bluuebunny/crossref_metadata_2025 huggingface dataset:
Reservoir Properties of the Bazhenov Formation
Authors: Khamidullin R. A. , Kalmykov G. A. , Korost D. V. , Balushkina N. S. , Bakay A. I.
Published: October 2012

The work is devoted to interpretation of results received from a wide complex of laboratory petrophysical investigations of the Bazhenov formation rocks collected from the core in several fields in Western Siberia. The main goal is comparison and substantiation of evaluation results received from using of different methodologies of petrophysical rock properties measurements. It is necessary for identification of the most adequate and applicable methodology of petrophysical investigations realization for the Bazhenov formation.

The Bazhenov formation draws attention of researchers for many years [2, 3, 4, 6]. It significantly differs from usual sedimentary rocks by both composition and physical properties. Lithological and petrophysical investigations of the Bazhenov formation core from different fields showed that it is represented by clayey-silty porous-fractured and fractured reservoirs characterized primarily by high variability of reservoir properties in the formation's distribution area. The majority of reservoirs have low porosity (1–2%) and permeability of less than 0,1 mD. However in some well columns there are interlayers with porosity reaching 16%.

Standard approaches of traditional in Russian Federation petroleum well logging practically don't allow quantitatively estimate the composition and reservoir properties of natural reservoirs. That's why it is extremely essential, on the one hand, to engage methods providing possibility of quantative definition of rock mineral-component composition and enhancing accuracy of its reservoir properties, effective porosity and permeability, and, from the other hand, to prepare new approaches for interpretation of the proposed complex.

The problem of effective porosity and oil and gas saturation determination is complicated by the fact that these natural reservoirs contain big amount of kerogen while mineral component consists of a silicon dioxide, clayey minerals, pyrite, albite, carbonaceous minerals. Selection of them could be defined by the core but it is essential to estimate its weighting in column of a definite well. Therefore main factors that should be kept in mind while evaluating porosity are complex mineralogical rock composition, shale content and high content of organic matter (reaching 40% by mass).

Existing methodology of reservoir identification and its properties evaluation by well logging don't rely on detailed investigations of the Bazhenov formation composition. This situation is explained by an attempt to average accumulated data of the Bazhenov formation in the whole Western Siberian oil and gas basin not always confirming it by results from a real object core investigation. In the present work there are results of core investigations in some areas allowing adjusting the interpretation of well logging to evaluate reservoir properties of the Bazhenov formation.
Drilling world-class ERD wells in the North Caspian Sea
Authors: Bogdanov Sergey , Deliya Sergej , Latsin Danil , Akhmetov Marat , Gagaev Yury , Udodov Alexander
Published: October 2012

This paper describes some of the major issues around drilling world class ERD wells in the North Sector of the Caspian Sea by a team of industry professionals from Lukoil, Schlumberger, Eurasia Drilling Company (BKE-Shelf) and Rostechnadzor (RTN). The ultimate goal of the well construction organisation is to deliver quality wells with zero environmental impact.

Drilling performance achieved on Korchagina field has considerably improved despite increased complexity of the wells. Key contributing factors to this success are in-depth understanding of well bore stability by 3D geomechanical modeling, comprehensive directional analysis, revised casing design, application of latest drilling technologies and creation of multi-discipline team with common goals.
Teaching the Distance Learner Using New Technology
Authors: Stern Claire M.
Published: October 2012

The distance learner may be a professional worker requiring upgraded skills in science and engineering, or a displaced worker unaccustomed to a traditional classroom, or students in rural junior and senior high schools. Lifelong learning has become more than personal fulfillment. For millions of people flexible opportunities for returning to school is now a necessity if they are to compete successfully in a complex information-based society. This article describes diverse methods of reaching the distance learner, illustrating innovative uses of technology—satellites, microwave transmission, fiber optics, and coaxial cable. The consensus of those persons interviewed, and of written sources consulted, points to an underutilization of a major resource, video transmission, to benefit the learners and the teachers.
Key Elements in a Framework for Helping Grieving Children and Adolescents
Authors: Corr Charles A. , Corr Donna M.
Published: October 2012

This article focuses on three main components: (1) some comments on the underlying philosophy and work of the Dougy Center, which are primarily intended to normalize experiences of grieving children and adolescents; (2) a description (based on the work of Sandra Fox) of four tasks for young persons who are bereaved; and (3) suggestions as to how adults might help grieving children and adolescents to address those four tasks. On this basis, the article concludes with ten guidelines for helping grieving children and adolescents.
Grieving and Mourning: Distinctions in Process
Authors: Marrone Robert
Published: October 2012

Psychothanatologists have begun to question the idea that the grieving process has a definitive ending in recovery and renewal, and instead, they are considering growing evidence that suggests that for some persons, the grieving process extends into the mourning process, which itself may extend throughout a person's lifetime. This article offers a number of distinctions between grieving and mourning which speak to the former as a short-term passive process and the latter as an active, long-term process—a process that involves a profound transformation of our assumptions about self in the world, a search for meaning in the loss, and the creation of and interaction with an inner representation of the deceased. These findings have profound implications for the practice of grief counseling and caregiving in the face of significant loss.
Serial Murder and Victim Responses: Events and Aftermath of the Jeffrey Dahmer Case
Authors: Knudten Richard D.
Published: October 2012

The Jeffrey Dahmer serial murder case broke the silence of Milwaukee, Wisconsin, with his detection and arrest on 22 July 1991. Officers Rauth and Mueller were approached by Tracy Edwards, then wearing a handcuff dangling from one wrist, who told them that some strange white man had handcuffed him. Returning to Dahmer's apartment, they discovered Dahmer's secrets. Seven skulls, four heads, and assorted body parts were recovered from his apartment. The ensuing turmoil was expressed in victim family denial and anger, community outrage and feelings of insecurity, legal debates over the appropriateness of the insanity plea, and news media sensationalism. Victim issues related to the case continued into 1996 when the final destruction of part of Dahmer's belongings appeared to close the sordid chapter of Jeffrey Dahmer's life. The author traces the path of the victims' families to case conclusion after the bludgeoning death of Dahmer in a Wisconsin prison.
Mourning the Loss of a Pet
Authors: Pratt Stephen R.
Published: October 2012

In this paper the author explores the process of mourning as experienced by bereaved pet owners. Losing a pet is an agonizing experience. It was expected that the process of mourning for a pet loss would be similar to the process associated with the loss of a human. Data were collected by viewing postings on the alt.support.grief.pet-loss newsgroup. Those who suffered the loss of a pet expressed qualities associated with Parks' (1987) four-phased process of mourning. Two serendipitous findings were the role of guilt and the strong belief in an afterlife for the pet.
Drying of oil palm frond particles in a fluidized bed dryer with inert medium
Authors: Yun May , Puspasari Ifa , Tasirin Masrinda , Talib Meor , Daud Wan , Yaakob Zahira
Published: October 2012

Drying characteristic of oil palm frond fibres was investigated in a
fluidized bed dryer with the presence of inert particles. Sand was used as
inert material. Effects of air temperature (60, 70 and 80?C), air velocity
(0.79 and 0.85 m/s) and mass ratio of fibres to sand (1:0, 1:1 and 1:2) on
the drying curves were investigated. The results showed that the shortest
drying time was obtained with the highest air temperature, air velocity and
fibres to sand mass ratio. The experimental drying data were fitted to nine
existing drying models namely Lewis, Page, Modified Page, Henderson and
Pabis, Logarithmic, Two-term, Two-term exponential and Wang and Singh models
and a proposed new model. The goodness-of-fit was determined based on the
values of r2, c2 and RMSE. The results showed that the best quality of the
fit was obtained using the proposed model. The new model was also validated
for the superheated steam drying of oil palm empty fruit bunch from other
work.
WebMonitoring software system: Finite state machines for monitoring the web
Authors: Pajic Vesna , Vitas Dusko , Pavlovic-Lazetic Gordana , Pajic Milos
Published: October 2012

This paper presents a software system called WebMonitoring. The system is
designed for solving certain problems in the process of information search on
the web. The first problem is improving entering of queries at search engines
and enabling more complex searches than keyword-based ones. The second
problem is providing access to web page content that is inaccessible by
common search engines due to search engine?s crawling limitations or time
difference between the moment a web page is set up on the Internet and the
moment the crawler finds it. The architecture of the WebMonitoring system
relies upon finite state machines and the concept of monitoring the web. We
present the system?s architecture and usage. Some modules were originally
developed for the purpose of the WebMonitoring system, and some rely on
UNITEX, linguistically oriented software system. We hereby evaluate the
WebMonitoring system and give directions for further development.
A scalable multiagent platform for large systems
Authors: Alberola Juan , Such Jose , Botti Vicent , Espinosa Agustín , García-Fornes Ana
Published: October 2012

A new generation of open and dynamic systems requires execution frameworks
that are capable of being efficient and scalable when large populations of
agents are launched. These frameworks must provide efficient support for
systems of this kind, by means of an efficient messaging service, agent group
management, security issues, etc. To cope with these requirements, in this
paper, we present a novel Multiagent Platform that has been developed at the
Operating System level. This feature provides high efficiency rates and
scalability compared to other high-performance middleware-based Multiagent
Platforms.
Physiological adaptation of anthropometric and cardiovascular parameters on physical activity of elite athletes
Authors: Djelic Marina , Saranovic Slavica , Zlatkovic Jovan , Ilic Vladimir , Radovanovic Dragan , Nesic Dejan , Dzodan Marija , Mazic Sanja
Published: October 2012

Introduction. Specific morphological and functional characteristics of
athletes have a significant role in determining athletes? sports results and
can be also used to assess the athlete?s individual potential. Objective. The
aim of the study was to compare anthropometric characteristics and
cardiovascular parameters in trained subjects to those of untrained subjects.
Methods. A total number of 25 trained (17.30?0.83 years) and 21 (18.52?1.52
years) untrained male subjects participated in this study. Body weight and
height were measured and these values were used to compute body mass index
(BMI). The bioelectrical impedance analysis (BIA) method was used to estimate
body fat percentage (%BF). Cardiovascular parameters were monitored in rest
(rest heart rate, systolic and diastolic blood pressure) during
ergospirometric testing (maximal oxygen consumption, maximal heart rate) and
in recovery (heart rate in the first and third minute of recovery). Results.
Body mass, height and BMI (p<0.01) were significantly higher, although BF%
was lower in trained group when compared to untrained, but the difference was
not statistically significant. Heart rate in rest and recovery were
significantly lower (p<0.05) in trained group when compared to untrained,
although maximal oxygen consumption and maximal heart rate were significantly
higher in trained group (p<0.01, p<0.05, respectevely). Conclusion. Our
results show that in trained subjects, water polo players, regular intense
physical activity lead to adaptive changes of anthropometric parameters and
adaptive changes on the cardiovascular system.
Evaluation of utilization and efficacy of general hospitals in Serbia: Is there a shift forward?
Authors: Crncevic-Radovic Ljiljana , Djokic Dragoljub , Zizic-Borjanovic Slavica
Published: October 2012

Introduction. In the Republic of Serbia the activity of general hospitals has
not been sufficiently evaluated. Objective. The aim of this study was to
evaluate, by analyzing the basic indicators of general hospitals condition
and functioning, the network, utilization and efficacy of general hospitals
for further improvement of their organization and work. Methods. The paper is
a part of a retrospective-prospective analysis of hospital healthcare
services which we performed in 2011. The research involved all 40 general
hospitals in Serbia evaluated as a general hospitals system. We selected
seven basic indicators of hospitals condition and functioning that we
followed-up in the period 2000-2009. As the data source we used the Reports
of the Office for Hospital Stationary Treatment of general hospitals and the
Report of the Republican Institution for Statistics entitled Vital Events in
the Republic of Serbia. Numerical data were analyzed using the methods of
descriptive statistics and the program Microsoft Office Excel 2007 and SPSS
for Windows. Statistical significance indicators of differences were
determined by Student?s t-test. Results. In general hospitals during the
studied years, the number of beds decreased by 16.5% (pt=0.057). The number
of discharged patients was increased by 11.8% (pt=0.035). The number of
hospitalization days was reduced by 11.2% (pt=0.038). The average length of
treatment was reduced by 1.9 days (pt=0.074). The average daily bed occupancy
was increased by 4% (pt=0.020). The utilization of beds was increased by 4.5%
(pt=0.019). Throughput capacity of beds increased by 8.5 patients per bed or
by 27.8% (pt=0.091). Conclusion. The most significant indicators of the
utilization and efficacy of general hospitals were improved. Nevertheless,
European and domestic guidelines were achieved only in the average length of
treatment.
Adrenocorticotrophin-dependent hypercortisolism: Imaging versus laboratory diagnosis
Authors: Tancic-Gajic Milina , Vujovic Svetlana , Ivovic Miomira , Stojanovic Milos , Marina Ljiljana , Barac Marija , Micic Dragan
Published: October 2012

Introduction. Cushing?s syndrome results from inappropriate exposure to
excessive glucocorticoids. Untreated, it has significant morbidity and
mortality. Case Outline. A 38-year-old woman with a typical appearance of
Cushing?s syndrome was admitted for further evaluation of hypercortisolism.
The serum cortisol level was elevated without diurnal rhythm, without
adequate suppression of cortisol after 1 mg dexamethasone suppression test.
24-hour urinaryfree cortisol level was elevated. Differential diagnostic
testing indicated adrenocorticotrophin (ACTH)- dependent lesion of the
pituitary origin. Pituitary abnormalities were not observed during repeated
MRI scanning. Inferior petrosal sinus sampling (IPSS) was performed: 1)
Baseline ratio ACTH inferior petrosal sinus/peripheral was <2; 2)
Corticotropin-releasing hormone (CRH) stimulated ratio ACTH inferior petrosal
sinus/peripheral was <3; 3) Baseline intersinus ratio of ACTH was <1.4; 4)
Increase in inferior petrosal sinus and peripheral ACTH of more than 50
percent above basal level after CRH; 5) Baseline ratio ACTH vena jugularis
interna/peripheral was >1.7. Transsphenoidal exploration and removal of the
pituitary tumor was performed inducing iatrogenic hypopituitarism.
Postoperative morning serum cortisol level was less than 50 nmol/l on
adequate replacement therapy with hydrocortisone, levothyroxine and
estro-progestagen. Conclusion. No single test provides absolute distinction,
but the combined results of several tests generally provide a correct
diagnosis of Cushing?s syndrome.
Heterotopic pregnancy after in vitro fertilization and embryo transfer: A case report
Authors: Sparic Radmila , Buzadzic Snezana , Argirovic Rajka , Bratic Danijela , Plecas Darko
Published: October 2012

Introduction. Heterotopic pregnancy is a life-threatening complication of
pregnancy defined as coexistent intrauterine and ectopic gestation. Its
diagnosis is frequently overlooked and delayed. Case Outline. A 28-year-old
woman experienced acute abdominal pain in pregnancy achieved by in vitro
fertilization. Since all previous checkups indicated a normal course of
pregnancy, the ectopic pregnancy was not suspected on admission. However, due
to persistent hypotension, this diagnosis was also considered. Transvaginal
ultrasound performed by an experienced obstetrician revealed an adnexal mass
highly indicative of ectopic pregnancy. No fetal heart beats were visualized
and the diagnosis of a missed abortion was made. A prompt laparotomy revealed
a ruptured right ampullary pregnancy, and salpingectomy was performed.
Conclusion. Although rare, heterotopic pregnancy should be considered in the
differential diagnosis of abdominal pain in pregnancy. Every physician
treating women of reproductive age should bear in mind the possibility of
heterotopic pregnancy not only in patients with predisposing risk factors but
also in those without them.
Vendor-Buyers relationship model for deteriorating items with shortages, fuzzy trapezoidal costs and inflation
Authors: Singh Chaman , Singh S.R.
Published: October 2012

In this paper, an integrated inventory model is developed from the
perspective of a single vendor and multi-buyers for deteriorating items under
fuzzy environment and inflation. In the development of the model, it is
assumed that all costs parameters, demand and the production rates are
imprecise in nature; they are represented by the trapezoidal fuzzy numbers,
as these parameters are not constant and can be disturbed due to daily market
changes. We use function principle as arithmetic operations to find the total
inventory cost in fuzzy sense and Graded Mean - Integration Representation
Method to defuzzify the fuzzy total inventory cost. Inflation is used to find
the present worth of total cost. Since the optimal policy of buyers may not
be the most economical for a vendor, thus to deal with this situation,
integrated cost policy is used to reach the optimal policy. Finally, a
numerical example is given to illustrate the model.
Auditor Attestation under SOX Section 404 and Earnings Informativeness
Authors: Chen Lucy Huajing , Krishnan Jayanthi , Sami Heibatollah , Zhou Haiyan
Published: October 2012

Section 404 of the Sarbanes-Oxley Act requires managers to assess, and their auditors to express an opinion on, the effectiveness of internal controls over financial reporting (ICFR). Policymakers expect the ICFR audits to enhance the credibility of firms' financial statements. Prior research argues that audit characteristics that enhance the credibility of financial reporting are associated with stronger earnings-return associations. We examine whether earnings accompanied by the first-time Section 404 ICFR reports were associated with higher informativeness compared with earnings in the prior year when only financial statement audit reports were available. We conduct our analysis for a test sample of accelerated filers with clean ICFR reports and clean previous Section 302 disclosures. Using a difference-in-differences approach, we compare the change in earnings informativeness for the test sample with that for a control sample of non-accelerated filers. We find that earnings informativeness for companies with clean internal control reports was greater in the Section 404 adoption year than in the previous year, while there was no change in earnings informativeness for the non-accelerated filers. Also, there is no difference in the increase in earnings informativeness across firms with small and large compliance costs (measured by change in audit fees), suggesting that both groups benefited from the Section 404 ICFR audits.
Patient experiences with the Forsus Fatigue Resistant Device
Authors: Bowman Amy C. , Saltaji Humam , Flores-Mir Carlos , Preston Brian , Tabbaa Sawsan
Published: October 2012

Objective:

To investigate patients' experiences with the Forsus Fatigue Resistant Device (FFRD).

Methods:

This was a survey focused on patient's comprehensive experience with FFRD, both initially and after several months of wear, including the patient's overall impression of the appliance. The survey was administered to 70 patients wearing FFRD in both university and private practice settings.

Results:

A high percentage (81.5%) reported a neutral to favorable experience with FFRD; 89.8% reported growing accustomed to the appliance within 4 weeks. The majority of those who had previously worn rubber bands found FFRD to be “easier.” Cheek irritation was the most serious side effect (about 50%). Cheek irritation and other negative effects generally decreased over time.

Conclusions:

The FFRD is relatively well accepted by patients. Most patients experience some discomfort and functional limitations; however, the effect generally diminishes with time, and patients adapt to the appliance. Practitioners should be especially vigilant about problems with cheek irritation.
Neural Correlates of Stress- and Food Cue–Induced Food Craving in Obesity
Authors: Jastreboff Ania M. , Sinha Rajita , Lacadie Cheryl , Small Dana M. , Sherwin Robert S. , Potenza Marc N.
Published: October 2012

OBJECTIVE

Obesity is associated with alterations in corticolimbic-striatal brain regions involved in food motivation and reward. Stress and the presence of food cues may each motivate eating and engage corticolimibic-striatal neurocircuitry. It is unknown how these factors interact to influence brain responses and whether these interactions are influenced by obesity, insulin levels, and insulin sensitivity. We hypothesized that obese individuals would show greater responses in corticolimbic-striatal neurocircuitry after exposure to stress and food cues and that brain activations would correlate with subjective food craving, insulin levels, and HOMA-IR.

RESEARCH DESIGN AND METHODS

Fasting insulin levels were assessed in obese and lean subjects who were exposed to individualized stress and favorite-food cues during functional MRI.

RESULTS

Obese, but not lean, individuals exhibited increased activation in striatal, insular, and hypothalamic regions during exposure to favorite-food and stress cues. In obese but not lean individuals, food craving, insulin, and HOMA-IR levels correlated positively with neural activity in corticolimbic-striatal brain regions during favorite-food and stress cues. The relationship between insulin resistance and food craving in obese individuals was mediated by activity in motivation-reward regions including the striatum, insula, and thalamus.

CONCLUSIONS

These findings demonstrate that obese, but not lean, individuals exhibit increased corticolimbic-striatal activation in response to favorite-food and stress cues and that these brain responses mediate the relationship between HOMA-IR and food craving. Improving insulin sensitivity and in turn reducing corticolimbic-striatal reactivity to food cues and stress may diminish food craving and affect eating behavior in obesity.
Magnetic resonance study of nanocrystalline 0.10MnO/0.90ZnO
Authors: Żołnierkiewicz Grzegorz , Typek Janusz , Guskos Niko , Narkiewicz Urszula , Sibera Daniel
Published: October 2012

Magnetic properties of nanosize ZnO powders doped with MnO magnetic dopand have been studied. Sample designated as 0.10MnO/0.90ZnO was characterized by XRD that revealed the presence of ZnO and ZnMnO3 phases. An average size of magnetic ZnMnO3 nanocrystallites was 9 nm. Magnetic resonance study has been carried out in the 4-290 K temperature range. The spectrum at each temperature was analyzed in terms of three components. The temperature dependences of resonance field, linewidth and integrated intensity of these components have been determined. Magnetic centers responsible for producing the observed spectra have been proposed.
ADMA and C-reactive protein as mortality predictors in dialysis patients
Authors: Ignjatović Aleksandra , Cvetković Tatjana , Pavlović Radmila , Đorđević Vidojko , Milošević Zoran , Đorđević Vidosava , Pavlović Dušica , Stojanović Ivana , Živanović Slavoljub
Published: October 2012

There is a higher mortality between patients with end-stage renal disease than patients in the general population. These circumstances have led to a search for risk factors as predictors of mortality in dialysis patients. Amongst those, inhibitors of the nitric-oxide (NO) synthesis deserve special attention, since patients with end-stage renal disease are also characterized by accelerated atherosclerosis. Asymmetric-dimethylarginine (ADMA) and symmetric-dimethylarginine (SDMA), as well as C-reactive protein (CRP), have also been recognized as predictors of mortality in patients on dialysis. The aim of our study was to compare the prediction power of ADMA, SDMA and CRP for all-cause mortality in patients with end stage renal disease during the fourteen month follow-up. In total 162 patients on hemodialysis were included. ADMA and SDMA were measured by the high-performance liquid chromatography (HPLC); CRP was measured using immunonephelometric assays. During the 14-month period 28 patients (34.1%) died from all-cause mortality. Using univariate analysis, hazard ratios (HR) of the potential independent predictors of mortality in hemodialysis patients were ADMA (HR 1.39 (1.01–1.91) p=0.043) and CRP (HR 1.024 (1.009–1.1.040) p=0.001). Further, multivariate analysis (MVA), however, showed that ADMA is the only predictor of all-cause mortality (HR 1.76 (1.002–3.11) P=0.049), while SDMA failed to predict death in this population. Therefore, our data shows that ADMA is an independent and better marker of all-cause mortality compared with CRP.
Urine saturation and promoter/inhibitor parameters and ratios in renal stone disease caused by ceftriaxone
Authors: Milošević Danko , Miše Branko , Habuš Ivan , Topalović-Grković Marija , Batinić Danica , Golubić Anja , Turudić Daniel
Published: October 2012

During ceftriaxone treatment of subdural empyema caused by Streptococcus intermedius urinary and biliary stones were noticed. Increased levels of urinary calcium excretion were detected during ongoing treatment in comparison with 2 months check-up. There were no significant changes in the promoter/inhibitor urolithiasis parameters, oxalate, citrate, urate, cistine, glycosaminoglycans or their ratios. Urine saturation was calculated using EQUIL 2 computer programme (calcium oxalate, brushite) and it was normal. Probable trigger for the ceftriaxone/calcium hydroxy carbonate phosphate mixture of stones was a critical boost of solubility products caused by ceftriaxone treatment and phospnate urine content with a subsequent large-scale spontaneous precipitation of crystals.
After the Culture War? Shifts and Continuities in American Conservatism
Authors: Dombrink John
Published: October 2012

Abstract:

Following the 2008 American election, some analysts concluded that the election had signalled an end to the polarization and culture wars that had typified American politics. To some, demographic changes would cause this demise. To others, the moderating of religious groups was crucial. As social conservatives came to grips with the 2008 electoral defeats, some argued for emphasis on culture-war issues to revive their role. Sin No More (John Dombrink and Daniel Hillyard, 2007) had argued that, despite conservative rhetoric, the tide was turning on the core legal and moral issues of the American culture war, moving them toward normalization. It challenged the representation of America as a “centre-right” country. This article analyzes enduring and shifting elements of the American culture war: the broadening of the role of religion, the reduced salience of wedge issues, and the paradox that some forms of polarization are increasing as others are receding.
Safety Evaluation of Sequential Warning Lights in Tapers at Nighttime Work Zones
Authors: Sun Carlos , Edara Praveen , Hou Yi , Robertson Andrew
Published: October 2012

Safety improvement at nighttime work zones is important because of visibility concerns after dark. The deployment of sequential lights is an innovative method to improve driver recognition of lane closures and work zone tapers. Sequential lights are wireless warning lights that flash in a sequence to delineate clearly the taper at work zones. The effectiveness of sequential lights was investigated with the use of controlled field studies. Traffic parameters were collected at the same field site with and without the deployment of sequential lights. Three surrogate performance measures (the speeds of approaching vehicles, the number of late taper merges, and the locations where vehicles merged into an open lane from a closed lane) were used to determine the impact of sequential lights on safety. The results of this study showed that sequential warning lights had a net positive effect: the warning lights reduced the speeds of approaching vehicles and enhanced driver compliance, and the lights shifted overall merge behavior upstream. Statistically significant decreases of 3.56 km/h (2.21 mph) mean speed and 1.61 km/h (1 mph) 85% speed resulted with sequential lights. The shift in the cumulative speed distributions to the left (i.e., speed decrease) was found to be statistically significant with the Kolmogorov–Smirnov test. With sequential lights, there was a statistically significant increase of 1.47 km/h (0.91 mph) in the speed standard deviation, and the percentage of vehicles that merged earlier increased from 53.49% to 65.36%.
Investigation of Travel Time Reliability in Work Zones with Private-Sector Data
Authors: Edwards Matthew B. , Fontaine Michael D.
Published: October 2012

The impact of work zones on mean travel time and travel time reliability has gained attention as agencies focus on performance measurement. Travel time reliability in work zones often has been difficult for agencies to quantify because of the time and expense required to collect travel time data. Several private-sector companies have begun to sell travel time data; this availability has created an opportunity to examine cost-effectively work zone impacts on travel time reliability on a broader basis. The Virginia Department of Transportation recently acquired probe vehicle-based travel time data for 2010 from a private-sector data provider. These data were used to calculate measures of travel time reliability at 15 work zones and to examine factors that affected travel time reliability. Travel time reliability was quantified with 95th percentile travel time, a buffer index, and a planning time index. The work zones experienced a statistically significant degradation across all measures of travel time reliability as compared with baseline conditions. Work zone mean buffer index, planning time index, and 95th percentile travel time rates were higher by 48%, 18%, and 16%, respectively. Although lane closures occurred during off-peak periods, work zones that involved lane closures experienced increases in their mean buffer index, planning time index, and 95th percentile travel time with rates of 67%, 23%, and 22%, respectively. Annual average daily traffic per lane and the number of access points per mile were found to have the most obvious relationships with declines in reliability at work zones.
Effectiveness of a Control Strategy for Forced-Detour Traffic in Continuous Lane Closure within a Rural Work Zone
Authors: Gallo Anthony A. , Dougald Lance E. , Demetsky Michael J.
Published: October 2012

During the 2011 construction season, the Virginia Department of Transportation completed an in-place pavement recycling project to rehabilitate a section of pavement on Interstate 81 southbound near Staunton, Virginia. During the project, the right lane of two lanes of traffic was forced to detour onto a parallel highway through an aggressive traffic control scheme. Electronic message signs were used to direct trucks into the left lane and remain on the Interstate. Signage for the right lane was deliberately sparse to increase the number of vehicles that detoured. During peak-volume periods, cars were specifically instructed to use the right lane. Field results showed that, during construction, approximately 45% of cars on average exited the freeway, whereas nearly 90% of trucks remained on I-81 through the work zone. This project compared the results of this unique traffic control strategy with simulated results from traditional work zone strategies: a lane closure with no suggested detour, a lane closure with a suggested detour, and a closure of both lanes with a full detour. Simulation results suggested that the forced-detour strategy reduced travel times and queue lengths more than traditional strategies did. This forced-detour strategy could be extended to similar locations along rural Interstate corridors.
Driver Feedback on Monetary Penalty and Its Impact on Work Zone Speed
Authors: Roberts Craig A. , Smaglik Edward J.
Published: October 2012

Across the nation, one work zone fatality occurs every 10 h (about 2.3 per day) and one injury, every 13 min (110 per day). Speed limit compliance in and around work zones concerns transportation agency officials because excessive speeds have proved to be primary causes of crashes in work zones. As much as 25% of fatal crashes in work zones may have involved high speeds. Research was conducted with the use of a changeable message sign with radar (CMSR) at one work zone location on a four-lane, divided highway in Arizona. The CMSR, which was triggered by radar-detected speed, provided feedback to drivers about the amount of their potential traffic fine. A review of the literature indicated that this type of feedback has received only limited study. The CMSR alternated one speed feedback message, “Your Speed XX mph,” with another, “Possible Fine $XXX.” The dollar amount varied according to the speed of the vehicle. The coupling of speeding-fine feedback with alternating feedback on vehicle speed led to an observed reduction of speeds in the tested work zone. Reductions in mean speeds were modest, at approximately 4 mph. However, the impact on excessive speeders was significant. The number of speeders that traveled 5 and 10 mph, or more, above the speed limit decreased by one-fourth. At the extreme speeds of 15, 20, and 25 mph over the speed limit, the number of speeding vehicles was reduced in each case by half.
Four-Regime Speed–Flow Relationships for Work Zones with Police Patrol and Automated Speed Enforcement
Authors: Avrenli K. A. , Benekohal Rahim F. , Ramezani Hani
Published: October 2012

This paper presents the development of a four-regime speed–flow relationship for highway work zones and the effects of police presence (police) and speed photo enforcement (SPE) on the speed–flow relationship and capacity. The base data were collected when signage typical of that shown in the Manual on Uniform Traffic Control Devices for an Interstate highway work zone with no lane reduction was present. Police and SPE data were collected, respectively, when a police patrol car and an SPE van were added to the typical work zone. From each data set, the step-by-step progression from a three-regime model based on least-squares regression to a four-regime speed–flow curve is presented. The four-regime model comprises four equations: (a) horizontal line for free-flow regime that covered the volume levels up to 900 passenger cars per hour per lane, (b) fourth-degree spline for the upper transition part of the speed–flow curve, (c) another fourth-degree spline for the lower transitions part, and (d) equation in the form of power function for the highly congested part of the speed–flow relationship. The speed–flow curve for the base case had a free-flow speed (FFS) of 61.3 mph and a capacity of 1,850 per car per hour per lane (pcphpl). In the police case, however, the FFS and capacity were reduced by 6.3 mph and 50 pcphpl, respectively. For the SPE case, the FFS and capacity were also reduced by 6.8 mph and 100 pcphpl, respectively. The new curves provided the more accurate speed and work zone capacity estimations required for efficient operation.
Interactive Lane Closure and Traffic Information Tool Based on a Geographic Information System
Authors: Bartin Bekir , Ozbay Kaan , Mudigonda Sandeep
Published: October 2012

This paper describes the development of the Rutgers Interactive Lane Closure Application (RILCA), an interactive computer tool to plan lane closures for work zones. This tool provides traffic engineers with a computerized and easy-to-use lane closure application, along with other useful features. RILCA was developed with the ArcView geographic information system (GIS) software package as the main development environment. ArcView displays the interactive GIS map of the New Jersey Turnpike, Garden State Parkway, and other major freeways in New Jersey and its surrounding network. RILCA provides various analysis and visualization options to plan lane closures interactively, obtain traffic volume information, and conduct accident queries. RILCA was tested successfully, and New Jersey Department of Transportation (DOT) and New Jersey Turnpike Authority engineers now use it with all of the features presented in this paper. RILCA received an annual implementation award from the New Jersey DOT in 2009. The award recognized RILCA's usefulness and potential to improve the efficiency of traffic operations as a practical decision-support tool for lane closure decisions.
Regional Impact of Roadway Construction on Traffic Operations
Authors: Pesti Geza , Chu Chi-Leung , Balke Kevin , Shelton Jeff , Zeng Xiaosi , Chaudhary Nadeem
Published: October 2012

The objective of this study was to develop a methodology for assessing the impact of road construction that could be used to (a) predict the network-level impact of road construction projects, (b) identify critical roadway segments and corridors in which the impacts of construction are expected to be the most severe, and (c) compare alternative construction scenarios and schedules. Dynamic traffic assignment formed the basis of an approach to assess the regional impact of road construction and compare alternative construction schedule scenarios. The application of the model was illustrated with the use of a hypothetical case of two road construction projects in the roadway system of El Paso, Texas.
Work Zones as a Series of Bottlenecks
Authors: Ramezani Hani , Benekohal Rahim F.
Published: October 2012

Studies on queue length and delay estimation have simplified the work zone as the location of a single bottleneck. However, if more than one bottleneck exists, such a simplification introduces considerable error into estimations of queue length and delay and can adversely affect traffic management strategies. The work space and the transition area are the two main locations in which bottlenecks are likely to occur. Drivers who pass a work space may reduce speeds or increase their headway and thus reduce capacity. Lane shifts or merges may also reduce capacity and cause queues. Work zones with inhomogeneous sections often have more than one bottleneck in a single work zone. The objective of this study was to develop a more accurate approach to predict queue length and delay when two bottleneck locations are assumed to exist in a work zone. Analyses were conducted for two-to-one work zones in which one of the two lanes was closed in a given direction. Shockwave theory was applied to study six conditions, each of which represented a relationship between the demand and capacity of the bottlenecks. Because of differing initial conditions and the interaction between the bottlenecks, 21 queue propagation patterns existed. Results from this approach were validated with field data. The average of the queue lengths did not differ significantly from the average of the observed queue lengths. The maximum queue length was overestimated by roughly 4%. This percentage was lower than that reported for queue length (above 20%) in estimates made with popular software packages, such as QUEWZ and QuickZone.
Truck-Mounted Changeable Message Signs with Symbols for Work Zone Operations
Authors: Ullman Brooke R. , Trout Nada D. , Sun Dazhi
Published: October 2012

Truck-mounted changeable message signs (TMCMSs) are desirable for scheduled and unscheduled short-duration work operations to inform drivers of unexpected conditions. Temporary traffic control for short-duration operations has been limited traditionally to arrow boards and static warning messages mounted to the work vehicle. With advances in technology, TMCMSs can fill a gap and provide drivers with better information about short operations and required actions by the driver. Through a study in a human factors laboratory, researchers evaluated message designs that incorporated text and graphic alternatives to warn drivers about accidents, work zone areas, and lane closures. In this study, researchers determined many key points about motorist interpretations of TMCMS symbols and text messages. The study found that (a) the accident symbol was well understood and enhanced motorists' abilities to recall the situation during limited viewing times, (b) the sign with the “Man Working” figure without the diamond background outline was recommended because it elicited the best reaction time by study participants, and (c) the lane-blocked symbols worked well to communicate lane conditions to drivers.
Evaluation of ASTM Standard Test Method E2177
Authors: Pike Adam M. , Schwenn Brandon
Published: October 2012

The purpose of this project was to determine the sensitivity of standard test method ASTM E2177 to various factors. The standard test method is a way to determine an accurate representation of the retroreflective performance of a pavement marking in a recovery condition. Consistency of a test method across the allowable range of factors reduces inconsistencies within the method that could produce inequitable or varied results. The following test factors were evaluated in a controlled laboratory setting: water application method, water volume, recovery time, pavement marking cross slope, and pavement marking type. All factors were tested against each other to determine all correlations between them. After laboratory data were collected, the results were examined statistically for the effect of each factor and any cross interaction between them. The results of the research showed a significant impact for all factors tested. Each marking type was affected differently by each factor, and recommendations were made on the basis of the significance of each impact. The research showed that ASTM E2177 can produce repeatable results. However, a narrower range of variables within the test could create more consistent results and reduce significant differences within the test.
Assessment of Presence Conditions of Pavement Markings with Image Processing
Authors: Zhang Yunlong , Ge Hancheng
Published: October 2012

This paper presents a systematic approach that can automatically determine the presence conditions of pavement markings from marking images developed with digital image processing techniques. These techniques are used to correct geometric deformity, detect colors of pavement markings, segment images, enhance images, detect edge lines of pavement markings, and recognize the features of pavement markings appearing in the photographs. The performance of this system was investigated with the photograph data sets provided by the National Transportation Product Evaluation Program Mississippi test deck. The empirical results (when compared with those from the manual method and expert observations) show that this method produced accurate and reliable results. The techniques in this study can be used to develop an automated system for accurate and speedy assessments of pavement marking conditions and might help agencies make a better decision in the maintenance of pavement markings.
Assessment of Sign Retroreflectivity Compliance for Development of a Management Plan
Authors: Evans Travis , Heaslip Kevin , Boggs Wesley , Hurwitz David , Gardiner Kevin
Published: October 2012

The Manual on Uniform Traffic Control Devices (MUTCD) specifies minimum retroreflectivity requirements that include an obligation for agencies to develop a strategy for maintaining compliance. States were given a deadline of January 1, 2012, for the implementation of an assessment or management plan, which led to an increased emphasis on sign asset management. However, a new rule was submitted to the Federal Register to extend and modify the deadlines. With budget considerations, it is important that a transportation agency implement an assessment or management plan that is efficient and provides compliance with the standards required by the MUTCD. The development of an efficient plan requires knowledge of the overall condition of an agency's assets as well as unique considerations regarding its performance. Through a review of previous data collection efforts, this paper details the development of a data collection strategy for assessing the performance of traffic signs maintained by the Utah Department of Transportation (DOT). Agency operations, site selection, and attribute collection were all considered during the development of a collection plan for an agency where limited inventory and installation data were available. Retroreflectivity measurements were taken for 1,433 Utah DOT signs. This sample provided a snapshot of current compliance and assisted in the selection of an asset management plan for maintaining sign retroreflectivity. Results from the study showed that the Utah DOT's signs were well over 90% compliant with the MUTCD standards and preliminary management strategies were presented to address vandalism and other damage.