bluuebunny/crossref_metadata_2025 huggingface dataset:
EL USO DE LOS SISTEMAS DE RESPUESTA INTERACTIVA COMO HERRAMIENTA PARA FAVORECER EL APRENDIZAJE PROACTIVO EN INGENIERÍA
Authors: Perea Moreno Alberto Jesús , Aguilera Ureña María Jesús , Laguna Luna Ana María , De la Cruz Fernández José Luis , Torres Roldán Manuel , Torres Castro Jesús , Sol Prieto María Carmen , Guzmán Díaz Gema , De la Cruz Lovera Carmen , Martínez Valle José Miguel , Manzano Agugliaro Francisco , Salmerón Manzano Esther María , Gil Montoya Francisco , Alcayde García Alfredo
Published: June 2018

El desarrollo de las tecnologías de la información y la comunicación (TIC) ha permitido el surgimiento de herramientas didácticas en el campo de la educación, proporcionando herramientas prácticas para apoyar a las clases presenciales. En este contexto, los sistemas electrónicos de respuesta estudiantil pueden ser útiles para introducir un elemento tecnológico motivador en las lecciones, así como una nueva metodología. En este estudio, además del uso de los sistemas de respuesta interactiva o clickers, se ha introducido la tecnología de aprendizaje móvil mediante la elaboración de una metodología de uso de las herramientas Kahoot y Telegram en la asignatura "Fundamentos Físicos en la Ingeniería II" del Grado en Ingeniería Electrónica Industrial. El Departamento de Física Aplicada de la Universidad de Córdoba tiene una amplia experiencia en el uso de Clickers en clases teóricas con grupos grandes para diferentes grados universitarios, pero ahora el uso de tecnologías móviles de aprendizaje se ha introducido en grupos de tamaño medio para clases prácticas. Usando esta nueva metodología, los estudiantes de grupos medianos realizan un cuestionario durante la lección de resolución de problemas, donde utilizaron sus conocimientos adquiridos durante la clase. La realización del cuestionario permite a los profesores evaluar en tiempo real el nivel del estudiante y utilizar la retroalimentación para abordar los problemas iniciales y los malentendidos. Los resultados muestran que los sistemas de respuesta interactiva son altamente valorados por los estudiantes, que lo perciben como una herramienta para mejorar el aprendizaje y aumentar la competencia en el aula.
Directional Control and Rathole Elimination While Underreaming Depleted Formations With a Rotary-Steerable System
Authors: Greenwood Jeremy A.
Published: June 2018

An oil and gas operator in the Gulf of Mexico (GOM) planned to drill a deepwater well section in one run by concurrently drilling and enlarging a 12¼- to 14½-in. hole while deviating from 60 to 30° inclination and crossing expected depleted formations. At section total depth (TD), the rathole below the underreamer needed to be eliminated to help ensure successful cementing of the liner. A bottomhole assembly (BHA) was designed to allow achieving these objectives in one run, and the field results obtained with the system are described.

The first step in determining the best BHA design was to compile drilling experiences through the target formations and perform a review of all pertinent offset-well information. Weaker zones had been encountered in the 12¼ × 14½-in. section, and an at-bit reamer (ABR) had to be included in the BHA to allow the liner to be set on the bottom of the section, rather than leaving an 85- to 135-ft rathole. Because the ABR placement in the BHA is between the bit and the rotary-steerable-system (RSS) tool, it was important to ensure that directional control could be maintained in the section and make certain no interference existed between the ABR and the wellbore that could compromise control. Stabilization and placement of the underreamer were also crucial to ensure that the necessary directional performance was obtained without overstressing the BHA components, and modeling was performed to optimize the design. Hydraulics and torque-and-drag modeling ensured that the BHA design could drill the depleted zone without premature activation of either reamer.

The modeling and analysis of offset performance resulted in successfully drilling the section and opening the rathole in one run. The BHA was steered to the final desired angle, and reached the section TD without incident and at the desired rate of penetration (ROP). After the section TD was reached, the ABR successfully opened the 12¼-in. rathole to the desired 14 in., allowing the liner to be set 3 ft from the bottom. Normally, this type of operation would require a separate dedicated hole-opening run. Using the new design eliminated the additional trip and the time necessary to open the hole, which was estimated at 56 hours.

A BHA solution was developed through modeling that allowed the operator to not only maintain the steerability needed to achieve directional requirements with an ABR between the bit and the RSS while drilling depleted formations but also to concurrently perform underreaming.
Development of an UV-Vis Spectrophotometric Method for Accurate Determination of Aqueous Sulphides in Exotic Scale Studies
Authors: Alduailej Y. , Boak L. S. , Alharbi B. , Graham A. J. , Sorbie K. S. , Oduro H. , Alkhaldi M. , Alqathami S.
Published: June 2018

An analytical technique was developed to directly determine the concentration of aqueous sulphide in exotic scale studies. The technique is based on measuring the absorbance of sulphide samples in a copper reagent using an ultra-violet visible (UV-Vis) spectrophotometer. Calibration curves, generated using stock sodium sulphide solutions, were compared and validated against earlier reports in the literature.

The instantaneous reaction of a stirred (1000 rpm) sulphide solution and a copper reagent produces copper sulphide nano-particles, which turn the solution colour from light blue to brown. Increasing concentrations of sulphides give more intense shades of brown, resulting in increased absorbance values when analyzed by UV-VIS at a wavelength of λ = 480 nm. The absorbance readings are proportional to the sulphide concentrations in the samples, thus generating a calibration curve.

The repeatability of these absorbance measurements has an average standard deviation of 1.9% and a correlation coefficient (R2) of 0.9998 over a range of 7-386 mg/L sulphide species in synthetic brines. The determination of sulphide concentrations from absorbance readings using a 2nd order polynomial equation reveals average variations of ±1.2 and ±9.67 mg/L over the ranges of 7-70 and 105-386 mg/L, respectively. Furthermore, this technique was able to determine excess sulphide concentrations in solutions containing sulphide scale particles, as long as only clear filtered samples were analyzed. An alternative copper chloride reagent was used to prevent the formation of sulphate scale when barium or strontium ions were present in the brine being examined.

Comparing the results from the new detection method against the currently used technique reveals higher accuracy and practicality for the straightforward UV-VIS technique over the ICP analysis of quenched solutions. The new detection method allowed for the determination of any oxidative effects on the sulphide solutions, which is not identifiable using ICP.
Study of Carbonatic Scale in Completion Tools Through Modeling and Simulation Techniques
Authors: Maciel R. S. , Maciel F. S. , Pereira F. A. , Ribeiro D. C. , Aldeia W. , Martins A. L. , Bloch M. , Ferreira M. V.
Published: June 2018

Scale prediction in downhole scenarios is somewhat complex due to the large range of variables that drive inorganic precipitation. While the reservoir fluid flow ascendant into the wellbore it passes through many different completion equipments such as downhole valves. In the scope of oilwell completion design, a typical wellbore configuration takes into account two or three intervals, so a selective completion is required. In this way, Sliding Sleeve Valves (SSV) are normally employed together with packers to allow the production selectivity. Despite the positive aspects of this arrangement, the turbulence, the change in the flow trajectory into the valves and the considerable pressure drop can generate a friendly environment for the occurrence of calcium carbonate (CaCO3) scale. The pressure drop in this tool induces the flash liberation of CO2 from the aqueous solution and consequently, the chemical equilibrium, which controls the precipitation of CaCO3, is displaced towards the direction of precipitation of this solid in the flowing stream. Through the computational fluid dynamics technique (CFD), this work aims to study the effect of geometric variables of a generic downhole valve and the effect of the influx flow rate and fluid properties on the minimization of the overall pressure differential in the valve. Through the discrete phase modeling (DPM), the effect of the flow intensity on the transport of the solids to the internal adhesion surfaces is verified, and which of these surfaces are more favorable to the scaling phenomenon. By comparative analysis, it is shown that the volumetric influx rate is the most significant factor in the pressure drop (response variable). For the geometric factors, the effect of the number of connections between the annular outer region and internal tube presented a greater relevance compared to the chamfer angulation effect considered at the inlet of these connections.
Unconventional Horizontal Scale Squeezes: Lessons Learned Drive Continued Development and Improved Cost Savings
Authors: Eagle L. M. , Spicka K. J. , Fidoe J. , Jordan M. M.
Published: June 2018

It has been proven that scale squeezes can be conducted effectively in the unconventional, horizontal fractured wells in the shale reservoir of the Bakken when using an optimal scale squeeze chemistry. Previous work has discussed inhibitor selection and performance testing along with early case histories and modeling work. This paper discusses new case histories and Place-iT modeling results based on several procedural variations including a range of overflush volumes in the squeeze treatment procedure and the inclusion of acid cleanouts.

Novel, reduced-volume squeeze designs have successfully protected wells from scale deposition while limiting the direct and indirect costs associated with extra placement water. For unconventional shale wells in the Bakken, where produced water is typically very high in TDS and TSS, fresh water is most commonly used to execute squeezes. Reducing the total water volume reduces the costs of purchasing, transporting and storing fresh water. The amount of time and cost to pump the job is decreased. Less time and money is spent lifting the placement water, and consequently, there is less deferred production. In addition, in unconventional production acid treatments are commonly carried out in isolation to maintain production. In this work, applying acidizing stages at the front of the squeeze procedures, provides a novel "squimulation" process to fractured reservoir scale control treatments.

For these unconventional horizontal wells, the use of larger water volumes—either several times full wellbore volume and/or several times daily water production—has not been shown to improve the longevity or cost-effectiveness of squeeze jobs. Contrary to conventional well applications modeled with Darcy flow, it appears diffusion is the more applicable mechanism for scale inhibitor transport in fractured shale wells. This mechanism is consistent with a reduced dependence on water volume deployed in the treatments.

The lessons learned from the unconventional horizontal scale squeezes conducted in the Bakken have resulted in enhanced production and cost savings. There are significant implications for the industry as other key unconventional regions in the U.S. and around the world are looking into scale squeezes as an option for scale control.
Recent Advances in Scale Prediction, Approach, and Limitations
Authors: Kan Amy T. , Dai Joey Zhaoyi , Deng Guannan , Ruan Gedeng , Li Wei , Harouaka Khadouja , Lu Yi-Tsung , Wang Xin , Zhao Yue , Tomson Mason B.
Published: June 2018

Numerous saturation indices and computer algorithms have been developed to determine if, when, and where scale will form, but scale prediction can still be challenging since the predictions from different models often differ significantly at extreme conditions. Furthermore, there is a great need to accurately interpret the partitioning of H2O, CO2, and H2S in different phases, and the speciations of CO2 and H2S. This presentation is to summarize current developments in the Equation of State and the Pitzer models to accurately model the partitioning of H2O, CO2, and H2S in hydrocarbon/aqueous phases and the aqueous ion activities at ultra high temperature, pressure and mixed electrolytes conditions. The equations derived from the Pitzer ion-interaction theory have been parametrized by regression of over 10,000 experimental data from publications in the last 170+ years using a genetic algorithm on the super computer, DAVinCI. With this new model, the 95% confidence intervals of the estimation errors for solution density are within 4*10'4 g/cm3. The relative errors of CO2 solubility prediction are within 0.75%. The estimation errors of the saturation index mean values for calcite, barite, gypsum, anhydrite, and celestite are within ± 0.1, and that for halite is within ± 0.01, most of which are within experimental uncertainties. This model accurately defines the pH of the production tubing at various temperature and pressure regimes and the risk of H2S exposure and corrosion. The developed model is able to predict the density of soluble chloride and sulfate salt solutions within ±0.1% relative error. The ability to accurately predict the density of a given solution at temperature and pressure allows one to deduce when freshwater breakthrough will occur. Lastly, accurate predictions can only be reliable with accurate data input. The need to improve accuracy of scale prediction with quality data will also be discussed.
Scale Deposition and Hydrodynamics - Benchtop to Pilot Rig
Authors: Goodwin Neil , May Mark , Nichols David , Graham Gordon
Published: June 2018

Scale deposition in oilfield production systems is influenced by thermodynamic supersaturation and kinetics, but also by hydrodynamic effects such as surface shear stress and turbulence. Results from experimental work investigating the impact of these hydrodynamic factors on scale location and correlating them to field flow regimes are presented.

Laboratory tests have been conducted using both a benchtop jet impingement method and large-scale, high flow rate "pilot rig" apparatus. Both of these systems result in high shear stress conditions and can simulate hydrodynamic regimes representative of those expected in devices such as inflow control valves, inflow control devices, and sand control screens. The pilot rig is able to reproduce field-representative flow rates and fluid flow dynamics through full-size test pieces containing nozzles and restrictions.

The results of this work demonstrate that the hydrodynamic regime has a significant influence on scale deposition. Increased levels of surface shear stress and turbulence result in a greater potential for scale formation than low shear, laminar flow conditions. This is particularly apparent in systems which are mildly supersaturated. The location of scale deposits was found to correlate with local shear stress and the pilot rig tests confirmed field observations that zones experiencing the highest level of shear are not necessarily those with the greatest deposit; the induced scale may deposit downstream in areas of lower surface shear. Additionally, the presence of these high shear locations upstream of the lower shear regime may lead to scaling in the lower shear region which would otherwise not be experienced. Supportive Computational Fluid Dynamic modelling of fluid flow within the pilot rig system correlated with the experimental findings is also described.

This work allows a greater understanding of the hydrodynamic factors, in particular surface shear stress, influence oilfield scale deposition and has demonstrated the utility of both benchtop and pilot-scale methods for testing under appropriate conditions.
Stress Corrosion Cracking in Twin Ferrule Compression Fittings in SS31600
Authors: Barker P. A.
Published: June 2018

Twin Ferrule Compression fittings are used worldwide in many industries for pressure containment including Oil and Gas. Stainless steel grade UNS S 31600 / 1.4401 is a common choice of material for such items as it offers corrosion resistance in its uncoated state and a high degree of internal cleanliness. As an austenitic stainless steel however the items are prone to chloride induced stress corrosion cracking (CSCC) in certain environments such as offshore marine and coastal areas where such failures were previously reported in SPE paper 157356-PP 2012.

It has since been suggested that a contributory factor to these failures may be over tightening of the fittings during installation inducing excessive tensile stresses above design intent and shortening the time to failure.

This paper will attempt to quantify these stresses and show how the act of over tightening the fitting (beyond the manufactures recommendation) may affect the susceptibility to CSCC and the time to failure. It will also detail the development of CSCC in the fittings over time and show how the degradation mechanism progresses to leak type failures.

These items are numerous on oil and gas production platforms with several thousand typically employed per installation so the importance of knowledge in this area may be significant to some users. If the morphology or stages of cracking can be identified then targeted inspection of fittings may be carried out to plan change outs in a timely manner rather than allowing the cracks to develop to cause larger leaks or unplanned shutdowns. If the precise morphology of the cracking is identified a better understanding of the consequences can be made.

Verifying tensile stress levels may also be used in the selection of alternative materials for the fittings. Fitting manufacturers offer a range of alternative materials which may be more resistant to stress corrosion cracking such as Duplex, SMo or Nickel alloys.

The test took a sample of new ½″ tubing connector twin ferrule fittings of S31600 material and fixed them to tubing using various degrees of tightening. The fittings were then subjected to the standard accelerated corrosion test of ASTM G123 00.
Sulfide Stress Cracking Resistance of 95 and 110 ksi OCTG Sour Service Grades Under High Partial Pressure of H2S - A Contribution to Corrosion Mechanism Understanding
Authors: Sales Daniella Guedes , Néel Guillaume , Oliveira Jonathas , Thébault Florian
Published: June 2018

The limit of Sour Service (SS) grades regarding Sulfide Stress Cracking (SSC) resistance is defined by ANSI NACE MR0175 / ISO 15156 standard. For instance, API T95 grade is acceptable to be used in all regions of environmental severity and for all temperatures. As per Annex B of the same standard, SSC laboratory testing in accordance with NACE TM0177 Methods A and D in Solution A saturated by 1 bar H2S partial pressure (PH2S) qualify a material for all SSC regions, up to 10 bar PH2S. To evaluate this statement and verify if the existing NACE guidelines apply also for SS 110 ksi Specified Minimum Yield Strength (SMYS), a procedure to assess the SSC resistance in high H2S pressure was developed. This procedure was applied to enhanced SS 95 ksi and 110 ksi SMYS materials. The methodology consists in regular purging and filling of the gas phase in order to keep constant the PH2S and to remove hydrogen gas produced by generalized corrosion. Investigations combined NACE TM0177 Method A and D tests, characterizations of the iron sulfide scales and hydrogen electrochemical permeations. This methodology enables to give some insights on the corrosion mechanism and the influence of high partial pressure of H2S on the SSC resistance.
Performance Variation of Quaternary Amine Corrosion Inhibitors as a Function of Hydrocarbon Chain Length with Respect to Temperature
Authors: Ali A. Al-Taq , Shaikh A. Ali , Abdullah A. Alrustum
Published: June 2018

Hydrocarbon chain, hydrophobic in nature, plays an important role in the efficiency of corrosion inhibitors. Increasing hydrocarbon chain length in a corrosion inhibitor tends to increase its inhibition efficiency (IE) but decrease its solubility in aqueous solutions. In this study, quaternary amine corrosion inhibitors with variable hydrocarbon chain lengths ranging from 10 to 16 carbons were synthesized and evaluated as acid corrosion inhibitors for coiled tubing steel. The substituents containing double and triple bonds were incorporated into the corrosion inhibitors to enhance their performance in HCl acid solutions. In addition to the quaternary nitrogen, three additional adsorption sites including propargyl and two allyl groups are present in this corrosion inhibitor.

Behavior of these compounds in concentrated HCl acids was examined using gravimetric and electrochemical methods (polarization and Electrochemical Impedance Spectroscopy (EIS)). Weight loss tests were conducted in 28 wt% HCl acid solutions at different temperatures and a soaking time of two hours was applied. The temperatures examined ranged from 30 to 90 °C. The results showed that IE increased in the order of C10 < C12 < C16 at 30 °C and while a reverse order was observed at higher examined temperatures (90 °C). At a temperature of 30 °C, an inhibitor concentration of 50 ppm gave the corrosion IE of 80.4, 78.3 and 67.2% for C16, C12 and C10, respectively, while at 90 °C, the corresponding inhibition efficiencies were 25.7, 21.1 and 15.4%. Polarization measurements showed that the inhibition mechanisms for C12 and C16 was via suppressing/retarding anodic reaction while a mixed- type mechanism was obtained for C10. The IE obtained by the polarization technique at 30 °C showed the same order obtained by weight loss method (C16>C12>C10) while at a temperature of 70 °C, the order was C16>C10>C12.

This paper will present in detail, 1) the synthesis and characterization of the corrosion inhibitors, 2) the variation in their performance, and 3) subsequently, the potential mechanisms for obtained variations as a function of temperature are discussed.
Corrosion of Steel Armour Wires in Flexible Pipes - History Effects
Authors: Dugstad Arne , Palencsár Simona , Berntsen Tonje , Børvik Linda
Published: June 2018

Flexible pipes used in oil and gas production are composed of densely packed steel wires enclosed in an annulus confined by inner and outer thermoplastic sheaths (pressure barriers). Hydrocarbons, water, CO2 and H2S from the bore diffuse through the inner sheath and form a corrosive environment in the confined space between the sheaths. A large steel surface to water volume ratio leads to rapid accumulation of dissolved corrosion products and precipitation of protective iron carbonate (FeCO3) films. Low corrosion rates (<0.01 mm/y) are usually experienced in the field and have been reported in a number of experiments where fresh abraded steel surfaces are exposed in environments with high concentration of dissolved corrosion products.

This paper presents results from experiments where the protective properties of iron carbonate films were studied when the armour steel was exposed to oxygenated water for some time, i.e. simulation of accidental ingress of aerated seawater into the annulus. The protective iron carbonate film broke down during the O2 exposure and was converted to a porous film of iron oxides and iron carbide. The porous film gave poor protection and the corrosion rate increased from less than 0.01 mm/y to more than 1 mm/y during the O2 exposure. The presence of the porous film disturbed the reformation of protective iron carbonate films when outer sheath repair was simulated by removing the O2 source. It was shown that reformation of protective films was strongly dependent on the duration of the O2 exposure and on the corrosion history of the steel surface prior to the O2 exposure. The experiments were performed at atmospheric pressure, at 25 and 60 °C and with a CO2 partial pressure of 0.2 bar. The paper discusses the experimental results, the experimental approach and the challenges of simulating the annulus conditions in small scale lab experiments.
Polar Diels-Alder Reactions Under Microwave Irradiation Employing Different Heterocyclic Compounds as Electrophiles
Authors: Mancini Pedro M.E. , Ormachea Carla M. , Kneeteman María N.
Published: June 2018

During the last twenty years, our research group has been working with aromatic nitrosubstituted compounds acting as electrophiles in Polar Diels-Alder (P-DA) reactions with different dienes of diverse nucleophilicity. In this type of reaction, after the cycloaddition reaction, the nitrated compounds obtained as the [4+2] cycloadducts suffer cis-extrusion with the loss of nitrous acid and a subsequent aromatization. In this form, the reaction results are irreversible. On the other hand, the microwave-assisted controlled heating become a powerful tool in organic synthesis as it makes the reaction mixture undergo heating by a combination of thermal effects, dipolar polarization and ionic conduction. As the Diels-Alder (D-A) reaction is one of the most important process in organic synthesis, the microwave (MW) irradiation was applied instead of conventional heating, and this resulted in better yields and shorter reaction times. Several substituted heterocyclic compounds were used as electrophiles and different dienes as nucleophiles. Two experimental situations are involved: one in the presence of Protic Ionic Liquids (PILs) as solvent and the other under solvent-free conditions. The analysis is based on experimental data and theoretical calculations.
Recent Progress in the Synthesis of Furan
Authors: Duc Dau Xuan
Published: June 2018

Furans are five-membered aromatic heterocycles containing one oxygen atom that are important
building blocks in organic chemistry, but also as natural products found in various natural
sources, mostly in plants, algae and microorganisms. In this review, we discussed recent advances in the
synthesis of furan compounds. Some classical methods have been modified and improved, while other
new methods have been developed. A vast variety of catalysts was used for these transformations. In
many studies, furan synthesis reaction mechanisms were also investigated and proposed.
Organizational Factors and Burnout of Perioperative Nurses
Authors: Sillero Amalia , Zabalegui Adelaida
Published: June 2018

Background:

Knowing the organizational factors that predict burnout in perioperative nurses is paramount for improving the care of patients and promoting nurses’ psychosocial well-being and health.

Objective:

To determine the influence of organizational factors of the perioperative nurse's work environment on the three burnout dimensions: emotional exhaustion, despersonalization, and personal accomplishment.

Method:

A cross-sectional study was conducted among 136 nurses in a perioperative care unit at a university hospital in Barcelona, Spain. Data were collected using a demographic data form, and the Spanish versions of the Practice Environment Scale of the Nursing Work Index and Maslach Burnout Inventory.

Results:

Findings showed emotional exhaustion in 43% (56) of nurses, depersonalization in 21% (28), and reduced personal accomplisment in 53% (69). The degree of general burnout was moderate.

The work environment was considered unfavourable as only one factor of five was favourable (Nursing foundations of quality care). Multiple regression analyses showed three organizational factors were associated with all three dimensions of burnout: “Nurse manager ability, leadership, and support of nurses”; “Staffing and resources adequacy”; and “Nursing foundations of quality care”.

Conclusions:

In this study three organizational factors played a significant role in predicting burnout among perioperative nurses. We recommend hospital management implement policies to improve these organizational factors. Promoting positive leadership styles, providing necessary resources, and creating a positive climate in the work environment could increase psychosocial wellbeing and decrease burnout among perioperative nurses.
A Randomized Controlled Trial Comparing Er:YAG Laser and Rotary Bur in the Excavation of Caries - Patients' Experiences and the Quality of Composite Restoration
Authors: Sarmadi Roxana , Andersson Elin Viktoria , Lingström Peter , Gabre Pia
Published: June 2018

Objective:

The aim of this study was to evaluate patients´ experiences of two excavation methods, Er:YAG laser and rotary bur and time required by the methods as well as objective assessments of quality and durability of restorations over a two-year period.

Methods:

A prospective, single-blind, randomized and controlled investigation was performed. Patients aged 15 to 40 years with at least two primary caries lesions, which had been radiographically assessed as of the same size, were recruited. In each patient, one cavity was excavated using rotary bur and one using Er:YAG laser technique. The time required for excavations and, where applicable, local anaesthesia, was measured during the treatments. Patient experiences were measured using questionnaires. The quality and durability of restorations were assessed over a two-year period in accordance with modified Ryges criteria and radiographs. Twenty-five patients (mean age 22.6 years) participated in the study. In total, 56 cavities were included of which 28 were treated with Er:YAG laser and 28 were treated with a rotary bur.

Results:

The patients associated the laser method with less discomfort. The mean time for excavation by laser was three times longer than by rotary bur (13.2 min vs. 4.3 min, P<0.0001). Over a two-year period, no statistically significant differences with regard to quality or durability could be seen between the restorations associated with the methods.

Conclusion:

The Er:YAG laser technique was more time-consuming than the rotary bur. Despite this, the laser technique caused less discomfort and was preferred as an excavation method by patients.
Phytochemical Analysis, Antibacterial and Antioxidant Activity of Calotropis procera and Calotropis gigantea
Authors: Rani Reena , Sharma Dushyant , Chaturvedi Monika , Yadav Jaya Parkash
Published: June 2018

Background:

Medicinal plants are having immense potential to cure various health ailments
and used as drugs and remedies for the treatment of various diseases since civilization. Medicinal
property of these plants lies in their secondary metabolites which covered various classes like
phenols, alkaloids, flavonoids, tannins, etc. Besides this, these secondary metabolites serve as a prototype
to synthesize the new synthetic drugs.

Objective: The present study was carried out to evaluate the antioxidant and antibacterial activity of
leaves extracts of Calotropis procera and Calotropis gigantea and characterization of their bioactive
metabolites by Fourier Transform Infrared (FTIR) spectroscopy and Gas Chromatography-Mass
Spectroscopy (GC-MS).

Methods:

Methanol, petroleum ether and water were used for the extract preparation using cold percolation
method. Antibacterial activity was assessed by agar well diffusion assay. The antioxidant
activity of both the plants of Calotropis species was carried out by using different assay. Phytochemical
analysis was carried out by using FTIR spectroscopy and GC-MS analysis.

Results:

Methanol extract of both the plants was found to possess highest antioxidant potential in
comparison to other extracts. Methanol extract of C. gigantea and aqueous extract of C. procera
showed the maximum antibacterial activity against the tested bacterial strains. FTIR analysis of
plants extracts indicates the presence of phenolic compounds, alkanes, carboxylic acids, aldehydes,
aliphatic and aromatic amines, allene, sulfoxides, phenyl ester nitrocompounds and imines. GC-MS
analysis of C. procera aqueous extract showed the presence of R-limonene, mannosamine, tridecane,
1-bromo-, 2-propenoic acid, tridecyl ester, pentatriacontane and 1-hexacosene as major phytochemicals.
C. gigantea methanol extract indicated the presence of hentriacontane, eicosane, 3,3-
dimethylnonadecane, pentacosane, 1-hexacosene, pentatriacontane and clocortolone as major phytochemicals.

Conclusion:

This study provides a systematic base for isolation of the novel bioactive phytochemicals
from the Calotropis plant species and to evaluate their efficacy especially for antioxidant and
antibacterial activities.
Image Fusion Method Based on Multi-scale Directional Fast Guided Filter and Convolutional Sparse Representation
Authors: Xian-Hong Liu , Zhi-Bin Chen
Published: June 2018

Background:

A multi-scale multidirectional image fusion method is proposed, which
introduces the Nonsubsampled Directional Filter Bank (NSDFB) into the multi-scale edge-preserving
decomposition based on the fast guided filter.

Methods:

The proposed method has the advantages of preserving edges and extracting directional
information simultaneously. In order to get better-fused sub-bands coefficients, a Convolutional Sparse
Representation (CSR) based approximation sub-bands fusion rule is introduced and a Pulse Coupled
Neural Network (PCNN) based detail sub-bands fusion strategy with New Sum of Modified Laplacian
(NSML) to be the external input is also presented simultaneously.

Results:

Experimental results have demonstrated the superiority of the proposed method over
conventional methods in terms of visual effects and objective evaluations.

Conclusion:

In this paper, combining fast guided filter and nonsubsampled directional filter bank, a
multi-scale directional edge-preserving filter image fusion method is proposed. The proposed method
has the features of edge-preserving and extracting directional information.
A Comprehensive Review of Power Quality Issues and Measurement for Grid-Integrated Wind Turbines
Authors: Zobaa Ahmed F. , Ahmed Ibrahim , Abdel Aleem Shady H.E.
Published: June 2018

Background:

Renewable energy generation using wind energy has emerged worldwide and has
opened up significant new markets in electrical power generation. However, different factors that affect
power quality performance of Wind Turbine (WT) applications such as wind speed fluctuation and use of
power electronic based devices have been presented due to the rapid increase of WT installations.

Methods:

Accordingly, it is worth to measure, assess and evaluate the quality of the generated power of
these WTs in order to ensure their compliance with the grid-integration conditions. In this work, first, a
general classification of WTs and their operating principle is reviewed. Because variable speed WTs are
frequently used in today’s power systems, much attention was paid to this type of turbines. Second, the
various power quality aspects caused due to the integration of the wind energy systems into the grid
were presented and discussed. Flickers, harmonic distortion, response to voltage dip, active power, and
reactive power requirements, fault-ride through and short-circuit current contribution were the addressed
power quality problems.

Results:

Further, the study pointed out the need for a unified evaluation process to assess the power
quality performance of the grid-connected wind systems.

Conclusion:

Also, it was concluded that success in integrating more wind energy systems hinges on accurate
power quality performance assessment.
Nötrofil Lenfosit Oranı ile Vitamin D Düzeyleri Arasındaki İlişki
Authors: YILDIRIM BAŞ Funda , ARSLAN Bahriye
Published: June 2018

Giriş: Nötrofil lenfosit oranı; sistemik inflamasyon belirteci olarak kullanılmaktadır. Vitamin D düzeyinin, enfeksiyonhastalıkları ile ilişkili olduğu gösterilmektedir. Bu çalışmada, Vitamin D düzeyi ile nötrofil lenfosit oranı arasındaki ilişkideğerlendirildi. Gereç ve Yöntem: Çalışmaya 1 Eylül-31 Mayıs 2015 tarihleri arasında Süleyman Demirel Üniversitesi TıpFakültesi Hastanesi Aile Hekimliği polikliniğine başvuran, sağlıklı, kronik hastalığı, ilaç kullanımı, inflamasyon bulgusu veinflamatuvar hastalık anamnezi olmayan, normal vücut kitle indeksine sahip, gebe olmayan 300 kişi dâhil edildi. KişilerinVitamin D düzeyleri ve hemogram bulguları geriye dönük olarak incelendi. Bulgular: Hastaların yaş ortalaması 29,6 ± 11 yılidi. Kadınların sayısı 232 (%77,3) ,erkeklerin sayısı 68 (%22,7) idi. Vitamin D düzeyi 73 (%24,3) kişide normal, 227(%75,7) kişide düşük bulundu. Vitamin D düzeyi ile nötrofil lenfosit oranı arasında negatif korelasyon, (p=0,01, r=-0,184),hemoglobin düzeyleri (p=0,01, r=0,187) arasında pozitif korelasyon gözlendi. Yaş ve hemoglobin düzeyleri arasında pozitifkorelasyon izlendi (p=0,04, r=0,114). Vitamin D düzeyi düşük ve normal olan iki grup arasında; yaş, hemoglobin, nötrofil,lenfosit, eozinofil, lökosit, platelet sayısı arasında anlamlı bir ilişki saptanmazken ( p=0,98, p=0,23, p=0,13, p=0,52,p=0,30,p=0,41,p=0,67), nötrofil lenfosit oranı arasında anlamlı ilişki tespit edildi (p=0,04). Sonuç: Bu çalışma; Vitamin Deksikliğinin inflamasyona yatkınlığı arttırdığını destekler niteliktedir. Sık enfeksiyon geçiren bireylerin Vitamin D düzeylerideğerlendirilmelidir. Enfeksiyon hastalıklarının destek tedavisi açısından normal Vitamin D düzeyinin gerekli olabileceğisonucuna varıldı
Commerce Ethics of Muhammad PBUH’ and Universal Values in Era of Prophet Hood
Authors: Suwandi Andi
Published: June 2018

Muhammad PBUH, primarily business along with his father since as early as his childhood. Whilst he grown up, he commenced to setup his own venture and also have a joint venture with Siti Khadijah based on mudharabah scheme. He is gifted with great wisdom in trading and has allowed him gaining great benefit through it. Due to his moral in trading, it leads to his marriage with Siti Khadijah. Unquestionably there were features on the ethics and morals in the trade that Muhammad PBUH has represented. A matter of concern was his morality that shown during trade leads to his marriage with Siti Khadijah who was initially his business colleague previously and what was the commercial strategy that empowers him to a vast profit during trading. Thus, this study endeavor to define and detail the ethics and morals in trading that has been shown by Muhammad PBUH prior his prophet hood. The results of this study display the conflicting fact in practices that has been applied amongst the community back at that time. His is abundant in honest, fairness, friendly and compassionate to the buyer, and never set up a high price, and also detail in transaction record consequential him loved by many people. Alongside the combination of his aptitude in negotiation and intelligence, he was proficient to “read” the market opportunities and learning cultural and geographical conditions of each target market led him to higher profits than other merchants. In addition, this study also articulated sixteen Muhammad PBUH’ universal values in commerce  such; honest, trustworthy, fair, polite and affectionate in trade, buy-sell applies only based on mutual consent, not involved in usurious practices', only legitimate and permitted item that will sell, avoid argument with partners and buyers, no oath in the name of idols, hoarding the goodies (ikhtisar) is not allowed, damaged item’ replacement policy, avoid competition on price, small profits is acceptable, pay his employee as soon as the job is done, always record transaction, and be generous. Those ethics and values actually resemble to such practice by Islamic merchants to highlight Islamic values in commerce nowadays.

 

Keyword: Trading Business Ethics, Muhammad PBUH, prior to prophet hood.

 
Implementasi Syariah Compliance pada Akad Murabahah dan Ijarah (Studi Kasus Pada KSPPS BMT Fastabiq Jepara)
Authors: Bonita Silvia Dora , Anwar Aan Zainul
Published: June 2018

This study aims to determine: 1) the principles of financing agreement murabaha and Ijarah in accordance with Islamic law, 2) the implementation of the financing agreement murabaha and Ijarah, and 3) the factors that caused the broken promise in murabaha and ijarah financing agreement in BMT Fastabiq Jepara well as a way to resolve. This research is a field research with a qualitative approach, the research has the characteristics that the data declared in a state appropriately or as their (natural setting), with no change in the shape of symbols or numbers and descriptive based on questions how. And data processing technique is to use a qualitative descriptive technique. The results of the analysis show that: 1) The principles of murabaha financing agreement on BMT Fastabiq Jepara accordance with Islamic sharia as the murabaha financing agreement executed included also wakalah. The principle of Ijarah financing agreement yet on BMT Fastabiq Jepara accordance with Islamic sharia because it is not included wakalah in it. 2) Execution of Murabahah and Ijarah financing agreement in Jepara Fastabiq BMT carried out according to established procedures BMT Fastabiq Jepara. And 3) the factors that led to broken promises in murabaha and Ijarah financing agreement in BMT Fastabiq Jepara is internal and external factors. The steps undertaken BMT Fastabiq Jepara in overcoming these factors include identifying the problem, if there is a problem that complicated it will be a step family, but if they can not be resolved then it will be taken legal action.
Implementasi Pendidikan Nilai Nasionalisme Dalam Pembelajaran Living Values
Authors: Apriani An-Nisa , Ariyani Yusinta Dwi
Published: June 2018

This research aims to investigate the implementation of educational values of nasionalism in the living values learning process on the preparation class at SD Tumbuh 1 Yogyakarta. The data were collected by qualitative-descriptive method. Participants of this research included the principal, the teachers, and the students. The object of this research is the process of living values learning. The data were collected by observation, interview, and documentation. The researcher used observation sheets and interview guides as the instruments of this research.  The data were analyzed by descriptive-analyzed technique and applied Miles and Huberman model. Many steps of data analysis were conducted, included measuring data reduction, displaying data, and conclusion. The validity of the data were checked by triangulation.

The result showed that the implementation of educational values of nasionalism in the living values learning process involving the value of the award in diversity (tolerance), unity, and peace. Living values learning process includes three stages: planning, implementation, and evaluation. Learning plan of living values is based on signs EYCG curriculum (Years Earlier Curicullum guidence) and modified with multiple sources of reference. The learning plan includes syllabus and program description. The implementation of living values learning process emphasizes three elements of embeding moral values such as knowledge, feeling, and moral behavior. The evaluation of the living values learning process includes the assessment of learning outcome and learning process. Assessment of learning outcome has reached the domain of comprehension and moral behavior. Learning process assessment is conducted orally but rarely carried out by the teacher.
Young People’s Attitudes and Motivations Toward Social Media and Mobile Apps for Weight Control: Mixed Methods Study (Preprint)
Authors: Nikolaou Charoula Konstantia , Tay Zoey , Leu Jodie , Rebello Salome Antonette , Te Morenga Lisa , Van Dam Rob M , Lean Michael Ernest John
Published: June 2018

BACKGROUND

Effective prevention at a young enough age is critical to halt the obesity epidemic. Mobile health (mHealth) apps would potentially reach large numbers at low-cost. While there is already a profusion of lifestyle apps, they are mostly non-evidence-based and evidently ineffective against rising obesity prevalence.

OBJECTIVE

The aim of this study was to explore preferences and usage of lifestyle apps among young people in 6 countries.

METHODS

A mixed methods study was conducted among young people aged 13 to 24 years residing in the United Kingdom, Belgium, Finland, Greece, Singapore, and New Zealand. Participants were recruited from Web advertisements on Facebook, asking for volunteers interested in mobile apps in general, not specific to lifestyle or health, to complete a short survey comprising 18 questions on demographics, weight gain, and mobile app preferences and then to join English-language online focus groups, which were held during 2017, in password-protected Web rooms, moderated by an experienced researcher. Descriptive statistics were carried out for the survey, and thematic analysis was applied to transcripts.

RESULTS

A total of 2285 young people (610 adolescents aged 13-17 years and 1675 young adults aged 18-24 years) responded and completed the survey, with 72.0% (1645) reported being concerned about weight gain for themselves or friends. Later, 807 young people (376 adolescents and 431 young adults) were selected based on age and country to participate in 12 online focus groups, with 719 young people completing. Analysis revealed 4 main themes: (1) feelings toward personal weight; (2) perception of lifestyle apps and desired content for weight gain prevention; (3) social media apps, lifestyle apps, and motivation for downloading and retaining; and (4) data safety and data usage and confidentiality. Young people are interested in evidence-based advice in programs incorporating their preferences.

CONCLUSIONS

Young people are commonly, and consistently across 6 countries, concerned about weight gain and obesity and would welcome evidence-based mHealth programs, provided the views of young people themselves are incorporated in the program content.
Pengaruh pendidikan dan pelatihan terhadap kinerja pustakawan Universitas Gadjah Mada
Authors: Sarwono Sarwono , Wiyarsih Wiyarsih , Isbandini Isbandini
Published: June 2018

Introduction. This study aims to examine the role of education and training in influencing librarians’ performance at the Main library of UniversitasGadjahMada(UGM). The purpose of this study is to determine the effect of education and training on the performance of librarians of UGM is important to consider the library of UGM to organize education and trainin every year.Data Collection Methods. This research used quantitative approach with survey. The subject of this study wais UGM librarian regarding their perspectives in the librarian traiing.Sample this research is 74 librarians.Data Analysis. The data was analysed by usingSPSSResults and Discussions. The results showed that library education did not affect the performance of librarians.  General knowledge training affected the performance of librarians. The performance of UGM librarians in the category is quite good. The data analysis shows that majority of UGM librarians have undergraduate education of 28 people (37.8%) and the second most have master's degree which is 21 people (28,4%). UGM librarians who have attended general knowledge training more than 5 times are 19 librarians (25.7%) and librarians who follow librarian training of more than 5 6 (8.1%). The performance score of UGM librarian is in interval of 56% -75% so it shows that the performance of UGM librarian in the category is quite good.Conclusion. Training of general knowledge field give positive influence to the performance of UGM librarian if given as much as 2-3 times in a year. Training in the field of librarianship gives a positive influence on the performance of UGM librarians. The more training the librarianship is given the better the performance