bluuebunny/crossref_metadata_2025 huggingface dataset:
La méthode française d’évaluation génétique des reproducteurs laitiers
Authors: BONAITI B. , BOICHARD D. , VERRIER E. , DUCROCQ V. , BARBAT A. , BRIEND M.
Published: August 2020

Les principales caractéristiques de la méthode d’évaluation génétique des reproducteurs laitiers, appliquée en France à partir de 1990, sont décrites. Les différences avec la méthode précédente sont soulignées. La méthode BLUP, appliquée à un modèle animal, permet d’utiliser toute l’information disponible de façon optimale. Pour chaque individu évalué, cette information est résumée en trois sources synthétiques : la moyenne des index de ses parents ; deux fois la moyenne pondérée des index de ses descendants, corrigés pour la valeur de ses conjoints ; la moyenne pondérée de ses propres performances, corrigées pour les effets de milieu. Les coefficients de pondération à appliquer à chacune de ces sources sont explicités et justifiés. Quelques exemples illustrent la contribution relative de chacune des trois sources d’information dans des situations courantes.
Effet de l’alimentation et de la race des vaches sur la fabrication de fromage d’Auvergne de Saint-Nectaire
Authors: GAREL J.P. , COULON J.B.
Published: August 2020

Cette étude, composée de 4 essais successifs, avait pour but d’analyser les effets de l’alimentation (foin et ensilage d’herbe, herbe pâturée), et de la race (FFPN et Montbéliarde) sur les caractéristiques du fromage affiné. Le fromage fabriqué à l’échelle artisanale (100 litres de lait par fabrication) était le Saint Nectaire fermier, fromage d’Auvergne d’Appellation d’Origine Contrôlée. Les différences de composition du lait entre races et régimes, essentiellement de taux protéique, se sont répercutées directement sur le rendement en fromage frais et affiné. Les rendements les plus élevés ont été obtenus avec les régimes à base de foin et d’herbe pâturée et avec les vaches Montbéliardes. La baisse du taux protéique du lait liée au régime ensilage d’herbe et à la race FFPN s’est traduite par une réduction du rendement fromager. La qualité du fromage affiné a été faiblement influencée par la race. Le régime à base d’ensilage d’herbe n’a pas eu d’effets sur le goût des fromages. Il a modifié les caractéristiques des fromages affinés, en accentuant l’ouverture de la pâte et le gonflement précoce, mais en améliorant la souplesse et la couleur jaune des fromages. Les critères simples retenus dans cette étude pour caractériser l’évolution du fromage, n’ont pas permis d’établir de liaisons entre la qualité du fromage frais et afimé, mais ont toutefois permis de mettre en évidence l’importance de la cave d’affinage.
Facteurs de variation du taux protéique du lait de vache : Etude dans des exploitations du Puy-de-Dôme
Authors: AGABRIEL C. , COULON J.B. , MARTY G. , CHENEAU N.
Published: August 2020

42 exploitations laitières du Puy-de-Dôme, adhérentes au Contrôle Laitier, ont fait l’objet d’une enquête détaillée concernant à la fois la structure de l’exploitation et du troupeau, la qualité des fourrages et les pratiques alimentaires hivernales et estivales. Ces données ont permis d’analyser les variations du taux protéique du lait d’une exploitation à l’autre. Bien que ces exploitations aient été homogènes par la race des animaux (Pie-noire) et le type de ration de base utilisée (ensilage d’herbe) des écarts importants ont été observés d’un troupeau à l’autre (3,2 g/kg entre les taux protéiques moyens annuels des étables extrêmes). Les taux protéiques élevés (hivernaux, estivaux ou annuels) ont été associés à la conjonction d’une maîtrise de l’alimentation (qualité de la ration de base, conduite du pâturage), d’un niveau génétique élevé (index TMMU) et d’un groupement des vêlages en début d’hiver. L’analyse des données individuelles mensuelles de la production et de la composition du lait de 1600 vaches de ces exploitations a permis de mettre en évidence les effets propres respectifs du stade de lactation et de la saison sur ces variables. A stade de lactation constant, les taux protéiques les plus faibles sont observés du mois de février au mois de juillet, mais les productions laitières sont les plus élevées à cette période. Les écarts entre mois extrêmes sont d’autre part plus importants pour les animaux en fin de lactation que pour ceux en début de lactation. Le mois d’août apparaît comme très défavorable pour la production laitière des animaux en début de lactation.
Prévision de la valeur énergétique des aliments composés pour les ruminants
Authors: GIGER-REVERDIN S. , AUFRERE J. , SAUVANT D. , DEMARQUILLY C. , VERMOREL M. , POCHET S.
Published: August 2020

La prévision de la valeur énergétique des aliments composés destinés aux ruminants était basée, jusqu’à présent, sur des données moyennes concernant des matières premières. Cette étude porte sur 83 aliments composés, les plus représentatifs possibles de l’éventail des types utilisés en pratique, et dont, par exenr ple, la teneur en céréales a varié de 0 à 90 %. Les mesures in vivo de digestibilités de la matière organique ou de l’énergie ont été effectuées par l’une des quatre équipes de recherche travaillant à Theix (INRA, France), à l’INA-PG (INRA, France), au Rowett Research Institute (Royaume-Uni) ou à Lelystad (IVVO, Pays-Bas). De plus, les pertes en énergie urinaire et sous forme de méthane ont été mesurées à Theix et au Rowett. Différents constituants ont été dosés suivant des méthodes utilisables par des laboratoires de routine : paroi cellulaire, lignocellulose, lignine (méthodes de Van Soest et de Christian), dégradabilités enzymatiques. Le calcul et la prévision de l’énergie nette procèdent d’une démarche par étapes successives. A chacune d’entre elles, le maximum de données mesurées in vivo, et dont la fiabilité a été préalablement testée, a été intégré. La validité des critères d’estimation nécessaires à chaque étape a été discutée tant au niveau de leur prévision que de leur fiabilité. Cette approche a conduit à proposer des équations de prévision des UFL et des UFV avec des écarts-types résiduels (E.T.R.) variant respectivement de 0,05 à 0,06 UFL/kg MO et de 0,06 à 0,08 UFV/kg MO suivant les critères analytiques considérés. Les trois dosages (lignine « directe », matières azotées totales, extrait éthéré) qui s’appuient sur des méthodes déjà appliquées en routine, conduisent à un E.T.R. de 0,056 UFL et de 0,0068 UFV/kg MO. L’intérêt de cette étude réside dans le nombre important de mesures effectuées in vivo, dans la représentativité des aliments étudiés, ainsi que dans la variété des méthodes de laboratoire impliquées.
Association de betteraves fourragères à de l’ensilage d’herbe pour des vaches laitières
Authors: DULPHY J.P. , ROUEL J. , BONY J.
Published: August 2020

Dans 4 essais (2 en début de lactation et 2 en milieu de lactation) des betteraves fourragères ont été distribuées avec une ration à base d’ensilage d’herbe apporté à volonté. Les apports de betteraves ont varié de 0 kg à 4 kg de MS par jour et par animal. Lors des 2 premiers essais, la teneur en MS des betteraves était en moyenne de 12 % contre 21 % lors des 2 autres essais. Les betteraves pauvres en MS ont fait baisser notablement la quantité d’ensilage ingérée et leur valeur d’encombrement a été proche de 1, valeur élevée pour un aliment riche en énergie. Par contre, les betteraves riches en MS se sont comportées comme un aliment concentré et ont eu une valeur d’encombrement proche de 0,5. Lorsque les animaux ont reçu des betteraves, leur production de lait a très légèrement baissé de 0,23 kg de lait par jour. Par contre, simultanément le taux protéique a augmenté de 0,85 point et le taux butyreux de 1,23 point. Dans nos conditions d’expérimentation et sous réserve de tenir compte de la teneur en cendres des betteraves, ainsi que des interactions digestives qu’elles induisent en tant qu’aliment concentré, la valorisation énergétique des rations avec betteraves est correcte et comparable à celle prévue à partir de la valeur des aliments distribués.
Bactériologie du sperme frais de lapin - Etude préliminaire
Authors: MERCIER P. , RIDEAUD P.
Published: August 2020

L’étude a porté sur 12 mélanges de spermes provenant de 39 lapins de 3 origines (Néo-Zélandais, Angora, Rex), élevés dans des conditions d’élevage différentes et prélevés avec plus ou moins de précautions hygiéniques. Les mélanges ont été constitués en fonction de la qualité biologique (motilité massale) de chaque prélèvement et une étude bactériologique qualitative et quantitative a été effectuée sur chacun des mélanges. Nous n’avons pas trouvé de relation entre la qualité bactériologique des mélanges testés et leur qualité biologique. Par ailleurs, la pratique de l’I.A. ne constitue pas en soi une barrière à la transmission des germes pathogènes, le sperme pouvant dans tous les cas véhiculer des germes dangereux. Nous avons mis en évidence l’importance des conditions d’environnement et des précautions hygiéniques prises dans la technique de prélèvement du sperme sur la qualité bactériologique des mélanges testés. Nous préconisons donc la mise au point d’un protocole sanitaire codifiant les opérations d’I.A. et l’assainissement des prélèvements devant servir à l’insémination par adjonction d’antibiotiques. Ceci permet d’envisager des recherches ultérieures sur l’évolution dans le temps du niveau de contamination du sperme, sur l’efficacité des antibiotiques ajoutés au milieu de dilution et sur ces mêmes questions appliquées au sperme réfrigéré, voire au sperme congelé. Enfin, il faudra vérifier l’influence de ces paramètres sur la fécondité des lapines.
Analysis of the Association Between Meteorological Variables and Mortality in the Elderly Applied to Different Climatic Characteristics of the State of São Paulo, Brazil
Authors: Barros Franciele Silva de , Gonçalves Fábio Luiz Teixeira , Gobo João Paulo Assis , ³ Júlio Barboza Chiquetto
Published: August 2020

With the rising trends in elderly populations around the world, there is a growing interest in understanding how climate sensitivity is related to their thermal perception. Therefore, we analyzed the associations between mortality in the elderly due to cardiovascular (CVD) and respiratory diseases (RD) and meteorological variables, for three cities in the State of São Paulo, Brazil: Campos do Jordão, Ribeirão Preto and Santos, from 1996 to 2017. We applied the Autoregressive Model Integrated with Moving Average (ARIMA) and the Principal Component Analysis (PCA) in order to evaluate statistical associations. Results showed CVD as a major cause of mortality, particularly in the cold period, when a high mortality rate is also observed due to RD. The mortality rate was higher in Campos do Jordão and lower in Santos (and intermediate values in Ribeirão Preto). Campos do Jordão results indicate an increased probability of mortality from CVD and RD due to lower temperatures. In Ribeirão Preto, the lower relative humidity may be related to the increase in CVD and RD deaths. This study emphasizes that, even among subtropical climates, there are significant differences. Therefore, this can assist decision makers in the implementation of mitigating and adaptive measures.
Biofunctionalization of UHMWPE Polymer and Its Application in Anterior Cruciate Ligament Reconstruction
Authors: Wahed Sonia B. , Dunstan Colin R , Boughton Philip A , Ruys Andrew J
Published: August 2020

The selection of biomaterials for biomedical application is a significant challenge. In the last few decades, various bioabsorbable and stable biopolymers have been applied for use as biomedical devices in orthopedic applications. Ultra-high molecular weight polyethylene (UHMWPE) has been extensively used in medical implants, notably in the bearings of hip, knee, and other joint prostheses, owing to its biocompatibility and high wear resistance. For the ACL graft, synthetic UHMWPE is an ideal candidate due to its biocompatibility and its extremely high tensile strength. Despite the appeal of new advanced materials such as carbon fiber, poly-ether-ether ketone, and other load-bearing materials, UHMWPE remains a primary load-bearing candidate material for ACL reconstructions because of its extremely high strength, the simplicity of the fabrication process, its biocompatibility, and low friction. However, some significant problems are observed in UHMWPE based implants, such as wear debris, and oxidative degradation due to the generation of free radicals when exposed to irradiation with gamma rays for grafting or sterilization. Various innovative methodologies have been developed to resolve those problems and enhance the properties of UHMWPE. In this review, we will explore in detail the methods for surface functionalization of UHMWPE and will apply these findings to the case study of UHMWPE for Anterior Cruciate Ligament repair.
Exploring perceived wellbeing from urban parks: Insights from a mega-city in Latin America
Authors: Parra-Saldívar Andrea , Abades Sebastián , Celis-Diez Juan L. , Gelcich Stefan
Published: August 2020

Urbanization has impacted biodiversity and ecosystems at a global scale. At the same time, it has been recognized as a driver of the gap between humans and nature. The lack of direct contact with nature can deteriorate several aspects of human wellbeing, and change knowledge and attitudes of people towards the environment. However, this phenomenon is still poorly understood in Megacities outside developed countries. Here, we explore the relationship between ecological knowledge and self-reported wellbeing in an important urban park in Santiago, Chile. We conducted semi-structured surveys to park users to explore their notions, preferences, ecological knowledge of plants and birds and self-reported wellbeing. Citizens associated urban parks mainly with “nature”, and particularly with the presence of trees and plants. Trees were recognized as the most relevant elements of urban parks, in turn, birds were ranked as the less relevant. Regarding ecological knowledge, respondents correctly identified an average of 2.01 plants and 2.44 birds out of a total of 10 for each taxon, and exotic species were more likely to be recognized. Park users also reported high scores for self-reported wellbeing. Interestingly, variance of self-reported wellbeing scores tended to increase at low levels of ecological knowledge of trees, but no significant relationship was detected with knowledge of birds, nor native species. These results suggest that parks can positively contribute to bring people closer to nature. Ecological knowledge was related to self-reported wellbeing. Improving ecological knowledge can be critical to restore the relationship between humans and nature in megacities.
Urgensi dan Eksistensi Undang-Undang Perlindungan Konsumen terhadap Praktik Bisnis
Authors: Latif Moh. Abdul
Published: August 2020

Business practices in the era of disruption are apparently very many who practice less ethical or even totally unethical so that of course it leads to criminal acts such as fraud and loss. The particular business practice of the seminar that promises great benefits for consumers, but the fact that it causes unrest among the people of Indonesia, The purpose of this paper is to analyze the form of Consumer Protection for victims of Business Practices that contain Criminal Elements Based on the Law of the Unitary Republic of Indonesia Number 8 years 1999 concerning Consumer Protection. This type of research that will be used is in the form of juridical-normative research which covers the systematic of a law. From this study it can be concluded that consumer protection against business practices is very important to be implemented in cases of fraudulent business practices under the guise of seeking profit.

 

Abstrak

Praktik bisnis di era disrupsi ternyata banyak sekali yang berpraktik kurang beretika atau bahkan sama sekali tidak beretika sehingga tentunya dalam praktik tersebut mengarah kepada tindak pidana seperti penipuan dan kerugian. Khsususnya praktik bisnis seminar yang menjanjkan keuntungan yang besar bagi konsumen, namun faktanya menimbulkan keresahan di kalangan masyarakat Indonesia.Tujuan dalam penulisan ini untuk menganalisis bentuk Perlindungan Konsumen terhadap korban Praktik Bisnis yang mengandung Unsur Tindak Pidana Berdasarkan Undang-undang Negara Kesatuan Republik Indonesia Nomor  8 tahun 1999 tentang Perlindungan Konsumen.Jenis penelitian yang akan digunakan adalah berupa penelitian yuridis-normatif yang mencakup tentang sistematika suatu hukum.Dari penelitian ini dapat disimpulkan bahwa perlindungan konsumen terhadap praktik bisnis sangat penting di implementasikan terhadap kasus-kasus penipuan praktik bisnis yang berkedok untuk mencari keuntungan.
Implementasi Pemerintah Daerah Dalam Pengembangan Model Pelayanan Publik Berbasis Sistem Informasi Desa Pada Pemerintahan Desa Di Kabupaten Jepara Perspektif Islam Terapan
Authors: Aristoni Aristoni
Published: August 2020

The implementation of the Village Information System is essentially a manifestation of the District / City Government in implementing the mandate of Law Number 6 of 2014 concerning Villages, namely developing a village information system and developing rural areas in order to facilitate and encourage the Village Government to improve and provide public services by utilizing technology Village-based Information and Communication (ICT) based on developments in the digital era, so that it can be accessed quickly and easily by the community and all stakeholders. The application of the Village Information System is expected to have positive implications and at the same time guarantee the implementation of village government to be more effective and efficient, transparent and accountable. The obligation to develop the village information system is attached to the Regency / City, not to the Central Government. During this time, the legal basis used in the development of public information systems based on the Village Information System refers to Law Number 6 of 2014 concerning Villages, Law Number 25 of 2009 concerning Public Services, Law Number 14 of 2008 concerning Openness of Public Information , and Governor Regulation of Central Java Province Number 47 of 2016 concerning Guidelines for the Development of Village Information Systems in Central Java Province.

Abstrak 

Pelaksanaan Sistem Informasi Desa hakikatnya merupakan perwujudan Pemerintah Daerah Kabupaten/Kota dalam mengamalkan amanat Undang-Undang Nomor 6 tahun 2014 tentang Desa, yaitu melakukan pengembangan sistem informasi desa dan pembangunan kawasan perdesaan guna menfasilitasi serta mendorong Pemerintah Desa untuk meningkatkan dan memberikan kemudahan pelayanan publik dengan memanfaatkan Teknologi Informasi dan Komunikasi (TIK) berbasis website Desa seiring perkembangan di era digital, sehingga dapat diakses dengan cepat dan mudah oleh masyarakat dan semua pemangku kepentingan. Penerapan Sistem Informasi Desa diharapkan dapat memberikan implikasi positif dan sekaligus menjamin dalam penyelenggaraan pemerintahan desa agar lebih efektif dan efisien, transparan dan akuntabilitas. Kewajiban pengembangan Sistem Informasi Desa tersebut melekat pada Kabupaten/Kota, bukan pada Pemerintah Pusat. Selama ini, landasan hukum yang digunakan dalam pengembangan pelayanan publik berbasis Sistem Informasi Desa yakni mengacu pada Undang-Undang Nomor 6 Tahun 2014 tentang Desa, Undang-Undang Nomor 25 Tahun 2009 tentang Pelayanan Publik, Undang-Undang Nomor 14 Tahun 2008 tentang Keterbukaan Informasi Publik, dan Peraturan Gubernur Provinsi Jawa Tengah Nomor 47 Tahun 2016 tentang Pedoman Pengembangan Sistem Informasi Desa di Provinsi Jawa Tengah.
Pengembangan Media Puppet Book Berbasis Pembelajaran Multiliterasi Pada Siswa Sekolah Dasar
Authors: Solihat Ayi , Hendracipta Nana , Yuliana Rina
Published: August 2020

Abstract: Books as a medium of literacy are presented normally, making students less interested. Developing puppet media needs to be done. This research aims to develop Puppet Book media. This research method, R&D with Borg and Gall research design. The results of the study were in the form of a one-horned rhinoceros puppet learning media complete with books and audio attached to the puppets. The results of the validation of media experts (average value 90.285%), linguists (average value 99.167%), material experts (average value 92.105%). The results of validation (media, language, material) with a very decent category. The results of the questionnaire responses of students in field trials showed 96.41% with very good criteria. Based on these results, the final product in the form of a puppet book based on multiliteration learning is suitable for the learning activities of fourth grade elementary school students.

Abstrak: Buku sebagai media literasi yang disajikan biasa, membuat peserta didik kurang tertarik. Pengembangkan media puppet perlu dilakukan. Penelitian ini bertujuan untuk mengembangkan media Puppet Book. Metode penelitian ini, R&D dengan desain penelitian Borg and Gall. Hasil penelitian berupa media pembelajaran puppet badak bercula satu yang dilengkapi buku serta audio yang terpasang pada puppet. Hasil validasi ahli media (nilai rata- rata 90,285%), ahli bahasa (nilai rata- rata 99,167%), ahli materi (nilai rata- rata 92,105%). Hasil validasi (media, bahasa, materi) dengan kategori sangat layak. Hasil angket respon siswa pada uji coba lapangan menunjukan 96,41% dengan kriteria sangat baik. Berdasarkan hasil tersebut, produk akhir berupa puppet book berbasis pembelajaran multiliterasi layak digunakan untuk kegiatan belajar siswa kelas IV SD.
Analisis Gaya Belajar Siswa ADHD (Attention Deficit Hyperactivity Disorder) di Madrasah Inklusi Lombok Barat
Authors: Widodo Arif , Rahmatih Aisa Nikmah , Novitasari Setiani , Nursaptini Nursaptini
Published: August 2020

Abstract: The learning styles of each student are different, and ADHD children are no exception. The purpose of this study is to explain the types of learning styles that ADHD children have. Qualitative research design. Data collection uses surveys. ADHD student research subject at MI NW Tanak Beak. This location was chosen because it has quite a lot of ADHD students. The instruments used were questionnaire, observation guide and interview guide. The main problems that will be examined in this study are how the learning styles that ADHD students have, and how the learning methods are carried out by the teacher. Findings in this study 81% of students have a kinesthetic learning style, 14% a visual learning style, and 5% an auditory learning style. The teacher designs learning into practical learning, observation and outdoor learning.                                          
Abstrak: Gaya belajar tiap siswa berbeda, tidak terkecuali dengan anak ADHD. Tujuan penelitian ini adalah menjelaskan jenis gaya belajar yang dimiliki anak ADHD. Desain penelitian kualitatif. Pengumpulan data menggunakan survei. Subjek penelitian siswa ADHD di MI NW Tanak Beak. Lokasi ini dipilih karena memiliki siswa berkategori ADHD cukup banyak. Instrument yang digunakan berupa angket, panduan observasi dan panduan wawancara.  Permasalahan utama yang akan dikaji dalam penelitian ini adalah bagaimana gaya belajar yang dimiliki siswa ADHD, dan bagaimana metode pembelajaran yang dilakukan guru. Temuan dalam penelitian ini 81% siswa memiliki gaya belajar kinestetik, 14% gaya belajar visual, dan 5% gaya belajar auditori. Guru mendesain pembelajaran menjadi pembelajaran praktik, observasi dan pembelajaran outdoor
The Imperativeness of Curriculum Improvement of Diniyah Education at the Wustha Level in South Kalimantan
Authors: Hamdan Hamdan
Published: August 2020

Islamic educational institutions in South Kalimantan are mushrooming both formally and informally. It is because Muslims are predominantly. They are known to be very religious and even steadfast in applying Islamic values. Most of the educational institutions grow and develop at the initiative of community members (self-help). The distribution of Islamic Religious and Religious Education Institutions in South Kalimantan is 582 institutions. This shows the potential as well as the great responsibility that is carried out in helping the government to realize the goals of National Education. However, it is unfortunate that the diniyah education curriculum experiences stagnation does not up to date. It is not connected to the needs and expectations of the community. It is due to the curriculum tends to focus more on the teacher center. Therefore, the curriculum needs to be adjusted to the needs and expectations of the community. Hence, there is no gap between educational institutions and the community. The research method of this study used Research and Development (R&D). The approach used 2 steps, namely preliminary activities and curriculum improvement (development). The data resources obtained from questionnaires, interviews, observations, and documentaries. Participants are ustadz/ustadzah who teach subjects on diniyah curriculum, experts, and graduates. The results of this study indicate that the curriculum for diniyah education especially the wustha level in South Kalimantan is needed to be revised or developed. The curriculum should be adjusted to the aspirations, needs, and expectations of the community.
Peningkatan Hasil Belajar IPA Dengan Menerapkan Model Contextual Teaching And Learning (CTL) Materi Penerapan Konsep Energi Gerak Pada Siswa Kelas III Sekolah Dasar Negeri 3 Ngabenrejo Kecamatan Grobogan Kabupaten Grobogan
Authors: Martini Sri
Published: August 2020

Penelitian ini bertujuan untuk meningkatkan kemampuan Hasil Belajar IPA pada pembelajaran IPA di kelas III SD Negeri 3 Ngabenrejo melalui model pembelajaran Contextual teaching and learning. Penelitian ini merupakan penelitian tindakan kelas dimana peneliti bekerja sama dengan teman sejawat sebagai observer pada pelaksanaan penelitian. Subjek penelitian adalah siswa kelas III SD Negeri 3 Ngabenrejo, sebanyak 22 siswa terdiri dari 6 siswa putra dan 16 siswa putri. Teknik analisis data yang digunakan adalah analisis deskriptif kualitatif untuk hasil observasi setiap siklus dan analisis deskriptif kuantitatif untuk menganalisis hasil tes setiap siklus. Penelitian dilaksanakan dalam 2 siklus. Hasil penelitian menunjukan bahwa penggunaan model pembelajaran CTL dapat meningkatkan kemampuan hasil belajar IPA di kelas III SD Negeri 3 Ngabenrejo. Hal ini ditunjukan dengan adanya peningkatan nilai dari sebelum pemberian tindakan hingga siklus II. Nilai rata-rata kelas yang diperoleh siswa sebelum tindakan adalah 57,04 pada siklus I, nilai rata-rata 70 Pada siklus II, nilai rata-rata yang diperoleh adalah 85,68. Kesimpulan penggunaan model pembelajaran CTL dapat meningkatkan kemampuan hasil belajar IPA pada pembelajaran IPA kelas III SD Negeri 3 Ngabenrejo.
Investigation of PDC Cutter Structural Integrity in Hard Rocks
Authors: Rahmani Reza , Pastusek Paul , Yun Geng , Roberts Tom
Published: August 2020

Robustness of round and V-shaped polycrystalline diamond compact (PDC) cutters against mechanical and thermal load was evaluated. Forensic analysis was used to estimate the range of loads and depths of cut (DOC) that cause structural overload of PDC cutters. Finite-element analyses (FEAs) were calibrated against these data and used to estimate the integrity of cutters. Thermal-abrasive wear was tested with single cutter tests on Sierra White granite with and without cooling for multiple material grades. The axial and tangential impact resistances were evaluated with drop and front face impact tests. In addition, full-scale laboratory drilling tests were conducted in granite [unconfined compressive strength (UCS) = 28,000 psi] and quartzite (UCS = 56,000 psi). Finally, failures for round and V-shaped cutters were evaluated in field trials.

The V-shaped cutters scored similar to baseline cutters in thermal-abrasive tests but lower in axial impact tests. They also failed at 13 to 18% lesser tangential load. By accounting for 16% reduction in contact area between the shaped cutter and load anvil, it was concluded that both cutter geometries fail essentially at the same stress. In all full-scale tests, round cutters failed before the shaped cutters. This was in contrast with drop tests and is attributed to the shaped cutter's cutting efficiency, resulting in lesser load on the cutters for the same rate of penetration (ROP). The results were compared with field runs in hard and interbedded application in Oklahoma and west Texas. The conclusion based on FEA, laboratory, and field data was that in most cases, this shaped cutter shows the same or better dull as its base grade.
Automated Well-Log Processing and Lithology Classification by Identifying Optimal Features Through Unsupervised and Supervised Machine-Learning Algorithms
Authors: Singh Harpreet , Seol Yongkoo , Myshakin Evgeniy M.
Published: August 2020

The application of specialized machine learning (ML) in petroleum engineering and geoscience is increasingly gaining attention in the development of rapid and efficient methods as a substitute to existing methods. Existing ML-based studies that use well logs contain two inherent limitations. The first limitation is that they start with one predefined combination of well logs that by default assumes that the chosen combination of well logs is poised to give the best outcome in terms of prediction, although the variation in accuracy obtained through different combinations of well logs can be substantial. The second limitation is that most studies apply unsupervised learning (UL) for classification problems, but it underperforms by a substantial margin compared with nearly all the supervised learning (SL) algorithms. In this context, this study investigates a variety of UL and SL ML algorithms applied on multiple well-log combinations (WLCs) to automate the traditional workflow of well-log processing and classification, including an optimization step to achieve the best output. The workflow begins by processing the measured well logs, which includes developing different combinations of measured well logs and their physics-motivated augmentations, followed by removal of potential outliers from the input WLCs. Reservoir lithology with four different rock types is investigated using eight UL and seven SL algorithms in two different case studies. The results from the two case studies are used to identify the optimal set of well logs and the ML algorithm that gives the best matching reservoir lithology to its ground truth.

The workflow is demonstrated using two wells from two different reservoirs on Alaska North Slope to distinguish four different rock types along the well (brine-dominated sand, hydrate-dominated sand, shale, and others/mixed compositions). The results show that the automated workflow investigated in this study can discover the ground truth for the lithology with up to 80% accuracy with UL and up to 90% accuracy with SL, using six routine well logs [vp, vs, ρb, ϕneut, Rt, gamma ray (GR)], which is a significant improvement compared with the accuracy reported in the current state of the art, which is less than 70%.
Best Practices in Gas Flaring and Emission Reduction - Importance of Safety Equipment
Authors: Onyeabor Samson , Zalewski Pawel
Published: August 2020

The objective is to investigate the importance of safety devices in mitigating the risks of emission (Fire, Smoke, Heat radiation and Noise, etc) associated with gas flaring during the LNG channeling and recovery mechanisms. The methods adopted is step by step investigative analyses of environmental considerations by looking at how various components (enclosures, flare tips, pressure relief valves, pilot ignition and detection systems of different types of flare systems (onshore/offshore) are designed and applied to monitor and analyze the fire and environmental risks generated during gas flaring and reduction as well as the disadvantages of these component applications. Such demerits range from faulty equipment, unsuitable devices, operating costs, lack of technical know-how and non-compliance to environmental regulations. Various results are acquired from both detection and monitoring devices. For a smoke-less operation to be achieved, the blower connected to the air-assisted flare tips must supply air to the flare system ranging within the fraction of 3/20-1/2. In reducing fire risks, the thermocouples are connected with retracted system to maintain change of components while the flare is still in operation. With respect to heat radiation, optical system like the flare monitoring telescope with optical diameter of 64mm was used to take the readings of the following light bandwidth: 6562.8, 6563.6, 6562.0 and 6562.8 and any data above 6564.0 was interpreted as high (increase in heat radiation). Poseidon and Coanda (highly improved) devices were also used for further monitoring and data/graphs generated for interpretation and summary. These will all be elaborated to ensure that all participants appreciate how the safety devices control gas wastes and prevent reduce environmental risks and the roles of pilot detection and monitoring system and integrated fire and gas detection systems in investigation and control of possible fire risks in any industrial plant.
Assessment of Safety Case Compliance in the Nigerian Oil and Gas Industry
Authors: Nwankwo Okechukwu. K , Muku Jennifer. S , Amosa Mutiu. K , Ike Chidi. B , Ogionwo Ebipador
Published: August 2020

The concept of Safety Case administration in oil and gas operations was one of the important fallouts from the public enquiry of Piper Alpha incident which happened in 1988 in the North Sea and claimed the lives of more than one hundred and fifty (150) personnel. Safety Case is a document which its process of preparation and approval ensures that operators or facility owners not only become aware of hazards in their operations but also put in place adequate mitigations to reduce the risk of accident occurrence to as low as reasonably practicable (ALARP), thereby assuring themselves and demonstrating to stakeholders (especially the relevant regulatory authority) that their facility is safe to operate or safe to continue in operation. Against this backdrop, the government has made the development and implementation of Safety Case a requirement for all installations operating, or to be operated, or to be decommissioned in the Nigerian oil and gas industry. Nigeria’s oil and gas industry regulator (Department of Petroleum Resources – DPR) established the Safety Case Regime as a means of ensuring, validating and tracking measures put in place by operators and facility owners towards mitigating the inherent risks posed by their oil and gas installations in Nigeria. This paper therefore examines the key elements as well as benefits in the implementation of the Safety Case regime in Nigeria by evaluating the extent of compliance amongst the operators and identifying common problems facing operators in the preparation of a Safety Case for submission. The basic contents of a typical safety case, step-by-step implementation procedure, and the approval criteria were reviewed with recommendations made to improve the overall process.
Experimental and Simulation Studies on the Use of Plant Oils as Flow Improver for Waxy Crude Oil
Authors: Olusegun Samuel , Omoladun Ruqayah , Alade Olalekan , Taiwo Elijah
Published: August 2020

Alteration of thermodynamic equilibrium conditions, most especially, temperature, during production and transportation of crude oil could cause destabilization, precipitation, and deposition of wax. This could affect the flow properties of the crude oil including the viscosity, pour point, and may eventually cause total blockage of the flow lines. In this investigation, synthetic waxy crude oil (containing different concentrations of dissolved paraffin wax (5 – 20% wt./wt.) was doped with selected plant seed oils, namely, Castor oil, Moringa oil and Coconut oil (0 – 1.5% v/v). The efficiency of each of the additives to improve the flow properties was compared with those of commercial flow improver, Triethanolamine (TEA). In addition, similar process was modelled and simulated using HYSYS process simulator. It was found that Moringa and Castro oils show good results to improve the pour point. On the other hand, the Coconut oil was observed to have negative effect by increasing the pour point of the oil. Ultimately, experimental studies reveal the potential of the plant oil to improve the flow properties of the waxy oil, while the simulation studies confirm the potential of the plant oil to reduce wax deposition volume and thickness, viscosity, and total pressure drop.
Use of New Approach in Estimating Skin in an ICD Completion
Authors: Uche Chukwunonso , Esieboma Samuel , Uche Jennifer , Onwukwe S. I. , Anyadiegwu C. I. , Boluwatife Oduyemi
Published: August 2020

Inflow control devices (ICD) have been used to balance flux around completions and also delay break-through of unwanted water into completions. Inflow-control devices (ICDs) were provided to curtail water production from heterogenous reservoirs with strong aquifer systems and/or supported with water injection. The model for the ICD consists of pressure-drop equations from the reservoir, through the screen, the flow conduit, the ICD nozzle, and into the production tubing, along with pressure drop through the lower-completion system. This additional pressure drop does not contribute to additional fluid inflow into the wellbore and this is seen to be an impairment to the productivity of horizontal wells. Pressure losses from horizontal wellbores which do not contribute to increased production is seen as skin and consequently, a new equation was derived to estimate skin due to ICD in horizontal completions.

In this paper, a horizontal well equipped with inflow control device which was drilled in one of the off-shore fields of the Niger Delta region was used as a case study in evaluating the performance of an ICD completion. The new equation was used to estimate the skin due to ICD of this completion and the result obtained is compared with the skin obtained using pressure transient analysis and the results obtained from both approach are similar. This paper shares how the new equation was used to estimate skin due to ICD and the result comparison with that of a pressure transient analysis.
Spatial Variations of Latent and Other Forms of Heat in a SAGD Process
Authors: Lawal Kazeem A. , Olamigoke Olugenga
Published: August 2020

Steam-assisted gravity drainage (SAGD) is characterized by the development and expansion of a steam chamber. It is generally assumed that all points within a steam chamber are at same temperature as the injected saturated steam. Hence, the view that the injected steam releases the full latent heat corresponding to its injection temperature. Leveraging on relationship between steam latent heat and temperature, as well as that between saturation temperature and pressure, this paper interrogates the general view that a constant amount of latent heat is released at all points within a steam chamber. We formulate and simulate a new mathematical model that reveals why and how the net specific latent heat released varies across a steam chamber. For completeness, a similar analysis is extended to examine the spatial variations of sensible and total heats in a SAGD. From parametric tests performed, spatial variations of the effective latent, sensible and total heats in a SAGD are quantified. The parametric tests show that the spatial variations of effective latent, sensible and total heats released are more sensitive to in-situ steam temperature than density contrast. For the range of density contrasts examined, simulation results suggest that the spatial variations are more pronounced at steam temperatures less than 150 °C. At higher temperatures, at which most SAGD and steam-based recovery processes are operated, spatial variations of the specific latent, sensible and total heats of steam are found to be negligible. These findings provide a technical basis not to operate SAGD and other steam-based recovery techniques below 150 °C.
Digital Transformation: After the Big Data, What Next?
Authors: Udofia Emmanuel , Buduka Stanley , Akpabio Julius , Egwu Saviour , Udofia Edwin , Olagunju Daniel
Published: August 2020

Our definition of ‘The Big Data’ is the ability of having all the data set at the point of decision-making. Several documented research shows that less than 5% of all the data acquired in the oil and gas industry are actually utilised. Despite these challenges most operating assets, still keep acquiring more data and creating data-load that are never utilised or put into use. This paper aims to demonstrate the reason(s) why we have this data-load and instigate a solution path in managing this challenge for value realisation.

Data is a corporate asset in any organisation but the default ‘silo’ work culture in most operating asset makes it difficult to get the relevant insight from these data. Organisation must be deliberate in creating the right data architecture from the data process domain through into the distributed control system, into the data historian, then within the data platform and the visualization realm and finally into the workflow domain. It is at the workflow domain that we get the ‘game-changer’ otherwise called value. This is the differentiating factor in delivering the ‘Big Data’ into the space of benefit realisation. This was what was achieved in a field in Niger Delta and has been shared compared to global best practice.

The documented result from this case study showed that any data architecture should be framed to address asset business need, right from the data process domain function through to the data historian into the workflow level where the business objective is addressed. Data must be application-centric accounting for scalability, accessibility, security and business performance.

Assets need to be clear on why they are acquiring data and not just continuous acquisition of more data with the resultant effect of data-load without answering the question; what next after data acquisition? This paper provides the answer of what next after data acquisition and serves as a quick reference tool for similar challenge elsewhere, not limited to the oil and gas industry.
Recovery Performance of Polymeric Anionic Surfactant Synthesized from Non-Edible Seed Oil
Authors: Ojo Temiloluwa , Oguntade Tomiwa , Efajemue Ewarezi , Lawal Oluwaseyi
Published: August 2020

Recovery agent formulated from a bio-based polymer and surfactant was targeted at extracting stuck reservoir fluid. Synthesized Methyl ester sulfonate directly from castor Oil was reacted at altered concentrations with Guar gum. With an important advantage involving a dual chemical component processing high viscosities with dual recovery nature that influences interfacial tension(IFT) and improvement of mobility ratio. Adsorption of surfactant on Berea sandstone noticeably reduced after engaging this blend. The performance was studied by Core flooding, and Rheological studies. Enhanced Oil Recovery (EOR) process was conducted employing with Berea sandstone cores as the porous medium with OFITE®'s reservoir permeability tester(RPT). EOR efficiency using this combination gave more recoveries ranging from 58-72% of the initial oil in place after water flooding and also a comparism was achieved with conventional surfactant and Polymer.
Comparison of Waterflood Oil Recovery under Different Oil Viscosities using Siljan and Sherwood Oils
Authors: Okoro Franklin
Published: August 2020

Two-phase flow through rock is controlled primarily by the pore structure, oil viscosities, wettability, and the flow. This paper considers the impact of oil viscosities on waterflood oil recovery from oil/water/rock systems, focusing specifically on mixed wet conditions characteristic of oil reservoirs. In mixed-wet reservoirs, the wettability of the surface of the grains that constitute the rock are heterogeneous at the pore scale and sub-pore scale. This heterogeneity is attributed to the preferential migration of crude oil into larger pores in initially water-wet (hydrophilic) reservoirs, and the subsequent alteration of oil-contacted grain surfaces to a less water-wet or an oil-wet (hydrophobic) state through, e.g., asphaltene adsorption. In this study, the wettability alteration to mixed-wet conditions was achieved by leaving the oil in the medium for 2 hours to render the grains less water-wet prior to waterflooding, this is known as aging. This work was restricted to a comparison of two oils with varying viscosities; Siljan and Sherwood oils. Image processing (flow visualization) technique was applied to analyse and compare the displacement efficiency in each experiment using an automated code developed with MATLAB. Experimental results suggested that long duration of aging (wettability alteration) alters the wetting system of the medium saturated with a light oil from a water-wet system to a more oil-wet system and results to a low waterflood oil recovery efficiency when flooded with brine whereas the long duration of aging is more favourable to heavy crude oil system when flooded with brine. However, the fractional water cut for the heavy oil system was higher as expected than that of the light-medium oil system.
Development of a Novel Compressibility Factor Correlation for High Pressure-High Temperature HPHT Reservoirs using Stochastic and Robust Optimization Approach
Authors: Ogbunike Jude , Adeyemi Temitayo
Published: August 2020

Accurate estimation of compressibility factor is of great importance in predicting the performance of gas reservoirs using the material balance approach and also in the designing of gas pipelines and flowlines. Over the years, several correlations for estimating gas compressibility factor have been developed. However, these correlations have not been so successful in predicting the compressibility factor for High pressure-High temperature (HPHT) reservoirs and this explains why the industry still relies on the expensive and time-consuming constant volume depletion (CVD) approach. Therefore, this paper presents a correlation suitable for estimating the compressibility factor for high pressure-high temperature (HPHT) reservoirs using stochastic and robust optimization approach with Gaussian probability distribution. The results obtained shows that the correlation outperforms other pre-existing correlations within the range of pressures and temperatures considered.