bluuebunny/crossref_metadata_2025 huggingface dataset:
A prospective study of management of subtrochanteric femur fracture using proximal femoral nail
Authors: Malik Shwetabh , Malviya Parimal , Vieira Alfven , Jain Deepak
Published: February 2020

Background: Proximal femur fractures present considerable challenge in management. They are due to high velocity trauma, with or without soft tissue injury and usually with a metaphyseal and diaphyseal involvement. The surgeon has to face many challenges like identifying the entry, reduction the fracture, and difficulty due to a narrow medullary canal and comminution. The present study was conducted to assess the utility and effectiveness of Proximal Femoral Nail for subtrochanteric fractures of femur.

Methods: In this study a total of 30 patients with Sub trochanteric femur fracture admitted to MGM medical college and hospital from June 2015 to July 2017 were selected for treatment with proximal femur nail.

Results: 30 patients were included in this study with subtrochanteric fractures of femur treated with Proximal femoral nail. Maximum 21(70%) of patients were below 61 yrs of age. Mean age was 47.9 years. There was 21 male and 9 females in the study.  There were 6 patients with local complications. Final result of our study, we had 26.7% excellent, 46.6% good, 20% fair and 6.7 % poor results according to Harris hip score.

Conclusions: In our study, looking at the results we found that Proximal femoral Nail proves to be a good implant in management of subtrochanteric fractures of femur.  However, it is a small study to conclude anything definitely.
Hand and foot syndrome secondary to capecitabine
Authors: Narasimhan Murali , Kumar Abhishek , Ramakrishnan Ramachandran
Published: February 2020

Hand and foot syndrome are an adverse effect often seen with chemotherapy or with the use of biologics. It is characterised by painful erythema and edema, dry or moist desquamation of palms and soles in mild to moderate case. Severe cases usually present with cracking, peeling, blister, ulcer and severe pain. Here we report a 65-year-old woman with breast carcinoma who was on treatment with capecitabine and presented with fissuring and bleeding over palms and soles, with progressive burning sensation. On examination, hyperpigmentation and scaling were also noted over both palms and soles. She was diagnosed with hand and foot syndrome and was treated with emollients, antibiotics and topical steroids.
Nail changes in various dermatoses: an observational study conducted at tertiary care center, Ujjain, Madhya Pradesh, India
Authors: Kumar Ujjwal , Varma Krishnendra , Shayalwar Ankur
Published: February 2020

Background: Nail apparatus forms an integral part to be examined for all dermatological conditions. Nail changes are seen in various dermatosis like psoriasis, onychomycosis, lichen planus, collagen vascular disease, vesicobullous diseases and other papulosquamous diseases. Aims and objective of the study was to determine the prevalence of nail changes in various dermatological conditions.

Methods: After applying inclusion and exclusion criteria, 269 cases with various nail changes were enrolled in the study. Detailed history and thorough nail examination was carried out along with other necessary investigations like CBC, RFT, LFT, nail clipping for fungal hyphae culture and microscopy.

Results: Out of 269 cases with nail disorders, male to female ratio was 1.5:1 and most common age group was 31-40 years. The most common abnormality observed was onychomycosis (34.2%) followed by nail changes in psoriasis (30.4%), LP (18.5%), eczema (4%), trachonychia (3.3%), paronychia (2.9%), lichen striatus (2.2%) and darier’s disease (0.37%). Among onychomycosis most common pattern observed was DLSO (82.6%) followed by PSO (7.6%), SWO (5.4%) and TDO (4.34%). The pattern of nail changes in psoriasis patients was pitting (30.4%), subungual hyperkeratosis (21.9%) and onycholysis (10.9%). Cases with LP had longitudinal striations (52%), thinning of nail plate and trachonychia (10% each). V shaped notching and distal splitting was seen in one of the Dariers’ disease patient.

Conclusions: Nail changes form an indispensible part of various dermatological conditions. The pattern of involvement is unique in each and every disease. Hence examination of all the 20 nails should never be missed.
Therapeutic efficacy of topical luliconazole versus topical ketoconazole in the treatment of pityriasis versicolor patients: a hospital based comparative study
Authors: Hassan Shahid , Ranjan Ashutosh
Published: February 2020

Background: To evaluate the clinical efficacy of 1% topical luliconazole versus 2% topical ketoconazole in pityriasis versicolor patients.

Methods: Mycological examination of all the pityriasis versicolor patient was done by using skin scrapings were collected from the skin lesions to prepare for 10% KOH mount, which was examined under the microscope to note the findings as KOH mount positive or negative for Malassezia fungi. KOH mount positive or negative was noted at 0 days, 2 weeks and 4 weeks continued treatments with luliconazole and ketoconazole.

Results: At the first days, majorities of patients 46 (92%) of luliconazole group were positive for KOH mount. At 14 days treatment with luliconazole, patients had 11 (22%) positive for KOH mount. At the 28 days treatment with luliconazole, only 2 (4%) patients were positive and most of the patients 49 (98%) were negative for KOH mount. Similarly, in ketoconazole group patients, 47 (94%) patients were positive for KOH mount in beginning of treatment. At 14 days treatment with ketoconazole 16 (32%) patients were positive and 34 (68%) patients were negative for KOH mount. And at the 28 days with treatment of ketoconazole 13 (26%) patients were positive and most of the patients 37 (74%) were negative for ketoconazole.

Conclusions: Male population as well as age 26-35 years were more prone for pityriasis versicolor infection. On two weeks of treatment luliconazole and ketoconazole had near about similar efficacy against pityriasis versicolor. But, on continue 4 weeks of treatment regimens topical luliconazole had more clinically efficacious than ketoconazole against pityriasis versicolor.
Estándares internacionales en materia de orientación sexual e identidad de género: interpretación evolutiva en el derecho interamericano
Authors: Núñez Marín Raúl Fernando
Published: February 2020

La discusión jurídica frente a los derechos de las minorías se encuentra en pleno auge. Tanto los sistemas domésticos como los sistemas de derecho internacional se enfrentan a los retos de un mundo cada vez más diverso, en el que la distinción entre mayorías y minorías tiende a ser innecesaria. Es así como la temática de los derechos de las comunidades LGBTI cobra vigencia. El derecho internacional ha fijado estándares que permiten dar una interpretación amplia y evolutiva a sus derechos, basándose en nuevos conceptos sobre la orientación sexual y la identidad de género, en lo referente a la igualdad, y, como consecuencia de sus derechos al matrimonio y a la familia. Su análisis requiere del uso de fuentes formales y de soft law, así como del derecho comparado.
Límites y alcances jurídicos sobre los derechos del nasciturus
Authors: Galvis Plazas Martha Ximena
Published: February 2020

El presente artículo, a través del análisis y la comparación de diferentes legislaciones, incluida la colombiana, tiene por objetivo presentar el conflicto que se da entre las posturas que, por un lado, reconocen al nasciturus en cualquier fase de su desarrollo como portador del derecho a la vida y, por otro lado, las que lo identifican únicamente como ser potencial que adquiere los derechos de una persona solo a partir del momento del nacimiento, incluido el derecho a la vida. Como conclusión, se determina que la ciencia del derecho ha aportado al significado y al rol del nasciturus, lo cual incide en el trato y en las responsabilidades y deberes no solo civiles, sino también morales que el Estado y las personas legalmente reconocidas tienen hacia él, sin embargo, en escenarios de guerra y violencia la realidad refleja desprotección y maltrato hacia el no nacido.
In praise of vital records. A few cases
Authors: Samborska-Kukuć Dorota
Published: February 2020

A literary historian finds birth, death, and marriage certificates incredibly useful as primary research sources. Detached as it is, this knowledge serves as a solid basis both for individual biographies and contexts meant to reconstruct a particular historical thread. Personalised documentation is subjective by nature, while the discussed documents tend to contain accurate and unbiased data. The cases discussed herein prove the need to consult both standard documents for personal data and dates of birth/death, as well as the information on occupation, place of birth/residence/death, kinship and affinity, even milieu. Thanks to the discovery of the birth certificate of Maria and Wawrzyniec Puttkamer’s daughter, the Philomaths’ letters of 1823 could be seen in a different light, as could the alleged affair between Maria Puttkamer and Adam Mickiewicz. To explicate and substantiate the personal data included in Maria Konopnicka’s letters and notes, a genealogical reconstruction of her family is in order. Bolesław Leśmian’s vital records revealed hitherto unknown details of his biography (and of people associated with him). A scrutiny of Maria Piotrowicz’s biography, based almost exclusively on certificates, disclosed the legendary story of her life. The above are mere examples of all the cases that can prompt researchers to explore archives in search of fundamental documentation, which can prevent paralogisms and help break the chain of errors with a view to further data mining.
Рождение текста в поэтической лаборатории Владимира Аристова: дискретно-уровневая модель
Authors: Andreeva Ekaterina , Vorobyov Vasily
Published: February 2020

В статье исследуется творческий метод поэта В. Аристова на примере двух стихотворений, с привлечением авторских комментариев и уникальных рукописных материалов. Прослеживаются все этапы создания этих текстов. Рассматривается особый тип творческого мышления Аристова – дискретный, или «слоистый», при котором каждый этап работы над произведением фактически представляет собой отдельный и относительно автономный слой, а процесс творчества присутствует в сознании автора как переход из одного слоя в другой. Показано, что каждое произведение не только создается послойно, но и его окончательный вариант имеет слоистую структуру, эксплицитно отражаемую разбивкой текста на части-уровни с помощью пунктирной горизонтальной черты. Наконец, мотивы слоев присутствуют и в семантике стихотворений Аристова (слои личной памяти, слои истории, геологические слои и др.).
Conversion and Reversion Rates of Tuberculosis Screening Assays in Patients With Rheumatic Diseases and Negative Baseline Screening Under Long-Term Biologic Treatment
Authors: Thomas Konstantinos , Hadziyannis Emilia , Hatzara Chrisoula , Makris Anastasia , Tsalapaki Christina , Lazarini Argyro , Klavdianou Kalliopi , Antonatou Katerina , Koutsianas Christos , Vassilopoulos Dimitrios
Published: February 2020

Background: To determine the conversion and reversion rates of tuberculosis (TB) screening tests (Tuberculin Skin Test-TST, Interferon Gamma Release Assay-IGRA: T-SPOT.TB) during biologic treatment in patients with rheumatic diseases and negative baseline screening.Methods: This was a long-term, longitudinal cohort study of 50 patients with rheumatic diseases and negative baseline TB screening (TST: < 5 mm, negative T-SPOT.TB) treated with tumor necrosis factor inhibitors (TNFi) or other non-TNFi biologics. Patients were rescreened at a mean time of 1.4 (first rescreening) and 6.9 (second rescreening) years from baseline, with both assays. The conversion (negative to positive) and reversion (positive to negative) rate was calculated for each TB screening test.Results: Fifty patients (mean age = 60 years) with various rheumatic diseases (rheumatoid arthritis: n = 24, spondyloarthropathies: n = 23, other: n = 3) were enrolled. During the first phase (baseline to first rescreening), all patients were treated with TNFi while during the second phase (first to second rescreening), TNFi (54%) and non-TNFi (46%) were used. Fifteen patients (30%) displayed conversion of at least 1 screening assay during follow-up (10 at the first and 5 at the second rescreening). This conversion rate was higher with TST (n = 11, 22% or 3.47/100 patient-years) compared to T-SPOT.TB (n = 4, 8% or 1.74/100 patient-years). Among the 10 converters at the first rescreening, 5 received isoniazid (INH) preventive therapy and 5 did not; an equal number of patients (3/5, 60%) reverted to negative with or without INH therapy. None of the patients developed active TB during follow-up (6.9 ± 1.0 years).Conclusions: Approximately one-third of patients with rheumatic diseases and negative baseline TB screening developed conversion of at least 1 screening test during long-term biologic treatment. This occurred most often with TST and was usually a transient event. These findings do not support routine serial TB retesting in biologic-treated patients with rheumatic diseases in the absence of TB risk factors.
CORRELATION BETWEEN PROLONGED STANDING AND PLANTAR FASCIITIS
Authors: Purvitagiri Ni Ketut Maya , Dewanti Linda , Bayusentono Sulis , Wardhani Indrayuni Lukitra
Published: February 2020

Background:  Plantar fasciitis (PF) is the most common heel pain in adult. It is estimated that it affects as much as 10% of the population over the course of their lifetime. Previous study mention that prolonged standing is one of the risk factor of PF, however other study suggests that there is low evidence of prolonged standing may cause PF. The objective of this study was to findout whether or not prolonged standing may correlate to PF. Methods: This cross-sectional with total sampling study involved 73 workers in total. 35 of them did not fulfill the inclusion criteria, hence only 38 of subjects were used. The data collected using questionnare and analyzed using Chi-square. with p-value (p) <0.05 and confidence interval (CI) 95%. Results: There is no correlation between prolonged standing and PF symptoms p= 0.249. Conclusion: There is no correlation between prolonged standing and plantar fasciitis and even though in other study suggest that BMI, and age also the risk factor of PF this was not consistently confirmed in this study. Further research may use larger number of subjects and use other measure to determine the definition of prolonged standing.
Evolution in the Correction of the Literature: Preprints, Manuscript Versioning, Error Amendment, and Retract and Replace
Authors: Teixeira da Silva Jaime
Published: February 2020

Academic publishing is undergoing a highly transformative process, and many rules and value systems that were in place for years are being challenged in unprecedented forms leading to the evolution of novel ways of dealing with new pressures. One of the most important aspects of an integrated and valid academic literature is the ability to screen publications for errors during peer review to weed out mistakes, fraud and inconsistencies, such that the final published product represents a product that has value, intellectually, and otherwise. It is difficult to claim the existence of perfect manuscripts. The level of errors that exist in a manuscript will depend on the rigor of the research group and of the peer review process that was used to screen that paper. When errors slip into a final published paper, either through honest error or misconduct, and are not detected during peer review and editorial screening, but are spotted during post-publication peer review, an opportunity is created to set the record straight, and to correct it. To date, the most common forms of correcting the literature have been errata, corrigenda, expressions of concern, and retractions. Despite this range of corrective measures, which represent artificially created corrals around pockets of imperfect literature, certain cases do not quite fit this mold, and new suggested measures for correcting the literature have been proposed, including manuscript versioning, amendments, partial retractions and retract and replace. In this commentary, a discussion of the evolving correction of the literature is provided, as are perspectives of the risks and benefits of such new measures to improve it.
Invasive Alien Species of Bangladesh
Authors: Mukul Sharif A. , Mohammed Abu Sayed Arfin Khan , Uddin Mohammad Belal
Published: February 2020

Bangladesh has a history of species introduction from different geographic regions. The country was a major trade route during the early-modern era and was under British colonial rule until 1947s. Many species of plants and animals are either domesticated or cultivated at different times that were brought into the country by the settlers, seamen, and traders. The deliberate preferences of fast-growing, high-yielding exotics in recent decades also threaten the existence of native species and their genetic resources in the country. Here we provide an overview of the invasive alien species in Bangladesh, likely pathways of their introduction, their impacts on ecosystem and people, and strategies for their effective management and regulation. Many exotic plants and animals both terrestrial and aquatic have found to be invasive in the country with negative impacts on local ecosystems, biodiversity, and livelihoods. Collectively, those species possess serious threats to country’s agriculture, forestry, and fisheries sector. Although initially introduced to favor primary productivity or other environmental benefits, many of these are now regarded as obnoxious pest or weed in Bangladesh. A comprehensive list of invasive species both for native and exotics and a framework to characterize them is also absent in the country. We recommend a separate statutory body and appropriate rules and policies for the introduction, monitoring, and management of alien species in the country. Community awareness, advocacy, surveillance, capacity building of relevant government staff and agreement with neighboring countries for transboundary management of invasive alien species is also necessary.
Performance Results of a Solar Adsorption Cooling and Heating Unit
Authors: Roumpedakis Tryfonas , Vasta Salvatore , Sapienza Alessio , Kallis George , Karellas Sotirios , Wittstadt Ursula , Tanne Mirko , Harborth Niels , Sonnenfeld Uwe
Published: February 2020

The high environmental impact of conventional methods of cooling and heating has increased the need for renewable energy deployment for covering thermal loads. Towards that direction, the proposed system aims at offering an efficient solar powered alternative, coupling a zeolite-water adsorption chiller with a conventional vapor compression cycle. The system is designed to operate under intermittent heat supply of low-temperature solar thermal energy (<90 °C) provided by evacuated tube collectors. A prototype was developed and tested in cooling mode operation. The results of separate components testing showed that the adsorption chiller was operating efficiently, achieving a maximum coefficient of performance (COP) of 0.65. With respect to the combined performance of the system, evaluated on a typical week of summer in Athens, the maximum reported COP was approximately 0.575, mainly due to the lower driving temperatures at a range of 75 °C. The corresponding mean energy efficiency ratio (EER) obtained was 5.8.
Towards More Powerful Antibodies for Fibroblast Growth Factor Receptors in Breast Cancer
Authors: Sobhani Navid , Fan Chunmei , O. Flores-Villanueva Pedro , Generali Daniele , Li Yong
Published: February 2020

Breast cancer (BC) is the most frequent form of malignancy and the second only to lung cancer as common cause of cancer-causing deaths in women. Notwithstanding many progresses in the field, metastatic BC has a very poor prognosis. As therapies are becoming more personalized to meet patients‘ needs, a better knowledge of the molecular biology leading to the disease unfolds the possibility to project more precise compounds or antibodies targeting definite alteration at the molecular level expressed in cancer cells of patients or as antigens on the surface of cell membranes. Fibroblast growth factor receptor (FGFR) is a druggable target -which is activated by its own ligands -namely the Fibroblast Growth Factors (FGFs). This pathway provides a vast range of interesting molecular targets pursued at different levels of clinical investigation. Herein we provide an update on the knowledge on genetic alterations of the receptors in breast cancer, their role in tumorigenesis and the most recent drugs against this particular receptor to treat the disease.
Comparación de herramientas quimiométricas de clasificación para la identificación de grasa perirrenal en corderos
Authors: Agudo B. , Delgado J.V. , López M.M. , Rodríguez P.L.
Published: February 2020

En el presente trabajo se prueba la capacidad de la técnica NIRS para clasificar correctamente dos tipos de grasa perirrenal de corderos provenientes de distintos tipos de alimentación. Se combinan distintos tratamientos espectrales (Asorbancia-A, Reflectancia-R, A-EMSC, R-EMS) con distintas técnicas de clasificación no supervisada (PCA-Projection) y supervisada SIMCA, PLS-DA, LDA, C-SVM. Los resultados indican que los espectros sin tratar, contienen información valiosa en términos de clasificación, a pesar de la dispersión luminosa existente. Igualmente, los métodos de clasificación más sencillos PCA-Projection y LDA resultan los más efectivos. De los métodos más sofisticados, el C-SVM resulta el más eficaz, aunque es sensible al tipo de semilla de iniciación utilizada. Se concluye que la espectroscopía NIRS combinada con técnicas quimiométricas es un método válido para clasificar corderos en matadero en función de su alimentación.
Caracterización zoométrica y evaluación de la condición corporal en la raza camellar canaria
Authors: Iglesias C. , Navas F.J. , Ciani E. , Arando A. , González A. , Marín C. , Nogales S. , Delgado J.V.
Published: February 2020

La conservación, mejora y uso racional de los recursos genéticos animales locales y su diversidad son propósitos prioritarios a nivel nacional e internacional de evidente carácter legítimo. Reconocida en situación de amenaza, la raza camellar canaria (Camelus dromedarius) se encuentra marginalmente reducida a las islas orientales del archipiélago. Su uso queda restringido fundamentalmente a la explotación turística y, de forma esporádica, a labores variadas en el ámbito agropecuario. La caracterización morfoestructural y zoométrica del camello canario es una tarea clave que permitirá la identificación de aquellos caracteres o rasgos fenotípicos implicados en la actividad productivo-económica de estos animales con el fin de recuperar posibles nuevos nichos funcionales. La presente propuesta metodológica se enmarca en un contexto de oportunidad y resurgimiento de una potencial industria de producción con el asentamiento de las bases para un programa de recuperación y cría selectiva de esta raza camellar a través de su sustentabilidad funcional.
Efectos de la aplicación de subsidios al mercado porcino en México
Authors: Rebollar L.A. , Velázquez M.R. , Gómez M.I. , Posadas M.I. , Martínez M.I.
Published: February 2020

El objetivo de esta investigación fue evaluar el efecto de la aplicación de subsidios sobre el mercado de la carne de porcino en canal en México 2015 y 2016, a nivel región, mediante un modelo de programación no lineal. Se utilizaron ocho regiones productoras, dos puntos de internación de importaciones y ocho regiones consumidoras: Noroeste, Norte, Noreste, Centro-oeste, Centro-este, Sur, Oriente, Península, Punto de internación uno, Punto de internación dos; el análisis se realizó en producción, importaciones y consumo. Bajo condiciones óptimas el modelo subestimó producción nacional en 0,4%, sobreestimó importaciones y consumo regional-nacional en 2,5 y 0,4% con un Valor Social Neto (VSN) óptimo de 216,563 millones de dólares. El subsidio a la oferta de carne de cerdo incrementaría la producción y consumo nacional e importaciones en 0,07, 0,006 y 0.03%, el VSN aumentaría en 0,006%. A nivel región, los precios óptimos al productor y al consumidor se reducirían debido al efecto del subsidio. Se concluye que, un subsidio a la función de oferta de carne de cerdo en canal, mejoraría el beneficio de la sociedad, incrementando la producción y protegiendo a consumidores. La política podría ser viable en favor de la producción, siempre y cuando, el objetivo gubernamental se encamine hacia ese sector.
Effect of Drainhole Drilling on Production Capacity
Authors: Landrum Bobby L. , Crawford Paul B.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 271–273.

Electrical model studies have been made of the effect of drain hole drilling on production capacity. Drain holes are those lateral holes which are sometimes drilled to assist in increasing the oil drainage into the main wellbore. The studies indicate that if the drainhole length is near 0.2 of the drainage radius, the increase in production capacity may be approximately 1.8, 2.08, and 2.33 for the case of one, two and four drain holes, respectively. If multiple drain holes are drilled, shorter holes are required to achieve a specific increase in production capacity than if one or two holes are drilled. To achieve increases in production capacities by factors near three it is shown that the drain hole lengths divided by the drainage radii must be approximately 0.64, 0.48, and 0.37 for the case of one, two and four drain holes, respectively.

Introduction

Recent developments in drilling techniques have permitted the drilling of lateral or horizontal holes to increase the rate of production. The number of these drain holes may vary from 1 to 10, and they have been drilled laterally as much as 100 ft. Drainhole drilling at substantial depths is of recent origin but has been used in the Spraberry field of West Texas, the La Pas field in Western Venezuela, and certain fields in California. The diameter of the drain holes has been approximately 6 in. In drilling drain holes it is desired to know how much increase in production capacity may be expected, what additional benefit may be gained by drilling more than one drain hole, and what increase in production capacity may be brought about by lengthening the existing drain holes. In realization of the importance of lateral drilling, electrical model studies were made to provide quantitative estimates on the effect of drain holes on production capacity.
A Method for Neutron Derived Porosity Determination for Thin Beds
Authors: Edwards J.M. , Simpson A.L.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 132–136.

The application of the Scintillometer to radioactivity surveys in boreholes of oil wells has made it possible to determine bed thickness with a high degree of accuracy. This fact, combined with known relation of logging variables, makes thin bed porosity determination practical.

With the use of the Scintillometer a method has been derived whereby the apparent level of radiactivity, as recorded on radiation logs, may be converted to the true level. The true level of radioactivity is that level to which the recording pen would have traveled had the detector remained at a given depth for an infinitely long period of time.

This method depends entirely on accurate measurement of bed thickness and drag. A thorough discussion of the concept of time constant and logging speed as related to drag is undertaken.

Introduction

Neutron curve interpretation has become one of the accepted methods for porosity determination in oil field practices. A great deal of literature has been published about neutron derived porosities, but this has been concerned with thick beds, or possibly even averaging of a series of thin beds as a single unit. There has been a lack of written information on methods whereby porosity can be evaluated for beds less than 10ft in thickness.

In certain areas, production is derived from relatively thin formations. The importance of thin bed evaluation, the fact that the Scintillometer is an adequate tool for this application, and the general lack of published information concerning neutron porosity for thin beds are the fundamental reasons for presenting this method of porosity determination. This concept is not put forth with the idea of discounting existing methods, but is merely suggested as a modification of other accepted methods of porosity determination which makes no allowance for quantitative evaluation of thin beds.
Differences in Behavior of Fresh and Aged East Texas Woodbine Cores
Authors: Richardson J.G. , Perkins F.M. , Osoba J.S.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 86–91.

Laboratory experiments have shown profound differences in the behavior of so-called "fresh cores" from the East Texas field and of the same cores after extraction with organic solvents. The residual oil saturation remaining after waterflooding fresh cores was appreciably lower than the corresponding saturations after flooding extracted cores. This behavior was also reflected in the water-oil relative permeability-saturation relations, which were more favorable for high oil recovery from the fresh cores.

These differences were evident not only in the amount of residual oil left after water flooding, but also in the saturation water remaining in the core after displacement by oil. Residual water saturation after displacement of water by oil was higher in the fresh cores than in the extracted cores. Capillary pressure-saturation relations were also different for the fresh and extracted cores.

Imbibition experiments indicated that both fresh and extracted East Texas cores imbibed water spontaneously, but the rate of imbibition of water was higher for samples after extraction than it was for fresh core material.

Introduction

Several years ago a series of waterflooding tests was made in the laboratory on a number of Woodbine core samples from the East Texas field. These samples had been stored in containers open to the air and were extracted with organic solvents before they were subjected to the laboratory tests. After water flooding, the residual saturation of kerosene, which was the oil used in the tests, was found to average about 30 per cent.

This saturation was higher than expected. In investigating the circumstances which might have been responsible for such a high residual oil saturation, attention was given to possible changes in wetting properties of the rock brought about by the procedure employed in extracting the cores. Preliminary results indicated that the explanation for the high residual oil saturation lay in the wetting behavior of the cores, though what effect extraction had on this behavior was not clear. In consequence, the work described in this report was undertaken in an attempt to investigate the mechanism responsible, and to ascertain the actual residual oil saturation to be expected in the reservoir after water flooding. It was soon found that there were profound differences in the behavior of so-called "fresh cores" from the East Texas field and of the same cores after extraction with organic solvents. These differences were evident not only in the amount of residual oil left after water flooding, but also in the saturation of water remaining in the core after displacement by oil.
A Study of Waterflood Efficiency in Oil-Wet Systems
Authors: Warren J.E. , Calhoun John C.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 22–29.

A study of waterflood efficiency, given in terms of oil recovery at water breakthrough and ultimate recovery, has been made on short, consolidated Pyrex glass cores rendered oil-wet by chemical treatment. Contact angle, interfacial tension, permeability and porosity were the variables considered. Oil and water viscosities, core length and velocity of flooding were held constant.

The data permit interfacial tension, contact angle, porosity, and permeability to be grouped into a scaling coefficient along with viscosity, velocity of flooding and length of core. Correlation of the scaling coefficient with recovery at water breakthrough is found to follow prediction; correlations of ultimate recovery demand a scaling coefficient different from that which correlates breakthrough recovery.

The work indicates that, with proper control, a group of similar natural cores, of permeability plug size, can be correlated to indicate basic flooding performance.

Introduction

The fraction of oil recovered from a porous medium is related to both reservoir conditions and production techniques. An investigation of all factors that enter into this relationship is necessary in order to arrive at the optimum method of exploitation for oil reservoirs.

To define this relationship, laboratory studies have been made by a great many investigators. However, an important obstacle arises if the results of these experiments on water flooding are to be applied to practice.

Differences in behavior are to be expected between reservoirs of the dimensions encountered underground and those used in laboratory work. Factors which play an important role under laboratory conditions may be of no consequence in reservoirs. Laboratory operating practices generally differ from field operating practices. Thus, a mere understanding of the mechanism of the displacement of oil by water is not enough. It is just as necessary that the process be analyzed dimensionally to give continuity and validity to the conversion from laboratory to field.
Effect of Unsymmetrical Vertical Fractures on Production Capacity
Authors: Crawford Paul B. , Landrum Bobby L.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 251–254.

Electrical model studies have been made of the effect of unsymmetrical vertical fractures on production capacity. The study was restricted to the case of two vertical fractures originating at the well and extending out into the reservoir for various distances and orientations. The ratio of the short fracture length to the long fracture length was varied from 0.1 to 1.0 in successive studies. The angle separating the two fractures was varied from 0 to 180 degrees.

The most effective fractured patterns were obtained when the fractures were oriented 180 degrees. It was found that when the total fracture length was equal to 0.2 of the drainage radius, the increase in production capacity may vary from approximately 1.55 to 1.95, depending upon the ratio of the short fracture length to the long fracture length and the angle separating the two fractures. If the total fracture length were 0.5 of the drainage radius, production capacity increases varying 1.95 to 2.65 were observed, depending on the angle between the fractures and the ratio of the short fracture length to the long fracture length.

The fractured well production capacity decreased approximately 1 to 10 per cent as the angle separating the fractures was varied from 180 to 90 degrees. It was dependent on the particular fracture.

Introduction

The commercial application of reservoir fracturing techniques has caused an interest to be expressed in the effect of vertical and horizontal fractures on production capacities. Some data have indicated that substantially vertical fractures may be created in some reservoirs. It is believed that the fractures are possibly unsymmetrical, that is, one fracture may extend due north 100 ft and a second fracture on the opposite side of the well may extend south or southeast only 50 ft. The total fracture length, ratios of the lengths and angles of separation may vary considerably. For this reason variations in these factors were considered. The study was restricted to the case of two vertical fractures originating at the well and extending out into the reservoir. It is not known that such will occur in a reservoir, but the results may be of value in interpreting or studying fracturing applications.
Well Productivity Increase From Drain Holes as Measured by Model Studies
Authors: Perrine R.L.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 30–34.

The use of drain holes drilled from a well to improve productivity is becoming increasingly common. This paper presents data on the productivity increase that may be expected. The data were obtained by use of an electrolytic tank model of a reservoir. Parameters varied in the study to show their effect on productivity include the length, number, and arrangement of drain holes, formation thickness, and damage near the wellbore.

The most important results are that very large increases in productivity can be expected only in damaged wells. The distance to which drain holes penetrate is of primary importance. Additional length is more effective than increasing the number of drain holes.

Introduction

In planning the use of drain holes to improve productivity, it is important to be able to estimate the increase in production that can be obtained for a given expenditure. It is also important to know what combination of parameters related to the use of drain holes can be chosen to give the largest production increase. This paper presents data on the productivity increase that may be expected, as obtained by use of an electrolytic tank model of the reservoir. In this study, a number of parameters were varied to show their effect on productivity. These included the length, number, and arrangement of the drain holes. The presence or absence of a damaged zone of low permeability around the wellbore and the thickness of the producing formation were also considered.

Definitions and Assumptions

The productivity increase that might be expected due to drain holes is presented as the ratio: productivity of a well after drain holes are drilled and completed to the productivity of the same well in an undamaged state without drain holes.
Analysis of Pressure Fall-Off Curves Obtained in Water Injection Wells To Determine Injective Capacity and Formation Damage
Authors: Nowak T.J. , Lester G.W.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 96–102.

The paper presents a practical method of utilizing pressure fall-off data obtained when a water injection well is shut in for determination of:the static reservoir pressure,the potential water injective capacity (md-ft) of the formation, andthe formation damage (skin effect) surrounding the wellbore.

In the development of the method, equations are presented which give the theoretical background for predicting the behavior of water injection wells. Certain physical factors which limit the application of the method are discussed. The procedure and the relevant precautions in obtaining the data are discussed. A sample analysis and computation from an actual pressure fall-off curve is illustrated. Finally, general characteristics of pressure fall-off curves obtained in several reservoirs are presented.

Introduction

Theoretically, in an injection well the flow of water into the formation will continue as long as the sand-face pressure is greater than the reservoir pressure. However, in practice, engineers have observed that upon stopping injection and opening the wellhead to atmospheric pressure, some wells backflow water for time intervals ranging from several seconds to several hours although the sand-face pressure, as calculated from the hydrostatic head, is considerably greater than the static reservoir pressure. Further, field observations indicated that upon shutting in a water input well, the wellhead pressure does not drop off immediately, but a pressure decline occurs lasting from several seconds to several days. These observations make it evident that when an input well is shut in, a residual pressure lingers in the vicinity of the wellbore which is greater than the average reservoir pressure. This residual pressure declines first rapidly, then more slowly, to the static reservoir pressure; therefore, it is called transient back-pressure or pressure fall-off.

The first step in investigating the mechanism of pressure fall-off is to establish what general conditions are necessary for its occurrence, and to this end, Dickey and Andresen have presented a qualitative explanation describing the mechanism. They point out that the formation pressure gradient in the vicinity of the well does not disappear immediately when the input well is shut in, as if the system were filled with a totally incompressible fluid, but it is maintained by the expansion of the compressible fluids and by the elasticity of the formation. In such a compressible system the decrease in pressure is possible only to the extent that the water front continues to advance until the pressure is equalized.

The principal aim of this paper is three-fold; namely,to present a theoretical quantitative analysis of pressure fall-off data,to present an application of the developed theory to field data, andto discuss the general characteristics of actual pressure fall-off curves.
The Effect of the Relative Permeability Ratio, the Oil Gravity, and the Solution Gas-Oil Ratio on the Primary Recovery From a Depletion Type Reservoir
Authors: Arps J.J. , Roberts T.G.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 120–127.

Introduction

Since the introduction of the relative permeability concept in the middle thirties various investigators have shown how the basic equations for the flow of oil and gas through porous media can be utilized to compute the recovery from depletion type or solution gas drive type reservoirs under certain conditions, when the necessary physical data pertaining to the reservoir rock and its reservoir fluids are known.

In the study by Muskat and Taylor in 1945, the effects of viscosity, gas solubility, shrinkage, and the permeability-saturation characteristics of the producing formation on the production histories and the recovery of gas drive reservoirs were analyzed. Each parameter was varied a limited number of times, while keeping the others constant. The work was not carried to the point where the data could be used directly to estimate the primary recovery in those cases where certain rock and fluid characteristics were known or could be assumed.

Since the publication of this classic study, the work by Beal in 1946 and Standing in 1952 has established general correlations of oil viscosity and shrinkage with gas solubility and oil gravity. In addition, a considerable number of relative permeability relationships for different types of reservoir rocks has been published. Also, the burden of the numerical work required in the solutions of the differential equation has, during the last few years, been greatly reduced with the availability of modern electronic computing facilities.

The purpose of this paper is therefore to present the results of a large number of such recovery computations covering the normal range of variation of the main parameters such as the type of rock, the API gravity of the oil, and the amount of gas in solution.

As is to be expected, the ultimate recovery is found to increase with the oil gravity, except for the higher solution gas-oil ratios.
Studies on Pressure Distribution in Bounded Reservoirs at Steady State
Authors: Matthews C.S. , Lefkovits H.C.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 182–189.

The purposes of this study areto determine the accuracy of a previously proposed method for calculating average reservoir pressure andto find a method for estimating the shape of the drainage area of each well in a bounded reservoir.

Both numerical and experimental methods are used to determine the pressure distribution and the location of drainage boundaries in idealized reservoirs at steady state. A number of photographs are included which show flowlines and drainage areas in reservoir models of various shapes. Results from these studies are then compared with those from the previously proposed method for calculating average reservoir pressure. It is concluded that the previously proposed method is sufficiently accurate for most reservoir engineering purposes. In addition, some simple methods are given for estimation of shapes of drainage boundaries.

Introduction

A method for the determination of the average pressure in a bounded reservoir was previously developed by Matthews, Brons, and Hazebroek, and presented at the Petroleum Branch Fall Meeting in 1953. In applying this method, the reservoir was first divided into drainage volumes; second, the average pressure in each drainage volume was calculated; and third, these drainage volume pressures were averaged volumetric ally to give the average pressure in the reservoir. It was shown that each well's individual drainage volume, at steady state, is proportional to the well's production rate; however, the question of how to estimate accurately the shape of these drainage volumes could not be answered. Furthermore, in calculating the average pressure for each drainage area, the actual drainage areas, which are in general quite asymmetric in shape, are replaced with one of the symmetric prototypes given in T.P. 3876. A question may then be raised as to how accurately the symmetrical figures depict the pressure behavior of the actual unsymmetrical drainage areas. The study reported on in the present paper was made in an attempt to shed light on the above questions.
Measles and Mumps Outbreaks in Lebanon : Trends and Links
Authors: Zarif Talal El , Kassir Mohamed Faisal , Bizri Nazih , Kassir Ghida , Musharrafieh Umayya , Bizri Abdul Rahman
Published: February 2020

Background: Lebanon has experienced several measles and mumps outbreaks in the past twenty years. In this article, a case-based surveillance of both measles and mumps outbreaks in Lebanon was carried out in an attempt to outline factors contributing to the failure of elimination plans and to provide potential solutions. The relationship between the outbreaks of both diseases was described and explored. Methods: A retrospective descriptive study of confirmed cases of measles and mumps in Lebanon between 2003 and 2018 collected from the Lebanese Ministry of Public Health Epidemiological Surveillance Unit public database was carried out. The information collected was graphically represented taking into consideration dates of reported cases, age groups affected, and vaccination status. Results: The mean number of measles cases was 150.25 cases/year in the 1-4 years age group, 87 cases/year in individuals aging between 5 and 14, and 63.68 cases/year in those > 14 years old. In the latter group, only 18.05% were unvaccinated. The mean number of mumps cases was 30.4 cases/year in the <4 year age group and 53.8 cases/year in the 10-19 years age group. During the study period, every spike in measles cases was followed by a similar spike in mumps. 9.66% of measles cases occurred in individuals who received at least 2 doses of the vaccine, 52.26% in the unvaccinated, and 38% in those whose vaccination status was undetermined. Conclusions: Measles in Lebanon is a disease of the pediatric population, but adults remain at risk. Outbreaks of mumps followed those of measles and were mainly among adolescents. Presence of a large number of Syrian refugees in the country may further complicate the situation. Vaccination activities need to be intensified.