bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanistic Modeling of Carbonated Waterflooding
Authors: Sanaei Alireza , Varavei Abdoljalil , Sepehrnoori Kamy 
Published: March 2018

Abstract
CO2 enhanced oil recovery is usually affected by poor sweep efficiency due to unfavorable mobility contrast between the injected CO2 and oil. To alleviate this problem, CO2 is added to the injected brine and transported in the reservoir by flood water. Therefore, Carbonated Water Injection (CWI), takes advantage of both CO2 and water flooding processes. Furthermore, geochemical reactions between the injected carbonated brine and rock can alter petrophysical properties of the reservoir and affect final oil recovery. While there are several CWI coreflood experiments reported in the literature, simulation studies for this process are scarce.
Accurate modeling of CWI performance requires a simulator with the ability to capture true physics of the CWI process. In this study, a compositional reservoir simulator developed at The University of Texas at Austin, UTCOMP, coupled with a state-of-the-art geochemical package developed by United States Geological Survey, IPhreeqc, is used to model CWI process. We considered the impact of CO2 mass transfer between brine and hydrocarbon phases based on thermodynamic constrains at the reservoir condition. In order to validate our simulation approach, the results of our CWI simulations were compared with a recently published coreflood experiment. Moreover, we investigated the fluid-rock interactions in CWI.
The results of the simulations, indicated that prior to water breakthrough the main drive mechanism is displacement. But as more carbonated water is injected, CO2 diffuses more into the trapped oil left behind, which results in oil swelling and subsequent oil viscosity reduction. Moreover, reaction of carbonate minerals such as calcite with carbonated brine results in dissolution of the main rock matrix which consequently creates wormholes similar to carbonates acidizing.
In this study we propose a novel approach for accurate modeling of carbonated waterflooding process. The results of this study highlight the importance of geochemical reactions in modeling CWI process. Our approach has been validated based on history matching at the backdrop of a recently published coreflood experiment.
Simulations of In-Situ Upgrading Process: Interpretation of Laboratory Experiments and Study of Field-Scale Test
Authors: Perez-Perez A. , Mujica M. , Bogdanov I. , Brisset A. , Garnier O. 
Published: March 2018

Abstract
In-situ upgrading (IU) is a promising method of improved viscous and heavy oil recovery. The IU process implies a reservoir heating up and exposition to temperature higher than 300°C for long enough time to promote a series of chemical reactions. The pyrolysis reactions produce lighter oleic and gaseous components while a solid residue remains underground. In this work, we developed a numerical model of IU based on lab experiences (kinetics measurements and core experiments) and validated results applying our model to an IU test published it the literature. Finally, we studied different operational conditions searching for energy-efficient configurations.
In this work, two types of IU experimental data are used from two vertical-tube experiments with Canadian bitumen cores (0.15 m and 0.69 m). A general IU numerical model for the different experimental setups has been developed and compared to experimental data, using a commercial reservoir simulator framework. This model is capable to represent the phase distribution of pseudo-components, the thermal decomposition reactions of bitumen fractions and the generation of gases and residue (solid) under the cracking conditions.
Simulation results for the cores submitted to 370°C and production pressure of 15 bar, have shown that oil production (per pseudo-component) and oil sample quality were well-predicted by the model. Some differences in gas production and total solid residue were observed with respect to laboratory measurements. Computer-assisted history matching was performed using an uncertainty analysis tool on the base of the most important model parameters. In order to better understand IU field-scale test results, the Shell's Viking pilot (Peace River) was modeled and analyzed with proposed IU model. The appropriated grid-block size was determined and calculation time was reduced using the adaptive mesh refinement technique. The quality of products, the recovery efficiency and the energy expenses obtained with our model were in good agreement with the field test results. Also the conversion results (upgraded oil, gas and solid residue) from the experiments were compared to those obtained in the field test. Additional analysis was performed to identify energy efficient configurations and to understand the role of some key variables, e.g. heating period and rate, the production pressure, in the global IU upgrading performance. We discuss these results which illustrate and quantify the interplay between energy efficiency and productivity indicators.
Morphological Description of Noun Formation Process: Case of Suffixation and Prefixation in Iguta Language
Authors: Ado Mohammed Ahmad , Bidin Siti Jamila 
Published: March 2018

<p>This paper dwells on a concise morphological description of Noun formation process involved in Iguta language (a minority endangered language in the north central, Nigeria). To this end, the paper explores the suffixation and prefixation processes involved in the formation of nouns of Iguta language. Ado’s (2017) 455 Iguta wordlists was employed as secondary data and was qualitatively used as instrument for the analyses in this paper. Ado’s 455 Iguta wordlists is primarily based on the standard dialect (i.e., Andirgiza) spoken by its native speakers in five selected towns in Jos North local government of the Plateau state, Nigeria. Hand analysis strategy and a thematic analytical process were used in developing insights on the language data during the analysis. The findings revealed <em>‘-char, -di and –e’ </em>morphs as suffixes<em> </em>to inflect while <em>‘t-, ti-, ha-, a-, an-, m-, i-, ma-, si-, ndu-, s-, tu-, tun-, tumu- </em>morphs as prefixes to either inflect or derive nouns. It is also observed that most singular nouns in Iguta are inflected to produce the plural forms using <strong><em>ti- </em></strong>or<strong><em> tu-</em></strong> prefixes especially when the pattern of the singular words begin with a vowel morpheme or phoneme. In accordance with the findings, it is suggested that prefixes and suffixes are part of the affixation process used in noun formation of Iguta language. In conclusion, the study has contributed in descriptive linguistics in terms inflectional or derivational suffixation and prefixation process used to build nouns in Iguta language. This paper may assist professional teachers and linguists in understanding the suffixations and prefixations existing in Iguta language.</p>
Indonesian EFL Learners’ Perceptions of Classroom Learning Environments in An EFL Context
Authors: Arigusman Anggi 
Published: March 2018

<p><em>A good learning environment will determine the students’ learning quality. Therefore, creating supporting classroom learning environment is really crucial. This study explored the students’ perceptions at an Indonesian senior high school of actual classroom learning environment in English teaching across gender and grade. What Is Happening In this Classroom (WIHIC) questionnaire was applied to see the participants’ perceptions of the language learning environment. As for data analysis procedure, the scores obtained from the questionnaire were analyzed and described qualitatively. The data was examined to see how how is the students perception of their actual classroom learning environment in EFL classes across grade and gender. The result demonstrated similar perception indicated by five of the seven categories of the WIHIC questionnaire among grades. Across gender, four of the seven categories also indicated similar perception between male and female students where the categories get positively dominant result.</em></p>
Research on method of vibration analysis of rubber tracked vehicle based on dynamic model
Authors: Zhang Jinzheng , Wang Qi , Jin Qichun 
Published: March 2018

To understand the vibration characteristics of rubber track system in traveling, this research studied the small harvester installed with rubber track system and the dynamic model reflecting vibration characteristics of rubber track system on the ground was constructed. Comparing analysis results with measured experimental data obtained from vehicle test, it is proved that the dynamic model established by theoretical analysis can correctly and effectively predict actual movement condition and vibration characteristics of rubber track system, especially at low test vehicle speeds. The relative difference between measured data of vibration acceleration obtained from real vehicle tests and the theoretical value was in the range of –1.2 %-+18.2 %. The vibration prediction and analysis method of rubber tracked vehicle was discussed in this study, and important basic data were provided for the research of comfort evaluation of working posture and lightweight design of rubber tracked mechanism.
Base-isolation design of single-tower cable-stayed bridges: a case study in meizoseismal area
Authors: Yan Bin , Xia Ye 
Published: March 2018

The single-tower cable-stayed bridge is one of the most popular types of bridges. Seismic design for this type of bridge, however, is rather difficult. When subjected to longitudinal earthquakes, the tower stands as the weakest part of all the bridge components. To solve this problem, a base-isolation design was developed and adopted for a practical single-tower cable-stayed bridge. In this design, laminated elastomeric bearings (EB) and liquid viscous dampers (LVD) were installed to serve as a base-isolation layer inside the tower cap. Numerical analysis was then conducted to investigate the variations of dynamic characteristics and seismic responses between conventional designs and base-isolation designs. LVD were used on the top of the transition pier to optimize the seismic system of the bridge. It was found that: i) the seismic loads acting on the bridge component were reduced as the seismic displacements increased. This was the result of amplification of the bridge vibration period by the EB in the base-isolation layer; ii) the seismic displacements were restrained by the LVD in the base-isolation layer, but the seismic forces increased due to improper parameter values; and iii) the seismic response decreased further by the transition pier’s LVD.
Monitoring of blast-induced ground vibration using WSN and prediction with an ANN approach of ACC dungri limestone mine, India
Authors: Ragam Prashanth , Nimaje D. S. 
Published: March 2018

Blast-induced ground vibration (BIGV) is an undesirable environmental issue in and around mines. Usage of a high amount of explosive causes ground vibrations that are harmful to the nearby habitats and dwellings. In this paper, an attempt has been made to monitor the BIGV with low-cost wireless sensor network (WSN) and prediction of peak particle velocity (PPV) using an artificial neural network (ANN) technique at ACC Dungri limestone mine, Bargarh, Odisha, India. Eleven blasts PPV were recorded at different locations using wireless sensor network prototype system. The data has been transmitted by ZigBee (IEEE 802.15.4) protocol. The results are very promising and the recorded PPV varies from 0.191 mm/s to 8.60 mm/s. A three-layer, feed-forward back propagation neural network consists of 6 input parameters, 5 hidden neurons, and one output parameters were trained. Obtained results were compared based on correlation of determination (R2) and standard error between recorded and predicted values of PPV.
Design and dynamic testing of a roller coaster running wheel with a passive vibration damping system
Authors: Gierlak Piotr , Szybicki Dariusz , Kurc Krzysztof , Burghardt Andrzej , Wydrzyński Dawid , Sitek Radosław , Goczał Marek 
Published: March 2018

This paper presents a design, a numerical analysis, a build-up and dynamic testing of an engineered and fabricated wheel with a passive vibration damping system designed for a roller coaster system. Taking into account the limited amount of space for fixing a wheel to a roller-coaster, this study shows an approach in which a special wheel design and viscoelastic inserts are used to reduce vibrations. A wheel comprises a rim and hub separated by a viscoelastic material and simultaneously connected by using spring steel fasteners with contractions ensuring elasticity. The dynamic tests of the wheel with a passive vibration damping system were completed with an assessment of the vibration reduction ratio in comparison to conventional roller coaster wheel types currently operated at the amusement park Energylandia located in Zator, Poland. Laboratory test results show reduction of vibrations by 36 % in the low frequency range, by 63 % in the medium frequency range and by 45 % in the high frequency range.
Numerical analysis of underwater flow past columnar projectile with different cross-sections at high Reynolds numbers
Authors: Yang Yongliang , Liu Rongzhong , Guo Rui , Chen Liang , Song Pu , Hu Hongwei 
Published: March 2018

Based on Detached Eddy Simulation (DES) technique, the flow around a columnar projectile with different cross-section shapes in the supercritical and extremely supercritical region is simulated by the Fluent. The cross-section of the projectile is regular polygon, which number of edges is 4, 6, 8, 10, 12, 24 and ∞, where ∞ means a circle. The vortex shedding pattern and flow field characteristics are analyzed at Reynolds number 2.5×105 to 2×107. Regarding circular cylinder projectile, when the flow velocity changes from 25 m/s to 200 m/s, the average drag coefficient decreases, and the St Number increases. Regarding regular polygon, when the number of edges for polygon changes from 4 to ∞ at flow velocity 50 m/s, the average drag coefficient decreases, and the St Number increases. The average lift coefficient is almost equal to zero and does not change with the flow velocity and the cross-section. The pressure coefficient Cp of 4-prism, 6-prism, 8-prism, 12-prism and 24-prism has multiple local minimum values at the polygon vertices of the cross section. According to the spectrum analysis, the vortex shedding frequency of 4-prism, 24-prism and cylindrical is single and fixed, so the projectile may cause resonance and deviates from a predetermined trajectory. But for the 6-prism and 8-prism and 12-prism, the cl and cd is multi-periodic vibration. So, considering the flow induced structural vibrations, drag, the power of shrapnel and manufacturing cost, the 8-prism are better choices for cluster warhead underwater in engineering design.
Development of Promising Thiopyrimidine-Based Anti-cancer and Antimicrobial Agents: Synthesis and QSAR Analysis
Authors: Syam Yasmin M. , Anwar Manal M. , Kotb Eman R. , Elseginy Samia A. , Awad Hanem M. , Awad Ghada E.A. 
Published: March 2018

Objective & Methodology:
New hybrids of thiopyrimidine-five/six heterocyclic rings were
synthesized and in vitro evaluated for their antiproliferative activity against three human cancer cell
lines, namely HCT116 (human colorectal carcinoma), PC-3 (human prostate adenocarcinoma) and
HepG2 (human liver carcinoma) cell lines. The most potency was elicited by the target candidates
against the viability of HCT116 cell lines. It was higher than that obtained by the positive control
5-Fluorouracil (IC50 range; 0.11-0.49 μM, IC50, 5-FU; 1.10 μM).

Results:
Cell cycle analysis and apoptosis activation revealed that compound 20 induced G2/M phase
arrest and apoptosis in HCT116 cells. In addition, compound 20 activates the caspases-9 and -3, a
process which might mediate the apoptosis of HCT116 cells.

Conclusion:
Furthermore, there is a good agreement between the observed pIC50 and the predicted
pIC50 values, in addition, the low RMSD and standard error values indicate the accuracy of the model.
Antimicrobial evaluation revealed that some of these compounds exhibited significant activities
against the tested pathogenic bacteria and fungi, wherein compounds 7a, 14, 15a, 21a, produced the
most potent and broad spectrum antibacterial and antifungal potency that was equivalent to that revealed
by Vibramycin and Ketoconazole (MIC; 125 μg/mL). Moreover, compounds 15a, 21c, investigated
dual potent antimicrobial and anticancer activity.
The Hepato-protective Effects of Portulaca oleracea L. extract: Review
Authors: Farkhondeh Tahereh , Samarghandian Saeed , Azimi-Nezhad Mohsen , Hozeifi Soroush 
Published: March 2018

Background:
Portulaca oleracea L. (Purslane) has been used in traditional medicine against
hepatic injury, although its actual efficacy has not been fully understood. The present study aimed to
critically review the recent literature data from 1990 to 2017 regarding the hepato-protective effects of
Portulaca oleracea L. and its underlying mechanisms.

Methods:
Online literature resources were checked using different search engines such as Medline,
PubMed, Iran Medex, Scopus, and Google Scholar to identify articles, editorials, and reviews about antidotal
effects of Portulaca oleracea L. against hepatotoxic agents.

Results:
Few studies have indicated that Portulaca oleracea L. shows protective effects against hepatotoxic
agents. However, due to lack of information in humans, more studies are needed to confirm the
efficacy of Portulaca oleracea L. as a hepato-protective agent.

Conclusion:
The study found that Portulaca oleracea L. may be effective on hepatotoxicity by modulating
oxidative stress and inflammation.
DNA Methylation in Osteoarthritis: Current Status and Therapeutic Implications
Authors: Miranda-Duarte Antonio 
Published: March 2018

Background:Primary Osteoarthritis (OA) is a multifactorial disease in which genetic factors are strongly associated with its development; however, recently it has been observed that epigenetic modifications are also involved in the pathogenesis of OA. DNA methylation is related to gene silencing, and several studies have investigated its role in thelociof different pathways or molecules associated to OA.Objective:This review is focused on the current status of DNA methylation studies related to OA pathogenesis.Method:A review of the literature was conducted on searching in PUBMED for original papers on DNA methylation in OA.Conclusion:The DNA methylation research oflocirelated to OA pathogenesis has shown a correlation between methylation and gene repression; however, there are some exceptions to this rule. Recently, the development of genome-wide methylation and genome-wide hydroxymethylation profiles has demonstrated that several genes previously associated with OA can have changes in their methylation status, favoring the development of the disease, and these have even shown the role of other epigenetic markers.
Cytogenetic characterization of a triploid mulberry (Morus spp.) cultivar Suvarna-2
Authors: Shafiei Daryoush , Prof. Basavaiah 
Published: March 2018

Mulberry exehibits a high degree of polyploidy ranging from haploidy to docosaploidy and its various species are being cultivated for foliage to practice sericulture and edible fruits. Triploid mulberries for sericulture porpuse and higher polyploids are proved to be superior. The cultivar Suvarna-2 is an improved high leaf yielding triploid in south India. The meiotic behavior of this cultivar has been presented here. Meiosis was highly irregular. Various anomalies such as univalent, bivalents, trivalent, hexavalent, loose association, unequal separation and precocious movement of chromosomes and laggards have been observed in pollen mother cells. These irregularities prevented the formation of viable gamete that leads to pollen sterility.
Comparative morphological screening of some species of Cenchrus L. (Poaceae) from Thar Desert of Rajasthan, India.
Authors: Kumar Ganesh , Sunita Arora 
Published: March 2018

In present study an attempt has been made to describe widely confused species of Cenchrus (Poaceae). The exact identification has been critically assessed. The name Cenchrus comes from the Greek word “Kenchrous” meaning millet. Cenchrus is an extremely variable genus having both annual and perennial species. Morphologically Cenchrus is very similar to Pennisetum. All species of Cenchrus are very much similar in their morphology except few micromorphological distinctions. It is a xerophytic C4 grass, which grows in bunches and more often with creeping rhizomes. These grasses can exist under minimal level of precipitation ranging from as low as 95 mm to 1000 mm. Cenchrus is very efficient in water usages as its root draws soil moisture rapidly as compared to other plants. Various traits are known to wild species of genus Cenchrus but due to lack of enough studies their full potential has not been exercised. An attempt has been need to study morphology of three species common in our region so that these details can further be utilized to exploit these species for their full potential.
Effect of Chemical Mutagens on Chromosomal behavior of Allium cepa L
Authors: Sharma Jyotirmoy , Rajkumari Jinu Devi , W. Ingtipi , Boro Rakesh , Das Shivani 
Published: March 2018

Effect of chemical mutagens was studied in mitotic cells of Allium cepa L. For this purpose root tips were treated with saturated solution of peradichloro benzene, 0.2% EMS and 0.2 % freshly prepared colchicines for 4hours to 9hours.The studies revealed a wide range of chromosomal abnormalities such as stickiness, laggards, chromosomal bridge, unequal separation, nuclear budding, multinuclear cells etc.The parentage of chromosomal abnormalities in different mitotic stages were calculated on mitotic index, frequency of phases and percentage of abnormalities in mitosis. The chromosomal abnormalities increase with increase duration of treatment. The results showed that in colchicines and EMS more than 50% abnormalities ware observed after 8 hrs of treatment, while in PDB it takes 6 hours treatment. Minimum MI was recorded as 65% in controlled cells. In colchicines and EMS treated cells 0.9.5%, 20% MI ware observed after 8hrs of treatment. Whereas in PDB maximum 23% MI was recorded in cells treated for 6hrs.
HPLC identification of bioactive flavonoids in methanolic and aqueous leaf extracts of Homalium zeylanicum Benth.
Authors: V. Anuradha Devi , I. Veera Kishore , R. Ragha Latha , Mallikarjuna Kokkanti 
Published: March 2018

Natural products continue to provide unique structural diversity in comparison to standard combinatorial chemistry, which presents opportunities for discovering mainly novel low molecular weight lead compounds. Homalium zeylanicum belonging to family Flacourtiaceae is an important medicinal plant having traditional uses in diabetes, rheumatism and wound healing activities. Chromatographic methods like TLC and HPLC were used for the separation and identification of flavonoids present in methanolic and aqueous leaf extract was studied. The chromatographic methods available for the separation of flavonoids in TLC and HPLC were adopted for the study. Three compounds were identified in TLC study in methanolic leaf extracts. In HPLC analysis, peaks corresponding to flavonoids were obtained and were identified by comparing with literature and confirm that methanolic extract contains Rutin, Quercetin and Myricetin where as in aqueous extract Quercetin, Myricetin and Kaempferol were observed. The anti diabetic activity of isolated compounds was determined by literature and confirms that compounds were found to having potent anti diabetic activity. This proves that the anti-diabetic activity of Homalium zeylanicum was due to the presence of these bio-active compounds