bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving Reservoir Characterization with Seismic Data Preconditioning—a Case Study of Saudi Arabian Channel Detection
Authors: Al-Dossary Saleh
Published: June 2015

Random seismic noise, present in every authentic seismic data set, hampers both geoscientists’ manual interpretation of data and computerized delineation and analysis of seismic features. Therefore, many noise suppression techniques have the goal of preserving image quality. For channel detection, accurately suppressing seismic noise without damaging image detail is crucial. Theoretically, channel patterns can be automatically detected owing to their unique spatial footprint, which differentiates them from other three-dimensional seismic features. One notable characteristic of channels is their local linearity: Their spatial extent is much greater in one direction than in any other direction. A variety of techniques, such as spatial filters, can enhance the "slender" characteristic of channels. Unfortunately, most of these techniques reduce noise by smoothing the data, resulting in a loss of edge definition. During the past few years the literature has revealed several new edge-preserving noise reduction techniques, including edge-preserving smoothing and complex wavelet transforms. In this case study I illustrate the performance of edge-preserving smoothing based on the redundant wavelet transform (RWT) and demonstrate its usefulness before running an edge detection algorithm to reveal channel patterns in seismic data from Saudi Arabia. Our examples demonstrate that RWT can successfully preserve, enhance, and delineate channel edges that are otherwise not readily visible on conventional seismic amplitude displays.
Streamlines Guided Assisted History Matching Methodology: A New Approach
Authors: Baddourah Majdi A , Alturki Ali A. , Al-Zawawi Ahmed S , Hayder M Ehtesham , Moriwawon Babatunde
Published: June 2015

Accomplishing an acceptable history match of a reservoir simulation model with historical field performance data is a challenging task. The resources needed for assisted history matching for giant reservoirs is very demanding. Providing engineers with an optimized workflow is essential for these giant simulation models to accomplish the desired history match objectives in a timely manner. Reservoir engineers typically use one of many available commercial packages, some of them are stochastic in nature. These methodologies require users to define regions to guide the optimizer where to apply the modifiers. It is difficult to define a modifier region that can be used to relate the physics and fluids movements in the reservoir while preserving key geological signatures. All these concerns, if addressed properly can contribute to better understanding of the reservoir dynamics, reduce turnaround time of the project, improve quality of the history match, and optimize resources utilization.

The work presented in this paper proposes a practical workflow to assist reservoir engineers identify important flow communications regions in the reservoir using streamlines properties. Many Producer-Injector pair regions are identified using streamlines, and an efficient strategy is used to select a handful of regions to apply permeability modifiers, for example. This workflow has been validated by history matching one of the giant fields in Saudi Arabia. A commercial history matching package and a customized streamlines tracing tool was used in this study. The results show improvements in the history match quality and reduction of overall history matching time with the current streamlines-guided workflow when compared to the conventional workflows that use the commercial package alone. The paper shows the impact of streamlines map choices on the quality of history match, turnaround time of history matching workflow, number of required simulation runs to complete a study and other relevant measures.
Reservoir Geomechanics: An Important Component to Better Understand Reservoir Behavior
Authors: Varela-Pineda Alfonso , Khan Khaqan , Mutairi Saad M. , Hutheli Ahmed H.
Published: June 2015

The present work integrates sonic logs, image logs, lab test, leak-off test (LOT), production, and injection data to build the basic geomechanical model in a mature field under peripheral water injection. In the modeling process, in-situ stresses (orientation and magnitude) were obtained and integrated form the available information. Additionally, rock mechanical properties derived from P and S-wave velocities, were calibrated with the static properties derived from lab tests (triaxial test). Statistical analysis of the dynamic rock properties allowed constructing the failure envelopes for reservoir intervals with different strengths using the Mohr-Coulomb failure criteria, giving extra information of the stiffness variation and anisotropy within the same reservoir rock. Moreover, the model was further validated by the stress polygon and the expected faulting regime was constraint, giving an insight of main fractures orientation. A wellbore stability analysis was also done to check on breakouts tendency and best trajectory for new sidetracks and horizontal wells to be drilled.

For this particular field, the effects of many years of depletion without pressure support and the subsequent effect of peripheral water injection are better understood under the geomechanical point of view. Changes in the effective stresses during pore pressure drawdown show a stress path that could easily activate natural fractures and might had created bigger fracture channels favoring flow of reservoir fluids to the wellbore after the power water injection was initiated. By the same talking, water injection seemed to enhance the far field stress stability, but it might create tensile fractures at the injector's vicinity. In other words, knowledge of the in-situ stresses and its effects while depleting or increasing the pore pressure is of vital importance in reservoir management. Stability analysis suggests a formation stiff enough that can be drilled to any direction at any inclination angle; a condition that favors well spacing, but it should be handled with care in avoiding fracture corridors.

The results of this work suggest that good reservoir management may require the geomechanics component to optimize well performance and reservoir development.
A Complex Naturally Fractured Reservoir Case Study: Fracture System Understanding is Key to Development Drilling Success
Authors: Lyngra Stig , Widjaja Danang R. , Al-Shammeri Faleh M. , Al-Otaibi Uthman F. , Barghouty Murad F.
Published: June 2015

The appropriate economic balance between oil production rate, ultimate oil recovery and development cost can be difficult to find for complex naturally fractured reservoirs. This makes development drilling decisions and reservoir management of these reservoirs a very demanding task. Successful life cycle development of a naturally fractured reservoir can only be achieved by fully understanding the role of fractures on fluid flow at different scales, both inside the reservoir and near wellbores. Systematic fracture characterization becomes an essential prerequisite to gain the critical understanding crucial for successful development and economic success.

This publication presents a complex low matrix permeability naturally fractured reservoir case study from a mature giant Middle Eastern oil field. Examples are provided illustrating the impact of fractures of different scales on reservoir fluid flow and well productivity, ranging from large scale fractures, previously often termed fracture corridors or fracture lineaments, to small scale micro fractures.

Systematic efforts have been exerted over the past years to collect fracture characterization data, e.g. pressure transient, image logs and advanced formation tester data, including mini-DST (Drill Stem Test) formation tests. This data set has been complemented by other dynamic data like rate tests, pressure surveys and time lapse production logs, plus seismic and electromagnetic surveys. Based on the presented observations, it is evident that small scale micro features and associated connected fracture networks also play a role. If near wellbore large scale fracture features are not dominant, the small scale fracture networks determine the well drainage areas and become a controlling factor for reservoir well productivity and the overall reservoir recovery mechanism.

As presented in this paper, the reservoir development strategy, including development well type, has been modified as a direct result on the improved understanding of the reservoir fracture system.
Devising and Optimizing Development Strategies for South Fuwaris Field Using Integrated Reservoir Simulation Models
Authors: Al-Aruri Ahmad , Al-Suwailem Majed , Al-Otaibi Saud , Al-Mutairi Saleh , Pederson Kris , Aldajani Saud , Garwan Ahmad
Published: June 2015

The South Fuwaris Field is located in the Partitioned Zone (PZ) between Saudi Arabia and Kuwait and is operated jointly by Saudi Arabian Chevron (SAC) and Kuwait Gulf Oil Company (KGOC). South Fuwaris produces light crude (240 API) from two prolific heterogeneous carbonate reservoirs: Ratawi Limestone and Ratawi Oolite. The field has been developed using vertical and horizontal wells with all wells on electric submersible pumps.

Fit-for- purpose static and dynamic models were constructed to validate the Original Oil In Place (OOIP) and to map the distribution of the remaining oil potential in order to devise an optimized development plan for both carbonate reservoirs.

This paper illustrates the steps used to build the dynamic model and adopted workflows to identify new infill and waterflood opportunities including the evaluation of pattern versus peripheral injection and optimize placement and completion strategies of vertical and horizontal wells.

The paper also presents the processes used to narrow the uncertainty range in Original Oil-Water-Contact (OOWC) surfaces, historical dump flooding volumes, aquifer size and flux, and Pressure Volume Temperature (PVT) data in order to reach a reasonable and defendable history match with an acceptable range of errors and deliver a reliable forecasting tool. Moreover, the paper demonstrates how the reservoir simulation work was efficiently utilized as a mentoring platform for young professional in reservoir simulation and earth science.
A Review of Recent Developments and Challenges in IGIP Estimation of Coal Bed Methane Reservoirs
Authors: Kalam Shams , Khan Rizwan Ahmed , Baig Mirza Talha , Al-Hashim Hasan Salman
Published: June 2015

During the past ten years, unconventional hydrocarbon resources have been receiving more attention, as a source of energy. Among these unconventional resources one is the coal bed methane (CBM). To find out the feasibility of the unconventional reservoir development, reserves is estimated and the economic analysis is carried out. The methods for the estimation of reserves requires the initial gas in place calculations, however, the methods describing the IGIP estimation using conventional method cannot be applied to CBM reservoirs without modifications.

This paper presents critical literature review of CBM material balance that identifies and examines challenges encountered in CBM recovery. The paper addresses the methods for the estimation of IGIP for Coal Bed Methane and included the review of the available techniques using volumetric, simulation and performance method i.e. decline curve and material balance. Also, the possible causes of error in calculation of IGIP and the limitations of each method have been identified. Additionally, the comparison between the material balance method proposed by King et al., Jenson and Smith et al., Seidel et al., Ahmed et al., Firanda et al. is conducted using available data set. The results obtained shows that Firanda et al. is more realistic as compared to other discussed methods, as it considers matrix and cleat shrinkage, moisture expansion, gas expansion, connate water expansion, water expansion, and water influx.
Application Suite for 24/7 Real Time Operation Centers
Authors: Al-Khudiri Musab M. , Al-Sanie Faisal S. , Paracha Sajjad A , Miyajan Ramzi A , Awan Mohammad W , Kashif Muhammad , Ashraf Hamood M
Published: June 2015

A suite of applications was developed to help real-time operation centers engineers and geoscientists to monitor drilling operations and improve the effectiveness of the decision making process. These robust applications automate monitoring of drilling and logging operations and provide various advance capabilities for engineers and geoscientists. Considering the recent immense increase in drilling operation in Saudi Arabia, a system with advanced capabilities of data quality control (QC), rescaling, filtering, alerting, and chatting is essentially needed to assist operation centers within Saudi Aramco to meet their targets.

Furthermore, one of main applications that are used by Real-Time Operation Center is RTOC toolbox which consists of the following systems: workflow, critical well scheduling, alert & recommendations, cost avoidance and reporting. Aramcolink System is another major application that is used in real-time operation centers and it visualizes the real-time data stream coming from the rig-site. Aramcolink System consists of several modules that serve different user community and objectives. These modules are: geo-steering, drilling, remote casing control, and unconventional resources.

In this paper, RTOC Tool Box system and Aramcolink system will be discussed in details including their impact on improving real-time operation center internal process automation and improving accuracy of well placement.
Virus removal vs. subsurface water velocity during slow sand filtration
Authors: Dizer Halim , Brackmann Bernhard , Rahman M. Azizur , Szewzyk Regine , Sprenger Christoph , Holzbecher Ekkehard , López-Pila Juan M.
Published: June 2015

In an attempt to obtain a conservative estimate of virus removal during slow sand and river bank filtration, a somatic phage was isolated with slow decay and poor adsorption to coarse sand. We continuously fed a phage suspension to a 7-m infiltration path and measured the phage removal. In a second set of experiments, we fed the phage suspension to 1-m long columns run at different pore water velocities. Using the data obtained, a mathematical model was constructed describing removal vs. pore water velocity (PWV), assuming different statistical distributions of the adsorption coefficient λ. The bimodal distribution best fit the results for PWVs higher than 1 m/d. It predicted a removal of approximately 4 log10 after 50 days infiltration at 1 m/d. At PWVs below 1 m/d the model underestimated removal. Sand-bound phages dissociated slowly into the liquid phase, with a detachment constant kdet of 2.6 × 10−5. This low kdet suggests that river bank filtration plants should be intermittently operated when viral overload is suspected, e.g. during flooding events or at high water-marks in rivers, in order for viruses to become soil-associated during the periods of standstill. Resuming filtration will allow only a very slow virus release from the soil.
Removal of natural organic matter (NOM) from an aqueous solution by NaCl and surfactant-modified clinoptilolite
Authors: Niri Mehdi Vosoughi , Mahvi Amir Hosein , Alimohammadi Mahmoud , Shirmardi Mohammad , Golastanifar Hafez , Mohammadi Mohamma Javad , Naeimabadi Abolfazl , Khishdost Maria
Published: June 2015

Zeolitic tuffs are found in different parts of the world. Iranian zeolite is a low-cost material that can be frequently found in nature. Surfactant-modified zeolite (SMZ) can be used for the adsorption of natural organic matter (NOM) from aqueous solutions. The adsorption study was conducted to evaluate the adsorption capacity of SMZ; furthermore, the effects of contact time, initial pH, and the initial adsorbent dose on the adsorption process were investigated in a batch system. The kinetic studies showed that the adsorption of NOM on SMZ was a gradual process. The optimum initial pH values for the adsorption of NOM on SMZ were in the acidic ranges. The batch kinetic experiments showed that the adsorption followed the pseudo-second-order kinetic model with good correlation coefficients. The equilibrium data were well described by the Langmuir isotherm model. The results show that the natural zeolite being modified with NaCl and hexadecyltrimethylammonium bromide as a cationic surfactant was an appropriate adsorbent for the removal of NOM.
Extraction, characterization and application of malva nut gum in water treatment
Authors: Ho Y. C. , Norli I. , Alkarkhi Abbas F. M. , Morad N.
Published: June 2015

In view of green developments in water treatment, plant-based flocculants have become the focus due to their safety, degradation and renewable properties. In addition, cost and energy-saving processes are preferable. In this study, malva nut gum (MNG), a new plant-based flocculant, and its composite with Fe in water treatment using single mode mixing are demonstrated. The result presents a simplified extraction of the MNG process. MNG has a high molecular weight of 2.3 × 105 kDa and a high negative charge of −58.7 mV. From the results, it is a strong anionic flocculant. Moreover, it is observed to have a branch-like surface structure. Therefore, it conforms to the surface of particles well and exhibits good performance in water treatment. In water treatment, the Fe-MNG composite treats water at pH 3.01 and requires a low concentration of Fe and MNG of 0.08 and 0.06 mg/L, respectively, when added to the system. It is concluded that for a single-stage flocculation process, physico-chemical properties such as molecular weight, charge of polymer, surface morphology, pH, concentration of cation and concentration of biopolymeric flocculant affect the flocculating performance.
Impact of cemeteries on groundwater contamination by bacteria and viruses – a review
Authors: Żychowski Józef , Bryndal Tomasz
Published: June 2015

In the process of decomposition of a human body, 0.4–0.6 litres of leachate is produced per 1 kg of body weight. The leachate contains pathogenic bacteria and viruses that may contaminate the groundwater and cause disease when it is used for drinking. So far, this topic has been investigated in several regions of the world (mainly Brazil, Australia, the Republic of South Africa, Portugal, the United Kingdom and Poland). However, recently more and more attention has been focused on this issue. This study reviews the results of investigations related to the impact of cemeteries on groundwater bacteriology and virology. This topic was mainly discussed in the context of the quantities and qualities of changes in types of microorganisms causing groundwater contamination. In some cases, these changes were related to the environmental setting of a place, where a cemetery was located. The review is completed by a list of recommendations. Their implementation aims to protect the local environment, employees of funeral homes and the residents living in the vicinity of cemeteries. In this form, this review aims to familiarize the reader with the results of this topic, and provide practical guidance for decision-makers in the context of expansion and management of cemeteries, as well as the location of new ones.
Sensitivity of Vermamoeba (Hartmannella) vermiformis cysts to conventional disinfectants and protease
Authors: Fouque Emilie , Héchard Yann , Hartemann Philippe , Humeau Philippe , Trouilhé Marie-Cécile
Published: June 2015

Vermamoeba vermiformis is a free-living amoeba (FLA) widely distributed in the environment, known to colonize hot water networks and to be the reservoir of pathogenic bacteria such as Legionella pneumophila. FLA are partly resistant to biocides, especially in their cyst form. The control of V. vermiformis in hot water networks represents an important health issue, but there are very few data on their resistance to disinfection treatments. The sensitivity of cysts of two strains of V. vermiformis to three disinfectants frequently used in hot water networks (chlorine, heat shock, peracetic acid (PAA) mixed with hydrogen peroxide (H2O2)) was investigated. In vitro, several concentrations of biocides, temperatures and exposure times according to the French regulation were tested. Cysts were fully inactivated by the following conditions: 15 mg/L of chlorine for 10 min; 60 °C for 30 min; and 0.5 g/L equivalent H2O2 of PAA mixed with H2O2 for 30 min. For the first time, the strong efficacy of subtilisin (0.625 U/mL for 24 h), a protease, to inactivate the V. vermiformis cysts has been demonstrated. It suggests that novel approaches may be efficient for disinfection processes. Finally, V. vermifomis cysts were sensitive to all the tested treatments and appeared to be more sensitive than Acanthamoeba cysts.
A pulsed light system for the disinfection of flow through water in the presence of inorganic contaminants
Authors: Garvey Mary , Rowan Neil
Published: June 2015

The use of ultraviolet (UV) light for water disinfection has become increasingly popular due to on-going issues with drinking water and public health. Pulsed UV light has proved to be an effective form of inactivating a range of pathogens including parasite species. However, there are limited data available on the use of pulsed UV light for the disinfection of flowing water in the absence or presence of inorganic contaminants commonly found in water sources. Here, we report on the inactivation of test species including Bacillus endospores following pulsed UV treatment as a flow through system. Significant levels of inactivation were obtained for both retention times tested. The presence of inorganic contaminants iron and/or manganese did affect the rate of disinfection, predominantly resulting in an increase in the levels of inactivation at certain UV doses. The findings of this study suggest that pulsed UV light may provide a method of water disinfection as it successfully inactivated bacterial cells and bacterial endospores in the absence and presence of inorganic contaminants.
Assessment of source tracking methods for application in spring water
Authors: Wicki Melanie , Auckenthaler Adrian , Felleisen Richard , Karabulut Fatma , Niederhauser Isabel , Tanner Marcel , Baumgartner Andreas
Published: June 2015

For discriminating between human and animal faecal contamination in water, microbial source tracking (MST) approaches using different indicators have been employed. In the current study, a range of 10 such MST indicators described in the scientific literature were comparatively assessed. Bacteriophages infecting host strains of Bacteroides (GA-17, GB-124 and ARABA 84) as well as sorbitol-fermenting bifidobacteria proved useful for indicating human faecal contamination while Rhodococcus coprophilus was associated with animal-derived faecal contamination. These potential source indicators were present in samples of faecal origin, i.e. either in human wastewater or animal waste, from many different regions in Switzerland and therefore showed a geographic stability. In addition, the MST indicators were abundant in surface water and were even sensitive enough to detect faecal contamination in spring water from two study areas in Switzerland. This is the first study that has compared and successfully applied MST methods in spring water.
Factors affecting decay of Salmonella Birkenhead and coliphage MS2 during mesophilic anaerobic digestion and air drying of sewage sludge
Authors: Mondal Tania , Rouch Duncan A. , Thurbon Nerida , Smith Stephen R. , Deighton Margaret A.
Published: June 2015

Factors affecting the decay of Salmonella Birkenhead and coliphage, as representatives of bacterial and viral pathogens, respectively, during mesophilic anaerobic digestion (MAD) and air drying treatment of anaerobically digested sewage sludge were investigated. Controlled concentrations of S. Birkenhead were inoculated into non-sterile, autoclaved, γ-irradiated and nutrient-supplemented sludge and cultures were incubated at 37 °C (MAD sludge treatment temperature) or 20 °C (summer air drying sludge treatment temperature). Nutrient limitation caused by microbial competition was the principal mechanism responsible for the decay of S. Birkenhead by MAD and during air drying of digested sludge. The effects of protease activity in sludge on MS2 coliphage decay in digested and air dried sludge were also investigated. MS2 coliphage showed a 3.0–3.5 log10 reduction during incubation with sludge-protease extracts at 37 °C for 25 h. Proteases produced by indigenous microbes in sludge potentially increase coliphage inactivation and may therefore have a significant role in the decay of enteric viruses in sewage sludge. The results help to explain the loss of viability of enteric bacteria and viral pathogens with treatment process time and contribute to fundamental understanding of the various biotic inactivation mechanisms operating in sludge treatment processes at mesophilic and ambient temperatures.
The presence of opportunistic pathogens, Legionella spp., L. pneumophila and Mycobacterium avium complex, in South Australian reuse water distribution pipelines
Authors: Whiley H. , Keegan A. , Fallowfield H. , Bentham R.
Published: June 2015

Water reuse has become increasingly important for sustainable water management. Currently, its application is primarily constrained by the potential health risks. Presently there is limited knowledge regarding the presence and fate of opportunistic pathogens along reuse water distribution pipelines. In this study opportunistic human pathogens Legionella spp., L. pneumophila and Mycobacterium avium complex were detected using real-time polymerase chain reaction along two South Australian reuse water distribution pipelines at maximum concentrations of 105, 103 and 105 copies/mL, respectively. During the summer period of sampling the concentration of all three organisms significantly increased (P < 0.05) along the pipeline, suggesting multiplication and hence viability. No seasonality in the decrease in chlorine residual along the pipelines was observed. This suggests that the combination of reduced chlorine residual and increased water temperature promoted the presence of these opportunistic pathogens.
Removal of perfluorinated compounds in wastewater treatment plant effluents by electrochemical oxidation
Authors: Zhang Chunhui , Wang Liangliang , Li Juan , Su Peidong , Peng Chen
Published: June 2015

The presence of perfluorinated compounds (PFCs) in the effluents of a wastewater treatment plant (WWTP) in Beijing was investigated in the current study. Perfluorooctanoate acid and perfluorooctane sulfonate were the predominant PFCs in wastewater, accounting for 19–27% and 18–31%, respectively. The concentrations of PFCs with long chains were much lower than those PFCs with short chains (≤C8). An electrochemical oxidation reactor was employed for advanced treatment of PFCs in WWTP effluents using stainless steel plates as anode and cathode electrodes. It was concluded that the removal efficiency of PFCs was improved accordingly with the increasing applied current density. The removal efficiencies of target PFCs ranged from 23.53 to 51.79% with a reaction time of 30 minutes, current density of 20 mA/cm2, electrode plate distance of 1.0 cm and electrode plate amounts of five pairs.
Globale Stability in a Viral Infection Model with Beddington-DeAngelis Functional Response
Authors: Zhanwei Wang , Xia He
Published: June 2015

The stability of a mathematical model for viral infection with Beddington-DeAngelis functional response is
considered in this paper. If the basic reproduction number R ≤1, by the Routh-Hurwitz criterion and Lyapunov function,
the uninfected equilibrium E is globally asymptotically stable. Then, the global stability of the infected equilibrium E
is obtained by the method of Lyapunov function
The Properties of Shuffle Screw Dislocations in Semiconductors Silicon and Germanium
Authors: Zhang Huili , Zhang Chun , Zeng Chunhua , Tong Lumei
Published: June 2015

The dislocation widths, Peierls barriers and Peierls stresses for shuffle screw dislocations in diamond structure
crystals, Si and Ge, have been calculated by the improved P-N theory. The widths are about 0.6b, where b is the Burgers
vector. The Peierls barrier for shuffle screw dislocation in Si and Ge, is about 3.61~4.61meV/Å and 5.31~13.32meV/Å,
respectively. The Peierls stress is about 0.28~0.33GPa and 0.31~0.53GPa, respectively. The calculated Peierls barriers
and stresses are likely the results of shuffle screw dislocation with metastable core which is centered on the bond between
two atoms.
Optimal Configuration Algorithm for Mechanical Products Based on the
Constraint of Carbon Footprint
Authors: Bo Wei , Renwang Li , Hui Zheng , Xianliang Zong
Published: June 2015

The concept of carbon footprint controllable product is proposed to assess carbon footprint during the stage of
product development and configuration. It’s different from carbon footprint assessment afterwards. As a result, the control
objectives can be quantified accurately and realized easily. Relations among product characteristics, which include carbon
footprint, are uncertain. In order to obtain the optimal product configuration scheme based on constraint of carbon footprint,
three-stage theory is proposed. These three stages refer to functional configuration, compliance evaluation of carbon
footprint, and optimal comprehensive evaluation. Using this theory, functional feasible solution set, carbon footprint conforming
set and the optimal scheme are generated respectively. Grey relation analysis is verified as an effective method
for comprehensive benefit evaluation. Reducer design is used as a case study to illustrate the proposed concept.
CATIA-Based Urban Mini EV Design
Authors: Pengfei Tian , Yiping Luo , Feng Zhou , Shu Yuan
Published: June 2015

This article introduces a mini EV for urban single drive,
a the car intended to work as conveyance for city workers,
thereby relieving urban traffic pressure, improving traffic congestion and
reducing urban pollution. The paper primarily designs a
electric reversed tricycle and determines its motor and battery parameters, fixes the cockpit installation location by ergonomics, and
finally completes vehicle arrangement. CATIA is mainly used for modeling and ergonomics analysis during the design process.
Retraction: Uranbey S. In vitro bulblet regeneration from immature embryos of endangered and endemic Muscari azureum. Arch biol sci. 2011; 63(1):209-15 doi: 10.2298/ABS1101209U
Authors: Editorial E
Published: June 2015

This is a notice of retraction of the article: In vitro bulblet regeneration
from immature embryos of endangered and endemic Muscari azureum, published
in the Archives of Biological Sciences in 2011, Vol. 63, Issue 1. The
Editor-in-Chief has been informed that this paper is a duplicate of an
earlier paper: Uranbey S. In vitro bulblet regeneration from immature
embryos of Muscari azureum. Afr J Biotechnol. 2010;9(32):5121-5. This claim
is correct and the entire paper is a verbatim copy of the earlier one. After
confirmation of this fact, the Editor-in-Chief of the Archives of Biological
Sciences has decided to retract the paper immediately. We apologize to the
readers of the journal that it took so many years to notice this error and
to retract the paper. We request readers of the journal to directly get in
touch with the editorial office and the editors of the journal for similar
cases in the future, so that they can be handled promptly.

 Link to the retracted article 10.2298/ABS1101209U
Extragradient algorithms for variational inequality, fixed point and generalized mixed equilibrium problems
Authors: Guo Baohua , Sun Lijuan
Published: June 2015

The purpose of this paper is to investigate variational inequalities, fixed
point problems and generalized mixed equilibrium problems. Anextragradient
iterative algorithm is investigated in the framework of Hilbert spaces. Weak
convergence theorems for common solutions are established.
Nonlinear fuzzy stability of a functional equation related to a characterization of inner product spaces via fixed point technique
Authors: Wang Zhihua , Sahoo Prasanna
Published: June 2015

Using the fixed point method, we prove some results concerning the stability
of the functional equation 2n?i=1 f(xi-1/2n 2n?j=1 xj)=2n?i=1 f
(xi)-2nf(1/2n 2n?i=1 xi) where f is defined on a vector space and
taking values in a fuzzy Banach space, which is said to be a functional
equation related to a characterization of inner product spaces.
A congruence relation for Wiener and Szeged indices
Authors: Gutman Ivan , Xu Kexiang , Liu Muhuo
Published: June 2015

In a recent paper [H. Lin, MATCH Communications in Mathematical and in Computer
Chemistry 70 (2013) 575-582], a congruence relation for Wiener indices of a
class of trees was reported. We now show that Lin?s congruence is a special
case of a much more general result.
Conservative matrices in summability of series
Authors: Yu Dansheng
Published: June 2015

Das [3] introduced the class of absolute kth-power conservative matrices for
k ? 1, denoted by B(Ak). In the present paper, we generalize the class B (Ak)
to a general one named B(?n, ?n, ?n, ?n, ?)and give some sufficient
conditions for a matrix belongs to the new class B(?n, ?n, ?n, ?n, ?) when ?
is convex. As applications of the general result, we investigate the
conservatives of Ces?ro matrices and Riesz matrices.
On the index of product systems of Hilbert modules
Authors: Keckic Dragoljub , Vujosevic Biljana
Published: June 2015

In this note we prove that the set of all uniformly continuous units on a
product system over a C* algebra B can be endowed with a structure of
left-right B-B Hilbert module after identifying similar units by the
suitable equivalence relation. We use this construction to define the index
of the initial product system, and prove that it is a generalization of
earlier defined indices by Arveson (in the case B=C) and Skeide (in the
case of spatial product system). We prove that such defined index is a
covariant functor from the category of continuous product systems to the
category of B bimodules. We also prove that the index is subadditive with
respect to the outer tensor product of product systems, and prove additional
properties of the index of product systems that can be embedded into a
spatial one.
Approximation by complex Szász-Mirakyan-Stancu-Durrmeyer operators in compact disks under exponential growth
Authors: Gal Sorin , Gupta Vijay
Published: June 2015

In the present paper, we deal with the complex Sz?sz-Stancu-Durrmeyer
operators and study Voronovskaja type results with quantitative estimates for
these operators attached to analytic functions of exponential growth on
compact disks. Also, the exact order of approximation is found.
Quotient structure of interior-closure texture spaces
Authors: Dost Şenol
Published: June 2015

In this paper, we consider quotient structure and quotient difunctions in the
context of interior and closure operators on textures in the sense of
Dikranjan-Giuli. The generalizations of several results concerning separation
and quotient mapping are presented. It is shown that the category of
interior-closure spaces and bicontinuous difunctions has a T0 reflection.
Finally, we introduce some classes of quotient difunctions such as bi-initial
and bi-final difunctions between interior-closure texture spaces.
Fixed point theorems for occasionally weakly compatible mappings, II
Authors: Rhoades B.E.
Published: June 2015

In this paper we point out that a number of fixed point papers, involving
several maps, are special cases of a general result proved several years ago
by the author and G. F. Jungck, and one proved by Aliouche and Popa [1].
On a class of operators with normal Aluthge transformations
Authors: Estaremi Yousef
Published: June 2015

In this paper, we show that the generalized Aluthge transformations of a
large class of operators (weighted conditional type operators) are normal. As
a consequence, the operatorMwEMu is p-hyponormal if and only if it is normal,
and under a weak condition, if MwEMu is normal, then the Holder inequality
turn into equality for w; u. Also, we give some applications of p-hyponormal
weighted conditional type operators, for instance, point spectrum and joint
point spectrum of p-hyponormal weighted conditional type operators are equal.
In the end, some examples are provided to illustrate concrete application of
the main results of the paper.
The Analysis Of Synchronous Blade Vibration Using Linear Sine Fitting
Authors: Przysowa Radosław
Published: June 2015

In Blade Tip Timing several sensors installed circumferentially in the casing are used to record times of arrival (TOA) and observe deflections of blade tips. This paper aims to demonstrate methodology of model-based processing of aliased data. It focuses on the blade vibration excited by the forces synchronous with engine rotation, which are called integral responses. The driven harmonic oscillator with single degree of freedom (SDOF) is used to analyse blade vibration measured by tip-timing sensors during engine deceleration. When integral engine order EO is known, the linear sine fitting techniques can be used to process data from sensors to estimate amplitude, phase and frequency of blade vibration in each rotation. The oscillator model is implemented in MATLAB and used to generate resonance curves and simulate blade responses observed with tip sensors, installed in the axial compressor. Generated TOA data are fitted to the sine function to estimate vibration parameters. The validated procedure is then employed to analyze real test data.
Standard Sine Fitting Algorithms Applied To Blade Tip Timing Data
Authors: Kaźmierczak Krzysztof , Przysowa Radosław
Published: June 2015

Blade Tip Timing (BTT) is a non-intrusive method to measure blade vibration in turbomachinery. Time of Arrival (TOA) is recorded when a blade is passing a stationary sensor. The measurement data, in form of undersampled (aliased) tip-deflection signal, are difficult to analyze with standard signal processing methods like digital filters or Fourier Transform. Several indirect methods are applied to process TOA sequences, such as reconstruction of aliased spectrum and Least-Squares Fitting to harmonic oscillator model. We used standard sine fitting algorithms provided by IEEE-STD-1057 to estimate blade vibration parameters. Blade-tip displacement was simulated in time domain using SDOF model, sampled by stationary sensors and then processed by the sinefit.m toolkit. We evaluated several configurations of different sensor placement, noise level and number of data. Results of the linear sine fitting, performed with the frequency known a priori, were compared with the non-linear ones. Some of non-linear iterations were not convergent. The algorithms and testing results are aimed to be used in analysis of asynchronous blade vibration.
A Method For Determination And Standardization Of Performance Parameters For Aircrafts With Electric Drives
Authors: Jakielaszek Zbigniew , Nowakowski Mirosław
Published: June 2015

The study outlines the technique for flight tests carried out for a plane powered by an electric drive and the method for standardization of performance parameters applicable to evaluation of test results. Due to the relatively new type of drive, which is an electric motor, the literature references provide no descriptions of such issues. Therefore the solutions presented in the paper are the own contribution of the research team from Air Force Institute of Technology (ITWL).
The Model Of One-Type Aircraft Fleet Behaviour While Service And Advantages SHM V. NDT Implementation
Authors: Lewitowicz Jerzy , Kustroń Kamila
Published: June 2015

The paper defines the essence of durability characteristics of the designing structure of an airframe in terms of flight safety. Particular attention is drawn to one of the main factors influencing the durability characteristics of the airframe – diagnostics system for the health assessment of the airframe during the process of operation. The effectiveness of the use of integrated solutions to the structure of the airframe providing a continuous assessment of the technical condition is presented. Continuous diagnostics system integrated with the airframe, SHM, is classified as an intelligent solution. This paper presents a model of the behavior of one-type aircraft operating in the air operator’s fleet in terms of susceptibility to failure. Justified assumption in the description of this behavior, in the form of a “bathtub curve”. The analysis is supported by real data of failures. The benefits of using a continuous diagnostics system integrated with the airframe, SHM, is interpreted in relation to the classical approach with the use of non-destructive testing, NDT, for the three phases of the bathtub curve.
Issues Related To Troubleshooting Of Avionic Hydraulic Units
Authors: Jastrzębski Grzegorz , Szczepaniak Paweł , Jóźko Michał
Published: June 2015

The paper outlines workflows associated with troubleshooting of avionic hydraulic systems with detailed description of the troubleshooting algorithm and classification of diagnostic signals provided by avionic hydraulic systems and their subassemblies. Attention is paid to measurement sequences for diagnostic signals from hydraulic systems, circuits and units. Detailed description is dedicated to an innovative design of a troubleshooting device intended for direct measurements of internal leaks from avionic hydraulic units. Advantages of the proposed measurement method are summarized with benefits from use of the presented device and compared against the methods that are currently in use. Subsequent phases of the troubleshooting process are described with examples of measurement results that have been acquired from subassemblies of hydraulic systems of SU-22 aircrafts currently in service at Polish Air Forces with consideration given to cases when the permissible threshold of diagnostic signals were exceeded. Finally, all results from investigations are subjected to thorough analysis.
Regionalization of Youth and Adolescent Weight Metrics for the Continental United States Using Contiguity-Constrained Clustering and Partitioning
Authors: Adu-Prah Samuel , Oyana Tonny J.
Published: June 2015

Contemporary spatial data collection techniques, analyses, and presentations have created new opportunities for public health analyses that sometimes render existing administrative and statistical boundaries unsuitable. This article presents an applied algorithm, regionalization with dynamically constrained agglomerative clustering and partitioning (REDCAP), to create regions other than pre-defined regions. The regions created in the study were based on the weight of youth in the continental United States. The REDCAP algorithm incorporates a spatial contiguity restriction to create regions with the same characteristics and value. The regions created overcome the existing challenge in cartography in which administrative and statistical regions are often used in presenting results. The study generated 10- and 25-class regions that reflected high and low obesity prevalence among US youth without using existing county and state boundaries. The results revealed new insights about regions comprising counties identified as having high obesity prevalence. Some of the counties identified in the established regions interestingly have not been recorded as at risk for high obesity prevalence in previous studies. A crucial advantage of the approach is that it minimizes the bias contained in existing administrative and statistical regions, a challenge in cartography. Furthermore, the approach effectively creates regions based on a specific theme and objective function.
The Applicability of Nanoindentation for the Examination of Microstructured Areas in CP Titanium Samples
Authors: Godard C. , Klingler A. , Junker T. , Kerscher E.
Published: June 2015

Microscale machining processes modifying component surfaces are applied in various fields: from drive technology through plant engineering to medical technology. The impact of the fine structures formed in the material on its behavior and mechanical properties need to be investigated in more detail. Besides the examination of the cyclic and quasi-static behavior of micromachined samples, analysing the near-surface microstructure and the hardness is of great importance. The nanoindentation allows for the determination of local mechanical properties in small analysis volumes. Its applicability to determine the hardness in micromachined near-surface areas including the metallographic preparation for commercially pure titanium is presented in this work.
Theoretical analysis and experimental study on loading process among stages of magnetic fluid seal
Authors: Wang Zhongzhong , Li Decai
Published: June 2015

A new experimental setup was designed in order to study the loading process among stages of magnetic fluid seal. Magnetic field distributions under the pole pieces of the magnetic fluid seal with six stages were simulated by finite element method, and the results proved its rationality. A series of tests on experimental setup were run in order to study the way of pressure transmission among stages of magnetic fluid seal and to extend our knowledge on the mechanism of seal operation. The results of the experiments not only proved the correctness of the corollaries of previous researchers and more detailedly shows the way of pressure transmission in each stage. A mathematical model of the way of pressure transmission among stages of magnetic fluid sea was constructed by previous inference and the present experimental results, and it is able to express the specific way of pressure transmission at certain extent. The experimental conclusion also shows that the quantity of magnetic liquid in each stage will be redistributed and the quantity of magnetic liquid in each stage may be unevenly distributed when the pressure of the pressure chamber is imposed. It has a certain value of reference in the improvement of design and structure process of magnetic fluid seal in engineering problem.
Polarization and wide angle independent perfect metamaterial triple band absorber based on hexagonal shapes
Authors: Ghandehari Mehdi Bahdorzadeh , Feiz Nooshin , Khazaei Ali Akbar
Published: June 2015

A novel metamaterial absorber (MA) based on triple hexagonal shaped resonators has proposed in this paper. This metamaterial unit cell absorber possesses a nearly wide angle perfect absorption of incidence wave and polarization independence. The absorption is occurred in three different frequencies. The absorptivity is as high as 94%, 95% and 99%, at 3.4 (GHz), 4.6 (GHz) and 6.4 (GHz), respectively. An important feature of this metamaterial absorber is easy fabrication and maximum absorption is observed in three different frequencies. The proposed metamaterial absorber has wide applications such as stealth technology, thermal detector and imaging. Moreover, a very good agreement between simulation and measurement results has been observed.
Geochemical Characterization of Groundwater in a Volcanic System
Authors: Bellia Carmelo , Gallardo Adrian , Yasuhara Masaya , Kazahaya Kohei
Published: June 2015

A geochemical investigation was undertaken at Mt. Etna Volcano to better define groundwater characteristics of its aquifers. Results indicate that the Na–Mg ± Ca–HCO3− ± (SO42− or Cl−) type accounts for more than 80% of the groundwater composition in the volcano. The remaining 20% is characterized by elevated Ca2+. Waters along coastal areas are enriched in SO42− or Cl−, mainly due to mixing with seawater and anthropogenic effects. The majority of the samples showed values between −4‰ to −9‰ for δ18O and −19‰ to −53‰ for δ2H, suggesting that precipitation is the predominant source of recharge to the aquifers, especially in the west of the study area. The analysis of δ13C and pCO2 shows values 1 to 3 times higher than those expected for waters in equilibrium with the atmosphere, suggesting a partial gas contribution from deep sources. The diffusion of gasses is likely to be controlled by tectonic structures in the volcano. The ascent of deep brines is also reflected in the CO2 enrichment (up to 2.2 bars) and enriched δ2H/δ18O compositions observed in the salt mounts of Paternò.