bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ligation, Transformation and Characterization of Rv 1926c Mycobacterium tuberculosis to Escherichia coli JM 109 For Latent Tuberculosis Immunodiagnostic
Authors: Agus Rosana 
Published: January 2019

Tuberculosis caused by Mycobacterium tuberculosis is the biggest infectious disease causing human death in the world. The main challenge in controlling tuberculosis is to quickly and accurately diagnose tuberculosis infection. Several kits have been produced to diagnose tuberculosis, but have different sensitivity and specificity. This shows that the kit is not yet ideal for diagnosing tuberculosis, so the search for candidates for specific antigens still needs to be done. One potential antigen is the Rv 1926c encoding MPT 63 protein. This protein is known to induce Th1 cells and produce IFN λ from PBMC cells of patients infected with tuberculosis. The purpose of this study was to clone the Rv 1926c from Mycobacterium tuberculosis as a tuberculosis immunodiagnostic kit. The method used is isolating Rv 1926c with PCR, ligation to pGEM-T vector and transformation to E.coli host cell JM 109. Clone characterization was carried out by PCR and migration analysis. The results obtained are the recombinant clones obtained have successfully inserted with the Rv 1926 c
Quality and Storability of Mango During Zero Energy Cool Chamber (ZECC)
Authors: Dirpan Andi , Sapsal Muhammad Tahir , Syarifuddin Adiansyah , Tahir Mulyati M , Ali Kamilia Nur Yaumil , Muhammad Abdul Kadir 
Published: January 2019

Many researchhavefound thatthe use of zero energy coolchamber (ZECC) extend the shelf life of stored fruits and vegetables. There is a lack of study conducted in Indonesia about the use of ZECC to keep mangos after harvesting though. The present study, therefore, was aimed to understand the quality and storability of stored mangos in ZECC. Three different storage containers, a ZECC, ambient, and refrigerator with different average RH and temperature, were used to place selected ripe mangos (Mangifera indica L) that were manually harvested from farmers’ field nearby. The ZECC was set up at the residential complex for lecturer of Hasanuddin University as the experiment site. Results showed that mangos inside ZECC were acceptable until eleven days of storage after considering both quality and sensory evaluation. The result suggests that ZECC can maintain mango’s quality and extend its shelf life, which reveals that ZECC seems promisingfor commercial application
PENGARUH ABILITY PEGAWAI MEMAHAMI ISU-ISU LINGKUNGAN DAN KEPEMIMPINAN TERHADAP PENGELOLAAN KONSERVASI HUTAN KOTA
Authors: Hidayat Rusdi , Nuryadin Suwirman , Jalaludin Muzani 
Published: January 2019

The purpose of this study is to reveal the strength of employee's ability factors to understand environmental issues and leadership on the effectiveness of urban forest management employees. This research was carried out in the PT JIEP Pulogadung industrial area in Jakarta for three months, starting from June to August 2017. The research method used was ex post-facto or comparative causal relationship with 2 x factorial design 2. Results of research on urban forest conservation management activities between employees with the ability to understand high environmental issues are higher than those with the ability to understand the low environmental issues. The average urban forest conservation management that has the ability to understand high environmental issues is 141.93 higher than employees who have the ability to understand low environmental issues, namely 125.93. Furthermore, there is an interaction effect between the application of the ability to understand environmental issues and Leadership on the management of forest conservation of the city. The effect of the interaction is 41%. Urban forest conservation management activities between employees who have the ability to understand high environmental issues are higher than employees who have the ability to understand low environmental issues in the group with Transformative Leadership as evidenced from the tuckey test results, that Qcount> Qtable is 5.91> 4 , 11
Keywords: Employee Ability, Environmental Issues, Leadership
HUBUNGAN ANTARA TANGGUNG JAWAB DAN KOMITMEN DENGAN KEPEMIMPINAN LINGKUNGAN DALAM PENERAPAN PEMBANGUNAN BERKELANJUTAN
Authors: Jayanto Sukiman , Zid Muhammad , Dewi Yusriani Sapta 
Published: January 2019

Abstract
This study aims to determine whether there is a relationship between responsibility and commitment with environmental leadership in sustainable development of correlational studies in West Sumbawa, NTB. The correlational method used by sampling 130 people in the employee in West Sumbawa Regency, NTB as a sample selected by multy stages random sampling. Environmental leadership in the implementation of sustainable development after the validity test then obtained 28 questions and 6 drop problems with reliability of 0.912. Test the validity of responsibilities (x1) of 27 valid issues that is 20 with reliability of 0.894. Test validity of commitment from 48 item valid matter that is valid 33 with reliability equal to 0,961 Data have been analyzed by applying descriptive statistic and correlational test (R) to verify there is relation between variable. The results show that there is a relationship between responsibility and commitment with environmental leadership in sustainable development.
Keywords: responsibility, commitmen, environmental leadership in the implementation of sustanable development
Relationships Between Mechanical Properties and Fracturing Conductivity for the Eagle Ford Shale
Authors: Enriquez-Tenorio O.. , Knorr A. F. , Zhu D.. , Hill A. D. 
Published: January 2019

Summary
Creating propped-fracture conductivity that is sustainable at the closure stresses occurring during production is critical to the success of hydraulic-fracture treatments in unconventional reservoirs. In addition, knowledge of the expected fracture conductivity is important information to guide the design of fracturing treatments. This study presents the results of an extensive set of fracture-conductivity experiments conducted using Eagle Ford Shale outcrop samples, as well as supporting measurements of mineralogy and mechanical properties of the shale samples.
The Eagle Ford Shale is subdivided into five different geological facies: A, B, C, D, and E (Donovan et al. 2012). Facies A lies just above the Buda Limestone, and is overlain by Facies B, which has the highest total organic content (TOC). Facies A and B are known as the Lower Eagle Ford, whereas Facies C, D, and E are the Upper Eagle Ford. Facies E underlies the Austin Chalk. Outcrop Eagle Ford Shale samples were collected over the entire vertical extent of a complete exposure of the Eagle Ford Shale in Antonio Creek and Lozier Canyon near Langtry, Texas. Unpropped and propped conductivities of fractured shale samples from all major subfacies of the Eagle Ford Formation were measured using a modified American Petroleum Institute (API) fracture-conductivity cell. Before the fracture-conductivity tests, the fracture surfaces were scanned with a laser profilometer, providing detailed maps of the fracture surfaces. With other samples from the same intervals, the mineralogy, Brinell hardness, Young's modulus, and Poisson's ratio were measured.
The measured fracture conductivities were compared with the fracture surface roughness, elastic mechanical properties, Brinell hardness, and mineralogy of the samples. It was found that propped and unpropped conductivities declined exponentially with closure stress. Propped-fracture conductivity was found to primarily depend on proppant size and loading, with less effect of the rock properties. Conductivity was positively related to rock brittleness and inversely related to Poisson's ratio.
Experimental Investigation of the Effects of Asphaltene Stability on Interfacial Behavior of Live-Reservoir-Fluid Systems
Authors: Ratnakar Ram R. , Mantilla Cesar A. , Dindoruk Birol 
Published: January 2019

Summary
Wettability alteration resulting from asphaltene precipitation in a reservoir affects rock/fluid interactions that have a potential impact on oil production, recovery, and flow in the production network. The current predictive wettability models are inherently inaccurate and do not consider asphaltene stability. This study investigates the impact of pressure-depletion-induced asphaltene precipitation on interfacial tension (IFT) and contact angle for live-oil and water systems at reservoir conditions (high pressure, high temperature), and it presents a graphical (quantitative) method for determining asphaltene onset pressure (AOP) based on interfacial behavior.
Water/oil IFT was measured at reservoir temperature using a pendant-drop-shape method for a system of live oils over a range of pressures above and below the AOP, which was already independently determined by means of particle-size-distribution and solid-detection-system techniques. The same pressure and temperature conditions were used to measure contact angle with quartz in the presence of deionized (DI) water as the surrounding medium. The temperature was controlled with an accuracy of ±0.1°C. Some measurements were performed twice to ensure the reproducibility of the experiments and methodology.
This work presents the experimental study to quantify the change in interfacial behavior because of asphaltene precipitation and deposition. IFT/contact-angle measurements above and below AOP show that the interfacial behavior follows the normal trends above AOP as observed in other water/hydrocarbon systems. However, as evident when the pressure was reduced below the AOP, a relatively sharp change in the trend is observed in both the IFT and contact angle, which is caused by asphaltene migration to the interface in a way that acts as a natural surfactant. As asphaltenes precipitate and deposit in the mineral substrate, the surface turns less water-wet and the contact angle naturally increases to balance the equilibrium forces.
This study sets a quantitative and alternative method to determine AOP, and presents new experimental data on IFT/contact angle of live-oil and water systems at reservoir conditions. Near the wellbore, asphaltene deposition can lead to pore plugging, where a large number of pore volumes flow through the productive life of the well. In this scenario, the size of aggregates (of asphaltene) is an important factor, especially when it is comparable with the pore size. On the other hand, deep in the reservoir, the effects of asphaltene precipitation and deposition on interfacial properties are more important because this can lead to wettability alteration. Thus, the results of this technique can be used to assess the potential impacts deep in the reservoir.
Wettability Estimation Using Surface-Complexation Simulations
Authors: Erzuah Samuel , Fjelde Ingebret , Omekeh Aruoture Voke 
Published: January 2019

Summary
Wettability controls the fluid-phase distribution and flow properties in the reservoir. The ionic compositions of brine, the oil chemistry, and the reservoir-rock mineralogy have profound effects on wettability. Wettability measurement can be obtained from special core analysis (SCAL), but those data are not readily available, and the cost and time of analyzing different possible injection waters can be excessive. There is thus a need for early evaluation of wettability because it is crucial for selecting optimal field-development options. Information about wettability can be indirectly obtained from logging of other rock properties, but the uncertainty in the estimated wettability range is often high. In addition, wettability alteration by injection brines cannot be analyzed by logging. This study seeks to estimate the wettability by assessing the electrostatic interactions existing between the mineral/brine and the oil/brine interfaces using a surface-complexation model (SCM) supported with relatively simple and fast flotation experiments.
The SCM is a chemical equilibrium technique of characterizing surface adsorption phenomenon. The SCM provides a cost-effective technique of characterizing the wettability of minerals at reservoir conditions. Ionic composition of the brine and the properties of the minerals were used as input to the model. In addition, the polar oil components in the crude oil were converted into their equivalent organic acid and base concentrations to be incorporated into the model. The electric-double-layer model that was used in the SCM was the diffuse-layer model. The SCM simulation is a fast and inexpensive wettability-characterization tool if reservoir cores and crude oil required in conventional wettability measurements are not readily available.
From the flotation and SCM results, it could be concluded that the latter could capture the oil-adhesion tendencies of the former. Not only does the SCM predict the wetting tendencies of the minerals, but also it has the capacity to evaluate the mechanisms that led to their wetting preferences. For instance, the SCM results reveal that for negatively charged mineral/brine and oil/brine interfaces, divalent cations such as Ca2+ and Mg2+ can serve as a bridge between the two interfaces, thereby leading to oil adhesion. On the other hand, for positively charged mineral/brine interfaces such as calcite, direct adsorption of the carboxylic oil component was the dominant mechanism for oil adhesion. The SCM technique of characterizing wettability can be used to screen possible injection-water compositions to assess their potential to alter the wettability to more water-wet. Finally, the SCM technique could capture the trend of ζ-potential measurements from literature.
Effect of Fluid Type and Multiphase Flow on Sand Production in Oil and Gas Wells
Authors: Wang Haotian , Gala Deepen P. , Sharma Mukul M. 
Published: January 2019

Summary
Controlled laboratory experiments and some field studies have shown that the onset of sand production in gas wells differs from that in oil wells. Results from a general 3D sand-production numerical model are presented to explain the differences in the onset of sanding and sand-production volume for different fluids and under different flow and in-situ stress conditions. The sand-production model accounts for multiphase-fluid flow and is fully coupled with an elasto-plastic geomechanical model. The sanding criterion considers both mechanical failure and sand erosion by fluid flow. Non-Darcy flow is implemented to account for the high flow rates. The drag forces on the sand grains are computed on the basis of the in-situ Reynolds number. Both the intact rock strength and the residual rock strength depend on water saturation. Water evaporation (drying) resulting from gas flow is modeled using phase equilibrium calculations.
The onset of sand production is compared for different fluid types (oil and gas). Model results are shown to be consistent with experimental observations reported in the literature. For example, the onset of sanding is observed at higher compressive stresses for gas wells as compared with oil wells. The primary mechanism for this is for the first time shown to be sand strengthening induced by evaporation of water. This effect is not observed in oil wells. The sand-production rate when non-Darcy effects are considered is lower than for Darcy flow. The reason for this is the lower fluid velocity (for the same drawdown) and, consequently, smaller drag forces on the failed sand grains. The effect of water breakthrough and water cut on sand production is studied from both mechanical and erosion perspectives. The model is shown to be capable of accurately predicting the onset of sanding and sand production induced by multiphase- and compressible-fluid flows, helping us to predict sanding issues in both oil and gas wells.
Combining Passive and Autonomous Inflow-Control Devices in a Trilateral Horizontal Well in the Alvheim Field
Authors: Langaas Kåre , Jeurissen Emile J. , Abay Hailu Kebede 
Published: January 2019

Summary
In this paper we describe the analysis, test, and design work to deliver an optimal lower completion for a trilateral well by integrating passive and autonomous inflow-control devices (ICDs) (AICDs) at the Alvheim Field offshore Norway.
In 2015, both passive ICDs and AICDs were tested in the laboratory with Alvheim fluids at reservoir conditions. The experimental flow testing demonstrated that the AICD chokes gas more efficiently than the passive ICD. The experimental results enabled correct modeling of AICDs in both the reservoir-simulation model and the simpler steady-state inflow model. The following lower-completion strategy was established for the new well: Where the well was close to the overlying gas cap, AICDs should be used, whereas passive ICDs with variable strength were to be used elsewhere to optimize the inflow.
During the drilling phase, the steady-state model was updated with the as-drilled information; the lower-completion design for each branch focused on obtaining what was estimated to be an optimal inflow depending on the oil volume per drainage area. A key uncertainty in the design work was whether shaly zones along the wellbore would creep/collapse with time and act effectively as packers.
The lower completion covered 7 km of reservoir penetration in the three branches, and 15 unique oil tracers were installed to evaluate the cleanup and the inflow profile along the well. The well started producing in May 2016 and a successful cleanup was confirmed by oil-tracer responses. In August 2016, a restart-tracer-sampling campaign was performed after a 12-day shut-in, and this formed the basis for a “chemical production log.”
The tracer-based inflow interpretation was compared quantitatively with the model-predicted inflow and qualitatively to the tracer responses seen during the cleanup. The comparison confirmed that the lower completion works as initially planned. The interpretation further indicated that the upper zone has a lower degree of pressure support than the lower zone, and that the larger shaly sections have creeped/collapsed and act as packers.
The well has exceeded predrill production expectations, with an average oil rate of 3375 std m3/d (21,240 STB/D) during the first production year. A large part of exceeding the predrill expectations is attributed to the lower-completion design, where the focus has been to optimize such that the whole well contributes, from the heel to all toes.
Real-Time Formation Evaluation and Contamination Prediction Through Inversion of Downhole Fluid-Sampling Measurements
Authors: Kristensen Morten , Chugunov Nikita , Gisolf Adriaan , Biagi Mario , Dubost Francois 
Published: January 2019

Summary
Acquisition of fluid samples using wireline-formation testers (WFTs) is an integral part of reservoir evaluation and fluid characterization. Recent developments in formation-tester hardware have enabled wireline-based fluid sampling in a wide range of downhole conditions. However, accurate quantification of oil-based-mud (OBM) filtrate contamination using data from downhole-fluid-analysis (DFA) sensors alone remains challenging, especially in difficult sampling environments and for advanced sampling tools that have complex inflow geometries and active guarding of filtrate flows. Such tools and conditions lead to contamination behaviors that do not follow simple power-law models that are commonly assumed in OBM-contamination-monitoring (OCM) algorithms.
In this paper, we introduce a new OCM algorithm derived from an inversion of DFA data using a full 3D numerical flow model of the contamination-cleanup process. Using formation and fluid properties and operational tool settings, the model predicts the evolution of filtrate contamination as a function of time and pumped volume, and can thus be used to forward model the DFA sensor responses. Sensor data are then inverted in real time to provide contamination predictions. Real-time computation is enabled through fast, high-fidelity proxy models for the cleanup process. The proxy models are trained on and thoroughly vetted against a large number of full-scale numerical simulations. Compared with existing algorithms, the new OCM method is now applicable for all types of sampling hardware and a wider set of operating conditions. By directly relying on a model of the cleanup process, the physical properties of the formation and fluids (such as porosity, permeability, viscosity, and depth of filtrate invasion) are estimated during the inversion, thus providing additional valuable information for formation evaluation.
The new method is demonstrated by practical application in both synthetic and field examples of oil sampling in OBM. The synthetic examples demonstrate the robustness of the algorithm and show that the true formation and fluid properties can be recovered from noise-corrupted sensor data. The field example presented demonstrates that contamination predictions are in good agreement with results from laboratory analysis, and the inverted formation properties are consistent with estimates derived from openhole logs and pressure measurements.
Development of an Empirical Equation To Predict Hydraulic-Fracture Closure Pressure From the Instantaneous Shut-In Pressure Using Subsurface Solids-Injection Data
Authors: Kholy S. M. , Mohamed I. M. , Loloi M.. , Abou-Sayed O.. , Abou-Sayed A.. 
Published: January 2019

Summary
During hydraulic-fracturing operations, conventional pressure-falloff analyses (G-function, square root of time, and other diagnostic plots) are the main methods for estimating fracture-closure pressure. However, there are situations when it is not practical to determine the fracture-closure pressure using these analyses. These conditions occur when closure time is long, such as in mini-fracture tests in very tight formations, or in slurry-waste-injection applications where the injected waste forms impermeable filter cake on the fracture faces that delays fracture closure because of slower liquid leakoff into the formation. In these situations, applying the conventional analyses could require several days of well shut-in to collect enough pressure-falloff data during which the fracture closure can be detected. The objective of the present study is to attempt to correlate the fracture-closure pressure to the early-time falloff data using the field-measured instantaneous shut-in pressure (ISIP) and the petrophysical/mechanical properties of the injection formation.
A study of the injection-pressure history of many injection wells with multiple hydraulic fractures in a variety of rock lithologies shows a relationship between the fracture-closure pressure and the ISIP. An empirical equation is proposed in this study to calculate the fracture-closure pressure as a function of the ISIP and the injection-formation rock properties. Such rock properties include formation permeability, formation porosity, initial pore pressure, overburden stress, formation Poisson's ratio, and Young's modulus. The empirical equation was developed using data obtained from geomechanical models and the core analysis of a wide range of injection horizons with different lithology types of sandstone, carbonate, and tight sandstone.
The empirical equation was validated using different case studies by comparing the measured fracture-closure-pressure values with those predicted by using the developed empirical equation. In all cases, the new method predicted the fracture-closure pressure with a relative error of less than 6%.
The new empirical equation predicts the fracture-closure pressure using a single point of falloff-pressure data, the ISIP, without the need to conduct a conventional fracture-closure analysis. This allows the operator to avoid having to collect pressure data between shut-in and the time when the actual fracture closure occurs, which can take several days in highly damaged and/or very tight formations. Moreover, in operations with multiple-batch injection events into the same interval/perforations, as is often the case in cuttings/slurry-injection operations, the trends in closure-pressure evolution can be tracked even if the fracture is never allowed to close.