bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential of Steam Solvent Hybrid Processes in Llanos Basin, Colombia
Authors: Andarcia L.. , Bermudez J.. , Reyes Y.. , Caycedo H.. , Suarez A..
Published: September 2014

Eastern Llanos in Colombia is a heavy oil prolific basin. Reservoirs in this area generally exhibit water intrusion and extensive transition zones which its origin is probably explained by a combination of lithology variation and a week density contrast in between the reservoir water and oil. If oil viscosity at reservoir temperature is low enough to allow primary production; it is feasible to develop heavy oil fields using horizontal wells and high volume lift pumps. However, operators have to prepare to treat and dispose large volumes of produced water. Other reservoirs with higher oil viscosity require an enhance oil recovery (EOR) processes to pursuit a commercial development. Among the recovery methods applied to heavy oil reservoirs, the most popular is steam injection in its different schemes. Nevertheless, in high initial water saturation environments the thermal efficiency of the steam is under concern. Other EOR options include but not limited to: polymer injection, Alkaline Surfactant and Polymer “ASP”, “In situ Combustion”, Single Well SAGD, SAGD, VAPEX, Solvent Injections and Steam Solvent Hybrid Processes. In hybrid processes an amount of solvent is added to the steam. It is thought that the efficiency of the thermal recovery can be improved by such solvent fraction. It is expected that the presence of solvent helps reducing the cumulative Steam to Oil Ratio (SOR), therefore the overall economic of the recovery project. The amount and kind of solvent are important factors to investigate for any particular reservoir. The production potential under steam hybrid process has been studied in this work with focus on heavy and extra heavy oil reservoirs exhibiting high initial water saturation in llanos basin.

It has been found that this process looks very promising to overcome the difficult task of producing very viscous oils in presence of mobile water. Numerical evaluations and laboratory displacement test conducted with reservoir fluids and rocks gathered from llanos basin heavy oil reservoirs; have shown a clear improvement on displacement efficiency in hybrid steam-solvent injection with regard to pure steam injection.
Factors Affecting SAGD Performance in Dipped Bed Extra Heavy Oil Reservoirs
Authors: Andarcia L.. , Bermudez J.. , Reyes Y.. , Caycedo H.. , Suarez A..
Published: September 2014

In reservoirs with certain dip, the steam chamber advances different than in conventional SAGD projects. Since the horizontal permeability is normally higher than vertical permeability and because reservoir pressure is lower toward up-dip; an early lateral growth of the steam chamber should be promoted to the uppermost reservoir position. If horizontal permeability controls the gravity drainage instead of vertical permeability, it is thought that a good gravity drainage process in dipped reservoirs could be achieved, even in cases were vertical transmissibility is poor. However, if there is mobile water within the reservoir, then the steam easily flows up-dip and away from the producer well diminishing the hot oil draining to the producer and affecting the SAGD well's performance.

The factors affecting SAGD efficiency in a dipped-bed extra heavy oil reservoir (6.5°API) located in southern llanos Colombia have been analyzed. An important extra heavy oil accumulation toward the outcrop of main production sands was encountered. The reservoir temperature is low (100°F) so bitumen viscosity is high (>100.000cp). In addition, oil saturation could be lower than is the standard for commercial projects in some areas.

A reservoir characterization was done using data from 18 wells. Information from basic and special logs, routine and special core analyses as well as displacement tests was used to build a robust numerical model. Several numerical simulations were run to address the performance of SAGD under such conditions. Particularly, the amount of mobile water and dip, play a major role in SAGD efficiency since the steam chamber behaves accordingly to both parameters. Numerical simulations done in this work have shown that SAGD thermal efficiency in dipped bed reservoirs is dramatically affected by energy losses toward the uppermost reservoir position since the steam tends to flow up dip far from producer wells. This effect is amplified when mobile water is within the porous medium.

Different strategies to improve SAGD efficiency were explored by numerical simulation. Well configuration was changed from parallel to staggered; electromagnetic heating was evaluated as well as hybrid processes. Hybrid processes could certainly open doors for economic development of highly viscous heavy oil reservoirs with mobile water saturation.
The Role of Asphaltenes in Emulsion Formation for Steam Assisted Gravity Drainage (SAGD) and Expanding Solvent - SAGD (ES-SAGD)
Authors: Kar Taniya , Williamson Matthew , Hascakir Berna
Published: September 2014

Steam Assisted Gravity Drainage (SAGD) and Expanding Solvent SAGD (ES-SAGD) have previously been compared and ES-SAGD has shown improved oil recovery with lower energy and water requirements and significant oil upgrading. However, solvent selection is the key factor which determines the performance of ES-SAGD due to the asphaltene-solvent interaction. The change in asphaltene stability with the solvent type can have several drawbacks during ES-SAGD. Stable emulsion formation is one of these problems which have not been investigated thoroughly for ES-SAGD. In this study, we characterized both water-in-oil and oil-in-water type of emulsions originating from SAGD, SAGD with n-hexane and SAGD with n-hexane and toluene mixture experiments. These three experiments were conducted on 8.65 °API Canadian bitumen with 34.3 wt% asphaltene content. Structural changes in produced oil, produced water, and spent rock samples were analyzed with Fourier Transform Infrared (FTIR) spectroscopy. Emulsions in produced oil and water samples were determined with microscopic images. The differences in emulsions were interpreted with the wettability change determined on spent rock samples. Moreover, the asphaltene fraction of produced oil samples is further analyzed with FTIR and zeta potential measurements. For produced oil, the greatest asphaltene content with more severe emulsion formations were detected on the sample originating from SAGD. In terms of stability, because the asphaltenes originating from both ES-SAGD experiments have higher zeta potential values, lower emulsion stability has been observed for the produced oil originating from ES-SAGD. In summary, the role of asphaltenes on emulsion formation has been studied for SAGD and ES-SAGD for bitumen extraction. ES-SAGD with asphaltene soluble solvents leads to the formation of less stable emulsions.
First Extra-Heavy-Oil Development in Caguan-Putumayo Basin, Colombia, Capella Field
Authors: Valbuena Amaris Oscar H. , Bernal Maria E. , Ramón Juan C. , Xiuxia Tian
Published: September 2014

Capella field is the first extraheavy oil development in the North part of the Caguan-Putumayo basin in Colombia. In addition to the normal reservoirs complexities of any new field, by this condition, no analogous reservoirs and developments are available, putting and additional challenge on the field development.

The field has two main development targets, both clastic, one conventional high porosity-permeability reservoir (Mirador Formation, main objective) and one naturally fractured; both with extraheavy oil as reservoir fluid, 9 API degrees, with viscosities in the range of 2500 - 4000 centipoises at reservoir conditions.

It was defined that the development with horizontal wells, complemented with vertical wells is the best alternative for the field, but even the efficiency of this alternative, the primary expected recovery factor will be below 10%, caused mainly by the high viscosity of the oil. Best identified alternatives to increase the recovery factor were thermal stimulation with steam, both cyclic and continuous, being already some pilots done at the field.

New cyclic steam stimualtion (CSS) pilots are being defined to be implemented on year 2015, having as main goal the definition of best conditions to implement the CSS around the field and the efficiency of the methodology on different areas and/or reservoirs.

This paper presents geological characteristics of the field, production mechanism and behavior, principal development conditionings, main uncertainties and details of the field development strategy.
Can SAGD Be Exported? Potential Challenges
Authors: Alvarez J. M. , Moreno R.. , Sawatzky R. P.
Published: September 2014

In spite of its relative youthfulness as a commercial IOR technology, SAGD has had a profound impact on the development of the oil sands in northern Alberta and consequently on Alberta's economy. The path from a concept as articulated and developed by an individual research engineer, Roger Butler, to a commercial recovery technology for exploiting Alberta's oil sands has at times been a rocky one. More than 30 years of applied research and development at both the laboratory scale and the field scale by a community of researchers has been necessary to advance the technology to its current state of development. The SAGD technology has faced countless challenges since its origin. The public literature is replete with examples of challenges it has faced in the past, and others that are predicted to be just over the horizon. For example, more research and development will be required to expand SAGD to more challenging areas of the Athabasca region. The challenges will include reservoirs that have shale barriers, those that have bottom/top water zones, and those that are marginally too thin for conventional SAGD. Variants of SAGD, such as fast-SAGD, X-SAGD, and ES-SAGD, were conceived in response to the need to expand SAGD beyond the sweet spots in Alberta's oil sands where the original technology was demonstrated. Lessons learned from the application of SAGD technology in Alberta's oil sands may be useful to international producers from around the world that are interested in trying to adopt SAGD for use in their reservoirs. This paper will discuss potential challenges that may be encountered in the implementation of SAGD as the technology is migrated from its birthplace in the Athabasca oil sands to heavy oil and bitumen reservoirs around the world.
SBH: A Thermal Hybrid Process Tailored for Challenging Reservoirs
Authors: Meza Diaz B.. , Lorimer S. A. , Bogatkov D.. , Lee K.. , Andarcia L..
Published: September 2014

Hybrid processes combine the benefits of both thermal and solvent processes. The results generated to date in this area demonstrate potential to develop improved processes that will significantly reduce energy, water and greenhouse gas (GHG) intensity, and therefore operating costs, while maintaining economic oil recovery rates. The Steam Butane Hybrid (SBH) process has emerged as a promising hybrid process that could be considered as an alternative to SAGD, where the performance of SAGD is expected to be less than ideal.

This paper summarizes the results of a study designed to evaluate the performance of the SBH process in comparison with the SAGD process for three different reservoir models (Geomodel I, II and III) using numerical simulation. Geomodel III is the cleanest (highest average permeability) and most homogeneous of the three reservoir models. Geomodel II has the lowest average permeability, and the highest shale content, while Geomodel I is midway between the other two, in terms of average permeability and shale content. Five well pairs were used in all of the simulations. Three different injection pressures were investigated: 2000, 1000 & 800 kPa*.

It was found that geology plays a very important role in determining the competitive advantage of SBH vs. SAGD. It also plays an important role in establishing optimal operating conditions for the process in the field. The predicted performance of SBH, in terms of cumulative oil production, was better than that of SAGD at low injection pressures in the two geomodels (I & II) with lower average permeabilities. In the geomodel with the highest average permeability (III), the predicted performance of the SBH process was slightly poorer than that of SAGD at a relatively low injection pressure (800 kPa), but slightly better than that of SAGD at a relatively high injection pressure (2000 kPa).

These numerical simulation results indicate that the relative performance of SBH as compared with SAGD is likely to be reservoir specific, meaning that the optimal injection pressures and butane concentrations should be tailored to specific reservoir characteristics, on a case by case basis, rather than generalizing the process to a range of reservoir conditions.
New Heat-Management Model for Steamflood Processes
Authors: Rincon Canas M. M. , Munoz Navarro S. F. , Naranjo Suarez C. E. , Palma Bustamante J. M.
Published: September 2014

Steamflooding is one of the most efficient alternative for heavy oil recovery; in spite of that, the steam generation and treatment represent a large percentage of economic investment in the project. One of the main consequences of the costs associated with the technique is that it limits the lifetime of the project. In many cases, it is common to use high steam injection rates in order to obtain the highest oil recovery, however on many occasions that influence negatively the project profitability.

Heat management ensures moreover as its name indicates optimize the energy injected into the reservoir with the objective of generate maximum profitability with lower injection rate. Until now, different authors have proposed some heat management analytical models, which aim to predict the energy injection rate required for the reservoir, including the thermal requirements of the rock-fluid system and the energy produced and lost. Given the need to generate greater applicability to heat management process, it has proposed a new heat management model (MMRC-Model). One of the most important characteristic is that the results of numerical reservoir simulation complemented the model, which favors their application in fields of different characteristics that will be included in the built of the reservoir simulation model.

The implementation of this new model can efficiently calculate the energy requirements of the reservoir increasing the project profitability in 42% compared to a process of continuous steam injection at a constant rate. On the other hand it is important to emphasize that the implementation of the MMRC heat management model can increase the life of the project from 50% – 80%, thus allowing made changes in the injection rate can be made into longer periods of time depending on the thermal maturity of the reservoir. Finally, the model included a variable that any author had not been taken into account previously was the oil viscosity, which varies over a wide range in heavy oil reservoirs and influences the energy requirements.
An Integrated Approach Using Commercial Monitoring and Surveillance Tools Coupled With Statistical Analysis Techniques to Optimize Oil, Heavy Oil and Extra-Heavy-Oil Reservoirs
Authors: Lee D.. , Valentine A. P. , Tewari C..
Published: September 2014

Modern monitoring and surveillance software are very powerful in analyzing all types of reservoirs including Heavy Oil and Extra Heavy Oil. In addition to the software, easy to use statistical tools can add enormous analytical value in understanding reservoir performance. The engineering focus is to analyze reservoirs to predict the locations of underperforming wells based on the integrated approach discussed in this paper. Wells in the reservoir are evaluated using spatial statistics (i.e. kriging or nearest neighbour) to locate underperforming wells or regions within the reservoir. This goal is achieved by using known (measured) petro-physical information from the reservoir and coupling it with their production history (production/injection flow and pressures). Spatial statistics including other statistical tools, such as multivariate regression analysis techniques is then used to evaluate the reservoir performance.

This paper presents a unique approach developed for reservoir monitoring and diagnostics. It shows that the combination of statistical techniques coupled with monitoring and surveillance software can be used to identify regions, as well as individual distressed wells, within Oil, Heavy Oil and Extra Heavy Oil reservoirs. The focus is to identify underperforming wells relative to their theoretical average well in a specific reservoir analyzed. The reservoirs that can be analyzed include any enhanced oil recovery (EOR) process: waterfloods, polymer floods, cyclic steam stimulation (CSS) and steam assisted gravity drainage (SAGD).

The process to achieve this analysis begins with collecting and statistically filtering data for erroneous data entries. The data collected includes but not limited to:

Production/Injection history; Pressure-volume-temperature (PVT) data; Petro-physical and seismic data; Well completion and work-over history data.

Production, PVT, Petro-physical and Geo-Statistical data are analyzed and mapped. The reservoirs total moving average production data is calculated and compared to its geological data to calculate a theoretical moving average well that is representative over the life of the reservoir. Once the theoretical average well is determined, it can be used as the basis for comparing each well individually to identify distressed wells or regions of the reservoir for the individual well and total reservoir optimization.
Polymer Flooding of Heavy Oil - From Screening to Full-Field Extension
Authors: Delamaide Eric
Published: September 2014

Thermal EOR has long been considered the sole Enhanced Oil Recovery method for heavy oil but this is no longer the case; several heavy oil polymer floods have proven successful and more are in the planning stages. In the US alone several billion barrels of oil could be targeted; in the rest of the world and in Latin America in particular the potential target is also probably large but mostly unknown at this point. Even though polymer flooding recovery is usually lower than with thermal methods, it is less capital intensive and may be the only economical solution for instance in thin reservoirs.

As any EOR project, polymer flooding of heavy oil is done in stages – screening, feasibility study, pilot preparation, pilot execution and eventually full field deployment. Each of these stages requires care and attention to details and many pitfalls need to be avoided in order to reach the final stage of full deployment.

This paper intends to provide guidelines on the whole process, based on practical experience and illustrated with actual field cases. This should allow operators to benefit from a better understanding of the challenges and potential of polymer flooding of heavy oil and open the door for more projects.
Multiphase Flow Meter for Testing Heavy Oil Wells Offshore Brazil
Authors: Maizeret P. -D. , Rocha P. S. , Marsili M. Danemberg , de Almeida Ferreira I.. , Lipovetsky T.. , Schubert E.. , Goncalves E.. , Theuveny B..
Published: September 2014

The difficulties associated with producing heavy oil have discouraged operators from developing the Atlanta field in the Santos basin offshore Brazil, despite more than 1.5 billion bbl of oil in place. The water depth in the area is more than 1,500 m, which makes operations even more challenging. Because Brazil has set aggressive production targets for the next decade, new interest has been given to the field, and a consortium of E&P operators began to reassess the field.

Well deliverability and test data are crucial to field development planning. Well test operations were planned with a multienergy gamma ray and venturi multiphase flow meter used as contingency. During the well test operations, the foaming propensity of the produced oil made it almost impossible to distinguish an interface between liquid and gas in the separator or tank, rendering the standard equipment useless. Only in the second test were some tank measurements available. The measurement principle used in this multiphase flow meter, however, is not sensitive to foam or emulsion because they respond to the atomic-level composition of the different components of the mixture independently of their arrangement, providing accurate flow rate measurements.

We detail the behavior of the multiphase flow meter during the well tests in the Atlanta field and the challenges caused by foaming oil. In the case of standard oils, the measurements are not sensitive to the viscosity value. However, in the case of high viscosities which lead to low Reynolds numbers, the viscosity value can drastically affect the results. In this case, some solvents were injected during the well test to reduce the liquid viscosity, and we present the consequences on the multiphase flow meter. We also compare the multiphase flow meter results to the gas/oil ratio measured in the laboratory on downhole samples from the same reservoir, to the water cut measured manually during the operations and to the tank measurements. Finally, we present some recommendations on the use of multiphase flow meters for heavy oil well tests.
Viscous Fingering Stimulation Option Applied on Heavy-Oil Carbonate Reservoirs
Authors: Ballinas Javier
Published: September 2014

Heavy-oil carbonate reservoirs are complicated to produce. Heavy-oil saturated fractured limestone formations present tremendous completion, stimulation and production challenges because they commonly contain thick completion intervals with extreme permeability ranges. In Mexico, completion and stimulation engineers must consider these complexities during the design stage and when selecting appropriate stimulation technologies to optimize production and hydrocarbon recovery.

A valid option to treat these complex reservoirs is the viscous fingering stimulation technique. The situation is further complicated when the reservoir is saturated with heavy-oil. Carbonate reservoirs are stimulated using acid-predominantly hydrochloric acid (HCl) strengthened with organic acetic acid to create conductive pathways from the reservoir to the wellbore, and to bypass the wellbore region that has been damaged during drilling and cementing.

Acid-fracturing techniques are also used in areas where the natural permeability of carbonate reservoirs is insufficient to promote effective matrix acid stimulations. The goal in carbonate reservoir stimulation is to effectively treat all latent productive zones, reducing formation skin and improving productivity, improving heavy-oil mobility.

Viscous fingering stimulation technique involves the displacement of a more viscous fluid by a less viscous fluid in porous media, the less viscous fluid tends to form fingers into the flow channel, hence the term viscous fingering. The viscous fingering acid injection technique maximizes acid contact time with reservoir faces and is essential to create long and highly conductive etched pathways to facilitate the viscous and heavy-oil flow from the reservoir to the wellbore.

Also, solvent/surfactant special additives are mixed then with acid system designed to stimulate heavy-oils wells for increased productivity. This article examines the viscous fingering stimulation procedures and designs performed in Mexico on heavy-oil carbonate reservoirs, onshore and offshore, reviewing historic cases, production results and the development and trends in the short and medium term.
Evaluation of the Effect of the Asphaltene Accumulation in Porous Media at Dynamic Conditions for a Colombian Crude Oil
Authors: Carrillo L. F. , Ariza León E. , García Padrón R. , Niño J. Lizcano
Published: September 2014

Asphaltene accumulation in porous media is considered a formation damage issue, which may happen during miscible flooding processes, EOR or even primary production, and this may have deep effects on oil production. Although asphaltene precipitation is widely known in literature, the works related to asphaltene accumulation in porous media are rather limited. This work consists in an experimental quantification of asphaltene accumulation in porous media, and a numerical simulation of this process. An experimental methodology was developed in order to recreate asphaltene accumulation on laboratory, using synthetic cores and stock tank oil samples from two different Colombian fields. This methodology consists in determinate basic properties (API, BSW, % asphaltenes), precipitation onset (using n-heptane as a precipitating agent) and perform core floodings at constant rates, these displacement tests showed damage due to asphaltenes between 18% and 27%. The numerical model was developed using Simulink tool, from MATLAB. This model was validated with the experimental results, obtaining a satisfactory agreement, with relative errors between this data less than 5%. Different regimes of accumulation were observed, varying flooding rate. Besides modeling permeability reduction, the model was able to evaluate other variables in the accumulation process.
Reviving the Discussion on the Rationale Underlying the Comparison Question Test
Authors: Elaad Eitan
Published: September 2014

There has been a long-standing debate around the rationale underlying the Comparison Question Test, which assumes that guilty suspects will have consistently larger responses to crime-related (relevant) than to general emotional (comparison) questions, whereas innocent suspects will show the opposite pattern of responding. This debate largely came to a close when the National Research Academy (2003) concluded that “The theoretical rationale for the polygraph is quite weak, especially in terms of differential fear, arousal, or other emotional states that are triggered in response to relevant or comparison questions” (p. 213). A recent study provides new insight into the test's logic and may restart a discussion about, the nature of the test.
DC-DC boost-flyback converter functioning as input stage for one phase low power grid-connected inverter
Authors: Kawa Adam , Penczek Adam , Piróg Stanisław
Published: September 2014

The paper treats about main problems of one phase DC-AC microinverters that allow single solar cell to be joined with the grid. One of the issues is to achieve high voltage gain with high efficiency in DC circuit, which is necessary for proper operation of inverter. The operating principles, results of practical implementation and investigations on boost-flyback converter, which meets mentioned demands, are presented. (high step-up DC-DC boost-flyback converter for single phase grid microinverter)
Faith and Patriotism: Some Snapshots and Reflections on 1914 and Beyond
Authors: Hill Rt Revd Christopher
Published: September 2014

This article offers some fascinating ‘snapshots’ into theological activity and awareness between British and German theologians just prior to WW1, between the wars and post WW2. He helpfully surveys the differences between German and English understandings of the Church-Struggle or Kirchenkampf and some of its struggles which we might now name as too much identification with the prevailing culture and not enough critical distance. He considers how public opinion was divided in the 1930s the role of significant Anglican leaders in and post WW2. He concludes with reflections on Luther's two ‘regiments’, the essential spiritual domain of the Church and the temporal, political power of the State and with Harnack's understanding of the church with thoughts on implications for how we relate to church and state today.
Effect of Pig Farm on Microbial Contamination of Soil
Authors: Trawińska Beata , Józwik Milena , Nowakowicz-Dębek Bożena , Chmielowiec-Korzeniowska Anna , Lechowski Jerzy , Tymczyna Leszek , Pyrz Magdalena
Published: September 2014

The objective of the study was to assess microbial contamination of soil collected in a swine farm and manure from animals housed there depending on the season of the year and the sampling site. The study was conducted from October to September. The soil samples were taken immediately at the pig house wall (GI), and at the distance of 15 m (GII) and 45 m (GIII) from the house wall. Besides, manure samples were collected inside the pig housing facility: at the entrance to the pig house (KI) and at 1/4 (KII) and 1/2 length of the animal facility (KIII). The soil and manure samples underwent qualitative and quantitative bacteriological evaluation. The study was conducted according to the procedure laid out in the Polish Standards. There was also assessed air temperature and relative moisture, air motion and cooling as well as sample moisture in the sampling site. The greatest number of all studied bacteria was determined in soil collected 15 m from the piggery (GII) in December/January. The highest coli titre (0.0001) was also established in the samples (GII) at that time. The qualitative analysis of soil showed solely the presence of E. coli bacteria which were recovered in the GII soils taken from November to May. The largest bacterial load in swine manure was determined in the samples collected at 1/2 length of the pig house (KII) at the end of December and January. The growth of all the analysed microbes was favoured by sample moisture, while air relative moisture prompted development of psychrophilic and proteolytic bacteria. E. coli were isolated in manure samples throughout the entire research period, whereas Enterobacter spp. were detected in the KI and KII samples from June to August and in KII samples from June to September. The winter period was shown to affect significantly microbial contamination of swine farm environment as at that time the highest bacterial load was determined in soil and manure. This is most likely to be associated with the climatic and microclimatic conditions observed in those days.
Effect of Adding Oregano Essential Oil, Garlic and Tomato Preparations Separately and in Combination on the Stability of Vacuum-Packed Minced Pork During Storage
Authors: Michalczyk Magdalena , Macura Ryszard , Banaś Joanna , Tesarowicz Iwona , Maciejaszek Ireneusz
Published: September 2014

This paper investigates the effect of adding oregano essential oil (0.02% v/w), freeze-dried garlic (1%), tomato concentrate (15%) and a combination of all three (in the same concentrations) on the shelf life of minced pork meat. Vacuum-packed samples with additives and a control were stored at 6±1°C for 16 days. Sensory, microbiological and biochemical changes were analysed over the whole storage period. The beneficial effect of oregano essential oil was generally to inhibit lipid oxidation, although its effect on bacterial growth was very weak. Adding tomato concentrate, combined with other additives, slowed the rate of microbiological and sensory changes, but had a marked effect on changes in proteins (SDS-PAGE analysis) and the proportion of meat pigments. The addition of freeze-dried garlic did not cause a substantial reduction of detectable bacteria count. Adding a combination of all three additives resulted in a product with a distinctly longer shelf life.
The Effect of a Coat Colour-Associated Genes Polymorphism on Animal Health – A Review
Authors: Charon Krystyna M. , Lipka Katarzyna R.
Published: September 2014

In recent years, the knowledge regarding molecular mechanisms of skin, hair and eye colouration in vertebrates has significantly broadened. It was found that some of the identified coat colour genes show negative pleiotropic effect. They are associated with hereditary diseases, often of a lethal character. Most of these diseases have their counterparts in humans. There is no effective treatment for these diseases, therefore animal models can help to identify the genetic background of diseases and to develop appropriate treatment. Much less is known on the association of coat colour with animal performance. However, there are reports on the effect of coat colour on body measurements and milk production in subtropical environments. The knowledge on pleiotropic effects of coat colour genes is important for breeders who should be aware of the consequences of their decision on mating animals with given genotype.
Characterization and Physicochemical Evaluation of Molecular Complexes Formed Between Umifenovir and Dicarboxylic Acids
Authors: Kons A. , Bērziņš A. , Krūkle-Bērziņa K. , Actiņš A.
Published: September 2014

The paper reports the investigation of three umifenovir molecular complexes with dicarboxylic acids, prepared to improve the bioavailability of this drug. All three molecular complexes were investigated by powder X-ray diffraction, infrared spectroscopy, and solid-state nuclear magnetic resonance spectroscopy. The solubility and thermal properties were determined as well. Polymorph and solvate screening of umifenovir molecular complexes were performed by recrystallization from various solvents, as well as neat and solvent-drop grinding
Białowieża Forest (Ne-Poland) and Valday Np ( Nw-Russia) – Biogeographical Characteristics of Eutrophic Deciduous Forests
Authors: Matuszkiewicz Jan Marek , Bielonowska Elena , Kowalska Anna , Cariewska Nadjeżda , Baranowski Jarosław , Vinogradowa Viera , Tishkov Arkadij , Litvinova Elena
Published: September 2014

During geobotanical studies in the north-eastern border of hemi-boreal zone, in Valday (NW Russia), rare eutrophic deciduous forests dominated by oak Quercus robur were observed. A comparison of these forests with the model of European deciduous forest in Białowieża National Park (NE-Poland) indicates a great similarity. Therefore, eutrophic deciduous forests in Valday can be classified to the Querco-Fagetea class, the Fagetalia sylvaticae order and to the Capinion betuli alliance, despite the absence of hornbeam Carpinus betulus in the region. Rarity of eutrophic deciduous forests in Valday region results probably from strong anthropogenic pressure in the past.
A new species of Eimeria (Apicomplexa: Eimeriidae) from tri-colored bats, Perimyotis subflavus (Chiroptera: Vespertilionidae), from the Ouachitas of Arkansas
Authors: McAllister Chris , Seville R. , Arlen Robert , Connior Matthew
Published: September 2014

Between February 2013 and October 2013, eleven tri-colored bats, Perimyotis subflavus were collected from Marion, Polk, and Searcy counties, Arkansas, and their faeces examined for coccidian parasites. Two of eleven (18%) harboured an eimerian that we describe here as new. Oocysts of Eimeria mcdanieli sp. n. were ellipsoidal to elongate with a bi-layered wall and measured (length × width, L × W) 28.3 × 17.9 μm, with an L/W ratio of 1.6. A micropyle and oocyst residuum were absent but a single polar granule was present. Sporocysts were ovoidal, 12.6 × 8.3 μm, with an L/W ratio of 1.5. A pronounced, nipple-like Stieda body was present as well as a substieda body. A sporocyst residuum was present as dispersed bubble-like granules. This is the third coccidian described from tri-colored bats and the sixth species reported from Arkansas chiropterans. In addition, both infected bats harbored a concurrent infection of Eimeria heidti McAllister, Burt, Seville, and Robison, 2011.
An Innovative Peer Assessment Approach to Enhance Guideline Adherence in Physical Therapy: Single-Masked, Cluster-Randomized Controlled Trial
Authors: Maas Marjo J.M. , van der Wees Philip J. , Braam Carla , Koetsenruijter Jan , Heerkens Yvonne F. , van der Vleuten Cees P.M. , Nijhuis-van der Sanden Maria W.G.
Published: September 2014

Background

Clinical practice guidelines (CPGs) are not readily implemented in clinical practice. One of the impeding factors is that physical therapists do not hold realistic perceptions of their adherence to CPGs. Peer assessment (PA) is an implementation strategy that aims at improving guideline adherence by enhancing reflective practice, awareness of professional performance, and attainment of personal goals.

Objective

The purpose of this study was to compare the effectiveness of PA with the usual case discussion (CD) strategy on adherence to CPGs for physical therapist management of upper extremity complaints.

Design

A single-masked, cluster-randomized controlled trial with pretest-posttest design was conducted.

Intervention

Twenty communities of practice (n=149 physical therapists) were randomly assigned to groups receiving PA or CD, with both interventions consisting of 4 sessions over 6 months. Both PA and CD groups worked on identical clinical cases relevant to the guidelines. Peer assessment focused on individual performance observed and evaluated by peers; CD focused on discussion.

Outcomes

Guideline adherence was measured with clinical vignettes, reflective practice was measured with the Self-Reflection and Insight Scale (SRIS), awareness of performance was measured via the correlation between perceived and assessed improvement, and attainment of personal goals was measured with written commitments to change.

Results

The PA groups improved more on guideline adherence compared with the CD groups (effect=22.52; 95% confidence interval [95% CI]=2.38, 42.66; P=.03). The SRIS scores did not differ between PA and CD groups. Awareness of performance was greater for the PA groups (r=.36) than for the CD groups (r=.08) (effect=14.73; 95% CI=2.78, 26.68; P=.01). The PA strategy was more effective than the CD strategy in attaining personal goals (effect=0.50; 95% CI=0.04, 0.96; P=.03).

Limitations

Limited validity of clinical vignettes as a proxy measure of clinical practice was a limitation of the study.

Conclusions

Peer assessment was more effective than CD in improving adherence to CPGs. Personal feedback may have contributed to its effectiveness. Future research should address the role of the group coach.
Transportation Network Vulnerability
Authors: Du Qianqian , Kishi Kunihiro , Aiura Nobunori , Nakatsuji Takashi
Published: September 2014

Transport is a fundamental part of logistics activities, which play a critical role in the development of society. The safety and the reliability of logistics transportation networks significantly affect those activities. Network vulnerability assessment has been applied in the passenger transport mode. However, the methodology to assess the vulnerability of logistics transportation networks should be developed differently from that of passenger or other transport modes because of the networks’ specific requirements for trip success. This paper proposes a methodology applicable in logistics transportation network vulnerability assessment. To evaluate the performance of logistics transportation networks, logistics value is included in the generalized cost of logistics transportation. Moreover, network vulnerability assessment is affected by the nature of the component degradation. Here, the performance of logistics transportation networks is evaluated in transportation facility degradation scenarios. A vulnerability scanning algorithm is applied in link and node degradation scenarios. To reduce computational demands, an efficient vulnerability scanning algorithm is applied to the simulation, and a computer program is developed to make this methodology feasible in large-scale networks. Finally, this methodology based on future highspeed railway planning is applied in a real logistics transport network in northern Japan. The research was undertaken to assist logistics managers, researchers, and transportation planners in defining and comprehending the basic views of the vulnerability of logistics transportation networks and their various applications.
Logistics Sprawl
Authors: Dablanc Laetitia , Ogilvie Scott , Goodchild Anne
Published: September 2014

The warehousing industry experienced a period of rapid growth from 1998 to 2009. This paper compares the growth in geographic distribution of warehouses in the Los Angeles, California, and Seattle, Washington, metropolitan areas during that period. These two West Coast cities were chosen because of their geographic spread, proximity to major ports, as well as their size difference. The phenomenon of logistics sprawl, or the movement of logistics facilities away from urban centers, which has been demonstrated in past research for the Atlanta, Georgia, and Paris regions, is examined for the two metropolitan areas. To measure sprawl, the barycenter, or geographic center of warehousing establishments, is determined, as is the average distance of warehouses to that center. The average distance of warehouses to the warehousing barycenter was compared with the average distance from the barycenter for all establishments. Between 1998 and 2009, warehousing in Los Angeles sprawled considerably, with the average distance increasing from 25.91 to 31.96 mi, an increase of more than 6 mi. However in Seattle, the region locations remained relatively stable, showing a slight decrease in average distance from the geographic center. Possible explanations for that difference are discussed.
Receding Horizon Approach for Container Flow Assignment in Intermodal Freight Transport
Authors: Li L. , Negenborn R. R. , De Schutter B.
Published: September 2014

Hinterland haulage between major deep-sea ports and the cargoes’ inland origins or destinations has become an important component in modern logistic systems. Intermodal freight transport integrates the use of modalities (e.g., trucks, trains, and barges) during the freight delivery process to improve the efficiency and reliability of hinterland haulage. In this paper, intermodal freight transport is introduced and existing intermodal container (freight) transport planning approaches are presented. Next, a dynamic intermodal transport network (ITN) model developed by the authors in an earlier work is briefly recapitulated. To deal with the dynamic transport demand and the dynamic traffic conditions in the ITN, a so-called receding horizon approach is proposed to address the intermodal container flow assignment problem between deep-sea terminals and inland terminals in hinterland cargo transport. The proposed approach considers the movement of containers as a flow and makes container flow assignment decisions in a receding horizon fashion during the container transport process. At each time step of the process, behavior of the ITN is predicted by using a dynamic ITN model with load-dependent freeway transport times fed with information on the current and estimated transport demands and traffic conditions. To determine container assignments with this model, a nonlinear optimization problem is solved at each time step. Simulation studies for intermodal container flow assignments are conducted by using an all-or-nothing approach and the proposed receding horizon approach.
Customer Loyalty Differences between Captive and Choice Transit Riders
Authors: Zhao Jinhua , Webb Valerie , Shah Punit
Published: September 2014

Traditionally, efforts to increase the customer base of public transportation agencies have focused primarily on attracting first-time users. Customer retention, however, has many benefits not often realized. Loyal customers provide recommendations to others, increase and diversify their use of the service, and do not require acquisition costs associated with new customers. An earlier study identified key drivers of customer loyalty, with the Chicago Transit Authority (CTA) in Illinois as a case study. A customer loyalty model was created with service value, service quality, customer satisfaction, problem experience, and perception of CTA as constructs. The present study examined customer loyalty differences of captive and choice riders. Captive riders had no viable travel alternatives and might have continued to use transit even if unhappy with service. Choice riders chose to use transit after they compared travel options and might have switched to an alternative if service degraded. Captive riders reported experiencing more problems and were more sensitive to problems; each additional problem brought significant drops in service quality ratings. Captive riders tolerated problems and continued to use transit but showed discontent through their ratings of service quality. Service value was insignificant in captive riders’ loyalty decisions because cost–benefit analysis defined service value as irrelevant to them. The relationship between perceptions of CTA and of service quality was stronger for choice riders. If they began the service with high opinions of the transit agency, they were much more likely to have high ratings of service quality than were captive riders.
Effect of RhOx/CeO2 Calcination on Metal-Support Interaction and Catalytic Activity for N2O Decomposition
Authors: Rico-Pérez Verónica , Bueno-López Agustin
Published: September 2014

The effect of the calcination conditions on the catalytic activity for N2O decomposition of 2.5% RhOx/CeO2 catalysts has been investigated. Ramp and flash calcinations have been studied (starting calcinations at 25 or 250/350 °C, respectively) both for cerium nitrate and ceria-impregnated rhodium nitrate decomposition. The cerium nitrate calcination ramp has neither an effect on the physico-chemical properties of ceria, observed by XRD, Raman spectroscopy and N2 adsorption, nor an effect on the catalysts performance for N2O decomposition. On the contrary, flash calcination of rhodium nitrate improved the catalytic activity for N2O decomposition. This is attributed to the smaller size of RhOx nanoparticles obtained (smaller than 1 nm) which allow a higher rhodium oxide-ceria interface, favoring the reducibility of the ceria surface and stabilizing the RhOx species under reaction conditions.
An Entropy-Based Upper Bound Methodology for Robust Predictive Multi-Mode RCPSP Schedules
Authors: Chen Angela , Liang Yun-Chia , Padilla Jose
Published: September 2014

Projects are an important part of our activities and regardless of their magnitude, scheduling is at the very core of every project. In an ideal world makespan minimization, which is the most commonly sought objective, would give us an advantage. However, every time we execute a project we have to deal with uncertainty; part of it coming from known sources and part remaining unknown until it affects us. For this reason, it is much more practical to focus on making our schedules robust, capable of handling uncertainty, and even to determine a range in which the project could be completed. In this paper we focus on an approach to determine such a range for the Multi-mode Resource Constrained Project Scheduling Problem (MRCPSP), a widely researched, NP-complete problem, but without adding any subjective considerations to its estimation. We do this by using a concept well known in the domain of thermodynamics, entropy and a three-stage approach. First we use Artificial Bee Colony (ABC)—an effective and powerful meta-heuristic—to determine a schedule with minimized makespan which serves as a lower bound. The second stage defines buffer times and creates an upper bound makespan using an entropy function, with the advantage over other methods that it only considers elements which are inherent to the schedule itself and does not introduce any subjectivity to the buffer time generation. In the last stage, we use the ABC algorithm with an objective function that seeks to maximize robustness while staying within the makespan boundaries defined previously and in some cases even below the lower boundary. We evaluate our approach with two different benchmarks sets: when using the PSPLIB for the MRCPSP benchmark set, the computational results indicate that it is possible to generate robust schedules which generally result in an increase of less than 10% of the best known solutions while increasing the robustness in at least 20% for practically every benchmark set. And, in an attempt to solve larger instances with 50 or 100 activities, we also used the MRCPSP/max benchmark sets, where the increase of the makespan is approximately 35% with respect to the best known solutions at the same time as with a 20% increase in robustness.