bluuebunny/crossref_metadata_2025 huggingface dataset:
Coiled Tubing Velocity String Hang-Off Solves and Prevents Liquid-Loading Problems in Gas Well: Case Study in the Gulf of Guayaquil, Ecuador
Authors: Quintana Juan , Duque Eusebio , Diaz Jose D. , Eras Jose , Rodas Jose , Vergara Enrique , Prieto Washington
Published: November 2015

The Amistad field in the Ecuadorian Gulf of Guayaquil has been producing dry gas since 2002 from the productive formation Subibaja. This field covers an area of 2,250 km2 and is located offshore about 100 km southwest of the city of Guayaquil. Six wells in the field produce 60 MMSCFD and 940 BWPD. Gas production from this field is affected by water production and reservoir pressure declination. In particular, liquid-loading is considered a critical problem in the gas wells productivity, with water intrusion occurring in the wellbores during temporary shut-in for workover operations.

A coiled tubing (CT) velocity string is a known method to unload liquids in gas wells; the correct choice of CT size may optimize gas well productivity. The smaller-diameter CT is installed inside the production tubing to improve gas velocity, thereby avoiding water column accumulation at the bottom of the well.

The reservoir inflow performance relationship (IPR) and tubing performance relationship (TPR) are considerations in velocity string design. Both curves are independent and their intersection, compared with the minimum gas flow rate on a J-curve, indicates whether liquid loading will occur in a gas well.

This paper discusses the technical concepts of velocity string design, as well as simulations and analysis for a case history of deploying velocity string technology in a gas well with optimal results.
Techniques and Benefits of Drilling into 2 Sections in the Ecuadorian Basin
Authors: Loaiza M. , Ramirez F. , Morales . , Colmenares E. , Tapia E.
Published: November 2015

The design of wells into two sections (16″ × 13 3/8″ and 12 ¼″ × 9 5/8″) in the Ecuadorian basin is a challenging effort of engineering. The success of the well depends on various techniques that will be analyzed in the following paper, which include precise casing seating depth, accurate fluid density for each section, appropriate formation bridging and sealing in the production zone (Napo), correct chemical selection as part of the fluid system to reduce formation damage on the producing reservoirs, plan a suitable directional trajectory if vertical section aloud (less than 2000') use "S" type design and appropriate BHAs for each section taking into account formation tendencies in terms to reduce slides in the case of PDM BHA is used. Other techniques applied that are going to be reviewed are include cementing production casing can be used slurries with higher densities to achieve better cement quality having less ECD during jobs; the two section design allows to run larger diameter guns and higher penetration bullets into productive sands, artificial lift systems can be set close to the producing reservoir. Using these techniques in the two sections design can provide several advantages compared with conventional three or four sections design in the Ecuadorian basin. This advantages are less cost for Drilling Event by time, by materials and equipment used, avoid adding risk when setting expandable 7″ Liner Hangers, reduce risk of drilling tools and Wireline logs to get stuck related to higher clearance between them also Casings can run smoothly, improving production from reservoirs drilled through.

The result of first well drilled using these techniques will be presented in the following paper taking into account design facts, programs and procedures during the operation, and the results that will demonstrate the value of the design.
Model-Based Adaptive-Predictive Control and Optimization of SAGD under Uncertainty
Authors: Guevara J. L. , Ortega A. , Canelón J. I. , Nava E. , Queipo N. V.
Published: November 2015

When it comes to SAGD optimization, two of the biggest challenges are controlling subcool to achieve conformance (a uniform growth of the steam chamber along the complete length of the well pair), and maximizing an economic performance measure, such as net present value (NPV); both desirable outcomes are not necessarily associated with the same values of the operational parameters (e.g., injection rates). Overcoming these challenges is necessary for achieving optimum SAGD performance, but this may be difficult through common operating policies, e.g. injecting steam at a empirically specified constant rate, considering well-known features of SAGD processes, e.g., complex dynamics (nonlinear, slow, high order, time varying, potentially highly heterogeneous reservoirs), operational constraints, model uncertainty and measurement noise. In the context of this work, the aforementioned challenges are both formulated as optimization problems of adjusting injection rates in order to optimize a particular objective function (e.g. minimizing subcool error or maximizing NPV). To address these challenges, this paper presents a nonlinear model-based adaptive-predictive control approach, alternative to the classical Proportional-Integral-Derivative (PID), for subcool control and NPV optimization of SAGD processes under uncertainty. Using case studies with an idealized heterogeneity pattern (subcool control) and multiple geological realizations based on logs from the Orinoco Belt region (NPV optimization), the proposed approach was compared with a decentralized PID for subcool control, in terms of response speed (mean square error and reaching time), steady state behavior (settling time, measured subcool mean and standard deviation) and control energy spending. While the proposed approach offered a slower response (not a critical issue in terms of oil recovery), it significantly outperformed the PID control during steady state and in control energy spending. On the other hand, the effectiveness for NPV optimization under uncertainty was demonstrated against constant steam injection strategies considering mean NPV, steam injection, water produced, and SOR, and when modeling alternative risk aversion scenarios.
Replacement of ESP with Long Stroke Pumping Units in Heavy and High Viscous Oil in Maranta Block Wells
Authors: Sarmiento D. B. , Prada J. W. , Quiros H. M. , Mora J. , Sun D.
Published: November 2015

Contribution of heavy oil in total oil production in Colombia has shown an increase year after year, currently representing around 50% of the market. The challenge for Artificial Lift is to offer an efficient design to obtaining an economical solution for wells of heavy oil with high pumping costs and failure rate.

Use of Long Stroke Pumping Units extends the operating range for reciprocation rod lift and represents a cost-efficient alternative instead of electrical submersible pumps (ESP) to produce oil wells with low to medium productions (up to a production rate of 1,500 STB/D) where operational and energetic optimization is needed. In wells with a high frequency of failures, long stroke pumping units can reduce rod failure, prevents pump problems, increases run lifes, and reduce workover costs.

Since March 2014, four artificial lift conversions to Beam Pumping were implemented in Maranta Block achieving significant reductions in operation and intervention costs compared to artificial lift system previously installed in each well (Electric Submersible Pumps - ESP). These savings are mainly represented by reducing of electric consumption around 79% and increasing run life 2.8 times that result in less production losses and workover costs considering fewer corrective interventions.
Nanoporous Copper Doped Aluminium Pillared Montmorillonite for Dye‐containing Wastewater Treatment
Authors: Tepmatee Pratyaporn , Siriphannon Punnama
Published: November 2015

Copper doped aluminium pillared montmorillonite (Cu‐Alpill‐MMT) was prepared by adding Cu2+ into the suspension of aluminium pillared montmorillonite (Alpill‐MMT) using high power ultrasonic treatment and calcining to CuO at 500 °C. The XRD and XRF data revealed that the doped CuO partially occupied both internal and external surfaces of the Alpill‐MMT. The N2 adsorption/desorption analysis showed that the Cu‐Alpill‐MMT consisted of slit‐like mesopores with two ranges of pore diameter, i.e. ~3.8 nm and ~6‐30 nm. The Cu‐Alpill‐MMT exhibited the superior adsorption capacity for Basic Yellow 1 (BY1), however, it hardly adsorbed Reactive Orange 16 (RO16). The decolorization of RO16 was achieved when the H2O2 or H2O2/UV was introduced into the treatment system together with the Cu‐Alpill‐MMT, acting as heterogeneous catalyst for Fenton or photo‐Fenton oxidation processes, respectively. The Cu‐Alpill‐MMT could exhibit the antibacterial activity after intimate contact with Escherichia coli ATCC®25922 under JIS L 1902: 1998 (Qualitative) test method.
An accuracy-assured privacy-preserving recommender system for internet commerce
Authors: Lu Zhigang , Shen Hong
Published: November 2015

Recommender systems, tool for predicting users? potential preferences by
computing history data and users? interests, show an increasing importance in
various Internet applications such as online shopping. As a well-known
recommendation method, neighbourhood-based collaborative filtering has
attracted considerable attentions recently. The risk of revealing users?
private information during the process of filtering has attracted noticeable
research interests. Among the current solutions, the probabilistic techniques
have shown a powerful privacy preserving effect. The existing methods
deploying probabilistic methods are in three categories, one [19] adds
differential privacy noises in the covariance matrix; one [1] introduces the
randomisation in the neighbour selection process; the other [29] applies
differential privacy in both the neighbour selection process and covariance
matrix. When facing the k Nearest Neighbour (kNN) attack, all the existing
methods provide no data utility guarantee, for the introduction of global
randomness. In this paper, to overcome the problem of recommendation accuracy
loss, we propose a novel approach, Partitioned Probabilistic Neighbour
Selection, to ensure a required prediction accuracy while maintaining high
security against the kNN attack. We define the sum of k neighbours?
similarity as the accuracy metric ?, the number of user partitions, across
which we select the k neighbours, as the security metric ?. We generalise the
k Nearest Neighbour attack to the ?k Nearest Neighbours attack. Differing
from the existing approach that selects neighbours across the entire
candidate list randomly, our method selects neighbours from each exclusive
partition of size k with a decreasing probability. Theoretical and
experimental analysis show that to provide an accuracy-assured
recommendation, our Partitioned Probabilistic Neighbour Selection method
yields a better trade-off between the recommendation accuracy and system
security.
Distributed locating algorithm MDS-MAP (LF) based on low-frequency signal
Authors: Zhou Chunyue , Xu Tong , Dong Hairong
Published: November 2015

The positioning error of distributed MDS-MAP algorithms comes from two
aspects: the local positioning error and the position fusion error. In an
attempt to improve the positioning result in both local positioning accuracy
and global convergence probability, this paper proposes a novel MDS-MAP(LF)
algorithm, which uses low frequency signal to measure the inter-sensor
distance rather than shortest path algorithms. The proposed MDS-MAP(LF)
algorithm leverages the propagation feature of low frequency signal to
acquire a more precisely two-hop distance. The simulation and analysis
results indicate that the accuracy of local positioning is improved by more
than 3%. With the use of cluster expansion, MDS-MAP(LF) also shows a better
convergence with comparison to the former classical distributed MDS-MAP
algorithm.
A parallel SRM feature extraction algorithm for steganalysis based on GPU architecture
Authors: Chen Kaizhi , Lin Chenjun , Zhong Shangping , Guo Longkun
Published: November 2015

The Spatial Rich Model (SRM) generates powerful steganalysis features, but
has high computational complexity since it requires calculating tens of
thousands of convolutions with image noise residuals. Practical applications
dealing with a massive amount of image transferred through the Internet would
suffer a long computing time if using CPU. To accelerate the steganalysis, we
present a parallel SRM feature extraction algorithm based on GPU
architecture. We exploit parallelism of the algorithm, modify the original
SRM extraction algorithm and employ some strategies to avoid the disadvantage
of its sequentiality. Some OpenCL optimization technologies are also used to
accelerate the extraction process, such as convolution unrolling, combined
memory access, split-merge strategy for co-occurrence matrix calculation. The
experimental results show that the speed of the proposed parallel extraction
algorithm for different size images is 25~55 times faster than the original
single thread algorithm. In addition, when using AMD GPU HD 6850, our
algorithm runs 2~4.2 times faster than using a Intel Quad-core CPU. This
indicates our algorithm makes good use of the GPU cores.
Topic-sensitive multi-document summarization algorithm
Authors: Na Liu , Di Tang , Ying Lu , Xiao-Jun Tang , Hai-Wen Wang
Published: November 2015

Latent Dirichlet Allocation (LDA) has been used to generate text corpora
topics recently. However, not all the estimated topics are of equal
importance or correspond to genuine themes of the domain. Some of the topics
can be a collection of irrelevant words or represent insignificant themes.
This paper proposed a topic-sensitive algorithm for multi-document
summarization. This algorithm uses LDA model and weight linear combination
strategy to identify significance topic which is used in sentence weight
calculation. Each topic is measured by three different LDA criteria.
Significance topic is evaluated by using weight linear combination to combine
the multi-criteria. In addition to topic features, the proposed approach also
considered some statistics features, such as term frequency, sentence
position, sentence length, etc. It not only highlights the advantages of
statistics features, but also cooperates with topic model. The experiments
showed that the proposed algorithm achieves better performance than the other
state-of-the-art algorithms on DUC2002 corpus.
Achieving inter-domain routing security based on distributed translator trust model
Authors: Kong Lingjing , Shen Hong
Published: November 2015

To resolve the difficulties in deployment of the classic security solution
S-BGP (Secure Border Gateway Protocol), the Translator Trust Model (TTM) for
a new solution SE-BGP (Security Enhanced BGP) was proposed to transform the
centralized deployment mode of S-BGP to distributed mode. However, the trust
(attestations of routing information) translation of TTM only depends on a
single hub node and this results in severe threats for the inter-domain
routing system. To overcome the deficiencies of TTM, in this paper we improve
TTM to Distributed TTM (DTTM) by expanding the single hub node to a set of
selected multiple hub nodes; in our DTTM, the task of attestations is
distributed over multiple hub nodes instead of on a single hub node. In order
to make the hub nodes respond to the case of single node failures, we design
a restoration mechanism to recover the network based on the neighbour-ring
structure. Besides, we develop Cooperative Secure BGP (CSBGP) to realize DTTM
in BGP. In comparison with SE-BGP, our experimental results show that CS-BGP
achieves an improved scalability, reduced convergence time and enhanced
security.
A comprehensive method to combine RFID indoor targets positioning with real geographic environment
Authors: Weiqing Huang , Chang Ding , Siye Wang
Published: November 2015

Nowadays RFID indoor targets positioning results display methods are
simplified. The positioning results visual effect is also unsatisfied. To
solve this problem, we design and realize a comprehensive method to implement
RFID indoor localization algorithms in a geographic information system. In
our method, the RFID indoor targets positioning results can display in the
real geographic environment, which can improve the application value of the
results. First, we establish the geographic environment using geographic
information system in order to combine RFID indoor positioning results with
the real environment. Then we design a distributed system architecture to
filter the useless data and implement the positioning algorithm. In this way,
indoor targets real-time positioning and the results visualization display
are realized. And the positioning results can also be combined with the real
geographic information environment. System test results indicate that this
method achieves ideal indoor positioning data display effect under well
indoor-positioning precision.
An integrated information-based similarity measurement of gene ontology terms
Authors: Zhang Shu-Bo , Lai Jian-Huang
Published: November 2015

Measuring the semantic similarity between pairs of terms in Gene Ontology
(GO) can help to compare genes that can not be compared by other
computational methods. In this study, we proposed an integrated
information-based similarity measurement (IISM) to calculate the semantic
similarity between two GO terms by taking into account multiple common
ancestors that they share, and aggregating the semantic information and
depth information of the non-redundant common ancestors. Our method searches
for non-redundant common ancestors in an effective way. Validation
experiments were conducted on both gene expression dataset and pathway
dataset, and the experimental results suggest the superiority of our method
against some existing methods.
Retraction notice to: Environmental cadmium and zinc concentrations in liver and kidney of European hare from different Serbian regions, Zoran I. Petrovic, Vlado B. Teodorovic, Mirjana R. Dimitrijevic, Suncica Z. Borozan, Milos T. Beukovic, Dragica M. Nikolic, Aurelija T. Spiric , [Hem. Ind. 67 (4) 593-599 (2013) DOI: 10.2298/HEMIND120815100P]
Authors: Editorial E
Published: November 2015

This article has been retracted at the request of authors. The retraction
has been made because the authors admitted that they have done dual
submission of the text and drawings from article named "Environmental Cd and
Zn Concentrations in Liver and Kidney of European Hare from Different
Serbian Regions: Age and Tissue Differences" published in Bull Environ
Contam Toxicol (2013) 90:203-207 DOI 10.1007/s00128-012-0901-7. One of the
conditions of submission of a paper for publication are that authors confirm
that their work is entirely originally written, someone else?s data and/or
text are appropriately cited or quoted and permission has been obtained for
use of copyrighted material from other sources. Therefore, the retracted
article represents a serious improperly usage of the scientific publishing
system. Apologies are offered to readers of the journal Hem.Ind. that this
abuse was not detected during the submission, i.e. peer review process.

 Link to the retracted article 10.2298/HEMIND120815100P
Considerations to Establish Ground-Borne Noise Criteria to Define Mitigation for Noise-Sensitive Spaces
Authors: Jue Deborah A. , Carman Richard A.
Published: November 2015

FTA provides guidance for the evaluation of impacts to a variety of noise-and vibration-sensitive uses along a rail transit system. Included under the category of special buildings are concert halls or sound-recording facilities and auditoriums. The impact criteria for ground-borne noise from the transit systems into such spaces are maximum noise levels of 25 or 30 dBA, respectively, far more restrictive than for any other category considered in the FTA Guidance Manual. Conformance with these impact criteria is necessary to avoid significant impact during environmental analysis but may not be a sufficient evaluation of the effect of the transit systems. Some special parameters that should be considered for any rail transportation project that seeks to become a close neighbor of such facilities are discussed.
Correlation of Noise Measurement Types in the Arizona Quiet Pavement Pilot Program
Authors: Donavan Paul R.
Published: November 2015

In cooperation with FHWA, the Arizona Department of Transportation initiated a program to reduce highway traffic noise in the Phoenix, Arizona, metropolitan area by overlaying many freeway segments constructed of transversely tined portland cement concrete pavement with an asphalt rubber friction course. The acoustic performance of this noise mitigation approach was documented with three types of measurements: tire–pavement noise source levels, short-term neighborhood noise measurements, and roadside noise measurements at research sites. Initial comparison of the noise reductions produced by the asphalt rubber friction course indicated good agreement between the Type 1 and Type 3 measurements. Reductions for the Type 2 measurements were about 3 to 4 dB lower on average than were the other two types. Almost all of the Type 2 locations had features that provided noise reduction prior to the overlay. The effect of these features on the Type 2 noise reductions were examined using a research version of the FHWA Traffic Noise Model that accounts for differences in tire–pavement noise source levels. With the use of Type 1 data and the characteristics of the Type 2 sites, it was found that when the effect of the reduced tire–pavement source strength was added to the already existing noise-reducing features, the predicted reductions were consistent with the Type 3 results. In this sense, Type 2 and Type 1 results were found to correlate with each other and, by extension, to the Type 3 results.
Evaluating Pavement and Barriers for Noise Mitigation
Authors: Lodico Dana M. , Donavan Paul R. , Rochat Judith L.
Published: November 2015

In NCHRP Project 10–76, methodologies were developed and demonstrated for evaluating the feasibility, reasonableness, effectiveness, acoustic longevity, and economic features of pavement strategies and barriers proposed for highway noise abatement. The essential elements of the methodologies are the use of an expanded pavement life-cycle cost analysis to examine economic features, a modified version of FHWA's Traffic Noise Model to integrate the noise reducing performance of pavements and barriers, and the use of onboard sound intensity data as input to the prediction model. The developed methodology is applied to state project–based examples. Barriers, quieter pavement, and combinations of both are evaluated for feasibility and reasonableness using the policies of three state highway agencies.
Assessment of Energy Consumption by Liquefied Natural Gas Carriers and Impact of Improving the Energy Efficiency on Natural Gas Supply Chain
Authors: Wang Haifeng , Rutherford Dan
Published: November 2015

With the booming natural gas trade, liquefied natural gas (LNG) carriers—the primary transportation method for intercontinental trade on natural gas—have been experiencing enormous growth. This study offers a novel analysis that connects 2011's in-use LNG fleet characteristics, global satellite data on ship movement, and literature on LNG trade to assess the long-term prospects for increasing the energy efficiency of LNG carriers. This analysis also investigates how efficiency characteristics (such as age, size, technology, and operational practices) influence the efficiency of the LNG fleet and develops a ship stock model to independently track technical and operational efficiency practices in LNG carriers. The findings indicate that industry-leading LNG carriers are about 40% more efficient than industry laggards. This analysis indicates that by fully embracing the available technical and in-use practices of the low-carbon industry leaders of today, the fleet could reduce CO2 emissions by 30 million metric tons by 2040—about 8 million metric tons of natural gas, equivalent to $4 billion savings in the LNG supply chain. This study has important implications for the shipping industry and policy makers. The industry has to address split incentives to take advantage of energy-saving opportunities. Regulations that set targets for the energy efficiency of the in-use fleet may ultimately help the industry harvest the efficiency gains while mitigating climate impact from the industry.
Driver Response to Hydrogen Fuel Cell Buses in a Real-World Setting
Authors: Lipman Timothy E. , Gray-Stewart Ananda L. , Lidicker Jeffrey
Published: November 2015

This study examined bus drivers' acceptance of fuel cell electric buses in Alameda–Contra Costa Transit in the San Francisco Bay Area of California. Of the 145 surveys issued, 47 drivers completed a written survey, for a 32% response rate. The study focused on a key attribute for potential success of alternative urban bus technology: the driver acceptance factor. Technology performance flaws that are undesirable or annoying to the bus drivers may also be disruptive to passengers. Furthermore, because of using the buses throughout their full duty cycle, drivers are in a unique position to identify key opportunities to improve the new technology options as they emerge and evolve. The study found that drivers, in general, rated the hydrogen fuel cell buses to be at the same or better performance than diesel buses for handling, ride quality, acceleration, and braking. For quiet operation, the drivers rated the new buses as excellent. When asked how they liked the experimental hydrogen fuel cell buses, drivers responded at just above neutral, with the most common response being “the same” as diesel buses followed by “much better.” Those drivers who said that they considered fuel economy when purchasing a vehicle liked the fuel cell buses more. Older drivers preferred the diesel buses, and male drivers preferred the new fuel cell buses. Perceptions of safety were mixed, with some drivers expressing safety concerns independent of how much training they had received.
Greenhouse Gas Impact of Ridership on Sheppard Subway Line, Toronto, Canada
Authors: Saxe Shoshanna , Cruickshank Heather , Miller Eric
Published: November 2015

Changes in travel behavior near the Sheppard Subway Line in Toronto, Ontario, Canada, and the associated greenhouse gas impacts were examined. A study looked at initial changes in mode share after the line opened in 2002 and examined ongoing mode share trends through 2012. The initial mode shift was assessed through an analysis of bus boardings, subway platform counts, and traffic counts made between 2000 and 2012. Longitudinal changes in mode share were assessed with the use of transit survey data. For the first 6 years of operation, the Sheppard Subway Line produced more greenhouse gas (GHG) per passenger kilometer traveled (PKT) than the bus that it had replaced. A net GHG reduction of 66.4 kilotons of CO2 equivalent was calculated but was wholly dependent on avoided car PKTs that may have been offset in their entirety by induced travel on Sheppard Avenue.
Effect of Improving Vehicle Fuel Efficiency on Fuel Tax Revenue and Greenhouse Gas Emissions
Authors: Soltani-Sobh Ali , Heaslip Kevin , Bosworth Ryan , Barnes Ryan
Published: November 2015

Vehicle fuel economy improvement has proved to be one of the most effective policies in controlling gasoline demand and greenhouse gas emissions in the transportation sector. However, such improvement also results in the decrease of fuel tax revenue, the main funding source for building and maintaining the U.S. transportation infrastructure. Conversely, fuel efficiency improvement reduces the marginal and average cost of travel, thus encouraging drivers to drive more, and that in turn increases gasoline consumption. The objective of this study was to estimate the potential loss of fuel tax revenue and greenhouse gas emissions, dependents of fuel consumption, that resulted from the fuel efficiency improvement. Accordingly, fuel consumption was modeled as a system of equations consisting of vehicle miles traveled and fuel efficiency (in mpg) as two explanatory variables. The model was estimated by the three-stage least squares method, with annual time-series data for Washington State over the period from 1976 to 2011. According to the results, Washington State will have a $106 million loss in revenue and an 8.7% reduction in emissions of carbon dioxide (CO2) in 2031.
Implications of Modeling Range and Infrastructure Barriers to Adoption of Battery Electric Vehicles
Authors: Barter Garrett E. , Tamor Michael A. , Manley Dawn K. , West Todd H.
Published: November 2015

Compared with traditional vehicles, light-duty battery electric vehicles (BEVs) currently have price premiums and noncost limitations, such as reduced range, sparse public recharging infrastructure, and long recharge times. These additional limitations can be captured in different ways in a consumer choice model. Three approaches are implemented to noncost barrier modeling, and results are compared. A penalty approach quantifies limitations as additional costs to the consumer, and two threshold approaches determine BEV suitability by the frequency that daily driving distance exceeds the vehicle range. GPS-based trip data are used to form ensemble distributions of low-, medium-, and high-intensity driving distances to support the analysis. All approaches show limited (5%) adoption of BEVs by 2050, and the BEV mileage fraction trails the stock fraction because of the use of substitute vehicles for high-mileage trips and adoption biased toward lower driving intensity segments. In fact, a majority of the electrified miles driven stem from plug-in hybrid electric vehicles, not BEVs. Of the BEVs, the powertrains offering 150- to 250-mi ranges are responsible for more than 50% of sales. Results also hint that longer-range BEVs act as primary household vehicles, but lower-range BEVs serve as secondary household vehicles. A parametric exploration shows that mechanisms to mitigate the hardship of the noncost barriers can significantly increase adoption rates but that reducing battery price alone does not. However, these mechanisms can be different for different modeling approaches.
Exploring Fuel-Saving Potential of Long-Haul Truck Hybridization
Authors: Gao Zhiming , LaClair Tim J. , Smith David E. , Daw C. Stuart
Published: November 2015

Comparisons are reported on the simulated fuel economy for parallel, series, and dual-mode hybrid electric long-haul trucks, in addition to a conventional powertrain configuration, powered by a commercial 2010-compliant 15-L diesel engine over a freeway-dominated heavy-duty truck driving cycle. The driving cycle was obtained by measurement during normal driving conditions. The results indicated that both parallel and dual-mode hybrid powertrains were capable of improving fuel economy by 7% to 8%. However, there was no significant fuel economy benefit for the series hybrid truck because of internal inefficiencies in energy exchange. When reduced aerodynamic drag and tire rolling resistance were combined with hybridization, there was a synergistic fuel economy benefit for appropriate hybrids that increased the fuel economy benefit to more than 15%. Long-haul hybrid trucks with reduced aerodynamic drag and rolling resistance offered lower peak engine loads, better kinetic energy recovery, and reduced average engine power demand. Thus, it is expected that hybridization with load reduction technologies offers important potential fuel energy savings for future long-haul trucks.
Woody Biomass Supply, Economics, and Biofuel Policy
Authors: Rubin Jonathan , Neupane Binod , Whalley Stephanie , Klein Sharon
Published: November 2015

The amount of woody biomass available for biofuel production depends on tree growth rate, harvesting techniques, harvest cost, government policies, and established traditions within the industry. Comparing estimates of biomass availability across studies is difficult because of different methodologies for estimating biomass supply, compounded by inconsistent and often unspecified assumptions. Studies differ in their definition of biomass (i.e., tree size, parts of tree) and consideration of ecological and economic factors (i.e., harvest productivity and costs, competing demand, compliance with existing regulations). In particular, existing restrictions on bio-mass harvesting for biofuels under the Federal Renewable Fuel Standard often are not included. Additionally, because most biomass availability studies ignore current biomass uses, an overestimation of available bio-mass for future uses results. Presented are new estimates for the amount of economically available biomass in Maine, taking into consideration both economic (integrated harvesting for pulp and precommercial thinning) and ecological factors. It is found that biomass availability varies greatly, depending on the relative location of the biorefinery, biomass harvesting site, and existing wood consumers (e.g., pulp mill). Indeed, harvesting and transporting woody biomass without an existing use for the high-value forest products (saw logs and pulp) probably makes woody biomass for energy production uneconomical. This finding is contrary to some existing studies and suggests that economic consideration needs greater emphasis in estimating biomass availability for biofuels.
Patent and Latent Predictors of Electric Vehicle Charging Behavior
Authors: Daina Nicolò , Polak John W. , Sivakumar Aruna
Published: November 2015

To anticipate the impacts of electric vehicle (EV) charging on grid systems and the effectiveness of demand response measures for load control, it is critical to understand the determinants of EV charging demand. Previous research suggests that these determinants include both observable patent metrics of travel demand and less easily measurable triggers of charging decisions (such as range appraisal or habit). Nevertheless, analyses accounting simultaneously for both aspects are lacking. Data are used from a survey administered to EV drivers participating in the Low Carbon London EV trial to explore charging decision triggers to test their predictive power of observable metrics of charging demand, while controlling for variability in travel patterns. Results show that charging demand is significantly affected by travel pattern metrics as well as charging decision triggers.
Electric Vehicle Fast Charger Planning for Metropolitan Planning Organizations
Authors: Ji Wei , Nicholas Michael , Tal Gil
Published: November 2015

Presented is a tool to estimate fast charger demand and sample results on a current and future battery electric vehicle (BEV) scenario. The results highlight the data and methods needed to plan for fast charger demand. To plan for existing BEVs, origin and destination data are necessary for identifying which traffic is relevant to assess fast-charging demand. Also, as the battery size for BEVs increases, demand shifts from primarily inside metro areas to long-distance corridors outside metro areas. The sample results show the interactions of battery size, frequency of charging, and energy needed per charge. Although energy per charge increases with battery size, overall electricity demand per vehicle decreases with larger batteries.
Experimentation and Innovation in Advance Mitigation
Authors: Sciara Gian-Claudia , Bjorkman Jacquelyn , Lederman Jaimee , Schlotterbeck Melanie , Thorne James H. , Wachs Martin , Kirkham Stuart
Published: November 2015

Advance mitigation is a process through which the environmental impacts and required mitigation are assessed for one or more transportation projects early in project planning and development. The approach enables mitigation to be planned, commenced, and completed earlier; applies regionally or programmatically across multiple projects; and takes ecosystem- and landscape-level concerns into account. Although there have been efforts to develop programmatic mitigation initiatives and funding to support them, there is little documentation of their establishment, operation, or accomplishments. A study documents and analyzes 10 prominent California experiences with advance mitigation undertaken by the state department of transportation in coordination with regional councils, local governments and transportation agencies, and environmental groups. Each effort is profiled, including the origin of the mitigation effort; its location, scale, and cost; its specific connection to transportation projects; funding, revenue sources, or financial options used to support it; key institutional partners; and lessons learned from the experience. California's initiatives offer some lessons: external conservation planning efforts can play a significant role in creating both momentum and structure for comprehensive mitigation planning; transportation-related advance mitigation is necessarily a highly interdependent undertaking, involving not only the state department of transportation and other transportation project sponsors but also federal and state natural resource agencies as well as local environmental groups; and the long-time horizons of advance mitigation planning and the complex nature of infrastructure development bring unavoidable uncertainty to such efforts and demand flexibility from mitigation partners in the process.
Submittal and Evaluation Procedures for Alternative Technical Concepts
Authors: Gad Ghada M. , Gransberg Douglas D. , Loulakis Michael
Published: November 2015

Alternative technical concepts (ATCs) have yielded innovative solutions to complicated design issues in a wide range of highway projects. Through ATCs, proposers are allowed to suggest modifications to a contract requirement to provide a project design equal to or better than the one described in the solicitation. However, the realization of such benefits requires a well-structured ATC mechanism, and the project's solicitation documents need to be drafted in a manner that clearly communicates the owner's project goals and ensures fairness and confidentiality to competing contractors. This paper describes the submittal, evaluation, approval, and review procedures currently followed by state transportation agencies to implement ATCs. The study employed a survey that was sent to all state departments of transportation (42 of which responded), in addition to a content analysis of the solicitation documents of 65 ATC projects from 24 agencies. The paper finds that care must be taken to ensure that competing contractors are not discouraged from pursuing ATCs as a result of onerous documentation requirements for ATC submittals. The results also show that the ATC submittal procedures should provide detailed guidance on the conduct and character of one-on-one meetings with competitors, the content of a responsive ATC submittal, and the procedures for the rectification of errors, omissions, and ambiguities. The document should also be clear about what constitutes an ATC and describe the ATC evaluation and review process, as well as the process for presenting proposed ATCs. The ATC evaluation criteria should be known when the solicitation is first published.
Determinants of Variability in Preliminary Engineering Funding
Authors: Miller John S. , Turner Bethany L.
Published: November 2015

Preliminary engineering (PE) is a phase in the Virginia Department of Transportation (DOT) project development process. PE funds support tasks such as planning or environmental studies, design, and public involvement. This study analyzed variability in the Virginia DOT's program-level PE expenditures [i.e., aggregate funds from all projects, completed or not, that were spent on PE as opposed to right-of-way (ROW) or construction, based on FY 2004 to 2012 data]. Although the mean percentage of total funds (PE + ROW + construction) spent on PE statewide from 2004 to 2012 was 14.7%, the mean annual district PE percentage for the Virginia DOT's nine construction districts ranged from 11.3% to 21.3%. Three statistically significant variables explained most (89%) of this variation: (a) percentage of expenditures for minimum-plan or no-plan projects (i.e., projects that use a design template), (b) percentage of expenditures each year for large projects, and (c) percentage of projects in the development phase (i.e., projects for which PE or ROW but not construction funds had been spent). Although the first and second variables showed that PE percentage reflected project attributes, the third variable suggested that PE percentage partly reflected a programming decision (i.e., the amount that should be invested in preparing projects for future construction versus building prepared projects). The model that explained district-level variation in PE percentage suggested that although the programming decision could affect it by as much as 8%, project attributes could influence PE by as much as 11%. Thus, programming decision and project attributes both affect PE percentage.
Mapping of Practices of State Transportation Agencies for Consultant Oversight of Construction Engineering and Inspection Services
Authors: Torres Valerie Carrasco , Uddin Mohammad Moin , Goodrum Paul M. , Molenaar Keith R.
Published: November 2015

Over the past few decades, state transportation agencies (STAs) have outsourced various functional activities traditionally performed by in-house personnel in reaction to increasing workloads and diminishing staff. To cope with the situation, STAs have developed and implemented various tools and practices for management and oversight of construction engineering and inspection (CEI) services. A national CEI survey was conducted to provide detailed mapping of various tools and practices used for CEI services and to understand the primary advantages and disadvantages of using CEI consultants. The survey found that STAs used a wide variety of tools and practices to define the scope of work for CEI services, select consultants, and administer CEI consultant contracts. Statistical analyses of variance estimated that CEI consultant management and oversight practices varied significantly; this finding may imply multiple underlying factors in the choice of one practice over another. One of the most important findings of this survey was the value of CEI consultant services to STAs. The survey found that the CEI consultant services provided STAs with an improved ability to handle peak workloads, the flexibility of quickly adding or reducing staff, and specialized expertise that might not be available in house. However, the reported challenges of working with CEI consultants included developing and maintaining consultants' familiarity with in-house processes and procedures, ensuring that consultants held appropriate CEI qualifications, and the relative cost of CEI consultants versus in-house staff.
Cost and Schedule Performance Benchmarks of U.S. Transportation Public-Private Partnership Projects
Authors: Ramsey David W. , El Asmar Mounir
Published: November 2015

The use of public–private partnerships (PPPs) has steadily increased in the United States since the early 1990s. Infrastructure design and construction projects have seen significant variations in costs and schedules. Therefore this paper aims to quantify the cost and schedule performance of recently completed PPP projects in the U.S. transportation sector and compare them to their non-PPP counterparts. The authors collected and verified data from professional data sets, publicly available websites, and structured interviews with key project constituents. The paper presents results from 25 completed PPP transportation projects. All projects in the data set were completed between 1995 and 2013; project costs ranged from $18 million to $2.1 billion and totaled about $14 billion. The results of the analysis showed an average cost growth of 3.22% and an average schedule growth of 1.2%; when compared with traditional design–bid–build delivery, these findings illustrate superior performance. This paper fills a gap in the knowledge of PPP project performance in the U.S. transportation sector and compares the results with previous research efforts in the international PPP market.
Relationship between Early Contractor Involvement and Financial Performance in the Rebuilding of Infrastructure in Christchurch, New Zealand
Authors: Botha Paul S. , Scheepbouwer Eric
Published: November 2015

Alliance contracting is a partnering project or program delivery method in which all parties work collaboratively to share risks. The Stronger Christchurch Infrastructure Rebuild Team (SCIRT) alliance has been set up to manage the high risk of the unknown scopes of work associated with disaster recovery projects after the 2011 earthquakes in Christ-church, New Zealand. SCIRT uses early contractor involvement (ECI) as a key measure of risk mitigation and to offer value for money. ECI provides constructability input during the design process to ensure that any issues and construction risks are identified early and taken into consideration. Because there has been considerable pressure to start the rebuilding, not all SCIRT projects have had the benefit of ECI. With the objective of quantifying the positive effect that ECI has on financial outcomes, 288 projects that were in construction or had been finished by the end of February 2014 were compared. The comparison was based on whether ECI had been used both during the design phase of a project and in the cost estimation of the project. The results clearly showed that across the alliance program there was significant improvement in cost performance and cost accuracy of reconstruction projects that received early contractor input.
U.S. Partnering Programs and International Partnering Contracts and Alliances
Authors: Gransberg Douglas D. , Scheepbouwer Eric
Published: November 2015

The term “partnering” has many meanings in the transportation industry. Some definitions are strictly legal, others are merely descriptive titles given to a set of team-building tools used to reduce adversarial relationships on individual construction projects. As collaborative methods of transportation project delivery increase, it is important for researchers and practitioners to be able to identify the precise meaning of an operative title from the context in which it is used. This paper presents a comparative analysis of advantages and disadvantages of three collaborative partnering methods: U.S. nonbinding partnering charter, binding partnering contract, and alliance agreements used internationally. The results are from an analysis of five U.S. and international studies on partnering and relational contracting based on case studies from more than 30 U.S. and international transportation projects. The paper found that although the U.S. partnering program has documented successes, its nonbinding nature provides no recourse if projects turn sour. In comparison, the international partnering and alliance contracts have specific remedies to which an agency can turn to mitigate negative impacts if one party fails to live up to contractual responsibilities. The paper recommends that U.S. agencies consider developing project partnering charters that can be incorporated into design and construction contracts as modifications in the same manner that alliance and partnering agreements are codified for international projects.