bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the influence of fuel gas on energy characteristics of a gas turbine
Authors: Marin G.E. , Osipov B.M. , Mendeleev D.I.
Published: February 2020

The purpose of this paper is to study and analyze the gas turbine engine and the thermodynamic cycle of a gas turbine. The article describes the processes of influence of the working fluid composition on the parameters of the main energy gas turbines, depending on the composition of the fuel gas. The calculations of the thermal scheme of a gas turbine, which were made using mathematical modeling, are given. As a result of research on the operation of the GE PG1111 6FA gas turbine installation with various gas compositions, it was established that when the gas turbine is operating on different fuel gases, the engine efficiency changes. The gas turbine efficiency indicators were determined for various operating parameters and fuel composition. The impact of fuel components on the equipment operation is revealed.
The impact of higher voltage and current harmonics on the operation of electrical systems
Authors: Egorov A.N. , Kharitonov Ya.S. , Khubieva V.M. , Yakushev I.A. , Golubtsov N.V. , Shakurova Z.M.
Published: February 2020

The article deals with the assessment of impact of higher harmonics on the operation of variablefrequency electric drive systems used in processing units at mining enterprises. Beyond that, energy efficiency and operation experience of variable-frequency electric drive usage at mining enterprises were studied. The advantages and drawbacks of implementation of variable-frequency electric drive systems were found. They include energy saving and reducing maintenance costs for processing units on one hand, as well as losses due to their incorrect selection and electromagnetic compatibility distortion on the other hand.
Improving the theory for calculating the rational modes of traction electrical equipment
Authors: Auhadeev A.E. , Idiyatullin R.G. , Pavlov P.P. , Butakov V.M. , Kisneeva L.N. , Tukhbatullina D.I.
Published: February 2020

Research shows that the existing theory and methods for calculating rational operating modes of traction electrical equipment do not provide a sufficient level of adequacy under real operating conditions of urban electric transport, which is due to the high complexity of the processes and the lack of a sufficiently developed methodology for their interpretation in industry theory. The purpose of the study was researching the process of electric traction as a result of transformation electrical energy in purposeful mechanical movement of electric rolling stock with the implementation of all technological conditions of production and technical system of urban electric transport. The scientific hypothesis that the modes of operation of electric traction equipment as part of an automated electric drive of the rolling stock of urban electric transport are formed under the influence of a complexly organized technological process of electric traction and are the topological basis of its structure is theoretically substantiated. The main result of the research is the formulated theoretical system which allows us to present the process of electric traction as a system consisting of five levels that are in hierarchical relations and solve each specific problem of building the movement of electric transport. Such an approach will contribute to the development of theory and methods for calculating rational operating modes of traction electrical equipment of urban electric transport, the improvement of the energy efficiency of which is the actual scientific problem.
Research of reliability of urban electric transport system
Authors: Auhadeev A.E. , Litvinenko R.S. , Fandeev V.P. , Pavlov P.P. , Butakov V.M. , Litvinenko A.R.
Published: February 2020

Modern methods for analyzing and assessing the reliability of complex technical systems consider only its individual elements. The specifics of structural-functional interactions and integration into subsystems of different hierarchical levels are not taken into account. Studies show that analyzing the reliability of urban electric transport, also focus on individual components: the reliability of electric traction rolling stock, the reliability of the power supply system, the reliability of the track infrastructure, etc. The authors propose an approach that allows to consider urban electric transport as a complex technical system consisting of several levels that are hierarchically subordinate. Each level combines the components directly involved in the transmission and transformation of electric power into mechanical operation of the rolling stock under the influence of the external environment by means of traction electrical equipment. This approach will allow to develop the theoretical foundations of methods for analyzing the impact of the reliability of individual components of a complex technical system of urban electric transport on the effectiveness of the electric traction implementation.
Determination of Antioxidant Compounds and Antioxidant Activity of Six Table Grapes with Red Skin
Authors: Shen Yanqiu , Cheng Xinyi , Gu Hui , Zhou Guihong , Xia Hui , Liang Dong
Published: February 2020

Red grapes are a better source of antioxidants. Although studies have reported the major antioxidant contents and activities of grape cultivars, but the literature lacks information on detailed antioxidant composition and capacities of grape cultivars grown with rain-shelter-cultivation in Chengdu plain, south of China. In the present study, the total phenolics content (TPC), total flavonoids content (TFC), total flavanols content (TFAC), total anthocyanins content (TMAC) and antioxidant activity (DPPH, ABTS and FRAP) were detected and the results will provide basic knowledge about antioxidants of six red skin grapes. The results indicated the content rank order as follow: seeds > skin > pulp. Furthermore, ‘Red Globe’, ‘Jintianmeizhi’ and ‘Hongbaladuo’ have more antioxidants than other cultivars. Our results will provide a basic theory basis for consumers and further utilization of antioxidants.
Analysis of Polyphenolic Content and Antioxidant Activity of Four Dark Skin Grapes
Authors: Shen Yanqiu , Zhang Wanling , Wei Xiaohan , Zhou Guihong , Xia Hui , Liang Dong
Published: February 2020

The polyphenolic of grape skins, pulps and seeds are potential source of natural antioxidant, which are receiving increased attention. In the present work, the total phenolics content (TPC), total flavonoids content (TFC), total flavanols content (TFAC), total anthocyanins content (TMAC) and antioxidant activity (DPPH, ABTS and FRAP) in different tissues of 4 table grapes cultivated in Chengdu plain, south of China, were investigated. In present study, expect TMAC was not be detected in seeds, and our results showed that seeds were the highest in polyphenolic content and antioxidant activity followed by skins, and then pulp. Besides, ‘Fenghou’ is richer in polyphenolic content than other three cultivars. Hence, ‘Fenghou’ extracts possesses higher free radical scavenging ability.
Antioxidant Capacity Assessment of Two White Table Grape
Authors: Shen Yanqiu , Zhao Jiayu , Zhou Guihong , Xia Hui , Liang Dong
Published: February 2020

Grapes can be an abundant source for polyphenols. This work was to extend the investigation to white grape antioxidants by determining antioxidants and antioxidant activity (DPPH, ABTS and FRAP). The results suggested the polyphenols of ‘Italia’ was significantly higher than ‘Rosario Bianco’. But except FRAP, DPPH and ABTS were no difference between two withe cultivars. Moreover, the seeds of tested grape cultivars were the best source of antioxidants content and activity, followed by skins and then pulps of grapes.
Analysis on Gel Electrophoresis in Biology
Authors: Cai Yiran
Published: February 2020

Gel electrophoresis is one of the basic methods used in modern biological laboratories to separate different compounds in a mixture. It is widely used in analyzing the amino acid sequence in proteins. In the following sections, we will discuss the principles of gel electrophoresis and the current challenges of this technology. Gel electrophoresis is used based on the size, mass, and charge of each particle while the movement of molecules depends on the potential differences in power supply and the channel through which the gel is formed. The composition, properties and indexes of the gel are introduced. The gels, nevertheless, have flaws for scientific studies. In this paper, the mechanism of gel electrophoresis and current challenges confronting it will be discussed as references for further improvement of this technology.
Optimization of insoluble dietary fiber preparation technology from rosaroxburghiipomace by chemical method
Authors: Xiao-li Zhou , Yan-sheng Yang , Qiao-mei Yang , Qing-lin Guan , Guang-xu Zhu
Published: February 2020

Rosaroxburghiiresidue as raw material, we studied the extraction process of dietary fiber fromrosa roxburghiipomace by chemical method. The effects of temperature, time, pH, solid-liquid ratio on the IDF yield under the effect of alkali and acid were explored by single factor experiments and orthogonal experiment. The results showed that the optimal condition of extracting IDF was as follows: the 60 meshrosaroxburghii pomace were 80 min in water bath at 60°C under the condition of the solid-liquid ratio 1:15 and the pH 12; and thenrosa roxburghiipomace were 100 min in water bath at 50°C on the condition of the solid-liquid ratio 1:15, and pH 3.0 after rinsing, the average IDF yield which reached (86.3±1.0)%. This experiment provides experimental basis for the selection of dietary fiber raw materials, and also provides theoretical basis for increasing the added value ofrosa roxburghii.
Advances in the mechanisms of Hibiscus sabdariffa L. on hypertension
Authors: Liu Hua , Liang Ze-Ming , Li Rui-ting , Yu Yi-Gang
Published: February 2020

As a traditional edible beverage and medicinal application for high-pressure blood treatment with no side effects, Hibiscus sabdariffa L. (HS) has high prospect to be nutraceuticals as diet additive for anti-hypertension. The anti-hypertension effect of HS has also been scientific validated recently especially in diabetic patient and post-partum mothers. In this paper, we reviewed up-to-date mechanisms found for the anti-hypertensive effect of HS extracts. Those included the inhibition of angiotensin-converting enzymes (ACE) activity, diuretic effect, endothelium-derived nitric oxide-cGMP-relaxant pathway and inhibition of calcium (Ca2+)-influx into vascular smooth muscle cells, cholinergic and/or histaminergic mechanisms, reduction in the diffusion distance between capillaries and myocytes as well as new vessel formation. Phenolic acids, anthocyanins (e.g. cyanidin-3-sambubioside and delphinidin-3-sambubioside) and anthocyanin metabolites probably contribute mostly to the hypotensive activity.
Research on the ecological restoration method for highway debris slope: A case study of Guidu Highway in China
Authors: Liu Shu , Zhang Nan , Qin Xiaochun , Wang Yaokai
Published: February 2020

To clarify the superiority of slope ecological restoration technology in slope restoration, the artificial slope in the section of Guiyang-Duyun highway as the case study was analyzed in this paper. Plant sample collection experiments were carried out by sample method, and the evaluation indicators factors were plant distribution density, biomass and soil nutrients. The effect of slope restoration was evaluated by comparing with the ecological effect of traditional slope restoration measures. The results showed that for the slope ecological restoration sample, the average cumulative plant density was 187 plants per square meter, about 3.8 times of the comparison sample. The average biomass was 333.25g/m2 , which was about 6.4 times that of the comparison sample. Soil nutrients were also much higher than those in the comparison sample. The ecological restoration of the slope with ProGanics and Flexterra materials was superior to the traditional slope restoration measures. The oretical research results will have important theoretical and technical significance for the ecological restoration method for highway debris slope of Guidu highway.
Effect of Winter Temperature Increase on Prolonging Green Period of Lawn
Authors: Ji Chunlei , Shi Huansheng , Liu Min , Chen Xiaqing
Published: February 2020

Taking mixed lawn of Festuca elata Keng ex E. Alexeev and Poa pratensis L. as the research object, through the comparison of the electric heating, covering by non-woven fabric or electric heating and non-woven fabric treatment group with the control group, exploring the effects of winter temperature increase on prolonging the green period of lawn. The results show that: compared with the control group, different temperature increasing measures have different effects on prolonging the green period of the lawn. The test group using only electric heating or only covering the non-woven fabric was completely yellow in mid-January, which was about 10 days longer than the green period of the control group. The effect of using electric heating and non-woven fabric was the best. During the research period, the lawn of this group did not appear completely yellow. Compared with the control group, the green period was prolonged by about 53 days.
Research on the construction of green highway construction technology system
Authors: Wu Yucai , Wang Wei , Wang Dan , Liu Zhiqiang , Qiang Rongrong
Published: February 2020

Combined with the characteristics and actual needs of expressway project, the demonstration application of green highway construction is mainly carried out from four aspects: “building traffic infrastructure system integrated into natural landscape”, “promoting green construction technology of environmental protection, energy saving and high efficiency”, “creating tourism type Expressway demonstration project” and “promoting safety intelligent construction and control technology”, forming “respecting nature and smooth” The supporting technology system should be established for the green road of “nature, nature protection and integration”, and Zihui expressway should be built into a demonstration project of green road in mountain area which is coordinated and integrated with the natural environment.
Effects of Different Pre-processing Methods on Dry Anaerobic Fermentation of Sugarcane Leaves and Pig Manure
Authors: Huang Xiaohong , Jiao Jing , Du Jihua , Li Zunxiang
Published: February 2020

Using agricultural wastes for anaerobic fermentation to produce biogas can not only realize the resource utilization of the wastes, but also prevent the environmental issues caused by straw burning. Sugarcane leaves contain waxy layer, which will cause problems such as difficulty in degradation, long-time fermentation and low biogas production. This paper studies the effects on three pre-processing methods of adding rush rot agent, natural retting for 7 days and water moisture for 24 hours of dry anaerobic fermentation of sugarcane leaves and pig manure. The results show that natural retting for 7 days has the advantage of daily biogas production when the fermentation period is less than 20 days, but this method is not obviously different from that of water moisture for 24 hours. When taking total biogas production volume and volume loading rate as the indicators, water moisture for 24 hours is the best pre-processing method for dry anaerobic fermentation of sugarcane leaves and pig manure when the fermentation period is more than 20 days.
Research on Sand-dust Separation Technology Based on Gas-solid Two-phase Numerical Simulation
Authors: Zhang Lei , Wang Junwei , Li Guohua
Published: February 2020

The separation technology in the large-scale sand-dust environment ground simulation test system applicable to the environmental adaptability and reliability verification of aerospace electromechanical products is studied. The gas-solid two-phase numerical simulation method is adopted, and the possible cyclone separation, inertial separation methods are used to study the separation efficiency and regularity technology, which provides a basis for the separation design and test of the sand-dust environment simulation of large electromechanical products.
Modelling the impacts of challenging 2030 DPRK’s GHGs mitigation targets on DPRK’s energy system
Authors: An Yongjae , Cao Haijun , Kwon Cholu
Published: February 2020

The DPRK ratified the Paris Agreement on 1st August 2016 and fully committed to achieving goals for reduction of greenhouse gas (GHG) in its Intended Nationally Determined Contribution (INDC) which was submitted on 3rd October 2016. The DPRK’s INDC includes a mitigation and an adaptation component. In the mitigation component, as unconditional contribution, DPRK intends to achieve with domestic resources the reduction of GHG emissions by 8% by 2030 as compared to Business as Usual (BAU) scenario. Moreover, the conditional contributions are measures that could be implemented if additional international financial support, technology transfer and capacity building are received. The national contribution could be increased up to 40% with international support. This paper focuses on these mitigation targets for DPRK by an interesting case study of GHG emissions for a 12 year period from 1990 to 2002. We proposed the DPRK’s GHGs mitigation model by analyzing the Irish TIMES (The Integrated MARKAL–EFOM System) energy systems modelling tool, and proved the technical availability of CO2-8 scenario delivering an 8% emissions reduction target by 2030. We then compared the scenario results in terms of changes in energy technology, the role of energy efficiency and renewable energy.
Evaluation on Safety Performance of Power Transmission Iron Tower Based on Stress Monitoring
Authors: Han Jiceng , Zhang Hongjie , Lin Deyuan , Weng Lanxi , Wang Fei
Published: February 2020

The on-line monitoring of power transmission line mainly refers to the observation of load parameters such as wind speed and ice coating thickness, and not many researches about monitoring and safety status are conducted directly targeting their stress states; however, through when calculating the stress status of structure via load, the simplified assumptions in calculation model and load model introduce some errors. This thesis realized real-time monitoring to stress states of main stress poles of iron tower based on the 36 strain monitoring points distributed on the power transmission iron tower; in addition, based on the analysis on monitoring data, this thesis evaluated the safe using performances of the iron tower.
Density Functional Hydrodynamics in Multiscale Pore Systems: Chemical Potential Drive
Authors: Dinariev Oleg , Evseev Nikolay , Klemin Denis
Published: February 2020

We use the method of density functional hydrodynamics (DFH) to model compositional multiphase flows in natural cores at the pore-scale. In previous publications the authors demonstrated that DFH covers many diverse pore-scale phenomena, starting from those inherent in RCA and SCAL measurements, and extending to much more complex EOR processes. We perform the pore-scale modelling of multiphase flow scenarios by means of the direct hydrodynamic (DHD) simulator, which is a numerical implementation of the DFH. In the present work, we consider the problem of numerical modelling of fluid transport in pore systems with voids and channels when the range of pore sizes exceed several orders of magnitude. Such situations are well known for carbonate reservoirs, where narrow pore channels of micrometer range can coexist and interconnect with vugs of millimeter or centimeter range. In such multiscale systems one cannot use the standard DFH approach for pore-scale modeling, primarily because the needed increase in scanning resolution that is required to resolve small pores adequately, leads to a field of view reduction that compromises the representation of large pores. In order to address this challenge, we suggest a novel approach, in which transport in small-size pores is described by an upscaled effective model, while the transport in large pores is still described by the DFH. The upscaled effective model is derived from the exact DFH equations using asymptotic expansion in respect to small-size characterization parameter. This effective model retains the properties of DFH like chemical and multiphase transport, thus making it applicable to the same range of phenomena as DFH itself. The model is based on the concept that the transport is driven by gradients of chemical potentials of the components present in the mixture. This is a significant generalization of the Darcy transport model since the proposed new model incorporates diffusion transport in addition to the usual pressure-driven transport. In the present work we provide several multiphase transport numerical examples including: a) upscaling to chemical potential drive (CPD) model, b) combined modeling of large pores by DFH and small pores by CPD.
The digital rock analysis of biogenically induced reservoir heterogeneities in Cretaceous reservoirs of Saudi Arabia
Authors: Deshenenkov Ivan , Polo Camilo
Published: February 2020

The characterization of the fluid-flow properties in biogenically altered formations is a key for successful exploration campaigns. This study assessed reservoir quality and evaluated permeability of the biogenically-modified Cretaceous carbonate section in Saudi Arabia. When dealing with these bioturbated carbonates, characterization of sedimentary heterogeneities is often overprinted by the complex spatial geometries of burrows. The high-resolution 3D X-ray microscopy imaging and analysis of these bioturbated sections lead to a better understanding of the interconnectivity between permeable burrows and tight matrix. The analysis deploys multiscale imaging from whole core to sub-micron scale. The coarse imaging at 20-50 microns resolution helped to identify bioturbated sections to select samples for higher resolution tomography. The 3D sample tomograms were segmented to define burrows and matrix distributions, where samples were extracted for thin-sections, scanning electronic microscopy (SEM) and mercury injection capillary pressure (MICP) analyses to refine the pore sizes and rock types. The analysis showed an intricate, highly connected, mixed horizontal and inclined burrow system dominated by Thalassinoides. Intergranular porosity, associated with the fill of Thalassinoides, constitutes a mechanism for permeability enhancement in a tight matrix. Increased permeability is associated with higher dolomite content that might be used as a sweet spot identifier from wireline logs.
Core-scale sensitivity study of CO2 foam injection strategies for mobility control, enhanced oil recovery, and CO2 storage
Authors: Alcorn Zachary Paul , Fredriksen Sunniva B. , Sharma Mohan , Føyen Tore , Wergeland Connie , Fernø Martin A. , Graue Arne , Ersland Geir
Published: February 2020

This paper presents experimental and numerical sensitivity studies to assist injection strategy design for an ongoing CO2 foam field pilot. The aim is to increase the success of in-situ CO2 foam generation and propagation into the reservoir for CO2 mobility control, enhanced oil recovery (EOR) and CO2 storage. Un-steady state in-situ CO2 foam behavior, representative of the near wellbore region, and steady-state foam behavior was evaluated. Multi-cycle surfactant-alternating gas (SAG) provided the highest apparent viscosity foam of 120.2 cP, compared to co-injection (56.0 cP) and single-cycle SAG (18.2 cP) in 100% brine saturated porous media. CO2 foam EOR corefloods at first-contact miscible (FCM) conditions showed that multi-cycle SAG generated the highest apparent foam viscosity in the presence of refined oil (n-Decane). Multi-cycle SAG demonstrated high viscous displacement forces critical in field implementation where gravity effects and reservoir heterogeneities dominate. At multiple-contact miscible (MCM) conditions, no foam was generated with either injection strategy as a result of wettability alteration and foam destabilization in presence of crude oil. In both FCM and MCM corefloods, incremental oil recoveries were on average 30.6% OOIP regardless of injection strategy for CO2 foam and base cases (i.e. no surfactant). CO2 diffusion and miscibility dominated oil recovery at the core-scale resulting in high microscopic CO2 displacement. CO2 storage potential was 9.0% greater for multi-cycle SAGs compared to co-injections at MCM. A validated core-scale simulation model was used for a sensitivity analysis of grid resolution and foam quality. The model was robust in representing the observed foam behavior and will be extended to use in field scale simulations.
A Surface Complexation Model of Alkaline-SmartWater Electrokinetic Interactions in Carbonates
Authors: Abu-Al-Saud Moataz , Al-Ghamdi Amani , Ayirala Subhash , Al-Otaibi Mohammed
Published: February 2020

Understanding the effect of injection water chemistry is becoming crucial, as it has been recently shown to have a major impact on oil recovery processes in carbonate formations. Various studies have concluded that surface charge alteration is the primary mechanism behind the observed change of wettability towards water-wet due to SmartWater injection in carbonates. Therefore, understanding the surface charges at brine/calcite and brine/crude oil interfaces becomes essential to optimize the injection water compositions for enhanced oil recovery (EOR) in carbonate formations. In this work, the physicochemical interactions of different brine recipes with and without alkali in carbonates are evaluated using Surface Complexation Model (SCM). First, the zeta-potential of brine/calcite and brine/crude oil interfaces are determined for Smart Water, NaCl, and Na2SO4 brines at fixed salinity. The high salinity seawater is also included to provide the baseline for comparison. Then, two types of Alkali (NaOH and Na2CO3) are added at 0.1 wt% concentration to the different brine recipes to verify their effects on the computed zeta-potential values in the SCM framework. The SCM results are compared with experimental data of zeta-potentials obtained with calcite in brine and crude oil in brine suspensions using the same brines and the two alkali concentrations. The SCM results follow the same trends observed in experimental data to reasonably match the zeta-potential values at the calcite/brine interface. Generally, the addition of alkaline drives the zeta-potentials towards more negative values. This trend towards negative zeta-potential is confirmed for the Smart Water recipe with the impact being more pronounced for Na2CO3 due to the presence of divalent anion carbonate (CO3)-2. Some discrepancy in the zeta-potential magnitude between the SCM results and experiments is observed at the brine/crude oil interface with the addition of alkali. This discrepancy can be attributed to neglecting the reaction of carboxylic acid groups in the crude oil with strong alkali as NaOH and Na2CO3. The novelty of this work is that it clearly validates the SCM results with experimental zeta-potential data to determine the physicochemical interaction of alkaline chemicals with SmartWater in carbonates. These modeling results provide new insights on defining optimal SmartWater compositions to synergize with alkaline chemicals to further improve oil recovery in carbonate reservoirs.
Permeability alteration by salt precipitation: numerical and experimental investigation using X-Ray Radiography
Authors: Lopez Olivier , Youssef Souhail , Estublier Audrey , Alvestad Jostein , Weierholt Strandli Christin
Published: February 2020

The injection of a gas phase through a water saturated porous medium can reduce the water saturation not only by displacement mechanisms but also by evaporation mechanisms. In the presence of brine, this process can induce salt crystallization and precipitation within the porous medium with a risk of permeability alteration. In the field of gas production and storage, the occurrence of such a phenomenon can have detrimental consequence on the well productivity or injectivity. In this work, we investigated experimentally and numerically the effect of dry gas injection on salt precipitation and permeability impairment. State of the art equipment designed for high throughput coreflood experimentation was used to capture the dynamic of salt migration using X-Ray radiography. A set of experiments have been conducted on a sample of Bentheimer sandstone (10mm in diameter and 20 mm in length) as well as a two layers composite sample with a significant permeability contrast. Experiments were conducted using Nitrogen and KBr brine with different boundary conditions (i.e. with and without capillary contact). Results showed that salt precipitation results from the interplay of different parameters, namely pressure gradient, brine salinity, capillary forces and vapor partial pressure. Experimental observations indicate that in the case of dry gas injection, salt systematically precipitates but permeability alteration is observed only if a capillary contact is maintained with the brine. We built a 2D flow model integrating two-phase Darcy flow, capillary forces, salt effect on vapor partial pressure, dissolved salt transport, as well as the different PVT equilibria needed to describe properly the systems. Once calibrated, the model showed good predictability of lab scale experiment and thus can be used for parametrical study and upscaled to the well bore scale.
Effects of gas pressurization on the interpretation of NMR hydrocarbon measurements in organic rich shales
Authors: Dang Son , Sondergeld Carl , Rai Chandra
Published: February 2020

The estimation of total hydrocarbons (HCs) in place is one of the most important economic challenges in unconventional resource plays. Nuclear magnetic resonance (NMR) has proven to be a valuable tool in directly quantifying both hydrocarbons and brines in the laboratory and the field. Some major applications of NMR interpretation include pore body size distributions, wettability, fluid types, and fluid properties. However, for tight formations, the effects of the factors on NMR relaxation data are intertwined. One purpose of this study is to review the interpretation of NMR response of HCs in a tight rock matrix through illustrated examples.

When comparing NMR data between downhole wireline and laboratory measurement, three important elements need to be considered: 1) temperature differences, 2) system response differences, and 3) pressure (mainly due to the lost gasses.) The effect of temperature on HCs would be presented with experimental results for bulk fluids. Whereas, the effect of pressure is investigated by injecting gas back into rock matrix saturated with original fluids. The experiments were performed within an NMR transparent Daedalus ZrO2 pressure cell, which operates at pressures up to 10,000 psi.

The results show that, at ambient temperature and pressure, NMR responds to a fraction of HCs, which is volatile enough to be observed as an NMR relaxation sequence. The invisible fraction of HCs to NMR sequence at ambient condition can be up to 20% of the total extractable HCs. Molecular relaxation is impacted by fluid viscosity, pore size, and surface affinity. In other words, the fluid with higher viscosity (either due to temperature or gas loss), presenting in smaller pore, or highly affected by the pore surface, will relax faster, and would be partially invisible to NMR, especially in the field. This is critical to the interpretation of NMR response for liquid rich source rocks, in which all of the above molecular relaxing restrictions can be found. Thus, engineers can underestimate movable HCs by using routine core analysis data.
A fast FFT method for 3D pore-scale rock-typing of heterogeneous rock samples via Minkowski functionals and hydraulic attributes
Authors: Jiang Han , Arns Christoph H.
Published: February 2020

The integration of numerical simulation and physical measurements, e.g. digital and conventional core analysis, requires the consideration of significant sample sizes when heterogeneous core samples are considered. In such case a hierarchical upscaling of properties may be achieved through a workflow of partitioning the sample into homogeneous regions followed by characterization of these homogeneous regions and upscaling of properties. Examples of such heterogeneities are e.g. fine laminations in core samples or different micro-porosity types as consequence of source rock components and diagenesis. In this work we utilize regional measures based on the Minkowski functionals as well as local saturation information derived through a morphological capillary drainage transform as a basis for such a classification/partitioning. An important consideration is the size of the measurement elements utilized, which could be considerable in the case of larger heterogeneities; in such case the calculation of the regional measures can be computationally very expensive. Here we introduce an FFT approach to calculate these measures locally, utilizing their additivity. The algorithms are compared against direct summation techniques and shift-overlap approaches for a selection of different averaging supports to illustrate their speed and practical applicability. We consider a range of artificial Boolean models to illustrate the effect of including hydraulic information on the resulting classifications scheme. This allows the determination of bias, since for these model systems local classes are known ab-initio. The classification framework is tested by comparing to the known initial micro-structure distribution and relative bias quantified in terms of choice of averaging elements (size and shape). Importantly, depending on the actual morphological transition between micro-type partitions, partitions including hydraulic attributes differ from pure morphological partitions with applications to electrofacies and hydraulic unit definitions.
Using Capillary Condensation and Evaporation Isotherms to Investigate Confined Fluid Phase Behavior in Shales
Authors: Barsotti Elizabeth , Lowry Evan , Piri Mohammad , Chen Jin-Hong
Published: February 2020

The abundance of nanopores (pores with diameters between 2 and 100 nm) in shale and ultra-tight reservoirs precludes the use of common pressure-volume-temperature (PVT) analyses on reservoir fluids. The small sizes of the pores cause capillary condensation, which is a nanoconfinement-induced gas-to-liquid phase change, that can occur at pressures more than 50% below the corresponding bulk phase change of the fluid due to strong fluid-pore wall interactions. We quantify this phenomenon by measuring propane isotherms both in a synthetic nanoporous medium and a core from a shale gas reservoir. Comparison of our results in the two porous media indicates the occurrence of capillary condensation in shale rock. At the same time, we observe capillary condensation hysteresis for shale, in which the density of the fluid is significantly lighter during desorption than adsorption. This indicates structural changes to the rock matrix caused by the phase behavior of the confined fluid. We use scanning electron microscopy to corroborate our findings. These results have significant implications for determining the PVT properties, porosity, and permeability of shale and ultra-tight formations for use in reservoir modeling and production estimations.
Effect of Tubifex and Carrot Meal Combination on Color Quality of Botia Chromobotia macracanthus
Authors: Andriani Yuli , Rosidah  , Iskandar  , Priyadi Agus , Firdaus Satria N.
Published: February 2020

Colour is the most important indicators of quality in ornamental fish, making the exploration to find new sources of pigments in ornamental fish is growing. This study aimed to determine the optimum dose of tubifex and carrot meal combination to enhance the quality of color in Botia Chromobotia macracanthus. This study was designed using Completely Randomized Design with six treatments in triplicates: a) commercial feed (control), b) 70% Tubifex + 3% carrot meal + 27% commercial feed, c) 60% Tubifex + 4% carrot meal + 36% commercial feed, d) 50% Tubifex + 5 % carrot meal + 45% commercial feed, e) 40% Tubifex + 6% carrot meal + 54% commercial feed, and f) 30% Tubifex + 7% carrot meal + 63% commercial feed. Parameters observed were color change level, which was tested using the Kruskal-Wallis method; survival rate (SR) tested using analysis of variance through the F test; and water quality. Results showed that the best color enhancement seen in treatment with 50% Tubifex + 5% carrot meal + 45% commercial feed combination with an average body color of 5.04 in Toca Colour Finder code 0605. The caudal fin color was enhanced with an average score of 3.93 in code 0805.
Effects of Probiotic Dosage on Water Quality, Total Count of Aeromonas spp. and Pseudomonas spp. in Eel Anguilla bicolor Cultivation
Authors: Triyatmo Bambang , Rustadi  , Isnansetyo Alim
Published: February 2020

This study was carried out to evaluate the effects of probiotic dosage on water quality, total number of Aeromonas spp. and Pseudomonas spp., in eel (Anguilla sp.) cultivation. Experiment was conducted by using fiber glass tanks (1x1 m2) with 800 L water volume. Eel fingerling with 50 g average body weight were stocked at a density of 20 eel/tank in triplicates. Observation was conducted on total number of bacteria and water quality. The results indicated that the total bacterial count increased gradually by the time of cultivation with highest density of 1.49x107 cfu/mL. Probiotics at a dose of 40 mL/tank weekly increased the total count of bacterial cells in water. Probiotic application was able to decrease the total number of both Aeromonas spp. from 1.95 x 105 to 5.44 x 104 cfu/mL, and Pseudomonas spp. from 3.57 x 104 to 8.1 x 103 cfu/mL. Water quality during this study was not significantly affected by the application of probiotic. This result suggested that the application of proper dose probiotics suppresses Aeromonas spp. and Pseudomonas spp. cells density in water, and might decrease the bacterial infections in eel culture.
Preliminary Study of Various Intervals and Administration of Feed Enriched with Turmeric and Garlic on the Growth Performance of Catfish
Authors: Basuki Fajar , Yuniarti T , AN Ristiawan , Hastuti Sri
Published: February 2020

As a food ingredient, turmeric curcumin increases appetite and increases the effectiveness of digestive organs function, while garlic increases fish growth. The combination of the two ingredients is believed to increase growth and survival rate of catfish. This study aimed to determine growth performance, Food Conversion Ratio (FCR) and Survival Rate (SR) of catfish seeds in high density fish farming based on biofloc, and supplemented with turmeric and garlic for feed. The research methodology was a complete randomized design, and treated with T1: turmeric and garlic given once a week; T2: turmeric and garlic were given twice a week, and T3: turmeric and garlic were given three times a week. Fish weight was recorded every week, then data were analyzed for fish growth using regression. The study was conducted in 4 weeks. The results showed that the best weight growth performance was obtained at T1 with the regression equation YT1 = −1.07 + 17.92. This equation provides predictions that fish harvesting can be carried out within 6 weeks, with the average weight of fish measured at 100 grams and FCR = 0.91 ± 0.016 and SR = 88.45 ± 8.89%.
Length-Weight Relationship, Condition Factor and Otolith shape of Marble Goby (Oxyeleotris marmorata) at Sermo Reservoir, Yogyakarta
Authors: Nur Aini Rury , Probosunu Namastra , Setyobudi Eko
Published: February 2020

This research aimed to know the length-weight relationship, condition factor, and otolith shape of marble goby (Oxyeleotris marmorata Blkr.) at Sermo Reservoir Yogyakarta. In total 211 samples (95 males and 116 females) were collected using gillnet and folded trap (bubu). Each sample was observed for sex determination, and then measured its total length, body weight, and otoliths diameter. The data were analyzed to determine the length and weight distribution, length-weight relationship, condition factor, and length-otolith diameter relationship. The result showed that the total length of the male was ranged 12.0-38.2 cm and female was ranged 12.2-44.5 cm. The weight of the male was ranged 21.0-704.8 g and female was ranged 21.1-1593.7 g. Both male and female have positive allometric growth with the equation W=0.0056L3.2894 for male and W=0.0051L3.311 for female. Condition factor was ranged 0.787-1.313 for male and 0.800-1.379 for female, and the majority of fish has a good condition (Kn ≥0.95 more than 50%). The shape of otolith edge was sinuate surrounded with regular wave-like curves, the diameter was increased in line with increasing of total body length by an equation of Y=0.2335+0.0248X (r=0.938).
A Standardized Abundance Index from Fishery Independent Data: A Case Study of Swordfish (Xiphias Gladius) from Indonesian Tuna Longline Fishery
Authors: Setyadji Bram , Fahmi Zulkarnaen
Published: February 2020

Most varieties of the billfish caught in the Indian Ocean are either swordfish or Indo-Pacific sailfish. Swordfish is mostly considered as by-catch from tuna longline fisheries, except for South African, Spanish and Portuguese fleets. Despite of its importance, little are known about their abundance. Relative abundance indices are the input data for stock assessment analyses that provide useful information for decision making and fishery management. In this paper, a Generalized Linear Model (GLM) was utilized to systematize the catch-per-unit-effort (CPUE) and to estimate relative abundance indices based on the Indonesian longline dataset. The data was collected by scientific observers from August 2005 to December 2016. Conventional models for counting data were used, but zero-inflated and hurdle models also considered, due to the high number of zero-catchper-set. Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) were applied to select the best models among all those evaluated. Both AIC and BIC suggested that the simple negative binomial (NB) model is the best option. The trends were relatively similar to the nominal series, but with smoother peaks. In general, there was a tendency of positive trends in the last decade, with the series varying throughout the period.
Food habits and trophic level of Anabas testudineus in floodplain lake, Lake Semayang, East Kalimantan
Authors: Mustakim Mohammad , Anggoro Sutrisno , Purwanti Frida , Haeruddin
Published: February 2020

This research studied the food habits and trophic level of A. testudineus in a floodplain lake, Lake Semayang, East Kalimantan. The lake has characteristics of both swamp and lake habitats. The research was conducted from February 2017 until January 2018. During the study, 558 samples of Anabas testudineus were analyzed. The Index of Stomach Content (ISC) in the swamp habitats ranged from 4.32 - 39.59%, with an average of 19.35%, while in the lake habitat ranged from 3.68 - 38.46% with an average of 16.03%. Index of Preponderance (IP) value showed the dominant food item in the fish stomach is animal (62.58 - 79.66%), plants (25.18 - 42%), and undetectable food (≥ 5%). Based on the type and composition of the food, A. testudineus can be classified as omnivorous more inclined to carnivorous. The trophic level of this species changes along with increasing size length.
Combination of Sodium Alginate and Kappa-Carrageenan Increases Texture Stability ofSpirulina platensisIce Cream
Authors: Farhah Anisa Nada , Ekantari Nurfitri
Published: February 2020

This study aimed to increase the texture stability ofSpirulinaice cream by addition of double stabilizers, sodium alginate and κcarrageenan. This study usedCompletely Randomized Design(CRD) with 6 treatments; N1 (sodium alginate 0,1%), N2 (sodium alginate 0,2%), NK1 (sodium alginate 0,09% + κ-carrageenan 0,01%), NK2 (sodium alginate 0,08% + κ-carrageenan 0,02%), NK3 (sodium alginate 0,19% + κcarrageenan 0,01%) and NK4 (sodium alginate 0,18% + κ-carrageenan 0,02%). The effect of stabilizers on physical properties, chemical characteristics, and consumer pReference were measured. Data were analyzed usingOne Way Anova95% and Duncan test (parametric),Kruskal WallisandMultiple Comparison(nonparametric), and correlation test usingRank Spearman.The results showed that the use of double stabilizer did not affect (p>0,05) color, taste, flavor, emulsion stability and overrun, while it affects (p<0,05) texture and first dripping time. Melting rate, hardness, adhesive force, cohesiveness, hardness in scoop, coarseness in scoop, brittleness, iciness, wateriness, sandiness and greasy mouth coating increased during storage period, while gumminess, smoothness and creaminess decreased. NK4 showed the lowest brittleness, wateriness and sandiness value also the highest smoothness value at the end of storage. The use of double stabilizer contain 0,18% sodium alginate and 0,02% κcarrageenan increased the texture quality ofSpirulina platensisice cream.
Production of Unsaturated Fatty Acids Concentrate Tablets fromSardinellasp. Oil
Authors: Sari Rodiah Nurbaya , Irianto Hari Eko , Hastarini Ema
Published: February 2020

Tablets are medicinal ingredients in solid dosage forms which are usually prepared with suitable pharmaceutical ingredients. In this study, unsaturated fatty acids concentrate fromSardinellasp. oil was used as raw material and then it was microencapsulated. The microcapsule was formulated into a tablet with proportion of 250 mg concentrated unsaturated fatty acids for each 450 mg tablet. Tablet granules were analyzed for compressibility, flow rate, and fixed angle. While, the tablets were determined for weight uniformity, released time, hardness, and tablet size uniformity. The results showed that compressibility, flow rate and fixed angle of the tablet granules were 5.6%; 10.36 g/sec; and 32.4° respectively. Tablets had 447.85 mg weight uniformity; 48’12” released time; and 0.775 kg hardness. In addition, the tablet size uniformity with diameter 10 mm and thickness 4 mm was 2.5. Based on the pharmacopoeia, the tablets of unsaturated fatty acids concentrate fromSardinellasp. oil had met these requirements, but optimization was still needed for improving the released time and hardness of the tablet.
Characteristics of Functional Materials Recovered from Indonesian Mangroves (Sonneratia alba and Rhizhophora mucronata) Using Subcritical Water Extraction
Authors: Pangestuti Ratih , Getachew Adane Tilahun , Siahaan Evi Amelia , Chun Byung Soo
Published: February 2020

Mangrove is the most productive ecosystem in marine environment, as it provides a unique habitat opportunity for many marine species and key goods and services for human beings. In Indonesia, mangroves are still considered as underexploited marine resources, and functional materials from Indonesian mangroves are not characterized yet. In this study, two mangroves Sonneratia alba and Rhizhophora mucronata from Kendari, were hydrolyzed using the subcritical water extraction (SCWE) system. Three different temperature conditions (150–230 °C with 40 °C increments) were applied to obtain the best functional materials. Mangroves hydrolysate was further analyzed for total sugar, protein, phenol content. The antioxidant capacity and functional material contents varied significantly based on the sample materials and extraction conditions, with R. mucronata hydrolyzed at temperature 230 °C showing the highest antioxidant activity. High-performance liquid chromatography (HPLC) analyses revealed high contain of phenolic acids in all mangroves hydrolisates especially R. mucronata fruit (RMF). Collectively, this study shows the potential of mangroves resources in Indonesia in Indonesia for different applications (food, cosmetics and pharmacy) using environmental friendly technology.