bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microseismic Studies of Hydraulic Fracture Evolution at Different Pumping Rates
Authors: Chitrala Yashwanth , Sondergeld Carl , Rai Chandra 
Published: June 2012

Abstract
Our objective is to improve hydraulic fracturing through an understanding of the fracture evolution. We used real-time acoustic emission (AE) monitoring to study the samples subjected to varying pumping rates which are diametrically stressed at 650 psi. Velocity analysis indicates the compressional velocity variation is less than 2% throughout the sample, so they are treated as isotropic. Higher breakdown pressures were observed at rapid injection rates. Shear failures are commonly found at low to intermediate injection rates, whereas tensile fractures are observed at rapid pumping rates. Fracture initiation occurs at pressures lower than the breakdown pressure. However, the difference between the initiation and the breakdown pressure is less at slower injection rates. Secondary activity coinciding with the pump shutoff was commonly observed at intermediate and rapid injection rates. Higher pressurization rates were observed at rapid injection rates, but the relationship was not linear. The fracture width and length are observed to taper away from the borehole.
Hydraulic Fracture Design and Well Production Results in the Eagle Ford Shale: One Operator's Perspective
Authors: Bazan Lucas W. , Lattibeaudiere Michael G. , Palisch Terry T. 
Published: June 2012

Abstract
Multiple stage hydraulic fracturing is a key technology driving the development of unconventional resources in North America. This technique began in the Barnett shale and its application has opened the door for the successful development of nearly every shale play in the world, including the Eagle Ford shale. Given the relatively new application of this technique, and the number of fracture treatments completed, initial fracture treatment designs in a given play are often transferred from other North American shale plays to serve as baseline treatments. Given the rapid pace of development in a new play, as well as the desire to get to a standardized completion program, many operators continue to use these baseline designs and fail to evaluate current designs to develop more optimal treatments.
This paper will discuss the successful evolution of hydraulic fracture designs in the Eagle Ford shale from one operator's perspective. It will detail the development from the traditional low conductivity slick water fracture treatments used initially in the play, to the use of higher conductivity hybrid fracture designs. In addition to detailing the theory and workflow of these design changes, this paper will also evaluate production data from multiple wells and evaluate production results for the hydraulic fracture designs. Discussion of enhanced conductivity will be presented along with the economic benefit of these changes.
Those working the Eagle Ford shale can directly apply the principles presented in this paper to enhance the productivity and economics of their completions. In addition, engineers working other resource developments can use the principles from this paper to compare their current fracture design methodology and develop best practice approaches for hydraulic fracture design optimization in their respective plays.
Development and Validation of the Type 1 Diabetes Nutrition Knowledge Survey
Authors: Rovner Alisha J. , Nansel Tonja R. , Mehta Sanjeev N. , Higgins Laurie A. , Haynie Denise L. , Laffel Lori M. 
Published: June 2012

OBJECTIVE
The purpose of this study was to develop a survey of general and diabetes-specific nutrition knowledge for youth with type 1 diabetes and their parents and to assess the survey’s psychometric properties.

RESEARCH DESIGN AND METHODS
A multidisciplinary pediatric team developed the Nutrition Knowledge Survey (NKS) and administered it to youth with type 1 diabetes (n = 282, 49% females, 13.3 ± 2.9 years) and their parents (82% mothers). The NKS content domains included healthful eating, carbohydrate counting, blood glucose response to foods, and nutrition label reading. Higher NKS scores reflect greater nutrition knowledge (score range is 0–100%). In youths, glycemic control was assessed by A1C, and dietary quality was determined by the Healthy Eating Index-2005 (HEI-2005) derived from 3-day diet records. Validity was based on associations of NKS scores with A1C and dietary quality. Reliability was assessed using the Kuder-Richardson Formula 20 (KR-20) and correlations of domain scores to total score.

RESULTS
Mean NKS scores (23 items) were 56.9 ± 16.4% for youth and 73.4 ± 12.5% for parents. The KR-20 was 0.70 for youth and 0.59 for parents, representing acceptable internal consistency of the measure. In multivariate analysis, controlling for youth age, family income, parent education, diabetes duration, and insulin regimen, parent NKS scores were associated with corresponding youth A1C (β = −0.13, P = 0.03). Both parent (β = 0.20, P = 0.002) and youth (β = 0.25, P &lt; 0.001) NKS scores were positively associated with youth HEI-2005 scores.

CONCLUSIONS
The NKS appears to be a useful measure of general and diabetes-specific nutrition knowledge for youth with type 1 diabetes and their parents.
Effects of Food-simulating Liquids on Surface Properties of Giomer Restoratives
Authors: Kooi TJM , Tan QZ , Yap AUJ , Guo W , Tay KJ , Soh MS 
Published: June 2012

SUMMARY
This study examined the effects of food-simulating liquid (FSL) on the hardness and roughness of giomer restoratives based on pre-reacted glass ionomer (PRG) technology. The materials investigated included a regular (Beautifil II [BT]) and a recently introduced injectable (Beautifil Flow Plus F00 [BF]) hybrid PRG composite. A direct hybrid composite (Filtek Z250 [ZT]) and an indirect hybrid composite (Ceramage [CM]) were used for comparison. The materials were placed into customized square molds (5 mm × 5 mm × 2.5 mm), covered with Mylar strips, and cured according to manufacturers' instructions. The materials were then conditioned in air (control), distilled water, 50% ethanol solution, and 0.02 N citric acid at 37°C for seven days. Specimens (n=6) were then subjected to hardness testing (Knoop) and surface profilometry. Data were analyzed using one-way analysis of variance and post hoc Scheffe test (p&lt;0.05). Mean Knoop hardness values for the control group (air) ranged from 53.4 ± 3.4 (BF) to 89.5 ± 5.2 (ZT), while mean surface roughness values values ranged from 0.014 ± 0.002 (ZT) to 0.032 ± 0.001 (BT). All materials were significantly softened by FSL. The degree of softening by the different FSLs was material dependent. The hardness of giomers was most affected by citric acid and ethanol. The smoothest surface was generally observed with the control group. Giomer restoratives were significantly roughened by citric acid.
The gap phenomenon in the dimension study of finite type systems
Authors: Kruglikov Boris 
Published: June 2012

Abstract
Several examples of gaps (lacunes) between dimensions of maximal and submaximal symmetric models are considered, which include investigation of number of independent linear and quadratic integrals of metrics and counting the symmetries of geometric structures and differential equations. A general result clarifying this effect in the case when the structure is associated to a vector distribution, is proposed.
On the sum of digits of some sequences of integers
Authors: Cilleruelo Javier , Luca Florian , Rué Juanjo , Zumalacárregui Ana 
Published: June 2012

AbstractLet b ≥ 2 be a fixed positive integer. We show for a wide variety of sequences {a n}n=1∞ that for almost all n the sum of digits of a n in base b is at least c b log n, where c b is a constant depending on b and on the sequence. Our approach covers several integer sequences arising from number theory and combinatorics.
De novo synthesis of protein phosphatase 1A, magnesium dependent, alpha isoform (PPM1A) during oocyte maturation
Authors: Chuderland Dana , Dvashi Zeev , Kaplan-Kraicer Ruth , Ben-Meir Daniella , Shalgi Ruth , Lavi Sara 
Published: June 2012

AbstractOocyte maturation in mammals is a multiple-stage process that generates fertilizable oocytes. Ovarian oocytes are arrested at prophase of the first meiotic division characterized by the presence of a germinal vesicle. Towards ovulation, the oocytes resume meiosis and proceed to the second metaphase in a process known as maturation; they undergo nuclear and cytoplasmic changes that are accompanied by translation and degradation of mRNA. Protein phosphatase 1A, magnesium dependent, alpha isoform (PPM1A), which belongs to the metal-dependent serine/threonine protein phosphatase family, is highly conserved during evolution. PPM1A plays a significant role in many cellular functions such as cell cycle progression, apoptosis and cellular differentiation. It works through diverse signaling pathways, including p38 MAP kinase JNK and transforming growth factor beta (TGF-β). Herein we report that PPM1A is expressed in mouse oocytes and that its mRNA level rises during oocyte maturation. Using quantitative real-time polymerase chain reaction (qPCR) and western blot analysis, we found that PPM1A mRNA is synthesized at the beginning of the maturation process and remains elevated in the mature oocytes, promoting the accumulation of PPM1A protein. Since PPM1A function is mainly affected by its level, we propose that it might have an important role in oocyte maturation.
Operational pattern and contribution of urban farming in an emerging megacity: evidence from Lagos, Nigeria
Authors: Lawal Mohamed , Aliu Ibrahim 
Published: June 2012

Operational pattern and contribution of urban farming in an emerging megacity: evidence from Lagos, NigeriaUrban farming is rapidly growing in many cities in Nigeria including a leading African megacity Lagos, although urban stakeholders have paid little attention to the trend over time. The rate of growth of urban farming and its contributions to Lagos state's food supply strategy is worthy of note. In Lagos farming activities are practiced and performed by some able bodied migrants from all parts of the country, who for many reasons could hardly have been absolved by the aggressive urban economy of the city. A close watch on the practitioners reveals a pattern of operation which requires deeper inquiry. A total of 202 urban vegetable farmers were interviewed in four areas of Lagos state to provide primary data for this study. Results from the study showed that an average farmer owns a farm plot of below 120 m by 60 m usually linear and along the expressway, the green vegetable (Celosia argientes) alone constitutes about 97% of what is grown, beds are arranged in sizes of about 1.8 m long by 0.9 m wide and 0.3 m high with furrows in between. The farmers use the simplest local tools, chemical fertilizers, and strategically located irrigation wells. It was also found that the farmers use some part of the vegetables for household consumption, sell others to the local marketers, and contribute their own quota to stem the rising prices of vegetable produce in the local markets. It is therefore imperative on the stakeholders to re-examine the relevance of urban farming in the city and provide support for its growth.
Demographic potential of the countries that have applied for the European Union membership
Authors: Sojka Elżbieta 
Published: June 2012

Demographic potential of the countries that have applied for the European Union membership
The purpose of the article is to analyse the demographic potential of the countries that have applied for the European Union membership against the background of the EU member states. The study involves eight candidate states: Croatia, Iceland, Macedonia, Montenegro, and Turkey, i.e. the countries that have been approved by the European Commission as official candidates for the EU membership, as well as Albania, Bosnia and Herzegovina, Serbia, i.e. the potential candidates. Albania and Serbia applied officially for the EU membership in 2009. Favourable population age structure and relatively high fertility rate that occur in these countries determine a significant demographic potential they can bring to the EU after their accession. Decrease in infant mortality rate and extension of life expectancy illustrate positive changes that have been taking place in these countries for the last several years.
Permian volcanics in the Northern Gemericum and Bôrka Nappe system: U-Pb zircon dating and the implications for geodynamic evolution (Western Carpathians, Slovakia)
Authors: Vozárová Anna , Šmelko Miloš , Paderin Ilya , Larionov Alexander 
Published: June 2012

Permian volcanics in the Northern Gemericum and Bôrka Nappe system: U-Pb zircon dating and the implications for geodynamic evolution (Western Carpathians, Slovakia)U-Pb dating (SHRIMP) of magmatic zircon ages from the Northern Gemericum Permian volcanics (Petrová Hora Formation) yielded the Concordia age of 272.4 ± 7.3 Ma for basaltic andesite, as well as the Concordia age of 275.2 ± 4 Ma for rhyodacites. Both zircon ages correspond to the Cisuralian Epoch in the time span of the Kungurian Stage. Acquired206Pb/238U zircon age data support the nearly contemporaneous origin of the acid and basic volcanogenic members in the Northern Gemericum Permian strata. The bimodal volcanic suite proves the transtension/extension tectonic regime in the North Gemeric sedimentary basin during the Late Cisuralian. The magmatic zircon ages of rhyodacites, occurring in the lower thrust sheet of the Bôrka Nappe (Jasov Formation), gave a younger Concordia age of 266 ± 1.8 Ma proving the Guadalupian Epoch, in the time span of the Wordian/Capitanian. In comparison to the Northern Gemericum realm, this age refers to the relatively younger stage of rift-related extensional movements. In the wide Alpine-Dinarides realm the Middle Permian (Guadalupian) movements are related to the beginning of the Alpine sedimentary cycle. Thus, the Middle Permian rifting expresses the beginning of the formation of the future Meliata oceanic trough.
The resistivity image of the Muráň fault zone (Central Western Carpathians) obtained by electrical resistivity tomography
Authors: Putiška René , Dostál Ivan , Mojzeš Andrej , Gajdoš Vojtech , Rozimant Kamil , Vojtko Rastislav 
Published: June 2012

The resistivity image of the Muráň fault zone (Central Western Carpathians) obtained by electrical resistivity tomographyThe paper describes the application of geophysical prospecting techniques for estimation of the fault's inclination. The field survey was carried out across the Muráň fault structure in the Slovenské rudohorie Mts (central Slovakia). Three different geophysical methods were used to map the fault zone: Electrical Resistivity Tomography (ERT), induced polarization (IP) and radon emanometry. All these methods have been used to locate the fault zone area, but the principal aims of this research are to test the efficiency of the 2D ERT technique to recognize the geometrical characterization of the fault and to improve our tectonic knowledge of the investigated area. For the synthetic cases, three geometric contexts were modelled at 60, 90 and 120 degrees and computed with the l2norm inversion method, the l1norm with standard horizontal and vertical roughness filter and the l1norm with diagonal roughness filter. In the second phase this geophysical methodology was applied to fieldwork data. Our results confirm that the ERT technique is a valuable tool to image the fault zone and to characterize the general geometry, but also the importance of setting up the right inversion parameters. The main contribution of the geophysical investigations in this case was the determination of the location and confirmation of the inclination of the Muráň fault. The result of this study is the ability to make a visual estimation of the direction and dip of the fault. Pursuant to this work the dipole-dipole electrode configuration produces the best resolution, particularly for the location of vertical and dipping structures. The advantage of this array is that it shows the ability to assess the trend of the dip and therefore it can be strongly recommended. The result is also a case study of a small scale tectonic survey involving geophysical methods.
Geochemistry and electron spin resonance of hydrothermal dickite (Nowa Ruda, Lower Silesia, Poland): vanadium and chromium
Authors: Premović Pavle , Ciesielczuk Justyna , Bzowska Grażyna , Đorđević Miloš 
Published: June 2012

Geochemistry and electron spin resonance of hydrothermal dickite (Nowa Ruda, Lower Silesia, Poland): vanadium and chromium
Geochemical analyses for trace V and Cr have been done on a representative sample of a typical hydrothermal dickite/kaolinite filling vein at Nowa Ruda. The mineralogy of the sample is comparatively simple, dickite being the principal component (ca. 91 % of the total sample). Geochemical fractionation and inductively coupled plasma-optical emission spectrometry (ICP-OES) indicate that most (> 90 % of total metal) of the V and Cr reside in the dickite. Electron Spin Resonance (ESR) shows that most (> 70 %) of the V in the dickite structure is in the form of vanadyl (VO2+) ions. A high concentration of Cr3+ is also detected in this structure by ESR. The combination of geochemical and spectroscopic tools applied to VO2+ and Cr3+ allow one to specify the Eh (> 0.4 V, highly oxidizing) and pH (≤4.0, highly acidic) of the solution during the formation of dickite from the Nowa Ruda Basin. Substantial proportions of the V and Cr (as well as VO2+ and Cr3+) in the dickite structure were probably contained in an original hydrothermal acid water. We suggest that hot hydrothermal waters leached the surrounding varieties of gabbroids enriched in V and Cr for the dickite-forming solution. The results of this work have shown V and Cr are potentially reliable indicators for geochemical characterization of the physicochemical conditions of their formation. The bulk-rock V/Cr ratio in hydrothermal dickites and kaolinites from Nowa Ruda, Sonoma (California, USA), Cigar Lake (Saskatchewan, Canada) and Teslić (Bosnia and Hercegovina) is also briefly explored here as a potential tracer of redox state during their formation.
Monitoring of facultative avian scavengers on large mammal carcasses in Dinaric forest of Slovenia
Authors: Krofel Miha 
Published: June 2012

Monitoring of facultative avian scavengers on large mammal carcasses in Dinaric forest of SloveniaFacultative vertebrate scavengers have an important role in forest ecosystems, however, not much is known as to their use of carrion in temperate forests. Three carcasses of Red DeerCervus elaphusand European Roe DeerCapreolus capreolusfound dead or killed by Grey WolfCanis lupuswere monitored in March and April 2010 and 2011 on Menišija Plateau in northern Dinaric Mountains (central Slovenia) using photo-trapping and video surveillance. Carcasses were monitored for 26 days, during which 708 photos and 43 video recordings of scavengers were taken. In the 91% of all visits recorded, birds were the most frequent scavengers, with Common BuzzardButeo buteoas the most frequent species present at 76% of all visits. On average, Buzzards returned to carcasses twice per day, with an average visit lasting 29 min. Common Buzzards used carcasses to a significantly higher degree on days with snow cover, which was due to the more frequent visits per day and not to longer visits. Recorded antagonistic interspecific interactions suggested that Common Buzzards were the dominant species in the observed avian scavenger guild, as they displaced RavensCorvus coraxand GoshawkAccipiter gentilisfrom the carcass. However, Ravens frequently mobbed Common Buzzards while scavenging. Once an Ural OwlStrix uralensisalso visited prey remains of Grey Wolf, but feeding could not be confirmed. Observations suggested that carcasses of large mammals could be locally and temporarily an important food source for some facultative avian scavengers in Dinaric forests, especially in times when other food is scarce. Data from the two wolf kills also confirm the importance of predation by large carnivores in providing food for scavengers. Given the small amount of meat consumed, kleptoparasitism by solitary raptors did not bring significant losses to large carnivores, whereas gregarious avian scavengers like corvids can importantly affect the consumption process and consume large amount of biomass in a relatively short time.
Metabolomics - Useful Tool for Study of Plant Responses to Abiotic Stresses
Authors: Kráľová Katarína , Jampílek Josef , Ostrovský Ivan 
Published: June 2012

Metabolomics - Useful Tool for Study of Plant Responses to Abiotic Stresses
Abiotic stresses are produced by inappropriate levels of physical components of the environment and cause plant injury through unique mechanisms that result in specific responses. Metabolomics is a relatively new approach aimed at improved understanding of metabolic networks and the subsequent biochemical composition of plants and other biological organisms. The paper is focused on the use of metabolomics, metabolic profiling and metabolic fingerprinting to study plant responses to some environmental stresses (eg elevated temperature, chilling and freezing, drought, high salinity, UV radiation, high ozone levels, nutrient deficiency, oxidative stress, herbicides and heavy metals). Attention is also devoted to the effects of some environmental factors on plants such as high or low levels of CO2 or different levels of irradiance. Alterations of plants metabolites due to multiple abiotic stresses (drought-heat, drought-salinity, elevated CO2-salinity) are analysed as well. In addition, metabolomic approach to study plant responses to some artificial abiotic stresses, mechanical stress or pulsed electric field-induced stress is discussed. The most important analytical methods applied in metabolomics are presented and perspectives of metabolomics exploitation in the future are outlined, too.
Long-Term Statistical Assessment of the Water Quality of Tundja River
Authors: Papazova Petia , Simeonova Pavlina 
Published: June 2012

Long-Term Statistical Assessment of the Water Quality of Tundja RiverTwo major environmetric methods (Cluster analysis(CA) andPrincipal components analysis(PCA)) were applied for statistical assessment of the water quality of trans-border river Tundja. The study used long-term monitoring data from 26 sampling sites characterized by 12 physicochemical parameters. Clustering of chemical indicators results in 3 major clusters: the first one shows the impact of anthropogenic sources, the second - the impact of agriculture and farming activities and the last one describes the role of the physical parameters on the water quality and also the impact of urban wastes. For better assessment of the monitoring data, PCA was implemented, which identified four latent factors. Two of them - "urban wastes" factor and "agriculture" factor correspond almost entirely to clusters 3 and 2 from the previous statistical analysis. The third one, named "industrial wastes" factor, reveals a specific seasonal behavior of the river system. The last latent factor describes the active reaction of the water body and is determined as "acidity" factor. The linkage of the sampling sites along the river flow by CA formed two clusters with the spatial "upstream-downstream" separation. The apportionment model of the pollution determined the contribution of each one of identified pollution factors to the total concentration of each one of the water quality parameters.