bluuebunny/crossref_metadata_2025 huggingface dataset:
Completion Optimization in the Fayetteville Shale Utilizing Rate Transient Analysis for Candidate Selection
Authors: McDonald B. , Wright T. H.
Published: January 2016

Areas of Southwestern Energy's Fayetteville Shale asset were identified as candidates for optimized completions by analyzing the y-axis intercept of the Rate Transient Analysis (RTA) square root time plot, an indicator of skin, and looking for those wells with values above the field average. It is hypothesized that the increase in the y-intercept from the typical average across the asset is due to proppant embedment in the formation and through optimized completions a reduction in the y-intercept, or skin, can be achieved.

The initial test program started in Q4 2014 and the area of interest (AOI) was established by conducting rate transient analysis on all Southwestern Energy Fayetteville Shale wells and then mapping the variable across the play. The initial test pads were located in areas where y-intercept values exceeded average and included 6 pads, 19 wells, with completion designs using 30 - 50% more sand/stage and 7 pads, 24 wells, with 30 - 50% reduction in fluid volume/stage versus the standard Southwestern Energy Fayetteville Shale completion. Success or failure was determined by comparing normalized pressure and well performance to the 9-section area of the test pad.

The wells with 30 - 50% more sand/stage have an average EUR/CLAT improvement of 4% and exhibit a reduction of 24% in the y-intercept. The wells with 30 - 50% reduction in fluid volume have an average EUR/CLAT improvement of 6% and exhibit a reduction of 68% in the y-intercept and the economics are more favorable due to the reduced costs of the completion.

Given the success of the initial test program in the AOI, more pads are being evaluated to have optimized completions. As the program progresses, the y-intercept will be used in conjunction with data analysis of the more than 3,500 wells currently in the Fayetteville Shale to further optimize completions in specific areas.
Sinuosity of the Hydraulic Fractured Horizontal Well Impact on Production Flow Assurance: An Eagle Ford Case
Authors: Qiu Fangda , Yuan Ge , Marongiu-Porcu Matteo , Xu Jian , Pope Timothy
Published: January 2016

Shale operators are finding it increasingly critical to find a reservoirs' sweet spot, choose the optimum landing point, geo-steer the well within the best rock, and run the optimal completion hardware in order to exceed investor expectations. Due to geological structures that vary across the field or geo-steering quality issues, many wells suffer severe sinuosity which potentially impairs completions and inhibits productivity.

This study presents a comprehensive evaluation of hydraulically-fractured wellbore productivity compared with relatively smooth and highly-sinuous wells of similar reservoir quality. The sharp contrast leads to the engineering investigation by coupling a reservoir model which imbeds a representative complex fracture network with a transient multiphase wellbore simulator. The integrated model provides insight behind the flow instability in horizontal wells that produce hydrocarbons from unconventional reservoirs and the remedy completion and production strategy by considering reservoir and wellbore coupled performance.

Hydraulically-fractured horizontal wells in shale reservoirs have unstable flow dynamics because of low effective productivity index, small fluid velocity (due to large production string), and multiphase flow under bubble-point pressure, etc. We found that all these reasons lead to vigorous terrain slugging for any toe-up or toe-down wellbore geometries. Furthermore, this flow assurance issue determines more serious problems while encountering a certain level of wellbore sinuosity. In fact, we observed how the stagnation of fluid may isolate entire sections of the lateral and lead to a huge impairment of well deliverability.

This study couples for the first time an unconventional fracture model with an unstructured grid reservoir simulator and a transient multiphase wellbore deliverability model, evaluating the hydraulic fracture networks productivity and irregular or sinuous wellbores.
Understanding Completion Performance in Niobrara-Codell Reservoirs Through the Use of Innovative Software-Guided Workflows and Models
Authors: Wallace K. J. , Aguirre P. Reyes , Jinks E. , Yotter T. H. , Malpani Raj , Silva Felipe
Published: January 2016

This paper describes a comprehensive field study of eight horizontal wells deployed in the stacked Niobrara and Codell reservoirs in the Wattenberg oilfield (Denver-Julesburg basin). The overall goal was to understand the geometry of the hydraulic fractures (propped), producing volume with respect to completions design, target reservoirs, and well spacing. Through this understanding we are able to develop the asset more effectively and economically.

In this study, an unconventional hydraulic fracture model was developed and calibrated against surface and downhole microseismic recordings, "frac hits" in offset vertical wells, chemical tracers, pressure interference testing, diagnostic fracture injection tests (DFITs), and treatment pressure/instantaneous shut-in pressure (ISIP) history matching. The hydraulic fracture geometry and conductivity were simulated using unconventional models populated with a natural discrete fracture network (DFN) defined through outcrop and image log observations along with a rigorous mechanical earth model.

A special unstructured grid that conforms to the shape of the calibrated hydraulic fracture model planes was constructed. This unstructured, fractured reservoir grid was fed into a compositional reservoir simulator that was tuned using pressure dependent permeability, offset vertical well pressure depletion, and relative permeability (among others) to match the production history available to date.

This workflow allowed for complete integration of geological, geomechanical, and production models in a single platform to produce a consistent set of results. This study concludes that 1) Increasing the hydraulic fracture treatment volume beyond a certain point does not significantly enhance the fracture geometry or improve early time well performance; 2) additional wells are needed to access undrained reservoir; 3) existing vertical-well depletion has a significant impact on early time well performance, and; 4) hydraulic fracture height extension allows initial communication between the Niobrara and Codell reservoirs, however this connectivity dissipates during production likely due to the loss of fracture connectivity vertically.
Expanding Interpretation of Interwell Connectivity and Reservoir Complexity through Pressure Hit Analysis and Microseismic Integration
Authors: Lehmann Jurgen , Budge Jessica , Palghat Abhinav , Petr Christopher , Pyecroft James
Published: January 2016

This paper presents a multi-disciplinary workflow for analyzing interwell hydraulic fracturing pressure interactions on multi-well horizontal pads in unconventional reservoirs. Over twenty wells in multiple fields with varied spacing across multiple landed zones are evaluated. The workflow provides a method for determining the degree of connectivity between the wells to assess the extent and complexity of the stimulated network. The analysis method provides a cost efficient, timely means of understanding the stimulated network in order to impact decisions regarding well spacing, injection rate, perforation design and frac order.

Prescriptive completions programs enable observation of pressure interactions between wells during multi-stage hydraulic fracturing. Wellhead pressures are continuously recorded during all completion and flowback operations. In the observation pads studied, wells experience varying degrees of pressure communication across the fracture network. Pressure hits are grouped by according to identifying characteristics and correlated to microseismic data where available.

Characterization of the stimulation network gained from analysis of pressure interactions closely aligns with available high resolution microseismic data. Networks are shown to have significant vertical and lateral growth establishing a highly complex network. Additional insights on the degree of connectivity and the definition of effective fracture network are gained. Results are fundamental to understanding well spacing and zonal placement.
Who wrote the book "Svestena istorija", translated by Jovan Rajic?
Authors: Vojnovic Zarko
Published: January 2016

In 1793 in Vienna was published the book called "Svestena istorija" ("Sacred
history"), in Serbian language. It was known that the translator was Jovan
Rajic, but the author remained unknown at that time. In the early 20th
century Dimitrije Ruvarac attributed the book to Platon Levsin. As relevant
information it became a part of almost all bibliographic sources. The paper
deals with the issue, trying to establish, on the basis of bibliographical
and literaryhistorical research, identity of the real author. In addition, it
considers the 18th century poetics of translation, as a necessary context for
understanding the book and literary issues.
Dubrovnik archive in the Kingdom of Yugoslavia
Authors: Djordjevic Bojan
Published: January 2016

The fundamental issue in the first years after the formation of the Kingdom
of Serbs, Croats, and Slovenes was related to the future organization of
Dubrovnik Archive, considering that the invaluable materials still lay in the
Rector?s Palace, which assumed a completely new role and a special place in
the newly formed Kingdom. Namely, following the end of World War I and the
foundation of the new state, the Rector?s Palace in Dubrovnik, as a cultural
property of national significance, was proclaimed a cultural-historical
monument, on the one hand, and also a residence of the king, on the other.
Therefore, it came under the jurisdiction of the Court of the Kingdom of
Serbs, Croats, and Slovenes (later the Court of the Kingdom of Yugoslavia),
i.e. of the Royal Office. The jurisdiction over the Archive itself,
specifically over the materials kept in it, was in the hands of the Ministry
of Education. In 1921, Antonije Vucetic was named the first administrator of
Dubrovnik Archive. Vucetic immediately and unequivocally advanced the thesis
that Dubrovnik Archive, despite not being of the rank of the Archives in
Zagreb and Belgrade, still is ?the most celebrated in the Kingdom of Serbs,
Croats, and Slovenes?. Above all else, he emphasized the historical
significance of this Archive, containing materials important for the history
of the Republic of Dubrovnik, but also for the Serbian and Croatian histories
from the 11th to the 19th centuries. In the year 1930, a new administrator
was appointed to Dubrovnik Archive. It was Branimir Truhelka. He realized
that in the case of the most important matters related to the Archive, in the
case of all the Archive?s needs, they should turn, if possible, directly to
the Court of the Kingdom of Yugoslavia, i.e. to the Minister of the Court.
The year 1931 marks the beginning of Truhelka?s systematic efforts to obtain
the most that could be obtained for Dubrovnik Archive, to explain its
significance to the authorities on the Court, and - without insisting on
moving the Archive from the Rector?s Palace, being aware of the lack of
support for this - to do everything to provide the safe keeping of valuable
materials and to secure research in the Archive. Until the beginning of World
War II and the occupation of Yugoslavia, Dubrovnik Archive prospered and an
increasing number of researchers came to work in it. Thus, Dubrovnik Archive
proved itself to be an unavoidable source for studying the past of both the
Republic of Dubrovnik and the Serbian people.
Literary-critical thought in the interwar journal “Our Reality” (1936-1939)
Authors: Mrkalj Zona
Published: January 2016

This work is a part of a comprehensive study of the role and importance of
the magazine ?Our Reality? (1936-1939) and is an extension of the already
published works by the same author: ?Our Reality? in the forties of the
twentieth century, Twilight of lyric poetry in ?Our Reality? and the
philosophical background of ?Our Reality?, the journal of literature,
science, art and all the social and cultural issues. In addition to numerous
critical articles about the old and new literary creations of writers who
have worked in the interwar period, or those whose ideas were in line with
program definition of this magazine, in ?Our Reality? are systematically
published and peer reviews on literature and other arts, and are parallel
presented as literary, theater, art, music and the film critique. Interesting
views of the editorial and other staff of ?Our Reality? (Djordje Jovanovic,
Jovan Popovic, Milos Savkovic, Alexander Vuco, Milovan Djilas, Radovan
Zogovic, Velibor Gligoric ...) represent a valuable testimony of literary
ideology based on the principles of engaged literary expression and based in
social realism.
Porikogolos in a transcript held by the Matica Srpska library
Authors: Jovanovic Tomislav
Published: January 2016

This narrative was probably created in the 12th century in the Greek
language, and represents a parody of a judicial hearing, containing allusions
to hagiographies. It also constitutes a parody ridiculing a deluge of titles
in Byzantine society. In the Greek language version, this work is known as A
Book on Fruit, or Porikogolos. It has been translated into the Serbo-Slavic
language, and the title of this version states that it is a narrative about
the blessed Grozdije (grapes). Several Serbian transcripts have been
preserved, and what has been edited on this occasion is the text of a
transcript dating from the end of the 17th century unknown so far, which
belongs to the Library of Matica srpska. It is compared textologically to the
other known transcripts.
Serbskoe Evangelie XVI veka iz Nizegorodskoj kollekcii
Authors: Beljakova Marina , Kurzina Elena
Published: January 2016

V stat'e predstavleny rezul'taty paleograficeskogo i arheograficeskogo
issledovanija serbskoj rukopisi Evangelietetr pervoj treti XVI veka,
hranjascejsja v Niznem Novgorode. Issledovanie vkljucaet v sebja datirovku,
opisanie sostava, sohrannosti i perepleta kniznogo pamjatnika, nabljudenija
nad osobennostjami ornamentiki, a takze pravopisanija i jazyka teksta rukopisi.
Privedeny teksty zapisej na priperepletnyh listah (1637 g., XVII-XIX vv.).
Survey participation and response
Authors: Bosnjak Michael , Danner Daniel
Published: January 2016

nema
The use and positioning of clarification features in web surveys
Authors: Metzler Anke , Kunz Tanja , Fuchs Marek
Published: January 2016

Clarification features are used in Web surveys to improve the quality of
responses. It is generally advised to place clarification features after the
question stem. However, based on initial findings of an eye-tracking study
(Kunz & Fuchs, 2012), we expected that the optimal position depends on the
respective stage of the question-answer process as it is referred to by the
clarification feature. In three Web surveys, the use and positioning of
clarification features were tested in open-ended questions, with three
different positions being experimentally varied: before the question stem,
after the question stem, and after the answer box. Results indicated that
contrary to expectations, the optimal position of clarification features did
not differ depending on the respective stage of the question-answer process.
Clarification features were principally most effective when they were
positioned after the question stem, whereas clarification features placed
before the question stem were least effective in improving the quality of
responses.
We take a look back to make a more successful step forward
Authors: Dobric Silva
Published: January 2016

nema
Porous silicon with double band photoluminescence fabricated by chemical-assisted picosecond laser irradiation
Authors: Lv Xiaozhan , Ji Lingfei , Wu Yan , Lin Zhenyuan , Yan Yinzhou
Published: January 2016

The fabrication of porous silicon with double band photoluminescence (PL) by chemical-assisted 1064 nm picosecond (ps) laser irradiation of polysilicon is presented. The hybrid method includes controlling of the laser scanning interval, number of scans to form dense micropores, and subsequently, short-time acid corrosion to form fine nanostructure. Along with the stable red PL visible to the naked eye, a new violet PL band at 432 nm existed in the fabricated samples. The double band photoluminescence was mainly attributed to the prepared micro/nano hierarchical structure. Moreover, dangling bond defects formed by high-energy photon impinging acted as the catalyzer in the subsequent acid corrosion resulted in good passivation of the nanostructure with the formation of Si-H and Si-O bond, which also contributed to the stable photoluminescence. The maximum surface porosity of the samples was concluded to be 90.48% which also bring good hydrophobicity for the prepared samples.
Estimation of Base-Year Floor Space Data
Authors: Shiravi Sajad , Zhong Ming , Beykaei Seyed Ahad , Hosseini Faranak
Published: January 2016

Base-year floor space data are essential for integrated land use transport models. This information has traditionally been estimated on the basis of limited population or employment data provided by the census, with unknown accuracy. Advances in geographic information systems (GIS) and remote sensing technology enable the accuracy of this conventional method to be evaluated with geographic data of high precision. This study assessed the accuracy of the census-based approach in estimating base-year floor space data; the paper describes the use of a hybrid method that combines lidar and geographic vector data (referred to as the “lidar-GIS method”) to develop a ground truth building floor space database for the City of Fredericton, New Brunswick, Canada. A ground survey proved that the developed ground truth building data set provided highly accurate estimates of building heights, footprint areas, and therefore floor space. Through a case study, the floor space at the dissemination area level estimated with the traditional census-based method was compared with the floor space estimated with the lidar-GIS method for various land use categories. The results showed that for the residential floor space estimation, the average absolute percentage error of the census-based approach was 15%. The accuracy of the conventional method was much lower for nonresidential land use categories, with average errors of 50% or higher. These statistics indicate that the traditional census-based approach is unreliable and inaccurate for use in the estimation of base-year floor space and suggests that a method that incorporates the above-mentioned modern information technologies be used.
Exploratory Analysis of a Smartphone-Based Travel Survey in Singapore
Authors: Zhao Fang , Pereira Francisco Câmara , Ball Rudi , Kim Youngsung , Han Yafei , Zegras Christopher , Ben-Akiva Moshe
Published: January 2016

Future Mobility Sensing (FMS) is an innovative smartphone-based travel survey that was field-tested in 2012 and 2013, together with the Household Interview Travel Survey (HITS), in Singapore. This paper presents the findings of an exploratory analysis of the data collected in this test. The clustering of the day patterns from the FMS data revealed a large day-to-day variability of user behavior that could not be captured by a snapshot with a 1-day survey. Even the high cross-sectional variability from the larger sample size of a traditional survey would not have achieved the comprehensive set of heterogeneous patterns provided by FMS. Some common problems in traditional surveys—such as the underreporting of trips, the overestimation of travel times, and the inaccuracy of locations and times—can apparently be reduced by FMS. The FMS data have higher resolution and better accuracy compared with the HITS data. In addition, FMS is well suited to the collection of multiday data because additional costs are marginal and the user burden decreases over time. FMS offers a promising technology for the next generation of travel data collection.
Effect of Aggregate Uniformity on Pullout Resistance of Steel Strip Reinforcement
Authors: Weldu Mehari T. , Han Jie , Rahmaninezhad Sayed Mustapha , Parsons Robert L. , Kakrasul Jamal I. , Jiang Yan
Published: January 2016

Results are presented of large-scale laboratory pullout tests on ribbed steel strip reinforcement embedded in six types of aggregates with uniformity coefficients (ratio of the particle size at 60% finer to that at 10% finer) ranging from 1.4 to 14. These aggregates satisfied the AASHTO standard gradation requirements for select backfill. Each backfill material was placed in two lifts and compacted until the required degree of compaction was achieved. The normal stress was applied with a pressurized air bag placed on top of the compacted backfill. A double-acting hydraulic jack was used to apply the pullout load, which was measured with a load cell. Displacement transducers were installed to measure the rear and front strip displacements. The test results demonstrated that the uniform aggregates generally behaved the same way as did the well-graded aggregates in terms of pullout resistance. The effect of uniformity was more obvious in the tests under a lower normal stress than those under a higher normal stress. Moreover, the pullout resistance factors, F*, from this study lie to the right of the default F*-values for ribbed strip reinforcement suggested by AASHTO. The comparison also shows that the pullout resistance factor for ribbed steel strips decreased with depth in the same way as that suggested by AASHTO. However, the F*-values recommended by AASHTO are conservative as compared with the test results when gravel backfill is used. The formula suggested by AASHTO can be used to conservatively estimate the F*-value with the uniformity coefficient ranging from 1.4 to 14.
Silage Maize and Sugar Beet for Biogas Production in Rotations and Continuous Cultivation: Dry Matter and Estimated Methane Yield
Authors: Brauer-Siebrecht Wiebke , Jacobs Anna , Christen Olaf , Götze Philipp , Koch Heinz-Josef , Rücknagel Jan , Märländer Bernward
Published: January 2016

Since silage maize is the main crop grown for biogas production (biomass crop) in Germany; its increasing cultivation is critically discussed in terms of social and agronomical aspects. To investigate if sugar beet is suitable as an alternative biomass crop to silage maize; three-year field trials with both biomass crops in rotations with winter wheat (food crop) and continuous cultivation were conducted at three highly productive sites. Dry matter (DM) yield per hectare was measured via field trials whereas methane yield per hectare was estimated via a calculation. Higher annual DM yield was achieved by silage maize (19.5–27.4 t∙ha−1∙a−1) compared to sugar beet root (10.7–23.0 t∙ha−1∙a−1). Dry matter yield was found to be the main driver for the estimated methane yield. Thus; higher estimated methane yield was produced by silage maize (6458–9388 Nm3∙ha−1) with overlaps to sugar beet root (3729–7964 Nm3∙ha−1). We; therefore; classify sugar beet as a suitable alternative biomass crop to silage maize; especially when cultivated in crop rotations with winter wheat. Additionally; we found that the evaluation of entire crop rotations compared to single crops is a more precise approach since it includes rotational effects.
The Role of Highly-Resolved Gust Speed in Simulations of Storm Damage in Forests at the Landscape Scale: A Case Study from Southwest Germany
Authors: Jung Christopher , Schindler Dirk , Albrecht Axel , Buchholz Alexander
Published: January 2016

Routinely collected booking records of salvaged timber from the period 1979–2008 were used to empirically model the (1) storm damage probability; (2) proportions of storm-damaged timber and (3) endemic storm damage risk in the forest area of the German federal state of Baden-Wuerttemberg by applying random forests. Results from cross-validated predictor importance evaluation demonstrate that the relative impact of modeled gust speed fields on the predictive accuracy of the random forests models was greatest compared to the impact of forest and soil features. Forest areas prone to storm damage occurring within a period of five years were mainly located in mountainous upland regions where maximum gust speed exceeds 31 m/s in a five-year return period and conifers dominate the tree species composition. While mean storm damage probability continuously increased with increasing statistical gust speed proportions of storm-damaged timber peaked at a statistical maximum gust speed value of 29 m/s occurring in a five-year return period. Combining the statistical gust speed field with daily gust speed fields of two exceptional winter storms improved model accuracy and considerably increased the explained variance. Endemic storm damage risk was calculated from endemic storm damage probability and proportions of endemically storm-damaged timber. In combination with knowledge of local experts the storm damage risk modeled in a 50 m × 50 m resolution raster dataset can easily be used to identify areas prone to storm damage and to adapt silvicultural management regimes to make forests more windfirm.
On some Integral Representations of Certain G-Functions
Authors: Thomas Seemon
Published: January 2016

This is a brief exposition of some statistical techniques utilized to obtain several useful integral equations involving G-functions.
Electrostatic Potentials, Intralattice Attractive Forces and Crystal Densities of Nitrogen-Rich C,H,N,O Salts
Authors: Politzer Peter , Lane Pat , Murray Jane
Published: January 2016

The computed electrostatic potentials on C,H,N,O molecular solids and nitrogen-rich C,H,N,O salts are used in analyzing and comparing intralattice attractive forces and crystal densities in these two categories of compounds. Nitrogen-rich C,H,N,O salts are not an assured path to high densities. To increase the likelihood of high densities, small cations and large anions are suggested. Caution is recommended in predicting benefits of nitrogen-richness for explosive compounds.
Three-Dimensional Lattice Boltzmann Simulation of Liquid Water Transport in Porous Layer of PEMFC
Authors: Han Bo , Ni Meng , Meng Hua
Published: January 2016

A three-dimensional two-phase lattice Boltzmann model (LBM) is implemented and validated for qualitative study of the fundamental phenomena of liquid water transport in the porous layer of a proton exchange membrane fuel cell (PEMFC). In the present study, the three-dimensional microstructures of a porous layer are numerically reconstructed by a random generation method. The LBM simulations focus on the effects of the porous layer porosity and boundary liquid saturation on liquid water transport in porous materials. Numerical results confirm that liquid water transport is strongly affected by the microstructures in a porous layer, and the transport process prefers the large pores as its main pathway. The preferential transport phenomenon is more profound with a decreased porous layer porosity and/or boundary liquid saturation. In the transport process, the breakup of a liquid water stream can occur under certain conditions, leading to the formation of liquid droplets inside the porous layer. This phenomenon is related to the connecting bridge or neck resistance dictated by the surface tension, and happens more frequently with a smaller porous layer porosity. Results indicate that an optimized design of porous layer porosity and the combination of various pore sizes may improve both the liquid water removal and gaseous reactant transport in the porous layer of a PEMFC.
A Fuzzy-Logic Power Management Strategy Based on Markov Random Prediction for Hybrid Energy Storage Systems
Authors: Wang Yanzi , Wang Weida , Zhao Yulong , Yang Lei , Chen Wenjun
Published: January 2016

Over the last few years; issues regarding the use of hybrid energy storage systems (HESSs) in hybrid electric vehicles have been highlighted by the industry and in academic fields. This paper proposes a fuzzy-logic power management strategy based on Markov random prediction for an active parallel battery-UC HESS. The proposed power management strategy; the inputs for which are the vehicle speed; the current electric power demand and the predicted electric power demand; is used to distribute the electrical power between the battery bank and the UC bank. In this way; the battery bank power is limited to a certain range; and the peak and average charge/discharge power of the battery bank and overall loss incurred by the whole HESS are also reduced. Simulations and scaled-down experimental platforms are constructed to verify the proposed power management strategy. The simulations and experimental results demonstrate the advantages; feasibility and effectiveness of the fuzzy-logic power management strategy based on Markov random prediction.
The Journal of Fluids: An International and Interdisciplinary Scientific Open Access Journal
Authors: Yilbas Bekir
Published: January 2016

The science of fluids started from early civilizations when mankind understood the nature of channel flow. Archimedes discovered the hydrodynamics of floating bodies in early 250 B.C. [...]
Changes in Volatile and Non-Volatile Flavor Chemicals of “Valencia” Orange Juice over the Harvest Seasons
Authors: Bai Jinhe , Baldwin Elizabeth , McCollum Greg , Plotto Anne , Manthey John , Widmer Wilbur , Luzio Gary , Cameron Randall
Published: January 2016

Florida “Valencia” oranges have a wide harvest window, covering four months after first reaching the commercial maturity. However, the influence of harvest time on juice flavor chemicals is not well documented, with the exception of sugars and acids. Therefore, we investigated the major flavor chemicals, volatile (aroma), non-volatile (taste) and mouth feel attributes, in the two harvest seasons (March to June in 2007 and February to May in 2012). Bitter limonoid compounds, limonin and nomilin, decreased gradually. Out of a total of 94 volatiles, 32 increased, 47 peaked mid to late season, and 15 decreased. Juice insoluble solids and pectin content increased over the season; however, pectin methylesterase activity remained unchanged. Fruit harvested in the earlier months had lower flavor quality. Juice from later harvests had a higher sugar/acid ratio with less bitterness, while, many important aroma compounds occurred at the highest concentrations in the middle to late season, but occurred at lower concentrations at the end of the season. The results provide information to the orange juice processing industry for selection of optimal harvest time and for setting of precise blending strategy.
Cadmium Chloride Induces DNA Damage and Apoptosis of Human Liver Carcinoma Cells via Oxidative Stress
Authors: Skipper Anthony , Sims Jennifer , Yedjou Clement , Tchounwou Paul
Published: January 2016

Cadmium is a heavy metal that has been shown to cause its toxicity in humans and animals. Many documented studies have shown that cadmium produces various genotoxic effects such as DNA damage and chromosomal aberrations. Ailments such as bone disease, renal damage, and several forms of cancer are attributed to overexposure to cadmium. Although there have been numerous studies examining the effects of cadmium in animal models and a few case studies involving communities where cadmium contamination has occurred, its molecular mechanisms of action are not fully elucidated. In this research, we hypothesized that oxidative stress plays a key role in cadmium chloride-induced toxicity, DNA damage, and apoptosis of human liver carcinoma (HepG2) cells. To test our hypothesis, cell viability was determined by MTT assay. Lipid hydroperoxide content stress was estimated by lipid peroxidation assay. Genotoxic damage was tested by the means of alkaline single cell gel electrophoresis (Comet) assay. Cell apoptosis was measured by flow cytometry assessment (Annexin-V/PI assay). The result of MTT assay indicated that cadmium chloride induces toxicity to HepG2 cells in a concentration-dependent manner, showing a 48 hr-LD50 of 3.6 µg/mL. Data generated from lipid peroxidation assay resulted in a significant (p < 0.05) increase of hydroperoxide production, specifically at the highest concentration tested. Data obtained from the Comet assay indicated that cadmium chloride causes DNA damage in HepG2 cells in a concentration-dependent manner. A strong concentration-response relationship (p < 0.05) was recorded between annexin V positive cells and cadmium chloride exposure. In summary, these in vitro studies provide clear evidence that cadmium chloride induces oxidative stress, DNA damage, and programmed cell death in human liver carcinoma (HepG2) cells.
Racial Differences in Length of Stay for Patients Who Leave Against Medical Advice from U.S. General Hospitals
Authors: Tawk Rima , Dutton Matthew
Published: January 2016

There is a paucity of published literature on the length of hospital stays (LOS) for patients who leave against medical advice (AMA) and on the factors that predict their LOS. The purpose of the study is to examine the relationship between race and the LOS for AMA patients after adjusting for patient and hospital characteristics. National Hospital Discharge Survey (NHDS) data were used to describe LOS for AMA patients aged 18 years or older. Patient characteristics included age, sex, race, marital status, insurance, and diagnosis (ICD-9-CM). Hospital characteristics consisted of ownership, region and bed size. LOS was the major outcome measure. Using data from all years 1988–2006, the expected time to AMA discharge was first examined as a function of race, then adjusting for year terms, patient and hospital characteristics, and major medical diagnoses and mental illness. The unadjusted effect of race on the expected time of leaving AMA was about twice the adjusted effect. After controlling for the other covariates, the expected time to AMA discharge is 20% shorter for Blacks than Whites. The most significant predictors included age, insurance coverage, mental illness, gender, and region. Factors identified in this study offer insights into directions for evidence based- health policy to reduce AMA discharges.
Synthesis of High Valence Silver-Loaded Mesoporous Silica with Strong Antibacterial Properties
Authors: Chen Chun-Chi , Wu Hsin-Hsien , Huang Hsin-Yi , Liu Chen-Wei , Chen Yi-Ning
Published: January 2016

A simple chemical method was developed for preparing high valence silver (Ag)-loaded mesoporous silica (Ag-ethylenediaminetetraacetic acid (EDTA)-SBA-15), which showed strong antibacterial activity. Ag-EDTA-SBA-15 exhibited stronger and more effective antibacterial activity than commercial Ag nanoparticles did, and it offered high stability of high valence silver in the porous matrix and long-lasting antibacterial activity. The synthesized materials were characterized using Fourier transform infrared spectroscopy, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) analysis, and transmission electron microscopy (TEM). Ag existed in both surface complexation and Ag particles. EDTA anchored within a porous structure chelated Ag ions in higher oxidation states and prevented their agglomeration and oxidation reduction. The XRD results showed that most Ag in the Ag-EDTA-SBA-15 existed in higher oxidation states such as Ag(II) and Ag(III). However, the XPS and TEM results showed that Ag easily reduced in lower oxidation states and agglomerated as Ag particles on the exterior layer of the SBA-15.
What is an Appropriate Temporal Sampling Rate to Record Floating Car Data with a GPS?
Authors: Ranacher Peter , Brunauer Richard , Van der Spek Stefan , Reich Siegfried
Published: January 2016

Floating car data (FCD) recorded with the Global Positioning System (GPS) are an important data source for traffic research. However, FCD are subject to error, which can relate either to the accuracy of the recordings (measurement error) or to the temporal rate at which the data are sampled (interpolation error). Both errors affect movement parameters derived from the FCD, such as speed or direction, and consequently influence conclusions drawn about the movement. In this paper we combined recent findings about the autocorrelation of GPS measurement error and well-established findings from random walk theory to analyse a set of real-world FCD. First, we showed that the measurement error in the FCD was affected by positive autocorrelation. We explained why this is a quality measure of the data. Second, we evaluated four metrics to assess the influence of interpolation error. We found that interpolation error strongly affects the correct interpretation of the car’s dynamics (speed, direction), whereas its impact on the path (travelled distance, spatial location) was moderate. Based on these results we gave recommendations for recording of FCD using the GPS. Our recommendations only concern time-based sampling, change-based, location-based or event-based sampling are not discussed. The sampling approach minimizes the effects of error on movement parameters while avoiding the collection of redundant information. This is crucial for obtaining reliable results from FCD.
The Anti-Inflammatory Compound Curcumin Enhances Locomotor and Sensory Recovery after Spinal Cord Injury in Rats by Immunomodulation
Authors: Machova Urdzikova Lucia , Karova Kristyna , Ruzicka Jiri , Kloudova Anna , Shannon Craig , Dubisova Jana , Murali Raj , Kubinova Sarka , Sykova Eva , Jhanwar-Uniyal Meena , Jendelova Pavla
Published: January 2016

Well known for its anti-oxidative and anti-inflammation properties, curcumin is a polyphenol found in the rhizome of Curcuma longa. In this study, we evaluated the effects of curcumin on behavioral recovery, glial scar formation, tissue preservation, axonal sprouting, and inflammation after spinal cord injury (SCI) in male Wistar rats. The rats were randomized into two groups following a balloon compression injury at the level of T9–T10 of the spinal cord, namely vehicle- or curcumin-treated. Curcumin was applied locally on the surface of the injured spinal cord immediately following injury and then given intraperitoneally daily; the control rats were treated with vehicle in the same manner. Curcumin treatment improved behavioral recovery within the first week following SCI as evidenced by improved Basso, Beattie, and Bresnahan (BBB) test and plantar scores, representing locomotor and sensory performance, respectively. Furthermore, curcumin treatment decreased glial scar formation by decreasing the levels of MIP1α, IL-2, and RANTES production and by decreasing NF-κB activity. These results, therefore, demonstrate that curcumin has a profound anti-inflammatory therapeutic potential in the treatment of spinal cord injury, especially when given immediately after the injury.
Molecular Evolution of Aralkylamine N-Acetyltransferase in Fish: A Genomic Survey
Authors: Li Jia , You Xinxin , Bian Chao , Yu Hui , Coon Steven , Shi Qiong
Published: January 2016

All living organisms synchronize biological functions with environmental changes; melatonin plays a vital role in regulating daily and seasonal variations. Due to rhythmic activity of the timezyme aralkylamine N-acetyltransferase (AANAT), the blood level of melatonin increases at night and decreases during daytime. Whereas other vertebrates have a single form of AANAT, bony fishes possess various isoforms of aanat genes, though the reasons are still unclear. Here, we have taken advantage of multiple unpublished teleost aanat sequences to explore and expand our understanding of the molecular evolution of aanat in fish. Our results confirm that two rounds of whole-genome duplication (WGD) led to the existence of three fish isoforms of aanat, i.e., aanat1a, aanat1b, and aanat2; in addition, gene loss led to the absence of some forms from certain special fish species. Furthermore, we suggest the different roles of two aanat1s in amphibious mudskippers, and speculate that the loss of aanat1a, may be related to terrestrial vision change. Several important sites of AANAT proteins and regulatory elements of aanat genes were analyzed for structural comparison and functional forecasting, respectively, which provides insights into the molecular evolution of the differences between AANAT1 and AANAT2.
The Effect of Marine Derived n-3 Fatty Acids on Adipose Tissue Metabolism and Function
Authors: Todorčević Marijana , Hodson Leanne
Published: January 2016

Adipose tissue function is key determinant of metabolic health, with specific nutrients being suggested to play a role in tissue metabolism. One such group of nutrients are the n-3 fatty acids, specifically eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). Results from studies where human, animal and cellular models have been utilised to investigate the effects of EPA and/or DHA on white adipose tissue/adipocytes suggest anti-obesity and anti-inflammatory effects. We review here evidence for these effects, specifically focusing on studies that provide some insight into metabolic pathways or processes. Of note, limited work has been undertaken investigating the effects of EPA and DHA on white adipose tissue in humans whilst more work has been undertaken using animal and cellular models. Taken together it would appear that EPA and DHA have a positive effect on lowering lipogenesis, increasing lipolysis and decreasing inflammation, all of which would be beneficial for adipose tissue biology. What remains to be elucidated is the duration and dose required to see a favourable effect of EPA and DHA in vivo in humans, across a range of adiposity.
Perspectives and Insights into the Competition for Aminoacyl-tRNAs between the Translational Machinery and for tRNA Dependent Non-Ribosomal Peptide Bond Formation
Authors: Fung Angela , Payoe Roshani , Fahlman Richard
Published: January 2016

Aminoacyl-tRNA protein transferases catalyze the transfer of amino acids from aminoacyl-tRNAs to polypeptide substrates. Different forms of these enzymes are found in the different kingdoms of life and have been identified to be central to a wide variety of cellular processes. L/F-transferase is the sole member of this class of enzyme found in Escherichia coli and catalyzes the transfer of leucine to the N-termini of proteins which result in the targeted degradation of the modified protein. Recent investigations on the tRNA specificity of L/F-transferase have revealed the unique recognition nucleotides for a preferred Leu-tRNALeu isoacceptor substrate. In addition to discussing this tRNA selectivity by L/F-transferase, we present and discuss a hypothesis and its implications regarding the apparent competition for this aminoacyl-tRNA between L/F-transferase and the translational machinery. Our discussion reveals a hypothetical involvement of the bacterial stringent response that occurs upon amino acid limitation as a potential cellular event that may reduce this competition and provide the opportunity for L/F-transferase to readily increase its access to the pool of aminoacylated tRNA substrates.
Energetic Study of Helium Cluster Nucleation and Growth in 14YWT through First Principles
Authors: Gan Yingye , Zhao Huijuan , Hoelzer David , Yun Di
Published: January 2016

First principles calculations have been performed to energetically investigate the helium cluster nucleation, formation and growth behavior in the nano-structured ferritic alloy 14YWT. The helium displays strong affinity to the oxygen:vacancy (O:Vac) pair. By investigating various local environments of the vacancy, we find that the energy cost for He cluster growth increases with the appearance of solutes in the reference unit. He atom tends to join the He cluster in the directions away from the solute atoms. Meanwhile, the He cluster tends to expand in the directions away from the solute atoms. A growth criterion is proposed based on the elastic instability strain of the perfect iron lattice in order to determine the maximum number of He atoms at the vacancy site. We find that up to seven He atoms can be trapped at a single vacancy. However, it is reduced to five if the vacancy is pre-occupied by an oxygen atom. Furthermore, the solute atoms within nanoclusters, such as Ti and Y, will greatly limit the growth of the He cluster. A migration energy barrier study is performed to discuss the reduced mobility of the He atom/He cluster in 14YWT.
A Novel Nitinol Spherical Occlusion Device for Liver Cancer
Authors: Hsiao Hao-Ming , Wang Yi-Ping , Ko Chun-Yi , Cheng Yu-Han , Lee Han-Yu
Published: January 2016

Liver cancer or hepatic cancer is a cancer that originates in the liver. It is formed from either the liver itself or from structures within the liver, including blood vessels or the bile duct. Liver cancer can be a life-threatening condition, but it may be cured if found early. Hepatic artery embolization is one of the treatment options involving the injection of substances to reduce the blood flow to cancer cells in the livers of patients with tumors that cannot be removed by surgery; however, this treatment has some limitations. In this paper, we propose a novel nitinol “spherical occlusion device” concept, the first of its kind in the world. Our proposed spherical occlusion device is able to reduce the blood flow to cancer cells by deploying it in the upstream hepatic artery supplying blood to the liver. Moreover, it could carry multiple chemotherapy or radioactive drugs for delivery directly to the target site. Nitinol alloy was chosen as the device material due to its excellent super-elastic property. Computational models were developed to predict the mechanical response of the device during manufacturing and deployment procedures, as well as its hemodynamic behavior. Simulation results showed that the presence of the spherical occlusion device with 14%–27% metal density deployed at the upstream location of the right hepatic artery had significant occlusion effects, with the average blood flow rate cut down by 30%–50%. A pulsed fiber laser and a series of expansions and heat treatments were developed to make the first prototype of the spherical occlusion device for the demonstration of our novel concept.
Activation of Aspen Wood with Carbon Dioxide and Phosphoric Acid for Removal of Total Organic Carbon from Oil Sands Produced Water: Increasing the Yield with Bio-Oil Recycling
Authors: Veksha Andrei , Bhuiyan Tazul , Hill Josephine
Published: January 2016

Several samples of activated carbon were prepared by physical (CO2) and chemical (H3PO4) activation of aspen wood and tested for the adsorption of organic compounds from water generated during the recovery of bitumen using steam assisted gravity drainage. Total organic carbon removal by the carbon samples increased proportionally with total pore volume as determined from N2 adsorption isotherms at −196 °C. The activated carbon produced by CO2 activation had similar removal levels for total organic carbon from the water (up to 70%) to those samples activated with H3PO4, but lower yields, due to losses during pyrolysis and activation. A method to increase the yield when using CO2 activation was proposed and consisted of recycling bio-oil produced from previous runs to the aspen wood feed, followed by either KOH addition (0.48%) or air pretreatment (220 °C for 3 h) before pyrolysis and activation. By recycling the bio-oil, the yield of CO2 activated carbon (after air pretreatment of the mixture) was increased by a factor of 1.3. Due to the higher carbon yield, the corresponding total organic carbon removal, per mass of wood feed, increased by a factor of 1.2 thus improving the overall process efficiency.