bluuebunny/crossref_metadata_2025_split huggingface dataset:
Host affinity and vertical distribution of epiphytic orchids in a montane cloud forest in southern Mexico
Authors: Hernández-Pérez Ezequiel , Solano Eloy , Ríos-Gómez Ramiro 
Published: June 2018

Background: The host´s structural characteristics provide diverse microhabitats that influence the distribution patterns of the epiphytes at different vertical zones and among tree species.Hypotheses: Epiphytic orchids have preference for larger host trees and with non-exfoliating rough bark, while the limiting hosts will be those of smaller size and smooth and exfoliating bark, and there will be fewer individuals in the upper canopy of the host trees because the micro-environmental conditions are more stressful compared to the middle and lower parts of the host trees.Methods: The host preferences and vertical distribution of the epiphytic orchids were analyzed in 20 montane cloud forest fragments. In each fragment, two transects of 2 × 50 m were drawn, and the trees with a diameter at a breast height ? 20 cm were recorded. In each tree, basal area was quantified and bark texture was characterized. In each tree and vertical zone, the orchid species present were identified and quantified.Results: Orchid distribution patterns vary between vertical zones and host tree species, and the richness is related to host size and bark texture. The highest species richness and number of epiphytic orchid’s individuals were recorded in host trees with fissured bark and larger size. The distribution of orchids in the host was not homogeneous nor was it related to any particular host species. However, five trees species were considered as host preferred, while five tree species were limiting hosts. The highest richness was recorded in vertical zone II and the lowest in zones I and V.Conclusions: Larger trees contain greater richness of epiphytic orchids, because they offer better conditions for their establishment, provide a great diversity of microhabitats, greater time and area for epiphytic colonization events. The texture of the bark is a relevant factor in the host preference, and in the hosts with smooth bark, the presence of epiphytic orchids depends on the accumulation of organic matter.
ERCP komplikasyonları; sıklığı, etkileyen faktörler ve yönetimi
Authors: TUNÇ Nurettin , KILIÇ Salih , ŞAHİN Abdurahman , DEMİREL Ulvi , POYRAZOĞLU Orhan Kürşat , BAHÇECİOĞLU İbrahim Halil , YALNIZ Mehmet 
Published: June 2018

Giriş ve Amaç: Safra yolları ve pankreas hastalıklarının tanı ve tedavisinde yaygın olarak kullanılan bir yöntem olan endoskopik retrograt kolanjiopankreatikografi ile ciddi komplikasyonlar bildirilmiştir. Bu komplikasyonlar endoskopik retrograt kolanjiopankreatikografi işlemine bağlı sfinkterotomi yerinden kanama, pankreatit, kolanjit, perforasyon ile kardiyopulmoner komplikasyonlar (hipoksi, hipotansiyon ve aritmi gibi) ve ölümdür. Bu çalışmadaki amacımız endoskopik retrograt kolanjiopankreatikografi işlemi ile kompliklasyon gelişen hastalarda risk faktörlerini saptamak ve bu hastalarda uygun tanısal ve terapötik yaklaşımı belirlemektir. Gereç ve Yöntem: 2016 yılı içinde endoskopik retrograt kolanjiopankreatikografi işlemi yapılan 487 hastanın verileri retrospektif olarak elde edildi. Bulgular: Endoskopik retrograt kolanjiopankreatikografi işlemi uygulanan 487 vakanın 304’ü (%62,4) kadın, 183’ü (%37,6) erkekti. Ortalama yaş 61,53 (min-maks: 18-99) yıl idi. Post-endoskopik retrograt kolanjiopankreatikografi komplikasyonları 53 (%10,8) vakada görülmüş; 37’si (%7,6) pankreatit, 15’i (%3,1) kanama, 1’i (%0,2) duodenum perforasyonu olarak raporlanmıştı. İğne uçlu sfinkterotom ile ön kesi yapılan 2/67 (%2,9) vakada post-endoskopik retrograt kolanjiopankreatikografi pankreatiti gelişmiş olmasına karşı ön kesi yapılmayan 65/420 (%8,33) vakada post-endoskopik retrograt kolanjiopankreatikografi pankreatiti gelişmişti. Post-endoskopik retrograt kolanjiopankreatikografi pankreatiti iğne uçlu sfinkterotom ile ön kesi yapılanlarda daha az oranda görülmekle birlikte istatistiksel olarak anlamlı değildi (p: 0,127). Yapılan endoskopik retrograt kolanjiopankreatikografinin kaçıncı endoskopik retrograt kolanjiopankreatikografi işlemi olduğu ve post-endoskopik retrograt kolanjiopankreatikografipankreatiti ilişkisi karşılaştırıldığında post-endoskopik retrograt kolanjiopankreatikografi pankreatiti gelişimi ilk kez endoskopik retrograt kolanjiopankreatikografi yapılanlarda (%91) anlamlı olarak daha sık gözlenmiş (p: 0,041), post endoskopik retrograt kolanjiopankreatikografi komplikasyon olarak mortalite hiç izlenmemişti. Sonuç: Post endoskopik retrograt kolanjiopankreatikografi pankreatiti endoskopik retrograt kolanjiopankreatikografinin en sık komplikasyonudur. Endoskopik retrograt kolanjiopankreatikografi ile ciddi komplikasyonlar görülebilmesine rağmen uygun endikasyonda endoskopik retrograt kolanjiopankreatikografi yapılması ve oluşan komplikasyonların erken tanınması morbidite ve mortalitenin önlenmesinde en önemli adımdır.
ESTUDO DA CINÉTICA DE SECAGEM DE POLPAS DE HIDRÓXIDO DE MAGNÉSIO
Authors: Campos Elaine Cristina , Chaves Diego Henrique de Souza , Souza Lucas De Oliveira , Sousa Matheus Andrade de , Birchal Marco De Souza , Birchal Viviane Santos 
Published: June 2018

<p><em>O presente trabalho teve por objetivo estudar a cinética de secagem em estufa através da obtenção de dados de secagem de suas curvas e aplicação dos modelos matemáticos aplicados à secagem de polpas de hidróxido de magnésio preparadas a partir da hidratação de duas fontes distintas de magnésia cáustica e de uma polpa de hidróxido de magnésio p.a., a título de comparação. As polpas preparadas a partir das fontes de magnésia cáustica foram obtidas por hidratação do óxido de magnésio em um sistema híbrido reator-moinho de bolas após 5 horas de reação. Para caracterização físico-química das amostras, foram utilizadas as técnicas de fluorescência de raios X e análise granulométrica por difração a laser. Os resultados mostraram alta velocidade de secagem das polpas com a etapa de secagem à taxa constante como sendo a controladora do processo, com transferência de calor e massa predominantemente a partir da superfície, apresentando um melhor ajuste ao modelo de Lei de Resfriamento de Newton.</em></p><p><em> </em></p><p><em>ABSTRACT</em></p><p><em></em><em>The aim of the present work was to study the kinetics of drying in stove by obtaining drying data of its curves and applying the mathematical models applied to the drying of magnesium hydroxide pulps prepared from the hydration of two different sources of caustic magnesia and one magnesium hydroxide pulp, for comparison purposes. The pulps prepared from the sources of caustic magnesia were obtained by hydration of the magnesium oxide in a reactor-ball mill hybrid system after 5 hours of reaction. For the physicochemical characterization of the samples, the techniques of X-ray fluorescence and granulometric analysis by laser diffraction were used. The results showed a high drying rate of the pulps with the drying step at constant rate as the process controller, with heat transfer and mass predominantly from the surface, presenting a better fit to the Newton Cooling Law model.</em></p>
Treatment of Adhesive Capsulitis of the Shoulder
Authors: Yip Michael , Francis Anna-Marie , Roberts Timothy , Rokito Andrew , Zuckerman Joseph D. , Virk Mandeep S. 
Published: June 2018

* Idiopathic adhesive capsulitis of the shoulder is a self-limiting condition with gradual improvement in symptoms over a variable period of time (1 to 3 years), although a small subset of patients can have permanent residual symptoms.* Nonoperative and operative treatments do not alter the long-term natural history of adhesive capsulitis, but they do provide short-term symptomatic relief of pain and improvement in shoulder range of motion.* There has been no consensus in scientific literature on a single treatment type, nonoperative, operative, or combined, which is more effective in the treatment of adhesive capsulitis.* There has been a general consensus that nonoperative management is the initial treatment of choice for adhesive capsulitis. Nonoperative treatments such as physical therapy, oral anti-inflammatory medications, corticosteroid injections, and hydrodilatation allow accelerated pain relief and/or improvement in range of motion compared with untreated controls, but these differences are short-term and there is no difference in final outcomes.* There has been insufficient evidence to support early operative treatment for adhesive capsulitis. However, there has been a general consensus that operative treatment (arthroscopic capsular release and/or manipulation under anesthesia) is an option if nonoperative treatment fails after a period of 6 months.* Arthroscopic capsular release with or without manipulation results in early relief of pain and improvement in motion compared with nonoperative treatment, but there is no difference in the final outcomes.* There has been insufficient evidence to make recommendations with regard to the indication for and timing of operative treatment or to the ideal surgical technique for arthroscopic capsular release.
Application of Sand-Ramp Fracturing Pumping Mode in Unconventional Shales Stimulation
Authors: Yang Guangzhi , Zhang Shicheng , Liu Ming 
Published: June 2018

Abstract
Sand-slug fracturing has been the main fracturing pumping mode due to the tightness of shale. This mode makes it easier to inject proppants. However, it may cause poor connectivity in the middle brittle formation due to the discontinuous propping. This paper describes an attempt to fracture the unconventional shales with conventional sand-ramp fracturing pumping mode. The results show that good effect is achieved compared with the sand-slug fracturing mode used in the adjacent wells.
Shale reservoir reconstruction has large construction displacement and high pressure, and it adopts fracturing technology of slickwater and linear glue1. In other blocks, Sand-slug mode causes large amounts of slickwater injecting into the formation. The role of water, in addition to carrying sand and making seams, will also cause "water lock" in the micro-fissure, reducing the gas permeability. Therefore, the large amount of liquid is not good to the reservoir.
The Sand-ramp modes using less fluid and higher sand content2-3, resulting in a greater height and length of the fractures. By using a small amount of proppant, Sand-ramp mode can also achieve high conductivity4, communicating the natural cracks5-7 at the same time. Two wells were designed for Sand-ramp mode in the test area.
Based on the understandings on geological characteristics and formation property, the sand-ramp fracturing pumping mode was designed. Two of six wells in the pad were selected to apply this mode. To maximize the stimulated reservoir volume, slickwater accounted for 40% to 60% of the total injected fluids. 100-mesh quartz sands were pumped in priority to improve the complexity of fracture. Then, the 40-70 mesh ceramsites was pumped with crosslinked gel to support the primary, secondary and natural fractures. The pumping rate is 12-13 cubic meters per minute and no acid is used throughout the whole pumping process.
The maximum proppant concentration of sand-ramp reached to 480 kilogram per cubic meters, which was much higher than that of sand-slugs. As a result, good propped fractures were obtained. Since no fluid sweep was used after the sand-slug, the average fluid injection per stage is declined by 27%, but the average sand injection volume was increased by 17%, which significantly reduced the cost and the possible influence to environment. With the sand-ramp mode, the highest test production of the block was up to 278500 cubic meters per day. This well produced 35 million cubic meters of shale gas in 270 days.
The practicability of the sand-ramp pumping mode used in unconventional shales is proven to be positive, especially in the formation with high horizontal stress difference. However, the development result needs to be continuously studied.
Acidizing Highly Permeable Sandstone Stringers: Drill-in Fluid Damage and Compatibility with Rock Minerals
Authors: Al Moajil Abdullah , Al-Khaldi Mohammed , Hazzazi Hassan , Caliskan Sinan 
Published: June 2018

Abstract
Drilling horizontal and highly permeable sandstone acid-sensitive reservoirs with oil based drilling fluids are normally followed by filter cake and associated organic sludge removal treatments. The acid or cleaning recipes should be compatible with the formation minerals, especially when losses are encountered. The objectives of this paper were to conduct a comprehensive evaluation of HCl/formic acid recipe to dissolve oil-based filter cake, characterize and dissolve associated organic sludges, and assess compatibility with highly permeable acid-sensitive sandstone core plugs.
Filter press experiments were conducted to optimize the fluid recipe. Core flood testing was conducted on sandstone core plugs at 160°F. Compatibility with reservoir fluids were assessed using aging cells. TGA was used to identify organic/inorganic composition of sludge samples XRD and ESEM were used to characterize core plugs and sludge samples. ICP analysis was conducted to analyses effluent from coreflood experiments. GC and GC-MS analysis was conducted to identify and characterize sludge samples. Micro CT scan was used to assess the dissolution of rock minerals.
The removal efficiencies of the oil-based filter cake were between 85-100% by weight using HCl/Formic acid recipe. The characterization of the sludge samples revealed the presence of mainly diesel. The inorganic compounds (50% by weight) were mainly quartz with small amounts of calcite, dolomite, kaolinite, microcline, and pyrite. Maximum solubility of nearly 60 wt% was achieved. Core flooding tests of the acid recipe indicated reduction in permeability of core plug. The coreflood effluent analysis indicated dissolution of mainly Ca, Fe, and Mg with small amounts of Al, Si, and Sr with indication of Si-based precipitation. No major indication of precipitation occured. ESEM and EDS spot analysis of the core plug particles showed the sample was comprised Si, O, Fe, S as the main constituents with small amounts of Al. XRD analysis of the core plug after coreflood testing showed the presence of mainly Quartz and small amounts of Microcline, Pyrite, and Palygorskite. The CT scan of core plug before/after coreflooding indicated the acid dissolved rock minerals. There was no clear indication of core damage or solids plugging.
An Evaluation of Enhanced Oil Recovery Strategies for Extra Heavy Oil Reservoir after Cold Production without Sand in Orinoco, Venezuela
Authors: Bao Yu , He Liangchen , Lv Xue , Shen Yang , Li Xingmin , Liu Zhangcong , Yang Zhaopeng 
Published: June 2018

Abstract
The Orinoco heavy oil belt in Venezuela is one of the largest extra-heavy oil resources in the world. It has become a major goal for the unconventional oil exploitation in these years. Now, the most common production method is to use the horizontal well cold production without sand. It is an economic and commercial process, and with the reservoir of this area have high initial gas to oil ratio (GOR), porosity and permeability with unconsolidated sand. However, after several years' production, the oil rate draws down quickly caused by the reservoir pressure drops; the key challenge of cold production is that the recovery factor (RF) tends to be only between 8% and 12%, implying that the majority of the oil remains in the oil formation. It is necessary to develop viable recovery processes as a follow-up process for cold production. Generally, steam based recovery method was widely used as a follow-up process for cold production. In this paper, steam fracturing (dilation) Cyclic Steam Stimulation (CSS) operation and Non steam fracturing (No dilation) CSS operation by using reservoir simulator is examined for a post cold production in extra heavy oil reservoir, in order to analyze the performance of the oil rate, cumulative steam-to-oil ratio (cSOR), steam depletion zone, greenhouse gas emission and some necessary parameters.
The key component of the steam fracturing (dilation) is the ability to inject high temperature and pressure steam into the formation to fracture the reservoir rock which in turn raises the rock permeability and mobilized the oil by lowering the visocisity. To compare the results of the dilation and no dilation CSS operation, this study reveal that due to the steam is injected into the reservoir by using the same cumulative cold water equivalent (CWE), the steam condensate; pressurized by steam vapour, fracture the formation. Dilation operation achieves higher oil rate, lower cSOR. The result also show that fraturing (dilation) of the reservoir during steam injection relieves the pressure which in turn lowers the steam injection pressure below the case where No dilation operation ouccurs.
Increasing Production Flow Rate and Overall Recovery from Gas Hydrate Reservoirs Using a Combined Steam Flooding-Thermodynamic Inhibitor Technique
Authors: Fakher Sherif , Abdelaal Hesham , Elgahawy Youssef , El Tonbary Ahmed , Imqam Abdulmohsin 
Published: June 2018

Abstract
When producing from gas hydrate reservoirs using steam flooding, since hydrate dissociation is an endothermic reaction, the heat is used up. This results in a decrease in reservoir temperature which causes the hydrate equilibrium conditions to be established again, thus causing hydrate reformation. This research studies the effect of injecting thermodynamic inhibitors during steam injection on overcoming the problem of hydrate reformation which in turn will increase hydrocarbon recovery significantly from hydrate reservoirs. The reservoir model was built based on data collected from previous models found in the literature. After specifying all parameters for the reservoir, and the hydrate layer, a systematic study was performed in order to assess the use of inhibitors with steam flooding. The production methods studied include depressurization, steam flooding, inhibitor injection including both brine and glycol, and finally the combined steam flooding inhibitor injection method. The conditions for the steam flooding were kept the same during all runs in order to be able to compare them. Results indicated that the use of the thermal stimulation alone without inhibitor managed to increase recovery, however, the problem of hydrate reformation occurred which caused a cessation of production. Using inhibitors alone managed to increase recovery as well, however the recovery increase was much less compared to thermal stimulation. The type of inhibitor also played a role in recovery with the glycol producing the most, followed by the brine. By combining both steam flooding and inhibitor injection, the recovery increased significantly more than what was observed when using each of the methods on its own. To the authors' knowledge, no extensive study has been performed by combining both steam flooding and inhibitor to increase hydrocarbon recovery from hydrate reservoirs. This research can help in improving real field gas hydrate projects by making the overall project much more economic by increasing hydrocarbon recovery.
A Newly Developed Mathematical Model to Predict Hydrolyzed Polyacrylamide Crosslinked Polymer Gel Plugging Efficiency in Fractures and High Permeability Features
Authors: Fakher Sherif , Bai Baojun 
Published: June 2018

Abstract
Reservoir heterogeneity is one of the most challenging problems facing the hydrocarbon industry nowadays. It results in excess water production and a substantial reduction in oil recovery from water flooding applications. Gel treatment is one of the most successful applications to overcome reservoir heterogeneity problems by plugging high permeability features in a reservoir. One of the most widely used gels is the Hydrolyzed Polyacrylamide-Chromium Acetate Gel (HPAM/CrAc). This research uses data from 70 sources, including more than 1050 experiments, to perform a thorough data analysis to understand the conditions under which this gel is mainly applied. Histograms, and boxplots were generated revealing the ranges under which this gel can be applied, and the frequency of each range. The histograms and boxplots are each divided into the gel properties, and the core and sand pack properties, thus revealing both the chemical and rock properties' ranges. Three dendrograms were also developed based on their equivalent cluster plots generated. The dendrograms can show the different ranges at which the data was distributed and also tell the extent to which each range is related to the other. A mathematical model was also generated and validated in this study. This model gives a relation between the polymer concentration and the oil residual resistance factor (Frro). This model is extremely important since it can predict the effect of polymer concentration on the reduction of the oil permeability, which can help avoid the excessive reduction in oil permeability. The gel was found to have very good disproportionate permeability reduction (DPR), which indicates that it can reduce the permeability of water much more that the permeability of oil. This research can help in revealing the conditions under which the HPAM/CrAc gel can be applied, which in turn can significantly improve the design of field projects.
Advanced HSP Ceramic Proppants— An Evaluation and Effect of Fines on Proppant Pack Conductivity
Authors: Al Moajil Abdullah , Alghizzi Ahmed , Alsalem Ali , AlDarweesh Sajjad 
Published: June 2018

Abstract
Fracturing fluids are normally injected at high rates and pressures to break the reservoir rock, where proppants ideally are suspended during fluid injection. High strength ceramic proppants are used to overcome hash environments (i.e., high closure stress and temperatures). Advancements in proppant manufacturing further added several characteristics to the proppants, such as self-suspending, multi-phase flow enhancer, and multifactional proppants. The objectives of this study were to compare the performance of HSP and ULW ceramic proppants though proppant characterization, wettability measurements, settling behavior, acid solubility, proppant pack conductivity, and proppant crush resistance.
Fracture cell was used to measure the proppant pack conductivity. Proppant crush resistance was conducted using hydraulic uni-axial loading frame. XRD and XRF were used to characterize proppant samples. Solubility in HCl solutions was examined. Elemental analysis was conducted using ICP. Light transmission and backscattering technique was used to compare the settling behavior of proppant samples. Drop Shape Analyzer was used to measure the contact angle on the surface of proppant samples.
The highest performance proppant among the five-examined proppants was proppant P-1. This was based on the conductivity values obtained, the correlation between conductivity and fines generated, settling behavior, and solubility in HCl acids. Proppant P-5 exhibited non-wetted properties for both water and condensate fluids. ULW proppants (i.e., P-7 and P-8) showed significantly improved suspension properties over the examined HSP proppants. The solubility of the HSP proppants in HCl acid depended on the acid concentration, soaking time, surface area. The solubilities obtained was up to 10 wt% in concentrated HCl acids. High concentrations of Fe were observed in concentrated acid solution (i.e. ~1800 mg/l). Proppant pack conductivity values for examined proppants were relatively similar except for proppants P-3 and P-5.A linear correlation was found between wt% of fines generated and proppant pack conductivity.