bluuebunny/crossref_metadata_2025 huggingface dataset:
Maturing a CO2-EOR Opportunity from Initial Screening to Field Testing - A Case Study
Authors: Samad Abdul , Al Ahmed Arwa , Al-Dayyni Taha , Kalam Zubair
Published: July 2013

Immiscible WAG (IWAG) processes, although proven quite useful in maintaining pressure in low permeability reservoirs, has the inherent drawback of leaving high residual oil saturation (Sor) behind the flood front. Often, dependent on the reservoir characteristics, the oil volume which is left behind by a secondary IWAG process can be of significant value and requires investigating tertiary EOR processes that could economically produce it. This case study discusses the approach taken to mature an EOR opportunity in a giant onshore carbonate reservoir currently being developed with IWAG injection.

A plan was put in place to assess the suitability of prospective EOR processes in the subject reservoir. This commenced with a detailed PVT lab study which involved specially designed EOR tests such as swelling, slimtube, forward contact, backward contact, equiphase and asphaltene deposition. The experimental data was used to develop an equation of state model (EOS) that is able to describe the reservoir fluid behavior. Next, analytical methods were used to screen out the EOR processes found most promising. The EOR processes were screened based on the performance indicators estimated using classical reservoir engineering techniques, empirical methods, experience and judgment. The favourable results for the CO2 injection, both from the PVT experiments and the analytical screening led to the design of 1D coreflood experiments on composite cores at full reservoir conditions.

Comparison of the different displacement tests showed CO2-WAG to be highly efficient recovery mechanism with 93% of the HCPV recovery potential. The PVT experiments and the coreflood injection tests, within their experimental limitations provided recovery profiles and CO2 injection characteristics to validate model predictions on a microscopic scale, and thus enhanced confidence in full field development studies based on the underlying reservoir simulation models. The proposed CO2-EOR strategy will help reduce the Sor significantly and hence improve Ultimate Recovery (UR). A field pilot is being considered to evaluate the CO2 injection recovery process optimally.
Fitting Foam Simulation Model Parameters for SAG Foam Applications
Authors: Rossen W. R. , Boeije C. S.
Published: July 2013

Foam improves sweep in miscible and immiscible gas-injection EOR processes. "SAG" foam processes (injecting alternating slugs of surfactant solution and gas) offer many advantages over co-injection of foam for both operational and sweep-efficiency reasons.  The success of a foam SAG process depends on foam behavior at very low injected water fraction (high foam quality), which means that fitting data to a typical scan of foam behavior as a function of foam quality can miss conditions that determine the success of a SAG process.  The result can be inaccurate scale-up of results to field application. A successful SAG foam process depends on behavior at very low fractional flow during gas injection and on behavior at larger water fractional flow further from the well where gas and surfactant slugs mix.

We illustrate how to fit foam-model parameters to steady-state foam data for application to SAG foam processes.  Dynamic SAG corefloods can be unreliable because of failure to reach local steady state  (because of slow foam generation), the increased effect of dispersion at the core scale, and the capillary end effect.  For current foam models the behavior of foam in SAG depends on the mobility of full-strength foam, the capillary pressure or water saturation at which foam collapses and the parameter governing the abruptness of this collapse.  We illustrate how to fit these model parameters to coreflood data, and the challenges that can arise in the fitting process, using the published foam data of Persoff et al. (1991) and Ma et al. (2012). For illustration we use the foam model in the widely used STARS simulator. Having accurate water-saturation data is essential to making a reliable fit to the data.  Model fits to a given experiment may result in inaccurate extrapolation to mobility at the wellbore and therefore predicted injectivity: for instance, a model fit in which foam does not collapse even at the extremely large capillary pressure at the wellbore.

We show how the insights of fractional-flow theory can guide the model-fitting process and give quick estimates of foam propagation rate, mobility and injectivity at the field scale.
The Use of Modeling and Monitoring to Control Scale in Alberta ASP Floods
Authors: Hunter Kate , McInnis Lee , Ellis-Toddington Tyler , Kerr Scot
Published: July 2013

Two commercial Alkali Surfactant Polymer (ASP) floods became operational in the Taber area of Alberta, Canada in 2006 and 2008. Both of these floods used NaOH as the Alkali. Throughout the course of both projects extreme scale deposition was observed in downhole production equipment, gathering systems, and in the production facility.  Early in the life of the floods the scale composition was predominantly calcium carbonate, however over time the scale changed to consist of greater amounts of amorphous silicate.

Scale inhibition and remediation strategies have been developed which include a comprehensive monitoring program, chemical scale inhibition, and mechanical scale prevention techniques. As a result of the large amount of data gathered, models were created to predict scale severity, content, and develop specific mitigation plans. Although clear field wide scaling trends can be identified over the life of these projects, scale mitigation strategies still need to be customized for each well.

Although scale remains an operational challenge in these fields, with proper mitigation procedures it can be managed. This report documents the success in reducing the impact of the scale problem and slowing the depositional rate. When designing ASP floods it is important to plan for scale deposition and be proactive on scale mitigation.
The Role of Advanced Well Architecture in Cost Efficient Offshore EOR Field Redevelopment
Authors: Chan Keng Seng , Chong Danny , Masoudi Rahim , Othman Mohamad
Published: July 2013

Enhanced Oil Recovery (EOR) has been touted as the Holy Grail for achieving the highest possible recovery factor. This technology is fairly matured in land based development, with older fields in Bakersfield and Indonesia achieving up to 90% recovery factors. However, EOR considerations take on a whole new dimension in an offshore environment. Astronomical rig rates and escalating operational costs have deterred operators from pursuing ambitious offshore EOR programs.

Most EOR pre-development studies are focused on the reservoir; in particular altering relative permeabilities, reducing residual hydrocarbon saturations, and improving sweep efficiencies. But with up to 40% of slated huge EOR capital development cost earmarked for well construction, more technical focus should be emphasized on well architecture.

This paper details the well architecture work done on several Malaysian fields scheduled for EOR redevelopment. A workflow featuring the various design and operational considerations is explained. Well architecture is composed of two main components: Trajectory and completions functionality. Malaysia's portfolio of complex reservoirs requires EOR development to be done through a creative lens of complex trajectories and multilateral wells. Marginal economics have precluded the practicality of conventional well construction.

A key enabler in cost efficient EOR redevelopment is advanced completions, namely remote downhole flow control and monitoring. In order to achieve incremental production beyond secondary recovery, reservoir conformance is of critical importance. Remote real time monitoring will allow decisions to be made accurately in a timely manner. Downhole flow control permits purposeful manipulation of injection and production streams. Proper installations of advanced completions will also reduce future intervention and operational costs.

Advanced well architecture however, also comes with a whole range of operational and installation risks. But these can be mitigated with proper planning and coordination with all parties involved.
Managing Chemical Flooding, and By-Products with Produced Water Re-Injection (PWRI) System in Offshore Environment
Authors: Sabzabadi Ali , Amirrudin Farahnajwa , Vai Yee Hon , Juhaida M. Johar
Published: July 2013

Angsi field is slated to be the first in the world for Alkaline-Surfactant and Polymer (ASP) chemical flooding via a floating structure in an offshore environment. The chemical flooding will be for 3 years with 6 months of low salinity water pre-flush injection prior to chemical injection to condition the reservoir, and 6 months of treated seawater with polymer injection as post-flush activity. The chemical flooding will be conducted via injection of treated and partially desalinated seawater mixed with ASP chemicals produced from the floater which is tie-in to the existing Angsi water injection pipeline network (Figure 1.0). Angsi reservoirs will experience three (3) different salinity range exposures with two (2) as invading fluids with effects of chemical cocktail, wettability and fluid distribution. One of the main challenges for ASP flooding in an offshore environment is handling the chemical residuals breakthrough in produced water causing the water unable to be disposed overboard. To overcome this problem and to eliminate environmental pollution,  a full scale Produced Water Re-Injection (PWRI) system with full integration to existing Angsi Produced Water Treatment (PWT) system should be adopted to meet the new water reinjection specifications. Since the PWRI water will be commingled with treated and partially desalinated seawater mixed with ASP chemicals from the floater, it is paramount to predict the range of salinity of the produced water over time to help to design the PWRI and Floater's water treatment system to achieve the final water quality and optimum salinity required for an effective ASP cocktail for re-injection. This paper will summarise the PWRI design and operation philosophy coupled with subsurface studies to predict salinity profiles for the produced water.
The First Application of IWAG Surveillance Program with Integrated Operation (IO) for Dulang Field Offshore Malaysia
Authors: W. Daud W. Ata , Sedaralit M. F. , Wong Fadhli , Affendi Amierul
Published: July 2013

With declining oil production, the Exploration & Production companies are in search of applying innovative methodologies to improve recovery factors from existing fields.  Immiscible Water Alternating Gas (IWAG) has been identified as one of the enhanced-oil recovery techniques for offshore Dulang oil field in Malaysia. The field redevelopment FDP study was initiated in 2007 to evaluate the optimum recovery scheme to increase oil production from all reservoirs in Dulang field. Results from the simulation study indicated that the major reservoirs will benefit from IWAG injection, with ultimate recovery as high as 50% in some reservoirs. Phase 1 of IWAG injection was started in April 2012

Prior to IWAG field implementation, extensive surveillance program was developed to ensure requires data is captured for monitoring the success of the project and provide a feedback for improvement.

This paper explores the selection of tools and testing programs adopted in surveillance program which include Integrated Operation (IO) for IWAG injection in the Dulang field. The new proposed surveillance program is expected to improve water flood and IWAG monitoring; Monitors stable front (water or gas) with high sweep efficiency to push oil to producerMonitors and forecasts displaced reservoir hydrocarbon and water volumesEnables to see and understand the status-quo of WF/WAG performance in each block and reservoir

The new IWAG surveillance program with the IO system will enable the surveillance team to move from reactive to a proactive asset management system. Real time data will enable engineers to know the status of injection facilities, well status and rate and the performance of IWAG EOR in Dulang.
Enhancing the Efficiency of Immiscible Water Alternating Gas (WAG) Injection in a Matured, High Temperature and High CO2 Solution Gas Reservoir- A Laboratory Study
Authors: Mohd Shafian Siti Rohaida , Kamarul Bahrim Ridhwan Zhafri , Abdul Hamid Pauziyah , A Manap Arif Azhan , Darman Nasir , Sedaralit Mohd Faizal , Tewari Raj Deo
Published: July 2013

This paper discusses laboratory results of enhancing the performance of water alternating gas (WAG) injection process. Currently, field is under primary and secondary phases. It is light oil with moderate to good reservoir characteristics and relatively higher in reservoir temperature between 92 – 101°C and higher CO2 percentage in produced gas. Field is in decline phase and rise in water cut and GOR values. Redevelopment strategy of the field includes optimization of well spacing and WAG application to maximizing the oil recovery. One of the key challenges faced on WAG injection is gas overriding. Therefore, it becomes important to control the gas flood front during gas injection cycle of WAG and allowing the reservoir to reach to Sorg level.

The study will focus on measuring the variation of petrophysical parameters for surfactants that has bulk foam stabilization properties. In addition to classical foam Mobility Reduction Factor (MRF) determination, effect of foam on gas saturation has also been monitored along the core using in-situ X-ray monitoring tool. Propagation of foam in porous media is less understood and application of X-ray monitoring for gas saturation in dynamic condition helps to understand this to great extent.

Experiments have been carried out on Berea and reservoir cores mounted on dedicated X-Ray-equipped core flood bench. The core, initially at Swi, is flooded up to Sorw with water followed by gas injection to Sorg level to establish the reference condition for WAG. A slug of surfactant solution is then injected followed by gas prior to co-injection of surfactant and gas (83 % quality foam). Fluid propagation in core is correctly monitored for every 0.1 PV injection of fluids. The results suggest efficient mobility control by achieving required MRF in presence of ROS. High MRF is an essential ingredient for the success of the process. These results are also correlated with a homogenization of the gas front in presence of foam.
Chemical EOR Injection Facilities – From Pilot Test to Field-Wide Expansion
Authors: Chang Harry L. , Yanming Gao , Wu Fengwu , Hou Huaye
Published: July 2013

Chemical injection in enhanced oil recovery (EOR) projects is a complex process because it involves multiple chemicals with complex fluids. Costs for even a small-scale pilot test could be up in the millions of US dollars (USD) and large-scale field-wide expansion would be in the 100s of millions USD for onshore projects. Costs for offshore projects would increase by multiple folds compared to onshore projects with comparable sizes.

This paper discusses (1) conventional designs for small- or large-scale injection facilities, (2) recent improvements in conventional designs, and (3) new concepts in chemical injection facility designs that can improve the quality, lower the cost, and reduce the lead time in the implementation of chemical EOR (CEOR) projects.
The Effects of Suspended Solids and Fine Migration on the Design of Immiscible WAG Process in the Bokor Field
Authors: Chee S. C. , Zain Z. M. , Osman A. M. , Ohen H. A.
Published: July 2013

Among the different Enhanced Oil Recovery methods being implemented in the matured fields of Malaysia, Immiscible Water Alternating Gas (iWAG) appears to be the most viable option. However, reduction in well injectivity and productivity would be very harmful to this process and render it ineffective. Therefore, extensive laboratory testing, interpretation and integration have been performed to reach the conclusions and recommendations presented in this paper.

The target reservoirs in the Bokor are made up of unconsolidated and very heterogeneous rock with high permeability streaks. The mineralogy of the target reservoirs shows over 10% of clay, with abundance of kaolinites and illites which tend to cause fines migration and mixed layer illites/smectite which can swell. Therefore special handling of core samples is necessary for the laboratory testing; this includes flow through cleaning and critical point drying.

The aim of the study is to establish the potential mechanisms of formation damage during the iWAG progress and determine preventive, mitigative measures and provide guidelines for treatment if damage occurs. The main focus is on formation damage by fines migration, dirty injection fluids (Mechanically induced damage) and clay swelling and de-flocculation (Chemical induced damage – fluid rock interaction) effect to Bokor field. The laboratory tests performed includes capillary suction time, filtration level test, critical velocity and fines stabilizer test, constant rate injectivity test and formation damage by iWAG injection test.

Key areas of interesting findings include (1) Potential formation damage mechanism during the iWAG process (2) Strategies to prevent damage and improved injectivity, (3) Recommended treatment frequency based on injection half-life established in this study and (4) Field monitoring strategies.
Potential of the Trifunctional Bispecific Antibody Surek Depends on Dendritic Cells: Rationale for a New Approach of Tumor Immunotherapy
Authors: Eissler Nina , Mysliwietz Josef , Deppisch Nina , Ruf Peter , Lindhofer Horst , Mocikat Ralph
Published: July 2013

Trifunctional bispecific antibodies (trAbs) used in tumor immunotherapy have the unique ability to recruit T cells toward antigens on the tumor cell surface and, moreover, to activate accessory cells through their immunoglobulin Fc region interacting with activating Fcγ receptors. This scenario gives rise to additional costimulatory signals required for T cell-mediated tumor cell destruction and induction of an immunologic memory. Here we show in an in vitro system that most effective trAb-dependent T-cell activation and tumor cell elimination are achieved in the presence of dendritic cells (DCs). On the basis of these findings, we devise a novel approach of cancer immunotherapy that combines the specific advantages of trAbs with those of DC-based vaccination. Simultaneous delivery of trAbs and in vitro differentiated DCs resulted in a markedly improved tumor rejection in a murine melanoma model compared with monotherapy.
Effects of Metformin on Burn-Induced Hepatic Endoplasmic Reticulum Stress in Male Rats
Authors: Hiyama Yaeko , Marshall Alexandra H. , Kraft Robert , Qa’aty Nour , Arno Anna , Herndon David N. , Jeschke Marc G.
Published: July 2013

Severe burn injury causes hepatic dysfunction that results in major metabolic derangements including insulin resistance and hyperglycemia and is associated with hepatic endoplasmic reticulum (ER) stress. We have recently shown that insulin reduces ER stress and improves liver function and morphology; however, it is not clear whether these changes are directly insulin mediated or are due to glucose alterations. Metformin is an antidiabetic agent that decreases hyperglycemia by different pathways than insulin; therefore, we asked whether metformin affects postburn ER stress and hepatic metabolism. The aim of the present study is to determine the effects of metformin on postburn hepatic ER stress and metabolic markers. Male rats were randomized to sham, burn injury and burn injury plus metformin and were sacrificed at various time points. Outcomes measured were hepatic damage, function, metabolism and ER stress. Burn-induced decrease in albumin mRNA and increase in alanine transaminase (p < 0.01 versus sham) were not normalized by metformin treatment. In addition, ER stress markers were similarly increased in burn injury with or without metformin compared with sham (p < 0.05). We also found that gluconeogenesis and fatty acid metabolism gene expressions were upregulated with or without metformin compared with sham (p < 0.05). Our results indicate that, whereas thermal injury results in hepatic ER stress, metformin does not ameliorate postburn stress responses by correcting hepatic ER stress.
Macrophage Migration Inhibitory Factor (MIF) and Thyroid Hormone Alterations in Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis (AAV)
Authors: Wendt Mårten , Börjesson Ola , Avik Aune , Bratt Johan , Anderstam Björn , Qureshi Abdul R. , Miller Edmund J. , Gunnarsson Iva , Bruchfeld Annette
Published: July 2013

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine known to be released from lymphocytes, macrophages and endothelial cells and also in animal models shown to be inducible with glucocorticoids (GC). In contrast, thyroxine seems to antagonize MIF activity. To investigate whether MIF is increased in active antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and possible correlations with GC dosing and thyroid hormone levels, 27 consecutive patients with active AAV were studied and followed prospectively. Disease activity was assessed using Birmingham Vasculitis Activity Score 2003 (BVAS) at baseline and at follow-up at 3 and 6 months, along with MIF, thyroid hormones free triiodothyronine (fT3) and free thyroxine (fT4), C-reactive protein (CRP) and creatinine. MIF was elevated significantly at baseline compared with follow-up at 3 and 6 months (8,618 pg/mL versus 5,696 and 6,212 respectively; P < 0.002) but did not correlate to CRP GC dose, creatinine or organ involvement. fT3 was depressed significantly at baseline compared with follow-up (1.99 pg/mL versus 2.31 and 2.67 respectively; P = 0.01) and correlated inversely to the BVAS score at baseline. We found a significant correlation between the MIF/fT4 ratio at baseline versus MIF/fT4 ratio at 6 months (p = 0.52, P < 0.005) and a trend between the baseline MIF/fT3 ratio versus MIF/fT3 ratio at 6 months (ρ = 0.39, P = 0.05). These results suggest a possible role for MIF and thyroid status in AAV. Further studies could reveal whether the association between AAV and thyroid hormone levels in the context of elevated MIF may present a link as well as a target of treatment.
Water Regime of Playa Lakes from Southern Spain: Conditioning Factors and Hydrological Modeling
Authors: Moral Francisco , Rodriguez‐Rodriguez Miguel , Beltrán Manuel , Benavente José , Cifuentes Victor Juan
Published: July 2013

Andalusia's lowland countryside has a network of small geographically isolated playa lakes scattered across an area of 9000 km2 whose watersheds are mostly occupied by clayey rocks. The hydrological model proposed by the authors seeks to find equilibrium among usefulness, simplicity, and applicability to isolated playas in a semiarid context elsewhere. Based in such model, the authors have used monthly climatic data, water stage measurements, and the basin morphometry of a particular case (Los Jarales playa lake) to calibrate the soil water budget in the catchment and the water inputs from the watershed (runoff plus groundwater flow) at different scales, from monthly to daily. After the hydrologic model was calibrated, the authors implemented simulations with the goal of reproducing the past hydrological dynamics and forecasting water regime changes that would be caused by a modification of the wetland morphometry.
Clinical bond failure rates of adhesive precoated self-ligating brackets using a self-etching primer
Authors: Ozer Mete , Bayram Mehmet , Dincyurek Cagri , Tokalak Fuat
Published: July 2013

Objective:

To comparatively assess the failure rate of adhesive precoated (APC) self-ligating metal brackets bonded with two different enamel surface preparation techniques: self-etching primer (SEP) and conventional two-step etch and primer method (CM).

Materials and Methods:

Fifty-seven patients with complete permanent dentition were included in this study. A total of 1140 APC self-ligating brackets (3M Unitek, Monrovia, Calif) were bonded using a split-mouth design. For each patient, SEP (Transbond Plus SEP, 3M Unitek) and CM (37% phosphoric acid) were used in alternate quadrants. All brackets were bonded by the same investigator after pumicing and rinsing of all of the teeth. The number, site, and date of first-time bracket failures were monitored throughout orthodontic treatment (mean, 22 months). The survival rates of the brackets were estimated by Kaplan-Meier and log-rank tests (P < .05). The adhesive remnant index was used to determine the bond failure interface.

Results:

The bond failure rates were 2.97% and 2.18% for the CM and SEP, respectively. No statistically significant difference in failure rates was found between the groups. The bond failure sites were predominantly at the enamel-adhesive interface in both groups.

Conclusion:

This long-term in vivo study showed that the combined use of SEP and the APC bracket system can be used effectively for bonding brackets after pumicing the enamel surfaces in clinical orthodontics.
The Factors Associated with Anxiety and Depression in Slovenian Armed Forces Members on a Peacekeeping Mission in the Western Balkans / Dejavniki, Povezani Z Depresijo In Tesnobnostjo Pri Slovenskih Vojakih Na Mirovni Misiji Na Zahodnem Balkanu
Authors: Selič Polona , Dzanic Unger Jasna , Pesjak Katja , Kersnik Janko
Published: July 2013

Objective: To identify the factors associated with the onset of depression and anxiety in professional soldiers on a peacekeeping mission in Kosovo in 2009.

Methods: A cross-sectional study of 244 members of the Slovenian Armed Forces on a peace-keeping mission, using the Depression Self Rating Scale, the Self-Rating Anxiety Scale and a background questionnaire, was performed.

Results: A 6.9% prevalence of depression and a 7.9% prevalence of anxiety were identified. The presence of a chronic pain condition and the recent termination of an intimate relationship were independently associated with the onset of either anxiety or depression or with a co-morbidity of anxiety and depression.

Conclusions: In spite of medical and psychological examinations prior to peacekeeping operations, the onset of anxiety and depression calls for special attention and empowerment by teaching peacekeepers how to use their social support and personal mastery resources.
Porazdelitev Telesnega Maščevja Študentk V Povezavi S Telesno Aktivnostjo In Tveganjem Za Obolevnost Kot Posledico Trebušne Debelosti / Body Fat Distribution of Female Students Related to Physical Activity and to Risk of Morbidity Due to Abdominal Obesity
Authors: Zerbo Sporin Dorjana
Published: July 2013

Izvleček

Izhodišča: Pomanjkanje telesne aktivnosti in neustrezna prehrana lahko pripeljeta do prekomerne mase telesa in povečanega obsega pasu, ki je dejavnik tveganja za pojav bolezni, odvisnih od centralne porazdelitve telesnega maščevja. Namen raziskave je bil ugotoviti, ali je telesna aktivnost študentk povezana s količino in porazdelitvijo maščevja ter oceniti njihovo ogroženost zaradi prekomerne trebušne zamaščenosti.

Metode: Raziskava je bila izvedena na Oddelku za biologijo Biotehniške fakultete v Ljubljani. Spremljano je bilo število tedenskih ur telesne aktivnosti, ki je pomenila kakršnokoli telesno gibanje, ki ga ustvarjajo skeletne mišice in ima kot posledico porabo energije. Študentke Fakultete za šport so bile združene v skupino »športnice« in telesno aktivne večinoma 15 ur tedensko več kot študentke »rekreativke«. Med skupinama so bile primerjane antropometrične vrednosti in ocena porazdelitve telesnega maščevja. Z indeksom pas - boki je bilo ovrednoteno tveganje za pojav bolezni, povezanih s prekomerno količino maščevja v predelu trebuha. Višja stopnja telesne aktivnosti športnic ni bila povezana z vrednostmi telesnih mer in s porazdelitvijo maščevja.

Rezultati: Glavnina študentk izkazuje sorazmerno več maščevja v predelu bokov kot na trebuhu. 5% študentk sodi v skupino z visokim do zelo visokim tveganjem za pojav bolezni, povezanih s centralnim tipom porazdelitve maščevja. Težje študentke imajo tudi statistično pomembno večji obseg pasu. Z vidika ocenjene količine in porazdelitve telesnega maščevja, se stopnja telesne aktivnosti študentk rekreativk ne razlikuje od tiste, ki jo izvajajo študentke Fakultete za šport.

Zaključki: Večina študentk ima periferno porazdelitev maščevja in nizko do zmerno tveganje za pojav srčno-žilnih bolezni. Potrebno je ustrezno obravnavati posameznice s centralnim tipom porazdelitve maščevja.
Soil as the landscape balance indicator
Authors: Ostaszewska Katarzyna , Szumacher Iwona
Published: July 2013

The subordinated position of soil in the geosystem allows it to be used as an indicator of the landscape balance. Examples where soil plays such an indicative role are presented in this paper. The theory of the “geochemical landscape” has been used as the theoretical-methodological basis. Soil properties indicating direction, intensity and quality of matter migration in the landscape have been discussed (profile environment, pH, redox, quantitative and qualitative humus properties). The indicative role of soil in the monitoring of “sustainable landscape” has also been characterized. According to the authors, three models of this landscape can be created: natural, rural and urban sustainable landscapes.
Social and ethnic segregation in the Paris metropolitan area at the beginning of the 21st century
Authors: Grzegorczyk Anna
Published: July 2013

Although the socio-spatial aspect of cities in the globalisation era has gained a new dimension, it cannot be explained by the globalisation process alone. The article presents the problem of social and ethnic segregation in Île-de-France between 1999 and 2009. Socio-economic and demographic data are used to measure indices of segregation and the description of characteristic chosen districts to show its spatial inertia. The analysis revealed a higher degree of social segregation in the entire Paris metropolitan region than in the city of Paris itself. The upper class is the most segregated group, followed by foreigners, immigrants and the lower class. The pattern emphasises the important role of autosegregation factors and functions. It is observed that a constant division into homogenous parts exists in the prestigious and affluent western districts and the impoverished immigrant north-eastern districts. Socio-spatial tendencies reveal the growing importance of the upper class.
A Peer-Delivered Social Interaction Intervention for High School Students with Autism
Authors: Hughes Carolyn , Harvey Michelle , Cosgriff Joseph , Reilly Caitlin , Heilingoetter Jamie , Brigham Nicolette , Kaplan Lauren , Bernstein Rebekah
Published: July 2013

Limited social interaction typically occurs between high school students with autism and their general education peers unless programming is introduced to promote interaction. However, few published social interaction interventions have been conducted among high school students with autism and their general education classmates. Such studies typically have involved considerable researcher assistance in arranging and supporting opportunities for interaction. This study represents a departure from previous interventions by teaching general education students a strategy to prompt themselves to increase their interactions with classmates with autism. Three general education high school students were taught to set interaction goals and monitor their interactions with a peer with autism in their classes. The goal-setting package was associated with increased social interaction among participating students. Based on findings, recommendations are provided for future research and practice.
The search for seismic signatures of movement at the glacier bed in a polythermal valley glacier
Authors: Pomeroy Joseph , Brisbourne Alex , Evans Jeffrey , Graham David
Published: July 2013

A passive seismology experiment was conducted across the main overdeepening of Storglaciären in the Tarfala valley, northern Sweden, to investigate the spatial and temporal distribution of basal microseismic waveforms in relation to known dynamics of this small polythermal sub-arctic glacier. The high ablation rate made it difficult to keep geophones buried and well coupled to the glacier during the experiment and reduced the number of days of good-quality data collection. The characterization of typical and atypical waveforms showed that the dominant waveforms were from near-surface events such as crevassing. Waveforms resembling basal microseismic signals were very rare, and seldom observed on more than two seismic stations simultaneously. The analysis of waveforms, amplitudes and particle motions suggested a near-field origin for most events. Even though basal sliding is known to occur in the overdeepening, no convincing examples of basal waveforms were detected, suggesting basal microseismic signals are rare or difficult to detect beneath polythermal glaciers like Storglaciären. We discuss the reasons for failing to locate basal signals, consider the origin of common waveforms and make recommendations for setting up passive seismology experiments on glaciers with high ablation rates.
Levoglucosan concentrations in ice-core samples from the Tibetan Plateau determined by reverse-phase high-performance liquid chromatography–mass spectrometry
Authors: Yao Ping , Schwab Valérie F. , Roth Vanessa-Nina , Xu Baiqing , Yao Tandong , Gleixner Gerd
Published: July 2013

Levoglucosan is a unique marker for biomass burning that can be transported in the atmosphere and preserved in archives such as ice cores. A new method to determine the concentrations of levoglucosan in Tibetan ice-core samples using high-performance liquid chromatography with electrospray ionization mass spectrometry (HPLC-ESI/MS) was developed. Levoglucosan was separated from coeluting water-soluble organic compounds using a C18column with a gradient program from 50% to 90% methanol in ultrapure water. An external standard calibration curve (R2= 0.9958) was established by plotting the ion m/z 163 [M+H]+peak area versus the amount of analyte. The repeatability ranges between 11% and 2% at a concentration around 10 and 150 ng mL−1. The limit of detection was 10 ng mL−1and the limit of quantification was 40 ng mL−1. Levoglucosan concentrations ranged from 10 to 718 ng mL−1in the Muztagh Ata ice core and from 10 to 93 ng mL−1in the Tanggula ice core. These concentrations, up to 1000 times higher than those measured in samples from Antarctic and Greenland, showed the higher vulnerability of the Tibetan Plateau glaciers to biomass burning events.
Assessing the Potential for Ion Selective Electrodes and Dual Wavelength UV Spectroscopy as a Rapid on-Farm Measurement of Soil Nitrate Concentration
Authors: Shaw Rory , Williams A. , Miller Anthony , Jones Davey
Published: July 2013

Current fertiliser recommendations for nitrogen are limited in their accuracy and may be improved by the use of simple on-farm soil rapid tests. This paper investigates the potential for using nitrate (NO3−) ion selective electrodes (ISEs) and dual wavelength UV spectroscopy as part of a rapid soil NO3− diagnostic test. Three soil types, representing the major soil types for agriculture in the western UK, were tested. For the three soils, the ISE rapid test procedure gave a near 1:1 response (r2 = 0.978, 0.968, 0.989) compared to the internationally-approved standard laboratory method. However, the accuracy of the ISE rapid test was reduced at low soil NO3− concentrations (<10 mg NO3− L−1). We also show that NO3− analysis of H2O soil extracts by dual wavelength UV spectroscopy was also highly correlated (r2 = 0.978, 0.983, 0.991) to the standard laboratory method. We conclude that both ISE and dual wavelength UV spectroscopy have clear potential to be used for the rapid on-farm determination of soil NO3− concentration. Barriers to use of these field-based assessment tools include, farmer perception of cost-benefit, general attitude to new technologies and the ability to generate useful fertiliser use strategies from soil NO3− measurements.
Spatial Rule-Based Modeling: A Method and Its Application to the Human Mitotic Kinetochore
Authors: Ibrahim Bashar , Henze Richard , Gruenert Gerd , Egbert Matthew , Huwald Jan , Dittrich Peter
Published: July 2013

A common problem in the analysis of biological systems is the combinatorial explosion that emerges from the complexity of multi-protein assemblies. Conventional formalisms, like differential equations, Boolean networks and Bayesian networks, are unsuitable for dealing with the combinatorial explosion, because they are designed for a restricted state space with fixed dimensionality. To overcome this problem, the rule-based modeling language, BioNetGen, and the spatial extension, SRSim, have been developed. Here, we describe how to apply rule-based modeling to integrate experimental data from different sources into a single spatial simulation model and how to analyze the output of that model. The starting point for this approach can be a combination of molecular interaction data, reaction network data, proximities, binding and diffusion kinetics and molecular geometries at different levels of detail. We describe the technique and then use it to construct a model of the human mitotic inner and outer kinetochore, including the spindle assembly checkpoint signaling pathway. This allows us to demonstrate the utility of the procedure, show how a novel perspective for understanding such complex systems becomes accessible and elaborate on challenges that arise in the formulation, simulation and analysis of spatial rule-based models.
Maximum Entropy Distributions Describing Critical Currents in Superconductors
Authors: Long Nicholas
Published: July 2013

Maximum entropy inference can be used to find equations for the critical currents (Jc) in a type II superconductor as a function of temperature, applied magnetic field, and angle of the applied field, θ or φ . This approach provides an understanding of how the macroscopic critical currents arise from averaging over different sources of vortex pinning. The dependence of critical currents on temperature and magnetic field can be derived with logarithmic constraints and accord with expressions which have been widely used with empirical justification since the first development of technical superconductors. In this paper we provide a physical interpretation of the constraints leading to the distributions for Jc(T) and Jc(B), and discuss the implications for experimental data analysis. We expand the maximum entropy analysis of angular Jc data to encompass samples which have correlated defects at arbitrary angles to the crystal axes giving both symmetric and asymmetric peaks and samples which show vortex channeling behavior. The distributions for angular data are derived using combinations of first, second or fourth order constraints on cot θ or cot φ . We discuss why these distributions apply whether or not correlated defects are aligned with the crystal axes and thereby provide a unified description of critical currents in superconductors. For J//B we discuss what the maximum entropy equations imply about the vortex geometry.
Modeling Future Life-Cycle Greenhouse Gas Emissions and Environmental Impacts of Electricity Supplies in Brazil
Authors: Dale Alexander , Pereira de Lucena André , Marriott Joe , Borba Bruno , Schaeffer Roberto , Bilec Melissa
Published: July 2013

Brazil’s status as a rapidly developing country is visible in its need for more energy, including electricity. While the current electricity generation mix is primarily hydropower based, high-quality dam sites are diminishing and diversification to other sources is likely. We combined life-cycle data for electricity production with scenarios developed using the IAEA’s MESSAGE model to examine environmental impacts of future electricity generation under a baseline case and four side cases, using a Monte-Carlo approach to incorporate uncertainty in power plant performance and LCA impacts. Our results show that, under the cost-optimal base case scenario, Brazil’s GHGs from electricity (excluding hydroelectric reservoir emissions) rise 370% by 2040 relative to 2010, with the carbon intensity per MWh rising 100%. This rise would make Brazil’s carbon emissions targets difficult to meet without demand-side programs. Our results show a future electricity mix dominated by environmental tradeoffs in the use of large-scale renewables, questioning the use tropical hydropower and highlighting the need for additional work to assess and include ecosystem and social impacts, where information is currently sparse.
Analysis and Experiment of a Novel Brushless Double Rotor Machine for Power-Split Hybrid Electrical Vehicle Applications
Authors: Zheng Ping , Wu Qian , Bai Jingang , Tong Chengde , Song Zhiyi
Published: July 2013

A novel brushless double rotor machine (BDRM) is proposed in this paper. The BDRM is an important component in the brushless compound-structure permanent-magnet synchronous machine (CS-PMSM) system, which is a promising technology for power-split hybrid electric vehicle (HEV) applications. Compared with common double rotor machines, the brushes and slip rings required by rotating winding have been omitted in the BDRM, thus there are no such problems as maintenance, friction losses and so forth. Firstly, the torque characteristics of the BDRM are analyzed. As the stator has ring-shaped centralized windings, the size characteristics of the BDRM are different from those of conventional machines. The new sizing and torque equations are analyzed and the theoretical results are applied to determine the main dimensions. Additionally, studies of the analytical magnetic circuit and finite element method (FEM) model show that the BDRM tends to have high leakage flux and low power factor. Although the scope for improving the serious flux leakage of the BDRM is limited by the special magnetic topology, a method to obtain higher power factor is provided. Finally, a 10 kW prototype machine was manufactured, assembly of the prototype is discussed in detail and experimental tests are performed to validate the analytical and simulation results.
Response to Baverstock, K. Comments on Rithidech, K.N.; et al. Lack of Genomic Instability in Bone Marrow Cells of SCID Mice Exposed Whole-Body to Low-Dose Radiation. Int. J. Environ. Res. Public Health 2013, 10, 1356–1377.
Authors: Rithidech Kanokporn , Udomtanakunchai Chatchanok , Honikel Louise , Whorton Elbert
Published: July 2013

We thank Dr. Baverstock [1] for his interest in reading our article and his time in writing his comments for our work [2]. We, however, respectfully disagree with his statement that we made “two category errors” associated with the assessment of the occurrence of “genomic instability” by determining the frequencies of delayed- or late-occurring chromosomal damage. Our disagreement is based upon the well-known fact that radiation-induced genomic instability (or delayed/late-occurring damage) can be manifested in many ways. These include late-occurring chromosomal damage, or mutations, or gene expression, or gene amplifications, or transformation, or microsatellite instability, or cell killing [3–9]. Such phenomena have been detected many cell generations after irradiation. We agree that genomic instability may well be the consequence of epigenetic changes. Another mechanism mentioned by Dr. Bavertock as being probably unlikely is the reversibility of damage. This potential may not be discarded off-hand, as Dr. Baverstock prefers to do. There is much reproducible evidence of adaptive protection that depending on absorbed dose precisely may reverse early damage, and damage appearing late may be due to some form of residual damage letting the cell become genetically unstable. In other words, the argument by Dr. Baverstock regarding upward or downward causation appears to be rather speculative and far from being settled.
KRAS and MAPK1 Gene Amplification in Type II Ovarian Carcinomas
Authors: Rahman Mohammed , Nakayama Kentaro , Rahman Munmun , Katagiri Hiroshi , Katagiri Atsuko , Ishibashi Tomoka , Ishikawa Masako , Sato Emi , Iida Kouji , Nakayama Naomi , Ishikawa Noriyuki , Miyazaki Kohji
Published: July 2013

In this study, we examined the clinical significance of KRAS and MAPK1 amplification and assessed whether these amplified genes were potential therapeutic targets in type II ovarian carcinoma. Using fluorescence in situ hybridization, immunohistochemistry, and retrospectively collected clinical data, KRAS and MAPK1 amplifications were identified in 9 (13.2%) and 5 (7.4%) of 68 type II ovarian carcinoma tissue samples, respectively. Interestingly, co-amplification of KRAS and MAPK1 seemed to be absent in the type II ovarian carcinomas tested, except one case. Active phospho-ERK1/2 was identified in 26 (38.2%) out of 68 type II ovarian carcinomas and did not correlate with KRAS or MAPK1 amplification. There was no significant relationship between KRAS amplification and overall or progression-free survival in patients with type II ovarian carcinoma. However, patients with MAPK1 amplification had significantly poorer progression-free survival than patients without MAPK1 amplification. Moreover, type II ovarian carcinoma cells with concomitant KRAS amplification and mutation exhibited dramatic growth reduction following treatment with the MEK inhibitor PD0325901. These findings indicate that KRAS/MAPK1 amplification is critical for the growth of a subset of type II ovarian carcinomas. Additionally, RAS/RAF/MEK/ERK pathway-targeted therapy may benefit selected patients with type II ovarian carcinoma harboring KRAS/MAPK1 amplifications.
Variations in Atmospheric CO2 Mixing Ratios across a Boston, MA Urban to Rural Gradient
Authors: Briber Brittain , Hutyra Lucy , Dunn Allison , Raciti Steve , Munger J.
Published: July 2013

Urban areas are directly or indirectly responsible for the majority of anthropogenic CO2 emissions. In this study, we characterize observed atmospheric CO2 mixing ratios and estimated CO2 fluxes at three sites across an urban-to-rural gradient in Boston, MA, USA. CO2 is a well-mixed greenhouse gas, but we found significant differences across this gradient in how, where, and when it was exchanged. Total anthropogenic emissions were estimated from an emissions inventory and ranged from 1.5 to 37.3 mg·C·ha−1·yr−1 between rural Harvard Forest and urban Boston. Despite this large increase in anthropogenic emissions, the mean annual difference in atmospheric CO2 between sites was approximately 5% (20.6 ± 0.4 ppm). The influence of vegetation was also visible across the gradient. Green-up occurred near day of year 126, 136, and 141 in Boston, Worcester and Harvard Forest, respectively, highlighting differences in growing season length. In Boston, gross primary production—estimated by scaling productivity by canopy cover—was ~75% lower than at Harvard Forest, yet still constituted a significant local flux of 3.8 mg·C·ha−1·yr−1. In order to reduce greenhouse gas emissions, we must improve our understanding of the space-time variations and underlying drivers of urban carbon fluxes.
Diminishing Risk for Age-Related Macular Degeneration with Nutrition: A Current View
Authors: Schleicher Molly , Weikel Karen , Garber Caren , Taylor Allen
Published: July 2013

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. Clinical hallmarks of AMD are observed in one third of the elderly in industrialized countries. Preventative interventions through dietary modification are attractive strategies, because they are more affordable than clinical therapies, do not require specialists for administration and many studies suggest a benefit of micro- and macro-nutrients with respect to AMD with few, if any, adverse effects. The goal of this review is to provide information from recent literature on the value of various nutrients, particularly omega-3 fatty acids, lower glycemic index diets and, perhaps, some carotenoids, with regard to diminishing risk for onset or progression of AMD. Results from the upcoming Age-Related Eye Disease Study (AREDS) II intervention trial should be particularly informative.