these efforts, a development plan was designed in order to ensure reserves depletion in the identified sweet spots by drilling new wells or sidetracking the existing wells. Despite the level of maturity, simulation forecasts indicate that the area of interest has lot of potential to sustain a high production rate.
Data Assimilation of InSAR Measurements for Large Scale Reservoirs
Authors: Katterbauer Klemens , Hoteit Ibrahim , Sun Shuyu
Published: June 2014

Optimizing and enhancing oil recovery is a key focus for the oil and gas industry. For economic success, good reservoir formation knowledge is important to optimize oil & gas extraction over the course of production time. Reservoir history matching plays a crucial role in the incorporation of production and logging data for efficiently forecasting the development of reservoirs and its depletion. While production and logging data have been readily incorporated, sparse spatial sampling of these data may yield insufficient information about the formation structure to accurately history match for large reservoirs such as Ghawar. InSAR (Interferometric Synthetic Aperture Radar) has revolutionized the way to measure the Earth's surface deformation and has been successfully and economically utilized for studying large surface deformation caused by hydrocarbon extraction (such as commercialized by Halliburton). Surface displacement is primarily caused by changes in the pressure level within the subsurface reservoirs that lead to an up-or downlift of the subsurface. With fluids travelling from high into low pressure environments, InSAR measurements can be used to forecast fluid displacements. We have developed an InSAR based history matching framework for oil & gas reservoirs that efficiently incorporates InSAR data for improved reservoir management and forecasts. Our numerical results suggest that InSAR data provide important information about the reservoir state which can be exploited to enhance the forecasting for large scale reservoirs.
Shale Gas Field: Exploration, Exploitation and Development Strategies Globally
Authors: Saleem Waleed Anwar , Baber Shahzaib , Jafri Muhammad Osama
Published: June 2014

Shale gas is natural gas that is found trapped within shale formations. Shale gas has become an increasingly important source of natural gas in the United States since the start of this century, and interest has spread to potential gas shales in the rest of the world. In 2000 shale gas provided only 1% of U.S. natural gas production; by 2010 it was over 20% and the U.S. government's Energy Information Administration predicts that by 2035, 46% of the United States' natural gas supply will come from shale gas. Some analysts expect that shale gas will greatly expand worldwide energy supply. China is estimated to have the world's largest shale gas reserves.. This paper covers a detailed study on the following topics: Shale Exploration Strategies and Techniques○3D Seismic SurveyShale Gas Monitoring Techniques○Micro-Seismic and 4D Seismic SurveyShale Gas Exploitation Techniques○Multi-Stage Hydraulic FracturingShale Gas Field Development Strategies

This paper also discusses different shale gas case studies which include seismic techniques, well log analysis, reserve estimations techniques, hydraulic fracturing techniques, production optimization and simulation. The objective of this paper is to give an understanding and insight of shale gas reservoirs.
A Streamlined Process to Track Field Operations through Management Operations Dashboard
Authors: Al-Buraik M. , Al-Naim H. , Alakeely A.
Published: June 2014

The rig operations and drilling activities around the Kingdom have drastically increased over the past few years. Tracking such operations tends to be an extremely complicated process. Furthermore, providing executive management with manual status update reports of the different jobs proves to be a time consuming and laborious task. Such executive summary reports involve collecting information from different sources, which becomes a full time daily job for the engineers, taking into account the size of the operation. With all these challenges, a solution was proposed to develop a streamlined approach to automate such a process. This solution was designed and implemented to be a one stop shop for all logging and well testing operation activities. The solution integrates data from different sources and provides the engineers with all the required information to kick-start the analysis.

This Management Operations Dashboard (MOD) enriches the decision making process by providing Upstream management with a high level, multilateral status overview of the operations, in a timely manner through a GIS enabled interface. It also automates the process of generating and distributing executive summary reports to higher management, allowing engineers to focus on analysis and setting strategies.

The paper discusses and shares major insights from the completed project and highlights the main incorporated features. It also outlines the MOD's workflow to prepare and send summarized operation reports.
Successful Inorganic Scaling Prediction in Early Conceptual Design Phase: Gas Field Development Experience
Authors: Nengkoda Ardian , Birkle Peter , Harbi Bader , Mufleh Jamal , Awwami Mofeed , Duailej Yasser , Khaldi Mohammed , Cai Xiaolong , Haas Michael , Alharith Ibrahim
Published: June 2014

The early stage in conceptual engineering design of a gas field development comprises an assessment study to evaluate the potential occurrence of inorganic scale within the upstream and downstream production system. Strategies for water treatment and water disposal are developed to avoid injectivity loss by scale generation. The contribution of drilling fluids or brine contaminants difficult the recovery of representative condensed water and formation water samples from HP/HT gas production wells and water disposal wells. The present study integrates bottom hole water sampling, well testing and geochemistry to predict future potential inorganic scaling during gas field development. A bottom hole water sample shows TDS concentration of 63,199 mg/l, a Cl-Na-Ca water type with slightly enriched trace elemental concentrations (Sr=40 mg/L, Ba=7 mg/L, Fe=2.8 mg/L) and neutral pH conditions (6.8). In contrast, K (1,340 mg/L) and Mg (1,126 mg/L) are relatively abundant in comparison to standard formation water concentrations across the formation, suggesting a mixing contribution with contaminant fluid. Representative formation water is characterized by a hypersaline brine composition with extremely high TDS abundance (231,000-297,000 mg/L). Various predicting scenarios for the scaling of self inorganic and water mixing scale were modeled and laboratory static testing were conducted. As a conclusion, all waters were compatible at pH range of 6.5-9.5 with different mixing ratios. No self-scaling was observed up to 140°F. A benchmarking to a nearby gas field and wells, being under production for about 2 years, also concur similar result. The study has successfully confirmed an optimum approach for scaling management during the initial phase of field design.
Simulation of Single Well Tracer Tests for Surfactant-Polymer Flooding
Authors: Bu Peter X. , AlSofi Abdulkareem M. , Liu Jim , Benedek Lajos , Han Ming
Published: June 2014

A single well tracer test (SWTT) is a method to investigate the residual oil saturation near the wellbore. It presents an important tool to evaluate enhanced oil recovery (EOR) processes. For EOR evaluation, two SWTTs (one before and another after EOR application) can be used to estimate the reduction in Sor due to the application of an EOR process. The change in Sor is a measure of the incremental oil recovery of the applied EOR technology.

In this work, we use University of Texas Chemical Flooding Simulator (UTCHEM) to guide the design of SWTTs that will be later run to evaluate chemical flooding potential. Firstly, we perform thorough sensitivity simulations using an idealistic homogeneous model. Secondly, we perform simulations using a realistic model, which was generated based on the selected evaluation well (Well-X).

In the sensitivity runs, we investigate the effects of various parameters such as partitioning coefficients, reaction rates, injection rates, injection volumes, and shut-in times. Based on the results, we provide recommendations for designing the SWTTs. Furthermore, simulations using the Well-X model suggest an incremental oil recovery factor of 14.7% OOIP due to surfactant-polymer flooding. This is consistent with lab data and provides assurance to multi-well field applications. More importantly, those simulation results support the utility of SWTTs in evaluating chemical flooding potential. Based on the results, we expect to observe distinct back-production peaks, clear separation between the reactive and product tracers, and measurable variation in separation due to chemical EOR application that can be categorically analyzed.
Unconventional Flare Gas Recovery Systems (FGRS)
Authors: Salu Samusideen A. , Soliman Mohamed , Ansari Nisar Ahmad
Published: June 2014

This paper presents unconventional flare gas recovery schemes that do not include gas compressors to collect the routine daily flared gas, to send it back to the process plant. The innovative recovery systems will provide significant capital and operating cost savings by eliminating the installation and operation of gas compressor(s) as part of conventional FGRS. Two different FGRS schemes without gas compressors were established, using only static equipment for the flared gas recovery. The first scheme involves providing carefully sized pipe to flow-back the collected flare gas to the plant at the required pressure. This scheme requires careful hydraulic simulation for the entire flare system network, to ensure that the recovery system will not have any negative impact on the relief and flare systems — thereby jeopardizing the safety of the entire plant — and at the same time ensure flow from the location of the flare line to the recovered gas destination. The second scheme includes the use of a gas ejector with high pressure motive gas to boost low pressure flare gas to the intermediate pressure required to deliver the gas back to the process. The case study — of applying the established unconventional flare gas recovery system at Saudi Aramco's Qatif North Plant, to continuously recover about 5MMscfd of valuable fuel gas, which is equivalent to 5,051 MMBtu/day in fuel energy savings — was presented. The proposed FGRS schemes will minimize greenhouse gas emissions and provide positive environmental benefits.
A methodology for quantifying global consumptive water use of coffee for sustainable production under conditions of climate change
Authors: Eriyagama Nishadi , Chemin Yann , Alankara Ranjith
Published: June 2014

Coffee is the second most traded commodity in the world after oil. A sustainable coffee industry is crucial to maintaining global agriculture, trade, human and environmental well-being, and livelihoods. With increasing water scarcity and a changing climate, understanding and quantifying the risks associated with water, a primary input in coffee production, is vital. This methodological paper examines the means of quantifying: (a) ‘current’ consumptive water use (CWU) of green coffee (coffee beans at harvest time) globally; (b) coffee ‘hot spots’ and ‘bright spots’ with respect to levels of CWU, yields and water stress; and (c) possible impacts of climate change on the CWU of coffee. The methodology employs satellite-derived monthly evapotranspiration data and climate projections from two global circulation models for three future scenarios. Initial estimates suggest that currently (on average) 18.9 m3/kg of water is consumed in producing one unit of green coffee. The same estimate for irrigated coffee is 8.6 m3/kg, while that for rain fed coffee is 19.6 m3/kg. Climate scenarios show that effective mean annual rainfall in many major coffee areas may decrease by the 2050s. The generic methodology presented here may be applied to other crops, too, if crop data are available.
Effects of changes in climatic variables on maize crop water requirements in Huang–Huai–Hai watersheds, China
Authors: Mou Xinli , Xia Xinghui , Gong Daoyi , Liu Qiang , Wu Qiong , Guo Jia
Published: June 2014

The study of crop water requirements (CWR) under climate change is critical for reasonable crop irrigation. In the present study, the effects of changes in climatic variables from 1961 to 2010 on maize CWR in Huang–Huai–Hai (HHH) watersheds in China were investigated. Five daily climatic factors including maximum temperature (Tmax), minimum temperature (Tmin), wind speed (u2), sunshine hours (nsun), and relative humidity (RH) from 121 weather stations during the maize growing season were studied. The Penman–Monteith method was employed to calculate crop evapotranspiration (ETc), and the spatiotemporal distribution characteristics of ETc and climatic factors were investigated via singular value decomposition. Results showed that the ETc of spring maize slightly increased by 0.4% during the past 50 years, which was primarily caused by the increase in Tmax. The ETc of summer maize decreased by 10.5%, which was primarily caused by the decrease in nsun and u2. Overall, the ETc followed the same spatiotemporal change trend as those of Tmax, nsun, and u2 in the HHH, whereas no coexisting spatiotemporal change between ETc and RH, as well as Tmin, was observed. This result suggests that changes in Tmax, nsun, and u2 are the main climatic factors that influence maize CWR in the HHH.
Climate change impact chains in the water sector: observations from projects on the East India coast
Authors: Kabisch Sibylle , Chakrabarti Ronjon , Wolf Till , Kiewitt Wilhelm , Gorman Ty , Chaturvedi Ashish , Arora Rachna
Published: June 2014

With regional variations, climate change has a significant impact on water quality deterioration and scarcity, which are serious challenges in developing countries and emerging economies. Often, effective projects to improve water management in the light of climate change are difficult to develop because of the complex interrelations between direct and indirect climate impacts and local perceptions of vulnerabilities and needs. Adaptation projects can be developed through a combination of participatory, bottom-up needs assessments and top-down analyses. Climate change impact chains can help to display the causal chain of climate signals and resulting impacts and thereby establish a system map as a basis for stakeholder discussions. This article aims to develop specific climate change impact chains for the water management sector in rural coastal India that combine bottom-up and top-down perspectives. Case studies from Tamil Nadu and Andhra Pradesh, India, provide a basis for the impact chains developed. Bottom-up data were gathered through a vulnerability and needs assessment in 18 villages complemented with top-down research data. The article is divided into four steps: (1) system of interest; (2) data on climate change signals; (3) climate change impacts based on top-down as well as bottom-up information; (4) specific impact chains complemented by initial climate change adaptation options.
Receptivity to sustainable urban water management in the South West Pacific
Authors: Poustie M. S. , Brown R. R. , Deletic A.
Published: June 2014

Small urban centres in the South West Pacific face many challenges regarding urban water management in the light of future uncertainties and climate change. Without implementing sustainable urban water management (SUWM), they risk adverse environmental and public health impacts, but little is known regarding the receptivity of urban water professionals towards its principles and practices. This paper assesses the willingness and ability of urban water managers from the region to implement SUWM. Results demonstrate that whilst aware of current failures, there was limited awareness of sustainable solutions, and a limited ability to identify benefits arising from SUWM implementation. There is a need to increase the opportunities for urban water professionals in the region to acquire skills and implement SUWM. This study identifies the capacity development needed in the region to increase receptivity to SUWM.
Decision support for ecological river rehabilitation using fish habitat database
Authors: Jung J. H. , Park J. Y. , Lim H. M. , Yoon Y. H. , Kim W. J.
Published: June 2014

After the recent success of several river rehabilitation projects including the Cheong-gye river case, a large number of local governments have been promoting their own projects in Korea. Most of the projects are aimed at securing the soundness of aquatic ecosystems according to the guidelines presented by the Korea Ministry of Environment. However, there is no clear guidance for the management goals of water quality and quantity. In this study, we have made an attempt to construct a habitat database (DB) for each domestic freshwater fish species. The fish population, and physical and physicochemical properties of the habitat of 70 domestic freshwater fish species were investigated using field monitoring data. After the statistical processing, the inhabitable range and optimal range of each species were suggested. Furthermore, based on the DB, a decision support system for ecological river restoration and rehabilitation has been developed, and applied for field tests. It became clear that the decision support procedure based on the fish habitat DB is useful in the planning stage of river rehabilitation projects to select the flagship fish, to decide the restoration goals considering their appropriate habitat and to suggest the optimum quantitative combination of each available water resource.
Kinetic studies of Cd (II) and Pb (II) ions biosorption from aqueous media using untreated and chemically treated biosorbents
Authors: Bakyayita G. K. , Norrström A. C. , Nalubega M. , Kulabako R. N.
Published: June 2014

Untreated and chemically treated Albizia coriaria, Erythrina abyssinica and Musa spp. were studied in batch for uptake of Cd2+ and Pb2+ ions at pH 2.0–9.0 and agitation time of 30–390 min. Optimum biosorption conditions were pH 4 for Pb2+ ions and pH 5 for Cd2+ ions, contact time was 3.5 hours at 24 ± 1 °C for 10 mg/L biosorbent dosage and initial metal ions concentration of 20 mg/L. Chemical treatment had a 10–17% biosorption efficiency enhancement for Cd2+ ions and a 1.6–2.3% reduction effect for Pb2+ ions. The sorption capacities for Cd2+ and Pb2+ ions for treated biosorbents were 1.760–1.738 mg g−1 compared to 1.415–1.539 mg g−1 for untreated materials. The pseudo second-order model suitably fitted the Cd2+ and Pb2+ ions biosorption data with regression coefficients (R2) of 0.9784–0.9999. Fitting of the Ho model to the experimental data showed that the biosorption mechanism for both metal ions studied was mainly a chemisorption process. Therefore, treated A. coriaria, E. abyssinica and Musa spp. were potential biosorbents for remediation of Cd2+ ions and the untreated materials suitable for removing Pb2+ ions from contaminated aqueous media.
Use of flocculants for increasing permeate flux in anaerobic membrane bioreactors
Authors: Díaz H. , Azócar L. , Torres A. , Lopes S. I. C. , Jeison D.
Published: June 2014

Biomass retention, required for high rate anaerobic wastewater treatment, can be accomplished coupling an anaerobic bioreactor with membrane filtration. However, low flux seems to be a common factor when operating anaerobic membrane bioreactors (AnMBRs). Modification of biomass properties may represent a strategy for improving membrane flux. The addition of flocculants was tested as a tool for flux increase. Six different products were tested in dead-end filtration experiments. Based on the results, two products were selected for cross-flow tests. The one presenting better performance (Nalco MPE50) was tested in a laboratory-scale continuous AnMBR. Results show that the flocculant was able to substantially increase flux. Indeed, the flux-increasing effect was observed for several weeks after flocculant addition. Therefore, the use of flocculants seems to be an interesting tool to cope with temporary increases in required flux.
Performance of aerobic granular sludge at variable circulation rate in anaerobic–aerobic conditions
Authors: Harun Hasnida , Anuar Aznah Nor , Ujang Zaini , Rosman Noor Hasyimah , Othman Inawati
Published: June 2014

Aerobic granular sludge (AGS) has been applied to treat a broad range of industrial and municipal wastewater. AGS can be developed in a sequencing batch reactor (SBR) with alternating anaerobic–aerobic conditions. To provide anaerobic conditions, the mixed liquor is allowed to circulate in the reactor without air supply. The circulation flow rate of mixed liquor in anaerobic condition is the most important parameter of operation in the anaerobic-AGS processes. Therefore, this study investigates the effect of circulation rate on the performance of the SBR with AGS. Two identical reactors namely R1 and R2 were operated using fermented soy sauce wastewater at circulation rate of 14.4 and 36.0 l/h, respectively. During the anaerobic conditions, the wastewater was pumped out from the upper part of the reactor and circulated back into the bottom of the reactor for 230 min. A compact and dense AGS was observed in both reactors with a similar diameter of 2.0 mm in average, although different circulation rates were adopted. The best reactor performance was achieved in R2 with chemical oxygen demand removal rate of 89%, 90% total phosphorus removal, 79% ammonia removal, 10.1 g/l of mixed liquor suspended solids and a sludge volume index of 25 ml/g.
Kinetics of the atrazine degradation process using H2O2-UVC
Authors: Sarmento Sandra M. , Miranda José T. G.
Published: June 2014

This work is concerned with the intrinsic reaction kinetic of the degradation of atrazine (ATZ) using H2O2-UVC. Experimental runs were carried out in annular photoreactor. The initial concentration of ATZ was 2.2 × 10−2 mol m−3 while the H2O2-ATZ molar ratio range was 0–578 mol H2O2 mol−1 ATZ. The ATZ molecules are decomposed by means of free-radical attack (95.2%) and direct photolysis (4.8%). There is an optimal H2O2/ATZ molar ratio (ROP = 347 H2O2 mol−1 ATZ) which maximizes the initial degradation rate and conversion at 300 s at 83% and 77%, respectively. The process is economically feasible as the values of the energy requirement, energy and H2O2 costs at ROP are 0.14 KWh m−3 order−1, US$0.02 kWh−1 m−3 and US$1.0 m−3, respectively. The kinetic model proposed is based on Lea's reaction scheme for the H2O2 direct photolysis, the hypothesis that unknown ATZ sub-products that absorb UVC radiation are generated, and the local volumetric rate of photon absorption. The radiation transport equation was solved and the linear spherical source emission model was used to represent the lamp emission. Intrinsic reaction kinetic parameters were estimated and the model was validated. The model predicted the data in a range of 90 to 98%.
A modified anaerobic digestion process with chemical sludge pre-treatment and its modelling
Authors: Hai N. M. , Sakamoto S. , Le V. C. , Kim H. S. , Goel R. , Terashima M. , Yasui H.
Published: June 2014

Activated Sludge Models (ASMs) assume an unbiodegradable organic particulate fraction in the activated sludge, which is derived from the decay of active microorganisms in the sludge and/or introduced from wastewater. In this study, a seasonal change of such activated sludge constituents in a municipal wastewater treatment plant was monitored for 1.5 years. The chemical oxygen demand ratio of the unbiodegradable particulates to the sludge showed a sinusoidal pattern ranging from 40 to 65% along with the change of water temperature in the plant that affected the decay rate. The biogas production in a laboratory-scale anaerobic digestion (AD) process was also affected by the unbiodegradable fraction in the activated sludge fed. Based on the results a chemical pre-treatment using H2O2 was conducted on the digestate to convert the unbiodegradable fraction to a biodegradable one. Once the pre-treated digestate was returned to the digester, the methane conversion increased up to 80% which was about 2.4 times as much as that of the conventional AD process, whilst 96% of volatile solids in the activated sludge was digested. From the experiment, the additional route of the organic conversion processes for the inert fraction at the pre-treatment stage was modelled on the ASM platform with reasonable simulation accuracy.
Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE)
Authors: Chang Y. C. , Huang S. C. , Chen K. F.
Published: June 2014

In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.