bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDI PEMANTAUAN AIR LIMBAH CAIR TAMBANG PADA PT. XXX DI MUARA TEWEH KALIMANTAN TENGAH
Authors: Annisa Annisa
Published: February 2020

Kegiatan penambangan Batubara sebagai salah satu komoditas penambahan devisa negara. Namun dampak negatif dari kegiatan penambangan batubara adalah sebagai penghasil air limbah dengan kandungan bahan-bahan yang berbahaya, terlebih jika kegiatan penambangan tersebut dekat di hulu sungai. PT. XXX adalah sebuah perusaahan yang bergerak dibidang pertambangan yang terletak di Muara Teweh Kalimantan Tengah. Guna mengetahui dampak lingkungan yang disebabkan olehkegiatan penambangan khususnya dampak dari air limbah batubara maka PT. XXX  melakukan pemantauan lingkungan pertriwulan. Kegiatan ini bertujuan untuk  mengetahui penurunan kualitas air. Analisis data lapangan dan laboratorium atas beberapa parameter diantaranya analisis pH, Total Suspended Solid (TSS), kandungan Fe dan Mn yang merujuk pada Peraturan  Gubernur Kalimantan Selatan  No. 036 Tahun 2008  Tentang Baku Mutu Air Limbah Kegiatan Penambangan, Pengolahan/Pancucian Batubara dan Kepmen LH No. 113 Tahun 2003 untuk keluaran dari kolam pengolahan limbah cair tambang batubara. Berdasarkan Hasil analisis laboratorium  didapatkan hasil uji parameter kualitas air  yaitu nilai TSS berkisar <2 mg/l – 13 mg/l, nilai pH antara 6,89 -7,78, kandungan besi (Fe) berkisar  0,06 mg/l - 0,78 mg/l dan kandungan Mangan (Mn) berkisar < 0,0022 mg/l – 0,004 mg/l.Kata kunci: Batubara, parameter, penambangan, pH, TSS. Coal mining activities as one of the commodity additions of foreign exchange. However, the negative impact of coal mining activities is as a producer of waste water with dangerous ingredients, especially if the mining activities are near the upstream of the river. PT. XXX is a mining company located in MuaraTeweh, Central Kalimantan. In order to know the environmental impact caused by mining activities, especially the impact of coal waste water, PT. XXX conducts quarterly environmental monitoring. This activity aims to determine the decrease of water quality. Analysis of field and laboratory data on several parameters such as pH analysis, Total Suspended Solid (TSS), Fe and Mncontents referring to South Kalimantan Goverment Regulation no. 036 Year 2008 About Quality Standard of Wastewater Mining, Processing / washing Coal and LH Decree No. 113 of 2003 for the output of liquid waste pools of coal mines. Pursuant to result of laboratory analysis got result of water quality parameter test that is value of TSS about <2 mg / l - 13 mg / l, pH value between 6,89 -7,78, iron content (Fe) 0,06 mg / l - 0 , 78 mg / l and Manganese content (Mn) ranged from <0.0022 mg / l - 0.004 mg / l.Key word: coal, mining, parameter, pH, TSS.
The Training of Technical Men for Management Positions
Authors: Dorman R.W.
Published: February 2020

AIME Annual Meeting, 15–19 February, San Francisco, California

Technical men have special characteristics which present unique problems in management development. They have the ability to grasp principles easily, to understand methods and procedures readily, to appreciate organization, and are orderly in their thinking and analytical in their approach. Yet they must develop new skills including the ability to deal with people's emotions, a willingness to snake decisions even though complete information is not available, and the imposition of a new kind of self discipline. Several methods are given to help the technical man develop for management positions.

Introduction

The problem of helping a technical man prepare himself for supervisory, management or executive positions is an important one today. While the technical man may be a true professional in his field; i.e., he has a store of knowledge, the skills and methods to use that knowledge, and the discipline necessary to keep him ethical — yet the transition from working as a professional engineer to a professional manager is an extremely difficult one for many individuals.

As we know, modern business is becoming increasingly complex. Today'smanagers direct activities which must cope successfully with complicated problems of engineering, legal restrictions, economic trends, public relations, employee relations—including dealing with local and national labor organizations, governmental regulations, and alert competition. Further, the manager who is just barely adequate today will be completely inadequate 10years from now unless he [or someone] makes plans for his development.

Competition will not allow us to take time to permit our people to mature as slowly and as loosely as the old style supervisor did. There is not as much room for management errors. Since employees are better informed today, their bosses must have more supervisory skill, better judgment and a broader view.

Again, if a company is to find and hold good men, it must have some clear plan for providing for its people opportunities for advancement. All this then suggests that positive action is required to broaden the training and experience of technical people in order to qualify them to direct units of the modern organization.
Effect of Directional Permeability on Sweep Efficiency and Production Capacity
Authors: Landrum Bobby L. , Crawford Paul B.
Published: February 2020

Permian Basin Oil Recovery Conference, 7–8 May, Midland, Texas

Theoretical and potentiometric model studies have been made of the effect of nonuniform lateral permeabilities on pattern sweep efficiency and production capacity in waterflooding and gas cycling programs.

It is shown that a difference in directional permeability by a factor of three may result in a sweep efficiency of only 43 per cent for a five-spot pattern or a sweep of 79 or 38 per cent for a direct line-drive square pattern depending on the direction of the line-drive flood. Changes in the pattern conductivity varied from about 0.8 to 1.34 over this same permeability variation, depending on the pattern used.

It is suggested that field measurements be made to determine the possible magnitude and extent of the directional permeability phenomenon early in the field development and certainly prior to the initiation of any fluid injection program.

Introduction

Irregularities in reservoir sand properties have long been a major difficulty to anyone attempting to explicitly describe the field characteristics of oil production. In particular, it is well known that vertical and lateral permeabilities often differ appreciably; however, the existence of large regions with lateral permeability variation is not widely recognized. A number of years ago, extensive studies were conducted by the Secondary Recovery Research Laboratory of the Pennsylvania Grade Crude Oil Association primarily on the Bradford Field. Johnson and Hughes reported a permeability trend in the northeast-southwest direction. They indicated that flow in the preferred direction may be 25 to 30 per cent greater than in the northwest-southeast direction. They also reported that similar effects may be found in other nearby fields. The origin of the permeability variation has been discussed by Griffith. Results of laboratory tests on limestone cores have led some to believe that directional permeabilities may differ by factors of ten to 100 or more. Certain areas of the Spraberry are believed to have effective directional permeabilities greater than 100 to one.

In order to prevent the reduction of sweep efficiency which would normally result from flooding or cycling in such reservoirs, well spacing could be varied from the customary square to a diamond shaped pattern. Johnson and Hughes presented a method for determining the desired shape. Another method will be discussed in detail in the next section.
Engineered Guide for Planning Acidizing Treatments Based on Specific Reservoir Characteristics
Authors: Hendrickson A.R. , Hurst R.E. , Wieland D.R.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 219, 1960, pages 16–23.

Analysis of acidizing techniques, in correlation with reservoir data and a backlog of past treatments, has resulted in the development of a valuable engineering guide for planning acidizing treatments. Such treatments fall into three categories:acid injection into the pores of the matrix;acid injection into natural formation fractures at less than parting pressure; andcombination acidizing-fracturing treatments in which acid solutions (without propping agents) are injected at treating pressures sufficient to open and extend fractures through which the acid flows.

Because the spending time of acid during a specific well treatment does not change appreciably, maximum penetration is attained when the first increment of injected acid is completely spent. Additional acid injection cannot be expected to further extend the benefits of the treatment. Depth of penetration will depend upon the reaction rate of the acid under treatment conditions, the injection rate of the acid into the matrix or fractures and the area-volume relationship existing in the flow channels.

Based on Darcy's flow formula, extremely low injection rates must be used in order to keep bottom-hole injection pressures below formation fracturing pressure. As a result, only limited penetration of unspent acid will occur. Treatment records indicate that, in most acidizing treatments, formation parting pressures are exceeded, greatly extending acid penetration.

Under these conditions, stimulation benefits are limited to the fracture area produced during the spending time of the first increment of acid injected into the formation. This area may be calculated from laboratory and well data to estimate depth of penetration. This, in turn, may be correlated with productivity data to assist in the selection of optimum treating techniques and materials.
The Effect of Some Drilling Variables on the Instantaneous Rate of Penetration
Authors: Outmans H.D.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 219, 1960, pages 137–149.

The paper presents a theoretical approach to the drilling problem based on rock mechanics and drilling fluid hydraulics at the bottom of the hole.

The volume of the fractured rock around the vertically penetrating bit tooth is expressed as a function of the tooth pressure, included tooth angle, drilling fluid pressure and formation characteristics on the assumption that fracturing is preceded by plastic flow. This assumption is verified by comparing the stress-strain state in the rock around the tooth to that in equivalent triaxial compression tests described in the literature.

An expression similar to the above is derived for the tooth penetration in the cuttings which have been retained at the bottom. Combination of these two expressions leads to a relation between depth of tooth penetration in the virgin rock, the amount of cuttings retained and the other variables. By relating the cutting volume to the drilling rate, the hydraulic bit horsepower and the drilling fluid pressure, it is possible to arrive at formulas which express the drilling rate for viscous or turbulent flow at the cutting surface, for instant clearance, for retained cuttings, or for false tooth foundering as functions of such variables as the drilling fluid pressure, hydraulic horsepower at the bit, rotary speed and bit weight.

Plotting the results as drilling curves and comparing them to published field and laboratory data justify the conclusion that the drilling model presented in this paper approximates the actual mechanism. The drilling curves serve to explain some characteristic features of the rotary drilling operation, and the equations may be used for numerical evaluation of the effect of changes in the magnitude of some of the variables on the drilling rate.

Introduction

Published laboratory data have established that consistent and relatively simple relations exist between the drilling rate and any one of the important variables. For instance, the drilling rate usually increases at an increasing rate with the bit weight. It increases at a decreasing rate with the rotary speed, decreases at a decreasing rate with increased drilling fluid pressure and plots as an S-shaped curve against the hydraulic horsepower at the bit.
Equilibrium in the Methane-Carbon Dioxide-Hydrogen Sulfide-Sulfur System
Authors: Kennedy Harvey T. , Wieland Denton R.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 219, 1960, pages 166–169.

The object of the work reported here was to determine the content of elemental sulfur in gaseous methane, carbon dioxide, hydrogen sulfide, and in mixtures of these gases, at pressures and temperatures encountered in natural gas reservoirs.

Sulfur content at equilibrium is reported for pure methane, carbon dioxide, hydrogen sulfide, and on three binary mixtures of each of the three pairs of gases at pressures of 1,000, 2,000, 3,000, 4,000, 5,000 and 6,000 psia and at temperatures of 150, 200 and 250F. In addition, the sulfur content of three ternary mixtures at the same temperatures and pressures are reported.

The results indicate that the sulfur content is higher in the gases at higher temperatures and pressures. The content is highest in hydrogen sulfide, intermediate in carbon dioxide and lowest in methane.

Introduction

At ordinary pressures and temperatures, the concentration of a non-volatile material, such as sulfur in a gas at equilibrium, is a function of the vapor pressure of the material and is independent of the nature of the gas. As the pressure and temperature increase, the gas assumes some of the properties of liquids, including the power to dissolve other liquids and solids, to an extent dependent on the nature of both the gas and the material dissolved. At equilibrium, the content of sulfur in the several gases considered here may thus be considered as solubilities which are fixed for a given composition of gas, temperature and pressure.

The study of the solubility of elemental sulfur in gases is of interest because sulfur is sometimes present in reservoirs producing natural gas and must be present in the vapor phase. Upon reduction of pressure and temperature, the sulfur precipitates from solution in the reservoir and in the tubing and fittings.

Due to the fact that the greatest pressure drop in the reservoir is around the wellbore, the volume of sulfur precipitated will be greatest in this locality and can cause a substantial reduction in the permeability of the formation in this area. As the natural gas flows up the tubing string, the pressure and temperature are further decreased, causing further sulfur precipitation. If the volume of free sulfur is large and remedial measures are not taken, complete plugging of the tubing can occur.
A Theoretical Analysis of Heat Flow in Reverse Combustion
Authors: Berry V.J. , Parrish D.R.
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 219, 1960, pages 124–131. Paper presented at Joint AIChE-SPE Symposium, Dec. 7–8, 1959 in San Francisco.

Reverse combustion is one thermal method of recovering hydrocarbons from porous underground formations containing oil or tar. In applying this method, air is introduced via an injection well and the mixture of air and hydrocarbons is ignited in the production well. A combustion zone then recedes toward the injection well, counter-current to the air flow. If the combustion-zone temperature is sufficiently high, the oil or tar in place is distilled and cracked. The hydrocarbon flows as a vapor to the production well and subsequently is condensed at the surface.

Maximum temperature and velocity of movement are the two dependent variables defining the progress of the combustion zone. A theoretical analysis has been made of heat flow in the reverse-combustion process assuming linear flow in a homogeneous system. The differential equations, which include the oxygen-hydrocarbon reaction rate, have been solved numerically. Results indicate that the maximum temperature reached and the combustion-zone velocity both increase with an increase in air-injection rate. Heat loss to surroundings has little effect on the maximum combustion-zone temperature achieved, but it is reflected in a reduced combustion-zone velocity. It is also predicted that an increase in the oxygen-hydrocarbon reaction rate results in a reduction in the maximum temperature reached. The calculated results are in agreement with results from reverse-combustion experiments using samples of a tar sand.

Introduction

Reverse combustion is one thermal method of recovering hydrocarbons from porous underground formations containing oil or tar. In applying this method, air is introduced into the underground formation via an injection well. In one or more adjacent production wells. the mixture of air and hydrocarbons is ignited at the sand face. The combustion zone thus formed recedes toward the injection well, counter-current to the air flow (Fig. 1).
A Radioactive Tracer Technique for Studying the Performance of Sand Packs Designed To Prevent the Movement of Loose Oil Sands
Authors: Rensvole Roger F.
Published: February 2020

Regional Fall Meeting of the Los Angeles Basin Section of SPE, 22–23 October, Pasadena, California

The migration and accumulation of formation fines in closely-sized sand packs under compaction pressure is studied. Finely ground, radioactive carnotite ore is used to represent formation fines. This material can be detected in extremely small concentrations due to its radioactivity. Pack sands investigated are 10–20, 10–30, 20–40 and 40–60 mesh rounded sands routinely used in fracturing and sand packing operations. Preliminary-tests indicate that viscosity of the fluid flowing through the pack is a definite factor in the migration and accumulation of fines in the pack. Localized concentrations of formation fines are found in the sand packs, often at a distance from the formation-sand pack interface. This is attributed to variations in pack-sandgrain geometry which affords greater possibilities for bridging by fines in one section of the pack than others. Short-time tests indicate that the migration of fines begins immediately upon beginning fluid flow. Finer-grained sand packs accumulate a greater concentration of fines than do coarser-grained sand packs.

Introduction

Sand control has been achieved with various degrees of success by a number of different techniques. Of these, sand or gravel packing has been employed in oil wells since 1932. Since that time the process has been improved through investigations in the laboratory and by practical field experience.

Laboratory work by Sage and Lacey, Gumpertz and Coberly and Wagner has established rules for designing sand packs to prevent the production of formation sand with the oil. The particle-size distribution of the unconsolidated formation is the determining factor in their application. These rules are based on experimental data obtained in the laboratory with relatively clean formation sands, i.e., sands containing little or no silt and clay. It is believed that this fine material in the formation affects the durability, effectiveness and productivity of a sand pack placed against the formation.
A Study of Variables in Linear Miscible Displacements
Authors: Scott E.Z. , Read D.L.
Published: February 2020

Regional Fall Meeting of the Los Angeles Basin Section of SPE, 22–23 October, Pasadena, California

Detailed studies of miscible displacement have been made on 45 ft of 2-in. Berea sandstone composed of 30 in. -sections. Displacements were made on all cores individually and in series. Series displacements were made with core sections in capillary contact and with fluid composition analyzer cells between the cores. Fluids of matched physical properties and selectively unmatched physical properties were used in these displacements. A continuous fluid composition measurement was taken at 30-in. intervals using an on-stream capacity cell technique to provide simultaneous compositional measurements through the entire length of the system. Material balances were maintained at each of these points to within one per cent of the measured pore volume. This unique method affords a precise definition of the mixing zone along the length of the entire system.

This paper presents the development of this zone in a linear system as a function of system volume traversed rather than system length traversed. It shows that miscible displacement performances are not directly related to conventional core measurements, but is related to pore geometry. The development of the mixing zone is dependent upon individual core displacement characteristics as well as fluid viscosity ratios. The effect of rate is presented as negligible and results of the rate investigation indicate little if any diffusion effects. The key factor in miscible displacement investigations is the maintenance of a rigorous material balance.

Introduction

The displacement of oil by miscible liquids has been of interest to the industry for some years. Although many investigations have been conducted in an effort to define the mechanism of the miscible displacement process, an exact analysis of all the pertinent variables has not been made. A more thorough understanding of the variables involved in this mechanism would provide the industry with a valuable tool for designing and evaluating appropriate recovery programs.
Case History - A Lansing-Kansas City Waterflood
Authors: Allison R.S.
Published: February 2020

Kansas Waterflood Symposium of the Society of Petroleum Engineers of AIME,19 November, Great Bend, Kansas

Water flood of the Lansing-Kansas City formation in a 320 acre portion of the Cheyenne View Pool, Barton County, Kansas is expected to produce 145,000barrels of secondary oil or an amount equal to 67% of the primary oil.

Utilizing a mixture of produced water and fresh water for injection fluid, the flood has produced 60% of the recoverable flood oil with minimum maintenance costs.

Location

This flood, consisting of five producing wells and four injection wells, is located in the Cheyenne View Pool of Barton County, Kansas; or approximately 21/2 miles northwest of Ellinwood. Figure 1 is a plat of the two leases involved.
Equilibrium Ratios for Reservoir Studies
Authors: Brinkman F.H. , Sicking J.N.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 219, 1960, pages 313–319.

A new method for obtaining equilibrium vaporization ratios (K-values) for reservoir fluids has been developed and tested. By application of the method, complex experimental measurements of liquid and vapor phase compositions are eliminated. This simplified technique reduces the cost of experimental equilibrium ratio data for reservoir studies of condensates and volatile crude-oil systems.

The method is designed for systems of constant composition and, therefore, is best suited for depletion studies where compositional changes at high pressures are minor. The basic data required, in addition to the composition of the initial reservoir fluid, are the relative vapor-liquid volumes and densities at reservoir temperature and various reservoir pressures.

Tests demonstrated that the method predicts equilibrium ratios accurately for condensates. A single test on a crude oil was not conclusive; further testing will be necessary before the accuracy of the method can be determined for crude-oil systems.

In addition to determining equilibrium ratios, the calculation method provides information on the physical properties of the "plus" component in the vapor and liquid phases. The "plus" component is that mixture of components heavier than the least volatile fraction analyzed. This information is useful in studies of both natural depletion and cycling operations for condensate reservoirs where the heptanes-plus component in the gas phase is produced from the reservoir.

Introduction

As more volatile oil and condensate reservoirs are found, the use of phase behavior techniques to predict their performance is increasing in importance. These techniques have long been used for condensate fields and have more recently been applied to crude-oil fields containing oils of medium-to-high volatility. In these phase behavior methods, equilibrium ratios (K-values) are used to predict compositional changes in the reservoir fluids-thereby accounting for the recoverable oil that exists in the gas phase. The reliability of the predictions depends to a large extent on the equilibrium ratios used. These values must be obtained for each component for the entire pressure range being investigated.
Conduction-Convection in Underground Combustion
Authors: Bailey H.R. , Larkin B.K.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 219, 1960, pages 320–331.

A model of heat flow in an underground combustion process is studied. This model includes convection effects and thus is more general than previous studies which considered conduction as the only mechanism for heat transfer. Both linear (tube run) and radial (field application) geometries are considered. The effects of ignition heaters, vertical losses and finite source width are considered for the linear case.

The results are in the form of equations and are presented in graphical form for a number of cases. Convection effects increase frontal temperatures about 25 per cent over those computed for conductive transfer for typical field operating conditions. This increase in temperature is a result of heat being transported toward the front by the injection gas. Even greater temperature increases are realized as the per cent oxygen in the injection gas decreases.

It is well known that compression costs are of considerable importance in estimating the economic feasibility of underground combustion. By assuming an ignition temperature for the combustion fuel, predictions of limiting conditions on fuel density and injection rate necessary to sustain the combustion zone are made. For typical field conditions, at least 0.75 lb/cu ft of fuel are needed with air as the injection gas. if the injection gas is 10 per cent oxygen and 90 per cent nitrogen, this figure is 0.69 lb/cu ft.

Introduction

The possibility of increasing oil recovery by underground combustion has been considered for many years. Recent field tests indicate that the underground combustion process is technically feasible. The economic feasibility depends to a large extent on the amount of air which must be injected to sustain combustion. Prediction of the success of employing underground combustion in a particular reservoir must be based on existing field tests, laboratory tube runs and solutions of mathematical or analog models.

Vogel and Krueger devised an electrical analog of the heat transfer problem in an underground combustion process. They considered the problem of heat conduction from a cylindrical source with increasing radius assuming no vertical losses. Bailey and Larkin, and Ramey solved the corresponding problem including vertical losses by considering a mathematical model of the conduction process. Ref. 9, 10 and 11 also present information related to the subject study.

The present paper generalizes these results to include both conduction and convection mechanisms for heat flow. A model of the conduction-convection process is described. The partial differential equations governing this model are written and solved for a number of cases of interest. The formulas are evaluated and the results are presented graphically.
Miscible Fluid Displacement - Prediction of Miscibility
Authors: Benham A.L. , Dowden W.E. , Kunzman W.J.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 219, 1960, pages 229–237.

The mechanism involved in creating a miscible fluid displacement of typical reservoir fluids through porous media by light hydrocarbon mixtures usually involves a number of mixing and separation stages in the contact area. This mechanism has been illustrated on ternary diagrams for miscible displacement of reservoir fluid by rich hydrocarbon gases.

A relatively simple method has been devised for calculating the approximate conditions for a miscible displacement of reservoir fluid by rich, light hydrocarbon gases or by LPG mixtures. Miscibility is favored by increased pressures, decreased temperatures, light reservoir fluids and light hydrocarbon-displacing fluids rich in the heavier components.

The conditions for miscible displacements of five typical reservoir fluids by various light hydrocarbon mixtures were determined for a range of temperatures from 700 to 260F and pressures from 1,000 to 3,000 psia. A correlation of these conditions was obtained using the variables of temperature, pressure, C5+ molecular weight of the reservoir fluid, C2+ molecular weight of the displacing fluid, and mol per cent methane in the displacing fluid. This correlation has been applied to data appearing in the literature with very good success. A partial check of the correlation has been made using a step-wise procedure with a windowed PVT cell.

Introduction

The term, "miscible fluid displacement", may be defined as any oil-recovery displacement process where there is an absence of a phase boundary or interface between the displaced and displacing fluids. A water flood would not be a miscible fluid displacement, although cycling in a condensate reservoir would be. Another example is displacement of oil by gasoline. Not so obvious, however, are the conditions under which fluids (such as propane, mixtures of propane and methane, or other similar systems) will give a miscible fluid displacement of oil.

There are four standard miscible-fluid-displacement processes being used for the recovery of oil from an underground reservoir-high-pressure dry-gas miscible displacement,rich-gas miscible displacement,miscible slug using a slug of LPG followed by a lean dry gas under miscible conditions, andgas driven-slug process using a slug of LPG followed by a lean dry gas under immiscible conditions.
An Improved Method for Calculating Water Influx
Authors: Carter R.D. , Tracy G.W.
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 219, 1960, pages 415–417.

A method based on an approach by Hurst is developed for calculating water influx behavior. Using this method, superposition calculations may be eliminated. The principal difference between this method and that of Hurst is that, over finite intervals of time, constant oil-production rates are assumed by Hurst whereas constant water influx rates are assumed in the presently described method.

By adopting the assumption of constant water influx rate for finite time periods, a method is developed for calculating water influx behavior which lends itself to convenient combination with the material balance equation in the Schilthuis form. Above the bubble point, an equation is given for the explicit step-wise calculation of pressure history for a prescribed oil-production history. Use of this method of calculating water influx behavior should result in a considerable saving of time as compared to superposition calculations when the calculations must be made without using a digital computer.

The connection is shown between the method described herein and the method developed by van Everdingen and Hurst (which requires superposition calculations). Also, results obtained using the two methods are compared.

INTRODUCTION

While the method of van Everdingen and Hurst is in many respects a satisfactory way of calculating water influx behavior, the superposition calculations involved make it a tedious procedure when the work is done without using a digital computer.

Hurst has presented an approach to the problem which eliminates superposition calculations, in many cases at small expense to accuracy. It is the purpose of this paper to present a method of calculating water influx which is based on the approach of Hurst and which may be conveniently combined with the material balance equation in the Schilthuis form. The relation will be discussed between the method of van Everdingen and Hurst and the method described herein. Examples of results using the two methods are given.
A novel retractor for reducing operation time and radiation exposure in percutaneous pedicle screw placement
Authors: Niu Lei , He Rui , Zhang Wenzhi , Duan Liqun , Li Xu , Cai Haiping
Published: February 2020

Background : Percutaneous pedicle screw fixation is less damage to the surrounding musculature and can decrease both blood loss and recovery time, but depends heavily on fluoroscopic guidance. An efficient instrument or system that allows for accurate pedicle screw placement and reduction in the fluoroscopy shot time would therefore be of value. Methods: 126 patients with single segment thoracolumbar vertebral fracture were surgically treated with percutaneous pedicle screws through our novel retractor technique（group A） or traditional fluoroscopic method(group B), the operation time and fluoroscopy shot times were compared, and the accuracy of screw placement were assessed. Results : There was no serious complications occurring during our study, such as infection, blood vessel injury, spinal cord or nerve root injury. We did not find any statistically difference between the two groups in corrected rate of regional Cobb’s angle or vertebral body height percentage(P>0.05); however, the mean operation time was found to be 75.9±2.37min in the novel retractor method group and 94.2±2.19min in the traditional method group. The difference was statistically significant (p﹤0.001). Fluoroscopy shot times averaged 9.01±0.41 in the novel retractor group versus 16.8±0.56 in the traditional group (P < 0.001), the novel retractor group had apparent advantages over the traditional method in postoperative improvement on visual analog scale (VAS) scores and Oswestry Disability Index (ODI) at 2days, 3month after operation and last follow-up (P<0.05). There was no statistical difference between the novel retractor group and traditional method group in the radiographic results and screw position violation grade. Conclusion: The novel retractor method had several advantages, including shorter operation time, less fluoroscopy shot times, and better postoperative improvement on visual analog scale( VAS) score and Oswestry Disability Index (ODI). It provides a new alternative method for effective management of thoracolumbar fractures.
Restoration and Enhancement of Underwater Under-Exposure Images with Detail-Preserving
Authors: Li Xujian , Liu Ke
Published: February 2020

Underwater images have great practical value in many fields such as underwater archeology, seabed mining, and underwater exploration. Due to the complex underwater environment, there are problems such as poor light, low contrast, and color degradation. Traditional underwater image processing methods cannot well achieve the goal of clear display under extreme conditions. This paper proposes a method for restoration and enhancement of underwater under-exposure images that protects edge details and enhances image color. Firstly, the underwater image was preprocessed, denoising with improved wavelet threshold function, defogging with the Multi-Scale Retinex Color Restoration (MSRCR) and guided filter method. Then, the method of adaptive exposure graph is used to enhance the under-exposure image. Finally, the deep learning algorithm combined with the Non-Subsampled Contour Transform (NSCT) technology is used to solve the problem of color degradation and edge texture weakening. Experiments show that compared with other underwater image processing methods, this method greatly improves the clarity of the image, enhances the color saturation and the edge texture details of the image, and has a better visual effect.
Regulation of RUNX3 expression by DNA methylation in prostate cancer
Authors: Yang Xin , Wang Shumei , Reheman Alimu
Published: February 2020

Background: Runt-related transcription factor 3 (RUNX3) is a developmental regulator, and methylation of the RUNX3 is significantly associated with the occurrence and development of carcinogenesis. Previous studies have identified an association of increased methylation level of RUNX3 in prostate cancer (PCa); however, the role and molecular mechanism underlying aberrant methylation of the RUNX3 gene in prostate tumorigenesis remain elusive. In this study, we will investigate the role of RUNX3 promoter methylation and its gene expression in PCa cells. Methods: The methylation of the RUNX3 in the promoter region in PCa cells was detected by bisulfite-sequencing PCR (BSP). Following treatment of the PCa cells with DNA methylation transferase inhibitor 5-AZA-2'-deoxycytidine (AZA), the effect on methylation level and expression of RUNX3 were analyzed by qRT-PCR, Western blot, and BSP assays. Furthermore, we investigated the effect of the demethylated RUNX3 on proliferation, cell cycle and apoptosis of PCa cells using CCK-8 and flow cytometry assays. Using the DNA methylation transferase (DNMT3b) knockout or overexpression models, the relationship between DNMT3b and RUNX3 methylation was further assessed by qRT-PCR, Western blot and methylation-specific PCR (MSP). Results: The results indicated that the methylation level of RUNX3 in PCa cell lines was significantly higher than that of normal prostate epithelial (RWPE-1) cells. Furthermore, treatment with AZA not only promoted the demethylation of RUNX3 but also restored the mRNA and protein expression of RUNX3, and the reactivation of expression of the later exhibited its anti-tumor effects through regulation of the cycle progression in PCa cells. Moreover, DNMT3b could regulate the expression level of RUNX3 by altering the DNA methylation of the RUNX3 in PCa cells. Conclusion: RUNX3 is hypermethylated in a panel of PCa cell lines; Inhibits DNA methylation of RUNX3 could restored its gene expression, which in turn induced its anti-cancer effects. Thus, RUNX3 may serve as a novel putative molecular target gene for PCa therapy.
Thermodynamic and thermoelastic properties of wurtzite-ZnS by density functional theory
Authors: Ulian Gianfranco , Moro Daniele , Valdrè Giovanni
Published: February 2020

In the present paper, we provide a detailed theoretical investigation on fundamental thermodynamic, thermomechanical, and electronic properties of wurtzite ZnS between 0–20 GPa and 0–2000 K, obtained by ab initio density functional theory and the B3LYP functional. Several properties, such as phonon dispersion relations, elastic and piezoelectric constants, and thermodynamic and thermoelastic behaviors were calculated and reported. The analysis of the data via volume-integrated third-order Birch-Murnaghan fitting resulted in K0 = 72.17(4) GPa, K′ = 3.87(1), and V0 = 85.781(1) Å3 at T = 0 K. The Born criteria for the mechanical stability of the mineral phase showed that wurtzite is unstable above about 19 GPa in static conditions. We calculated a direct bandgap for wz-ZnS of 4.86 eV at zero compression, which became an indirect one by increasing pressure above 17 GPa. The results are in good agreement with the experimental and theoretical ones reported in the literature, and further extend the knowledge of an important zinc sulfide phase, for both geological and industrial applications.
Calculation of asymptotic normalization coefficients in the complex-ranged Gaussian basis
Authors: Sailaubek Dinmukhamed , Rubtsova Olga
Published: February 2020

A new technique towards finding asymptotic normalization coefficients
in the complex-ranged Gaussian basis is presented. It is shown that a
diagonalisation procedure for the total Hamiltonian matrix in the given
basis results in approximation for a radial part of the bound state wave
function from the origin up to the far asymptotic distances, which
allows to extract ANCs rather accurately. The method is illustrated by
calculations of single-particle ANCs for nuclei bound states in cases of
non-local nucleon-nucleus interactions, in particular, phenomenological
global potentials with the Perey-Buck’s non-locality.
Meningkatkan Kemampuan Berbicara Anak melalui Media Gambar dengan Pendekatan BCCT
Authors: Istianingsih Siti Nur
Published: February 2020

Berbicara merupakan alat komunikasi yang penting dalam berkelompok. Secara normatif, anak akan saling berkomunikasi terutama dalam kegiatan yang dikeijakan secara kelompok. Apabila anak pasif bicara atau diam, pola keija kelompok tidak efektif, sebab pada keija kelompok, kecakapan bicara merupakan alat komunikasi yang jjienjadi bagian dari alat utama untuk saling bekeija sama. Kemampuan berbicara anak dapat ditingkatkan salah satunya melalui media gambar. Kata Kunci: kemampuan berbicara, anak, media gambar, BCCT
MENINGKATKAN KEMAMPUAN KEAKSARAAN RESEPTIF ANAK MELALUI PERMAINAN POLA SUKU KATA DI TAMAN KANAK- KANAK NEGERI PEMBINA YOGYAKARTA
Authors: Amini -
Published: February 2020

Permainan pola suku kata adalah salah satu teknik pembelajaran yang dilakukan guru untuk  meningkatkan             kemampuan keaksaraan reseptif anak dalam hal membaca sambil bermain di Taman Kanak- Kanak. Pengenalan keaksaraan ini dilakukan melalui permainan pola suku kata dengan media pola suku kata MDF dan menggunakan instrument dari buku panduan perkembangan keaksaraan, minat baca, dan permainan pola suku kata. Alat penilaian  yang digunakan dengan menggunakan matriks indikator yang dibuat dalam bentuk cheklist, unjuk kerja  dan dokumentasi. Subyek dalam penelitian ini adalah anak- anak kelompok B4 TK Negeri Pembina Yogyakarta yang berjumlah 23 anak terdiri dari 14 anak laki- laki dan 9 anak perempuan. Dari hasil penelitian menunjukkan adanya peningkatan kemampuan keaksaraan  anak melalui permainan pola suku kata dengan media kartu huruf secara signifikan dibuktikan dengan data hasil awal 52,17% meningkat menjadi 88,25%.Sedangkan data hasil  minat baca dari 50,29% meningkat 85,53%. Hal ini dapat menunjukkan bahwa permainan pola suku kata dapat meningkatkan kemampuan keaksaraan reseptif anak.Kata Kunci: Bermain Pola Suku Kata
PERAN PENDIDIK PAUD DALAM MEMBANGUN KARAKTER ANAK
Authors: Maryatun Ika Budi
Published: February 2020

Artikel ini bertujuan untuk menjabarkan peran pendidik PAUD dalam membangun karakter anak sejak dini di lembaga. Lembaga pendidikan anak usia dini (PAUD) terdiri dari TPA, KB, dan TK. Pendidik PAUD yang dimaksud adalah guru dan pengasuh di sekolah, baik formal maupun nonformal. Karakter yang dikembangkan mengacu pada perkembangan moral anak melalui tiga pendekatan penanaman moral Lickona, yaitu konsep moral, sikap moral, dan prilaku moral.  Peran pendidik dalam membangun karakter anak sejak dini meliputi empat hal, yaitu (1) pendidik sebagai pendidik, (2) pendidik sebagai panutan, (3) pendidik sebagai perancang pengembangan, dan (4) pendidik sebagai konsultan dan mediator.Kata Kunci: Pendidik PAUD, Karakter Anak
Patients’ Convergence of Mass and Interpersonal Communication on an Online Forum: Hybrid Methods Analysis (Preprint)
Authors: Sanders Remco , Araujo Theo B , Vliegenthart Rens , van Eenbergen Mies C , van Weert Julia CM , Linn Annemiek J
Published: February 2020

BACKGROUND

Patients are increasingly taking an active role in their health. In doing so, they combine both mass and interpersonal media to gratify their cognitive and affective needs (ie, convergence). Owing to methodological challenges when studying convergence, a detailed view of how patients are using different types of media for needs fulfillment is lacking.

OBJECTIVE

The aim of this study was to obtain insight into the frequency of reported convergence, how convergence affects what posters write online, motives for posting, and the needs posters are trying to fulfill.

METHODS

Using a hybrid method of content analysis and supervised machine learning, this study used naturally available data to fill this research gap. We analyzed opening posts (N=1708) of an online forum targeting cancer patients and their relatives (Kanker.nl).

RESULTS

Nearly one-third of the forum opening posts contained signs of convergence in mass or interpersonal media. Posts containing mass media references disclosed less personal information and were more geared toward community enhancement and sharing experiences compared to posts without convergence. Furthermore, compared to posts without signs of convergence, posts that included interpersonal media references disclosed more personal information, and posters were more likely to ask for the experiences of fellow users to fulfill their needs. Within posts containing signs of convergence, posts including interpersonal media references reported fewer shortages of information, disclosed more information about the disease, and were more active in seeking other posters’ experiences compared to posts containing mass media references.

CONCLUSIONS

The current study highlights the intertwining of media platforms for patients. The insights of this study can be used to adapt the health care system toward a new type of health information–seeking behavior in which one medium is not trusted to fulfill all needs. Instead, providers should incorporate the intertwinement of sources by providing patients with reliable websites and forums through which they can fulfill their needs.
Effect of sandwich bone augmentation using hydroxyapatite and demineralized freeze- dried bone on infrabony pocket treatment
Authors: Ramadhany Eka Pramudita , Soesilowati Al Sri Koes , Lastianny Sri Pramestri
Published: February 2020

Periodontitis is periodontal inflammation in response to plaque bacterial antigens, causing damage to periodontal ligament and alveolar bone resorption. Bone graft material combination i.e. demineralized freeze-dried bone allograft (DFDBA) and hydroxyapatite (HA) using sandwich bone augmentation (SBA) method will support each other and will be beneficial to be used as a scaffold. The body takes long time to resorb HA so this could complement DFDBA which is more easily dissolved. This study aimed to reveal the effect of bone graft addition using SBA method on the treatment of infrabony pocket with open flap debridement in terms of probing depth, relative attachment loss, alveolar bone height, and density. This study was carried out to 20 infrabony pockets, where 10 of them were treated using open flap debridement with HA addition, while the other 10 groups were treated using open flap debridement with DFDBA and HA using SBA method. Probing depth  and relative attachment loss were measured on days 0, 30 and 90. Bone height and density were measured using cone-beam computed tomography (images on day 0 and 90). The study showed that probing depth reduction on SBA group was greater than HA group. There were significant differences in probing depth and relative attachment loss examinations. However, bone height and bone density reduction did not show any significant difference. The conclusion from this study is open flap debridement using SBA method yields better regeneration in terms of probing depth and relative attachment loss than open flap debridement with HA addition. There is no difference in bone height and bone density between the two groups.
An Analysis of Financing Scheme Effect on Non-Performing Financing Asset at Islamic Banks In Indonesia
Authors: Aprilianto Fitrian
Published: February 2020

This research aims to identify the impact of financing contracts on the risks confronted by Islamic banks measured by Non-Performing Financing (NPF). The data indicate that the value of NPF tends to annually increase along with a value close to the maximum limit set by Bank Indonesia (BI). The data of this study utilized secondary data in the form of monthly time series data in the period of January 2014 to December 2017 and cross-section data from the two types of Islamic Banking (Bank Usaha Syariah and Unit Usaha Syariah). The result indicates that the financing scheme which is based on the empirical scheme of profit-sharing schemes is proven to increase financing risk.