bluuebunny/crossref_metadata_2025 huggingface dataset:
Generic Correlations for Proppant Pack Conductivity
Authors: Barree R. D. , Miskimins J. L. , Conway M. W. , Duenckel R.
Published: January 2016

With the large number of fracture stages, and size of jobs being pumped in horizontal wells, many companies have elected to use non-standard, or non-commercial natural sands as propping agents. The Stim-Lab Proppant Conductivity Consortium, supported by approximately 50 proppant suppliers, pumping service companies and operators, has developed consistent laboratory conductivity test procedures over the past 30 years that have become de-facto industry standards. One outcome of this long history of proppant testing is a set of correlations that can predict the baseline conductivity, as a function of closure stress and rock (substrate) properties, within the range of uncertainty of laboratory tests. Inputs to the correlations are basic material property measurements such as specific gravity and median particle size of the sieve distribution. The correlations can be used to compare materials of unknown properties to standardized data sets, or to develop useful predictions of how a non-standard material is likely to perform. The correlations are general enough for application to brown sand, white sand, resin-coated materials, and ceramic proppants of various sizes and densities. These correlations have been found to be sufficient for comparing proppants and for estimating their performance in production computations, when adjustments for appropriate damage and cleanup are made to the calculated baseline conductivity values.
Mesh-Free Numerical Simulation of Pressure-Driven Fractures in Brittle Rocks
Authors: Douillet-Grellier T. , Pramanik R. , Pan K. , Albaiz A. , Jones B. D. , Pourpak H. , Williams J. R.
Published: January 2016

A better understanding of failure in heterogeneous rock materials can benefit a wide range of areas, from earthquake engineering to petroleum engineering. Study of such failure is of particular interest in the field of hydraulic fracturing. The prediction of this breakage phenomenon is a big challenge for the scientific community. Traditional continuum modeling techniques have the advantage of using classical nonlinear material models, however they often fail to accurately capture the complexity of the fractured geometry and path of multiple intersecting fractures. In particular, mesh dependence of the fracture path, 3D representation of natural fractures and their intersections, closing of an opened fracture, or shear in fractures, are difficult to accurately capture using these techniques.

The use of the smoothed particle hydrodynamics (SPH) method for simulation of fracture in solids is relatively recent, where mesh free methods like SPH have the potential to overcome the previously mentioned limitations of mesh based methods. Simulation of the initiation and propagation of pressure-driven fractures in brittle rocks is presented in this study. By exploiting techniques commonly used in traditional continuum methods, we have implemented an elasto-plastic SPH model, which is based on the Drucker-Prager yield criterion, and the Grady-Kipp damage model. Results show that SPH is able to correctly predict the evolution of fracture in brittle rocks.

The SPH method has been applied to the solution of crack propagation in a variety of test cases, including a pressurized borehole, 2D line crack, and 3D penny shaped crack. The influence of initial in-situ stresses was also accounted for. Comparison of SPH results for these cases to analytical solutions shows that SPH may be applied to accurately simulate the evolution of fluid-driven fractures in brittle rocks. Such model is a vital tool in correctly predicting fracture propagation in highly heterogeneous formations, for instance, shale formations.
Lessons Learned From Refractured Wells: Using Data to Develop an Engineered Approach to Rejuvenation
Authors: Li Chunlou , Han Jiahang , LaFollette Randy , Kotov Sergey
Published: January 2016

During the life time of a production well, sometimes it is inevitable that remediation methods have to be adopted for different reasons. Hydraulic fracturing is one of the common ways to boost production by either reopening existing fractures or creating new fractures. Considering the large number of unconventional wells that have experienced sharp production declines and the current tight budget for drilling new wells, refracturing will certainly become an important technology worthy of more investigation.

This paper reviews the production and completion data for a number of wells that have been re-stimulated by hydraulic fracturing since 2011. Wells with enough production data were selected to evaluate their production responses by comparing both the cumulative production in a fixed period of time before and after the re-stimulation and by evaluating incremental production increase normalized by amount of proppant used to restimulate the well. Wells involved in the study had been producing from various formations for different periods of time before restimulation. In addition to the analysis above, this study went a step further by attempting to understand the reasons behind inconsistent results after refracturing: high performance of some wells and the failure of the others to meet production expectations.

Two re-completion effectiveness indexes are defined in the paper based on production performance before and after restimulation and on re-completion job size. Overall, the study shows mixed results. Although some formations demonstrated much more favorable response than others, it was also possible for wells producing from the same formation to have extremely different responses to the restimulation. Candidates for restimulation should be evaluated carefully, to include their level of depletion, the petrophysical and geomechanical properties of the rock, and previous well completion and stimulation. These data and measurements are required to engineer an appropriate refracturing or recompletion design. The study also shows very promising results from refracturing some long-producing conventional wells, which indicate opportunities to rejuvenate old wells with hydraulic fracturing.

This study provides an overview of the lessons learned from examination of a limited data set of hydraulic fracturing restimulations done in the past five years.
A Case Study of Completion Effectiveness in the Eagle Ford Shale Using DAS/DTS Observations and Hydraulic Fracture Modeling
Authors: Wheaton B. , Haustveit K. , Deeg W. , Miskimins J. , Barree R.
Published: January 2016

The objective of this study was to evaluate treatment distribution and fracture geometry in a multi-stage, multi-cluster fracture completion performed in a horizontal Eagle Ford well. Distributed Acoustic Sensing (DAS) and Distributed Temperature Sensing (DTS) data were acquired on the subject well. The DAS/DTS-observed fracture treatment distributions were then modeled in a three-dimensional fracture model in an effort to visually represent resultant fracture geometries. This process was used to evaluate the impacts on the resulting treatment distributions that occurred as a result of stress-shadowing between fractures. The ultimate goal was to understand the influence that adjacent fractures within a stage and adjacent stages have on fracture distribution, fracture geometry, and completion effectiveness.

DAS/DTS data suggest a high level of interference between adjacent fractures. Interference between adjacent fractures within a given stage, and from adjacent fracture stages, results in a consistent geometric predominance for fracture growth in the most heel-ward perforation cluster. DAS/DTS results also indicate that an excessive number of perforation clusters, spaced closely together, magnify the negative effects of stress shadowing, and potentially diminish completion effectiveness.

Operationally, the DAS/DTS data showed that the surface pressure response originally attributed to downhole diversion from particulate diverters was in fact not due to diversion. Once a dominate fracture was established in a given stage, it remained dominate throughout the entire stage even though two diverter drops per stage were incorporated into the treatment. Finally, the DAS/DTS data indicated that a significant portion (71%) of the stages experienced intra-stage communication. The large majority of this communication was due to plug leakage.
Acoustics-Based Flow Monitoring During Hydraulic Fracturing
Authors: Stokely Christopher L.
Published: January 2016

A "semi-empirical" acoustics-based flow model is presented based on large scale flow loop testing using water, water thickened with a linear gel, and linear gel slurries containing various amounts of proppant. The flow model predicts volumetric flow rate through individual perforation clusters from calibrated high fidelity accelerometer measurements and knowledge of the fluid type and perforation cluster geometry. This model is applicable to the plug-and-perf completion often used in hydraulic fracturing of unconventional resources. The accelerometer data provides a benchmark for downhole fiber-optic distributed acoustic sensing (DAS).

Custom flow loops were constructed and tested to measure acoustic signals generated by fluid turbulently flowing through simulated downhole perforations using water, water with a linear gel, and slurries containing ceramic proppant. Flow rates, perforation-hole sizes, number of clusters, number of perforations per cluster, fluid viscosity, and proppant slurry density were varied in a controlled way. These parameters were adjusted to represent a downhole stimulation treatment. The data was evaluated using symbolic regression with a 1,000-core compute cluster. Approximately three trillion analytic models were evaluated and scored for prediction accuracy and model simplicity.

The data indicated that all of the fluids became significantly louder above a critical threshold. This threshold was observed to strongly depend on fluid viscosity, while no dependence was observed on the amount of proppant in the slurry. The discharge coefficient showed significant variability, even among repeated experiments when no erosion was present. Very different behaviors for the coefficient of discharge were observed between water and gelled water. The measurements and model provide a benchmark for wellbore monitoring with fiber-optic distributed acoustic measurements during stimulation. Accurate real-time flow allocation estimation allows for an immediate adjustment of treatment strategy using, for example, diverter spheres. Accurate flow allocation could possibly allow changes in stage designs to tune individual flow rates.

Analytic expressions were derived relating the root-mean-square of the acoustic signal to both the perforation pressure loss and the flow speed per perforation as a function of cluster injection rate, viscosity, perforation diameter, and number of perforations. The relative importance of each of these variables was investigated and is quantitatively described. Several models for flow and accuracy were investigated and are discussed.
Identification of Activated Fracture Networks Using Microseismic Spatial Anomalies, b-values, and Magnitude Analyses in Horn River Basin
Authors: Yousefzadeh Abdolnaser , Li Qi , Virues Claudio , Aguilera Roberto
Published: January 2016

We analyzed microseismic spatial and temporal distribution, magnitudes, b-values and treatment data to interpret and explain the observed anomalies in microseismic events recorded during exploitation of Shale Gas reservoirs in the Horn River Basin of Canada.

We estimated the directional diffusivity to define the microseismicity front curve for each stage of hydraulic fracturing. Based on our definition of front curves, we managed to separate most of the microseismic events data that are related to natural fracture activation from hydraulic fracturing events. We analyzed the b-values for microseismic events of each stage before and after separating fracture activation microseismic events from original data and created a map of b-values in the study area. This allowed us to locate activated fractures mostly in the northeastern part of the study well pad. The b- value map agrees with our assumption of activated fracture locations and high ratio of seismic activities.

Suggested fracture locations agree with anomalous events' density, energy distribution and treatment data. We are defining and proposing intermediate b-values for calculation of the stimulated reservoir volume (SRV) in areas with both hydraulically fractured events and events related to natural fracture network activation in those instances where the separation of events based on their origin is not viable.
Recent Advancements in Far-Field Proppant Detection
Authors: Palisch Terry , Al-Tailji Wadhah , Bartel Lew , Cannan Chad , Czapski Matt , Lynch Keith
Published: January 2016

The combination of multistage hydraulic fracture treatments with horizontal drilling technology has been the primary driver to the successful development of resource plays. More than 85% of wells drilled in North America today employ these methods. However, while these technologies have been wildly successful, only recently has the industry begun to address in earnest, the efficiency of current practices. These completion and development optimization efforts require an understanding of which portions of the reservoir have not been adequately contacted/stimulated and are thereby failing to contribute to production, and ultimate hydrocarbon recovery. Understanding where the proppant is located, both near- and far-field, is the starting point for these evaluations, and is the basis for this paper.

Traditional fracture mapping technologies provide indirect estimates of fluid distribution within the fracture network. However, there is little direct correlation between fluid distribution and proppant location, and since most unpropped portions of fractures rapidly collapse, identification of the proppant location better represents the region which contributes to ultimate recovery. Near-wellbore detection of proppant can provide insight into whether all perf clusters (in the case of plug and perf) have received proppant as well as the impacts of proppant overflush. Conversely, accurate determination of far-field proppant placement will affect everything from well and stage spacing, to stage design and refrac candidate selection, and allow significant optimization of diversion techniques. While knowledge of both near- and far-field proppant location is necessary for the industry to overcome the single-digit recovery factors that are now projected in many unconventional plays, far-field proppant detection techniques have been largely absent to date.

This paper briefly reviews the current "state of the industry" regarding near-wellbore proppant detection technology. It then presents a novel far-field proppant detection technique which utilizes electro-magnetic differencing and a specialty detectable proppant. This includes a description of the technology as well as the methodology of the technique. In addition, the paper reviews the design and results from a recent (first-ever) field deployment of this technology in a horizontal Permian Basin well. Visualization of the proppant in the far-field is also shown.

This paper should be beneficial to all engineers and technologists currently interested in evaluating completion efficiencies as well as fracture stimulation effectiveness. Understanding proppant location in both the near- and far-field regions has significant impact on well spacing, stage and perf cluster spacing, and ultimate recovery from stimulated horizontal wells.
The Application and Misapplication of 100-Mesh Sand in Multi-Fractured Horizontal Wells in Low-Permeability Reservoirs
Authors: Al-Tailji W. H. , Shah K. , Davidson B. M.
Published: January 2016

With multi-fractured horizontal wellbores being the primary means to economically access hydrocarbon resources in low- and ultra-low permeability reservoirs, a multitude of completion and stimulation practices can be employed along the lateral section of the wellbore. Completion (staging method, perforations, cluster spacing, etc.) and stimulation (fluid type, proppant type, proppant concentrations, etc.) design parameters are typically adjusted in order to accelerate hydrocarbon recovery and improve ultimate recovery.

One practice that has been gaining popularity as a method of maximizing contact area and accelerating hydrocarbon recoveries in many shale plays is the combination of thin water-based fracturing fluids, small-mesh proppants (mostly 100 mesh sand with some 40/70 mesh sand), and a high intensity of injection points in each fracture stimulation stage. The theory behind this practice is that thinner fluids and smaller mesh proppants can generate more fracture complexity in shale formations, thereby increasing contact area which is of high importance in very low permeability reservoirs, and smaller mesh proppants can be transported at larger distances than larger proppants such as 20/40 and 30/50 mesh.

Historic hydraulic fracturing practice prior to the shale boom had previously utilized small quantities of small mesh proppants such as 100 mesh sand to assist with hydraulic fracture generation and placement. However, many publications often cautioned against the use of significant quantities of these small proppants, due to the adverse impact it would have on fracture conductivity in tight gas reservoirs with permeabilities on the order of 0.01 to 1 millidarcy or greater. However, many shale plays currently in development, such as the Bakken, Eagle Ford, and Haynesville formations, have significantly lower permeabilities than tight gas plays, on the order of 1 to 1,000 nanodarcy (Walls and Sinclair, 2011), potentially elevating 100 mesh sand to "proppant" status.

This paper will critically evaluate the historic and contemporary uses of 100 mesh sand both as a placement aid as well as a proppant in very low permeability reservoirs. The effects of fracture conductivity in naturally-fractured reservoir will be explored in order to determine how much conductivity is sufficient to adequately drain the reservoir, and if using 100 mesh sand as a proppant is appropriate for this purpose. An evaluation of large datasets from publically-derived completion and production data to statistically evaluate the successes of different completion practices and a couple of specific case studies will be presented to illustrate some ways where operators can exceed the statistical mean well performance in their particular area, without needing to resort to using large fluid volume waterfrac treatments with small mesh proppants.
A Coupled Geomechanics and Fluid Flow Modeling Study for Hydraulic Fracture Design and Production Optimization in an Eagle Ford Shale Oil Reservoir
Authors: Curnow Jennifer S. , Tutuncu Azra N.
Published: January 2016

The benefits of hydraulic fracturing horizontal wells in unconventional reservoirs for production enhancement are evident; however, the best methods to truly increase recovery efficiency through these stimulations are still under examination. Analogous to how operators and service companies discovered that Barnett-style slickwater treatments were not successful in all reservoirs, companies are beginning to recognize the importance of engineered stimulations, specifically in regard to geomechanics. Rather than perforating for only production purposes, hydraulic fracturing design has now turned its focus to perforating for reservoir rock stimulation. Enhanced fracture network complexity through induced fractures greatly increases the contact area and reservoir drainage for maximum productivity. However, to accomplish the stimulation of both primary and secondary fracture networks, the coupled behaviors of geomechanics and fluid flow in response to the hydraulic fracturing operations must be considered. In this research study, development of a coupled geomechanics and fluid flow model for the purpose of hydraulic fracture design optimization through the evaluation of different stimulation patterns with primary focus on how the stress and strain distributions within the reservoir that affect porosity and permeability, ultimately influence flow has been discussed in detail. The patterns under consideration include the Zipper, Texas Two-Step, and Modified Zipper designs. Although the Texas Two-Step Pattern requires a special down-hole tool and as such is very difficult operationally to perform, it is being considered in this analysis for conceptual purposes concerning the stress behavior within a single lateral well. Furthermore within these patterns, the well locations and hydraulic fracture properties have been analyzed to determine the optimum design for a shale oil reservoir based on recovery efficiency and generated fracture complexity.

The results of this study indicate that with the staggered fracture placement offered by the Modified Zipper Pattern, a highly conductive secondary complex fracture network is generated allowing for enhanced hydrocarbon recovery. In comparison to the Zipper and Texas Two-Step Patterns, the Modified Zipper Pattern reduces the stress anisotropy within the formation to a much greater extent, aiding in the fracture generation process to increase the flow area. This advantage coupled with its high oil recovery factor and potential for greater drilling density discerns the Modified Zipper as the ideal pattern for the development of an Eagle Ford-type shale oil reservoir.
Interpretation Methodology for Fracture Calibration Test Before-Closure Analysis of Normal and Abnormal Leakoff Mechanisms
Authors: Liu Guoqing , Ehlig-Economides Christine
Published: January 2016

Recent analytical models for abnormal and normal leakoff mechanisms of the pressure falloff behavior in fracture calibration tests (DFITs) provide means to match virtually all of the behavior. The match provides both the parameters related to normal leakoff behavior including closure pressure and the leakoff coefficient as well as abnormal leakoff parameters including tip extension distance and minimum fracture propagation pressure, closure pressures, leakoff coefficients, and leakoff areas for the coupled primary and secondary fracture system. The purpose of this paper is to provide a methodology for identifying these behaviors and quantifying all of the before closure parameters of interest to design of the main fracture treatment.

We use the behaviors seen on the log-log Bourdet and the G-function derivatives to identify a sequence of flow regimes and to estimate starting values for the parameters associated with each leakoff behavior. Simulation result with these starting estimated values are able to catch all identified leakoff features. Then we adjust the parameter starting values to achieve a global smooth match for the falloff data.

Equations developed for quick estimation of the starting values facilitate the model match with data. Several field cases with pressure dependent leakoff (PDL), tip-extension, multiple-closure phenomenon and transverse storage are taken as examples to illustrate the comprehensive modeling capability. The additional parameters quantified by this methodology have their reasonable physics and greatly enhance understanding of the role of tip extension and the induced secondary fracture system in the hydraulic fracture stimulation.
Advanced Modeling of Interwell Fracturing Interference: An Eagle Ford Shale Oil Study - Refracturing
Authors: Morales Adrian , Zhang Ke , Gakhar Kush , Marongiu Porcu Matteo , Lee Don , Shan Dan , Malpani Raj , Pope Tim , Sobernheim David , Acock Andrew
Published: January 2016

This paper continues the investigation of interwell fracturing interference for an infill drilling scenario synthetic case based on Eagle Ford available public data and explores pressure and stress-sink mitigation strategies applied to the simulation cases developed in the previous publication (SPE 174902). Emphasis is given to refracturing scenarios, given the intrinsic restimulation value for depleted parent wells and the strategic importance due to the current low oil prices.

The stress and pressure depletion methodology is expanded in this paper, adding a refracturing scenario before the infill child well is stimulated. Changes in stress magnitudes and azimuths caused by new and reactivated fractures are calculated using a finite element model (FEM). After refracturing the parent well, modeling shows that stress deflection and repressurization of the originally depleted production zone will reduce subsequent fracture hits from infill wells.

The first mechanism to reduce fracture hits is the stress realignment, which promotes transverse fracture propagation from the infill well away from the parent well. The second fracture-hit-reduction mechanism is repressurization of depleted zones to hinder fracture propagation in lower-pressure zones. Prevention of fracture hits by active deflection results in an increased stimulated reservoir volume (SRV) for both the parent and child wells. Overall pad level and individual wellbore cumulative production experience a significant increase due to increased SRV. With proper reservoir and geomechanical data, this approach can be applied in a predictive manner to decrease fracture-hit risk and improve overall recovery.

This workflow represents the first comprehensive multidisciplinary approach to coupling geomechanical, complex hydraulic fracture models, and multiwell production simulation models aimed towards understanding fracture-hit reduction using refracturing. The workflow presented can be applied to study and design an optimum refracturing job to prevent potentially catastrophic fracture hits during refracturing operations.
The role of word frequencies in detecting unfamiliar terms and their effect on response quality
Authors: Slavec Ana , Vehovar Vasja
Published: January 2016

Research into cognitive aspects of survey response has indicated unfamiliar
terms as one of the psycholinguistic determinants of question
comprehensibility problems. In this paper the estimates of wording
familiarity based on text corpora for the English and Slovenian languages
were used to detect potentially incomprehensible wordings in two web survey
questionnaires for international exchange students at the University of
Ljubljana, one for incoming (English) and the other for outgoing students
(Slovenian). Two versions of the questionnaire were developed for each
language, one with low-frequency (complex) and the other with high-frequency
(improved) wordings, and compared in a split-ballot experiment. The results
show a lower drop-out rate and a decreased subjective perception of
difficulty for the improved language versions.
Controlling acquiescence bias in measurement invariance tests
Authors: Aichholzer Julian
Published: January 2016

Assessing measurement invariance (MI) is an important cornerstone in
establishing equivalence of instruments and comparability of constructs.
However, a common concern is that respondent differences in acquiescence
response style (ARS) behavior could entail a lack of MI for the measured
constructs. This study investigates if and how ARS impacts MI and the level
of MI achieved. Data from two representative samples and two popular short
Big Five personality scales were analyzed to study hypothesized ARS
differences among educational groups. Multiple-group factor analysis and the
random intercept method for controlling ARS are used to investigate MI with
and without controlling for ARS. Results suggest that, contrary to
expectations, controlling for ARS had little impact on conclusions regarding
the level of MI of the instruments. Thus, the results suggest that testing MI
is not an appropriate means for detecting ARS differences per se.
Implications and further research areas are discussed.
Residential Preference and Choice of Movers in Light Rail Neighborhoods in Minneapolis, Minnesota
Authors: Cao Xinyu (Jason)
Published: January 2016

Light rail transit (LRT) has advocated for ridership growth, but not all residents move to LRT corridors because of transit. This study explores motivations of people moving to the Hiawatha LRT corridor in the Minneapolis–Saint Paul, Minnesota, metropolitan area and how their preferences factor into location choice. Few differences in residential preferences, except for transit preferences, are found between people moving to the Hiawatha and urban control corridors. Transportation-disadvantaged people and people who prefer transit are more likely to live in a location that is mismatched with their preferences for transit characteristics. Good transit service and job accessibility are important for urban and suburban residents, but affordability and safety dominate location choice. These findings highlight the importance of neighborhood design in addition to rail transit investment.
Adaptive Transport Supply and Demand Management Strategies in an Integrated Land Use and Transport Model
Authors: Ma Xiaosu , Lo Hong K.
Published: January 2016

The importance of a robust transport and land use development policy is widely recognized because the economy and population growth are subject to uncertainty. This study incorporated recourse considerations into the formulation of transport supply and demand management strategies that could be implemented adaptively over time as the uncertain phenomena were gradually revealed. The formulation took the form of a multistage stochastic program with equilibrium constraints and the planning horizon was divided into stages. A numerical example was constructed to illustrate and evaluate the additional benefits of this adaptive approach under demand uncertainty compared with the traditional deterministic approach.
Activity Space of Older and Working-Age Adults in the Puget Sound Region, Washington
Authors: Kim Sungyop , Ulfarsson Gudmundur F.
Published: January 2016

This work investigated the effect of personal, household, and neighborhood characteristics on variations in activity space through the use of a shortest network path buffer approach. A special focus was on the comparison of older adults (age 65 years and older, sample size of 591) with working-age adults (age 25 to 59 years, sample size of 1,806) to understand better the changes in activity space with age. Because activity space was a limited measure of social activity dependent on assumptions, this work investigated relative differences in the geographic reach of activity space and factors that increased or decreased that reach. The data were from the 2006 Household Activity Survey conducted in the Puget Sound, Washington, region. Descriptive data analysis showed that older adults on average had a substantially smaller (23%) geographic reach of activity space compared with working-age adults and that older adults who did not drive had the smallest geographic reach of activity space, only 16.7% of the overall average. The regression model results showed that low household income, often correlated with reduced mobility, was associated with a reduced geographic reach of activity space for older adults. Activity frequency significantly increased the geographic reach of activity space, and the effect was larger for older adults. The geographic reach of activity space was associated with neighborhood characteristics. Living in suburban and exurban neighborhoods led to a larger geographic reach of activity space for both older and working-age adults, while living in mixed use neighborhoods led to a smaller geographic reach of activity space.
Travel Patterns, Needs, and Barriers of Adults with Autism Spectrum Disorder
Authors: Deka Devajyoti , Feeley Cecilia , Lubin Andrea
Published: January 2016

Although autism spectrum disorder (ASD) has received a substantial amount of attention in other fields, very little appears in the transportation literature about people with ASD. Because the National Household Travel Survey and metropolitan travel surveys do not classify people with ASD as a separate category of persons with disabilities, very little information is available about their travel patterns, needs, or barriers. To bridge the existing information gap, this paper provides results from a recent survey that focused exclusively on adults with ASD in New Jersey to learn about their travel patterns, the importance of the various types of trips they make, and the barriers they encounter regarding the use of different transportation modes. The survey, distributed through various organizations throughout the state, was completed by or for 703 adults. Because the objective of the paper is to provide as much information as possible from the survey, no attempt has been made to compare the travel patterns, needs, and barriers of the survey respondents with those of the general population. However, other researchers can easily compare the survey results provided in this paper with data from other sources. Although the survey generated other valuable information, the most revealing information pertained to barriers to walking, driving, taking public transit, and even taking rides from others. The information collected through this research is being shared through outreach efforts with agencies that provide or fund transportation to persons with disabilities in New Jersey.
Approach Integrating Mixed-Integer Programming and Constraint Programming for Planning Rotations of Inland Vessels in a Large Seaport
Authors: Li Shijie , Negenborn Rudy R. , Lodewijks Gabriel
Published: January 2016

During the past decade, inland vessels have gained importance in container transport because of their reliability, low environmental impact, and major capacity for increased exploitation. Although inland vessels are crucial in container transport between terminals in the port and the hinterland, in a large seaport like the one in Rotterdam, Netherlands, only 62% of the inland vessels leave the port on time. The other vessels have to stay in the port area for a longer time than planned. This situation leads to uncertainty in waiting times of vessels at terminals and low utilization of terminal quay resources. A two-phase approach is proposed that integrates mixed-integer programming (MIP) and constraint programming (CP) to solve the problem by generating optimal rotation plans for inland vessels. In the first phase, the single-vessel optimization problem is formulated on the basis of MIP and solved with state-of-the-art MIP solvers. In the second phase, the multiple-vessel coordination problem is formulated on the basis of CP, and a large neighborhood search–based heuristic is proposed to solve the problem. Commercial CP solvers are also used for comparison. Simulation results show that the proposed large neighborhood search–based heuristic outperforms the commercial CP solver with regard to both the solution quality and the computation time. Moreover, simulation results with respect to departure time of the last vessel, total sojourn time, and waiting time show significant improvement with earlier departure times and shorter sojourn times and waiting times.
Pricing complexity options
Authors: Alikhani Malihe , Kjos-Hanssen Bjørn , Pakravan Amirarsalan , Saadat Babak
Published: January 2016

We consider options that pay the complexity deficiency of a sequence of up and down ticks of a stock upon exercise. We study the price of European and American versions of this option numerically for automatic complexity, and theoretically for Kolmogorov complexity. We also consider run complexity, which is a restricted form of automatic complexity.
Estimating the algorithmic complexity of stock markets
Authors: Brandouy Olivier , Delahaye Jean-Paul , Ma Lin
Published: January 2016

Randomness and regularities in finance are usually treated in probabilistic terms. In this paper, we develop a different approach in using a non-probabilistic framework based on the algorithmic information theory initially developed by Kolmogorov (1965). We develop a generic method to estimate the Kolmogorov complexity of numeric series. This approach is based on an iterative “regularity erasing procedure” (REP) implemented to use lossless compression algorithms on financial data. The REP is found to be necessary to detect hidden structures, as one should “wash out” well-established financial patterns (i.e. stylized facts) to prevent algorithmic tools from concentrating on these non-profitable patterns. The main contribution of this article is methodological: we show that some structural regularities, invisible with classical statistical tests, can be detected by this algorithmic method. Our final illustration on the daily Dow-Jones Index reveals a weak compression rate, once well- known regularities are removed from the raw data. This result could be associated to a high efficiency level of the New York Stock Exchange, although more effective algorithmic tools could improve this compression rate on detecting new structures in the future.
Synthesis and Anticancer Activity of Novel Thiazole-5-Carboxamide Derivatives
Authors: Cai Wen-Xi , Liu Ai-Lin , Li Zheng-Ming , Dong Wei-Li , Liu Xing-Hai , Sun Na-Bo
Published: January 2016

A series of novel 2-phenyl-4-trifluoromethyl thiazole-5-carboxamide derivatives have been synthesized and evaluated for their anticancer activity against A-549, Bel7402, and HCT-8 cell lines. Among the tested compounds, highest activity (48%) was achieved with the 4-chloro-2-methylphenyl amido substituted thiazole containing the 2-chlorophenyl group on the two position of the heterocyclic ring. Other structurally similar compounds displayed moderate activity. The key intermediates have been fully characterized.
Disease Transmission by Misfolded Prion-Protein Isoforms, Prion-Like Amyloids, Functional Amyloids and the Central Dogma
Authors: Daus Martin
Published: January 2016

In 1982, the term “prions” (proteinaceous infectious particles) was coined to specify a new principle of infection. A misfolded isoform of a cellular protein has been described as the causative agent of a fatal neurodegenerative disease. At the beginning of prion research scientists assumed that the infectious agent causing transmissible spongiform encephalopathy (TSE) was a virus, but some unconventional properties of these pathogens were difficult to bring in line with the prevailing viral model. The discovery that prions (obviously devoid of any coding nucleic acid) can store and transmit information similarly to DNA was initially even denoted as being “heretical” but is nowadays mainly accepted by the scientific community. This review describes, from a historical point of view, how the “protein-only hypothesis” expands the Central Dogma. Definition of both, the prion principle and the Central Dogma, have been essential steps to understand information storage and transfer within and among cells and organisms. Furthermore, the current understanding of the infectivity of prion-proteins after misfolding is summarized succinctly. Finally, prion-like amyloids and functional amyloids, as found in yeast and bacteria, will be discussed.
Analysis of Entropy Generation in Natural Convection of Nanofluid inside a Square Cavity Having Hot Solid Block: Tiwari and Das’ Model
Authors: Sheremet Mikhail , Oztop Hakan , Pop Ioan , Abu-Hamdeh Nidal
Published: January 2016

A computational work has been performed in this study to investigate the effects of solid isothermal partition insertion in a nanofluid filled cavity that is cooled via corner isothermal cooler. Mathematical model formulated in dimensionless primitive variables has been solved by finite volume method. The study is performed for different geometrical ratio of solid inserted block and corner isothermal cooler, Rayleigh number and solid volume fraction parameter of nanoparticles. It is observed that an insertion of nanoparticles leads to enhancement of heat transfer and attenuation of convective flow inside the cavity.
Review of the Thermo-Physical Properties and Performance Characteristics of a Refrigeration System Using Refrigerant-Based Nanofluids
Authors: Patil Mahesh , Kim Sung , Seo Jae-Hyeong , Lee Moo-Yeon
Published: January 2016

Nanofluids are considered a promising choice for several heat transfer applications. With the increasing awareness for energy saving and efficiency improvement in various thermal systems, including refrigeration systems, there is a growing interest in the refrigerant-based nanofluids owing to their superior thermo-physical properties. Nanorefrigerants are a class of nanofluid, which consist of suspended nanoparticles in a base refrigerant. In this paper, it is intended to include many articles on refrigeration systems that use nanorefrigerants, published in the period from 2005 to 2015. Although this is an extensive review, it could not include all the papers, and only some major research works were selected. It is believed that the dependency of thermal conductivity and other properties on temperature will make the thermal systems more efficient while operating at a high temperature. The literature reviews associated with the performance characteristics of nanorefrigerants in refrigeration systems for the last 10 years have been compiled and presented in this paper. Furthermore, recent studies related to thermo-physical properties of nanorefrigerants and nanolubricants have also been summarized and reviewed in this paper.
Decomposing Industrial Energy-Related CO2 Emissions in Yunnan Province, China: Switching to Low-Carbon Economic Growth
Authors: Deng Mingxiang , Li Wei , Hu Yan
Published: January 2016

As a less-developed province that has been chosen to be part of a low-carbon pilot project, Yunnan faces the challenge of maintaining rapid economic growth while reducing CO2 emissions. Understanding the drivers behind CO2 emission changes can help decouple economic growth from CO2 emissions. However, previous studies on the drivers of CO2 emissions in less-developed regions that focus on both production and final demand have been seldom conducted. In this study, a structural decomposition analysis-logarithmic mean Divisia index (SDA-LMDI) model was developed to find the drivers behind the CO2 emission changes during 1997–2012 in Yunnan, based on times series energy consumption and input-output data. The results demonstrated that the sharp rise in exports of high-carbon products from the metal processing and electricity sectors increased CO2 emissions, during 2002–2007. Although increased investments in the construction sector also increased CO2 emissions, during 2007–2012, the carbon intensity of Yunnan’s economy decreased substantially because the province vigorously developed hydropower and improved energy efficiency in energy-intensive sectors. Construction investments not only carbonized the GDP composition, but also formed a carbon-intensive production structure because of high-carbon supply chains. To further mitigate CO2 emissions in Yunnan, measures should promote the development and application of clean energy and the formation of consumption-based economic growth.
Research on Heat Recovery Technology for Reducing the Energy Consumption of Dedicated Ventilation Systems: An Application to the Operating Model of a Laboratory
Authors: Zhang Lian , Zhang Yu
Published: January 2016

In this research, the application of heat pipes in the air handler dedicated to decoupling dehumidification from cooling to reduce energy consumption was simulated and investigated by simulations and experimental studies. The cooling load profiles and heat pipes with effectiveness of 0.45 and 0.6, respectively, were evaluated in achieving the desired space conditions and calculated hour by hour. The results demonstrated that for all examined cases, a heat pipe heat exchanger (HPHX) can be used to save over 80% of the energy during the hours of operation of air conditioning. The overall energy reduction rate was from 3.2% to 4.5% under air conditioning system conditions. It was found that the energy saving potential of a laboratory was higher than for other kinds of buildings. Therefore, the dedicated ventilation system combined with heat recovery technology can be efficiently applied to buildings, especially for laboratories in subtropical areas.
Chemical Analysis of the Sugar Moiety of Monohexosylceramide Contained in Koji, Japanese Traditional Rice Fermented with Aspergillus
Authors: Hamajima Hiroshi , Fujikawa Ayami , Yamashiro Mikako , Ogami Takatoshi , Kitamura Seiichi , Tsubata Masahito , Tan Sei , Matsunaga Haruka , Sawada Kazutaka , Kumagai Satoshi , Hayashi Nobuyuki , Nagao Koji , Yanagita Teruyoshi , Oka Takuji , Mitsutake Susumu , Kitagaki Hiroshi
Published: January 2016

Koji, rice fermented with Aspergillus, is used for saccharification of starch contained in crops during the manufacturing of many of Japanese traditional foods and drinks. Japanese people have long eaten koji, and many beneficial substances have been reported to be contained in koji. However, there has been no report on the existence or content of galactosylceramide in koji. To address this issue, we analyzed the chemical composition of the sugar moiety of monohexosylceramide contained in koji, and elucidate that 30.3% of yellow koji is galactosylceramide, 69.7% of that is glucosylceramide, 19.2% of white koji is galactosylceramide, and 80.8% of that is glucosylceramide. This is the first report of the existence and content of galactosylceramide in koji.
Removal of Fecal Indicators, Pathogenic Bacteria, Adenovirus, Cryptosporidium and Giardia (oo)cysts in Waste Stabilization Ponds in Northern and Eastern Australia
Authors: Sheludchenko Maxim , Padovan Anna , Katouli Mohammad , Stratton Helen
Published: January 2016

Maturation ponds are used in rural and regional areas in Australia to remove the microbial loads of sewage wastewater, however, they have not been studied intensively until present. Using a combination of culture-based methods and quantitative real-time PCR, we assessed microbial removal rates in maturation ponds at four waste stabilization ponds (WSP) with (n = 1) and without (n = 3) baffles in rural and remote communities in Australia. Concentrations of total coliforms, E. coli, enterococci, Campylobacter spp., Salmonella spp., F+ RNA coliphage, adenovirus, Cryptosporidium spp. and Giardia (oo) cysts in maturation ponds were measured at the inlet and outlet. Only the baffled pond demonstrated a significant removal of most of the pathogens tested and therefore was subjected to further study by analyzing E. coli and enterococci concentrations at six points along the baffles over five sampling rounds. Using culture-based methods, we found a decrease in the number of E. coli and enterococci from the initial values of 100,000 CFU per 100 mL in the inlet samples to approximately 1000 CFU per 100 mL in the outlet samples for both bacterial groups. Giardia cysts removal was relatively higher than fecal indicators reduction possibly due to sedimentation.