bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fracture of a Coupling in a Line-Shaft Vertical Turbine Pump
Authors: Eryürek I.B. , Aran A. , Capa M. 
Published: May 2019

Abstract
A coupling in a line-shaft vertical turbine pump installed in a dam foundation fractured after a very short time. The coupling material was ASTM A582 416 martensitic stainless steel. Visual, macrofractographic, and scanning electron microscopic examination of the coupling showed that the fracture was brittle and was initiated by an intergranular cracking mechanism. The mode of fracture outside the crack initiation zone was transgranular cleavage. No indication of fatigue was found. The failure was attributed to improper heat treatment during manufacture, which resulted in a brittle microstructure susceptible to corrosion. The crack initiated either by stress-corrosion or hydrogen cracking. It was recommended that the couplings in the system be examined for surface cracking and, if present, corrective measures be taken.
Anomalous Fractures of Diesel Engine Bearing Cap Bolts
Authors: Walter G.H. , Hendrickson R.M. , Zipp R.D. 
Published: May 2019

Abstract
Sudden and unexplained bearing cap bolt fractures were experienced with reduced-shank design bolts fabricated from 42 CrMo 4 steel, quenched and tempered to a nominal hardness of 38 to 40 HRC. Fractographic analysis provided evidence favoring stress-corrosion cracking as the operating transgranular fracture failure mechanism. Water containing H7S was subsequently identified as the aggressive environment that precipitated the fractures in the presence of high tensile stress. This environment was generated by the chemical breakdown of the engine oil additive and moisture ingress into the normally sealed bearing cap chamber surrounding the bolt shank. A complete absence of fractures in bolts from one of the two vendors was attributed primarily to surface residual compressive stresses produced on the bolt shank by a finish machining operation after heat treatment. Shot cleaning, with fine cast shot, produced a surface residual compressive stress, which eliminated stress-corrosion fractures under severe laboratory conditions.
Failed Bolts From an Army Tank Recoil Mechanism
Authors: Champagne Victor K. 
Published: May 2019

Abstract
The heads of two AISI 8740 steel bolts severed while being installed into an Army tank recoil mechanism. Both broke into two pieces at the head-to-shank radius and the required torque value had not been attained nor exceeded prior to the failure. A total of 69 bolts from inventory and the field were tested by magnetic particle inspection. One inventory bolt failed because of a transverse crack near the head-to-shank radius. It was deduced that either a 100% magnetic particle inspection had not been conducted during bolt manufacturing, or the crack went undetected during the original inspection. Optical and electron microscopy of the broken bolts revealed topographies and the presence of black oxide consistent with quench cracking. The two bolts failed during installation due to the presence of pre-existing quench cracks. Recommendations to prevent future failures include: ensuring that 100% magnetic particle inspections are conducted after bolts are tempered; using dull cadmium plate or an alternative to the electrode position process, such as vacuum cadmium plate or ion-plate or ion-plated aluminum, to mitigate the potential for delayed failures due to hydrogen embrittlement or stress-corrosion cracking; ensuring that the radius at the shoulder/shank interface conforms to specifications; and replacing all existing bolts with new or reinspected inventory bolts.
Failed Main Rotor Pitch Horn Bolt from an Army Attack Helicopter
Authors: Champagne Victor K. , Pepi Marc , Wechsler Gary 
Published: May 2019

Abstract
One of the two AISI 4340 steel pitch horn bolts from the main rotor hub assembly failed while in service. Optical microscope revealed evidence of corrosion pitting in regions adjacent to the fracture. Fractographic examination utilizing a scanning electron microscope revealed multiple crack origins which assumed a “thumbnail” shape and displayed surface morphologies which resulted from intergranular decohesion. Many of the crack sites initiated from corrosion pits. Energy dispersive spectroscope performed on areas within the crack initiation site showed the presence of chlorides. The failure was attributed to stress-corrosion cracking. Short- and long-term recommendations to prevent future failures are given.
Arcing Fault Burndown in Low Voltage Residential Service Entrance with Aluminum Conductors
Authors: Prosser Howard F. , Shipley Roch J. , Bouldin Peter C. 
Published: May 2019

Abstract
Three instances involving the failure of aluminum wiring at the service entrance to single-family homes are discussed. Arcing led to a fire which severely damaged a home in one case. In a second, the failure sequence was initiated by water intrusion into the service entrance electrical box during construction of the home. In the third, failure was caused by a marginal installation. Strict adherence to all applicable electrical codes and standards is critical in the case of aluminum wiring. Electrical components not specifically designed for aluminum must never be used with this type of wiring. All doors, panels and similar portions of electrical boxes should be secured to prevent damage to surroundings in the event of an electrical fault. If symptoms of arcing are observed, professional service should be sought. The latest designs of connectors for use with aluminum wiring are less susceptible to deviations in installation practice.
Failure of Nickel Anodes in a Heavy Water Upgrading Plant
Authors: Gill T.P.S. , Gnanamoorthy J.B. , Rangarajan V. 
Published: May 2019

Abstract
Nickel anodes failed in several electrolysis cells in a heavy-water upgrading plant. Dismantling of a cell revealed gouging and the presence of loosely attached black porous masses on the anode. The carbon steel top, plate was severely corroded. An appreciable quantity of black powder was also present on the bottom or the cell. SEM/EDX studies of the outer and inner surfaces of the gouged anode showed the presence of iron globules at the interface between the gouged and the unattacked anode. The chemical composition of the black powder was determined to be primarily iron. Cell malfunction was attributed to the accelerated dissolution of the carbon steel anode top, dislodgment of grains from the material, and subsequent closing of the small annular space between the anode and the cathode by debris from the anode top. Cladding of the carbon steel top with a corrosion-resistant material, such as nickel, nickel-base alloy, or stainless steel, was recommended.
Fatigue Failures of Connecting Bolts in a Truck Crane
Authors: Kitsunai Yoshio , Maeda Yutaka 
Published: May 2019

Abstract
JIS SCM435 steel bolts that connected the slewing ring to the base carrier on a truck crane failed during the lifting of steel piles. The bolts were double-ended stud types and had been in operation for 5600 h. Failure occurred in the root of the external thread that was in contact with the first internal thread in the slewing ring. Examination of plastic carbon replicas indicated that failure was the result of fatigue action. Failure was attributed to overloading during service and increased stress concentration on a few bolts due to nonuniform separations around the slewing ring. A design change to achieve equal separation between bolt holes was recommended.
Termination Delamination of Surface-Mount Chip Resistors
Authors: Runge-Marchese Jude M. 
Published: May 2019

Abstract
Several surface-mount chip resistor assemblies failed during monthly thermal shock testing and in the field. The resistor exhibited a failure mode characterized by a rise in resistance out of tolerance for the system. Representative samples from each step in the manufacturing process were selected for analysis, along with additional samples representing the various resistor failures. Visual examination revealed two different types of termination failures: total delamination and partial delamination. Electron probe microanalysis confirmed that the fracture occurred at the end of the termination. Transverse sections from each of the groups were examined metallographically. Consistent interfacial separation was noted. Fourier transform infrared and EDS analyses were also performed. It was concluded that low wraparound termination strength of the resistors had caused unacceptable increases in the resistance values, resulting in circuit nonperformance at inappropriate times. The low termination strength was attributed to deficient chip design for the intended materials and manufacturing process and exacerbated by the presence of polymeric contamination at the termination interface.
Explosion of an Oxygen Line
Authors: Leeser David O. 
Published: May 2019

Abstract
An oxygen line that was part of a mobile, truck -mounted oxygen-acetylene welding unit exploded in service. Analysis revealed that the failure occurred at the flexible hose-to-valve connection. It was further determined that a steel adapter had been installed at the point of failure to make the connection. Use of the adapter which joined with a brass nipple, created an unacceptable dissimilar metal joint. The steel also provided a source for the generation of sparks. Loctite, a hydrocarbon sealant that is highly flammable and explosive in contact with pure oxygen, had been used to seal the threaded joint. It was recommended that only brass fittings be used to assemble removable joints and that use of washers, sealants, and hydrocarbon lubricants be strictly avoided.
ANALISIS KESULITAN BELAJAR SISWA PADA MATERI OPERASI ALJABAR BAGI SISWA KELAS VII SMP NEGERI 3 SALATIGA
Authors: Dwi Kusumawati Asri , Sutriyono Sutriyono 
Published: May 2019

Abstrak: Penelitian ini bertujuan untuk mengetahui kesulitan-kesulitan yang dialami siswa dalam menyelesaikan persoalan aljabar yang berkaitan dengan konsep dan prinsip, serta faktor-faktor yang menyebabkan kesulitan belajar siswa kelas VII SMP Negeri 3 Salatiga dalam mempelajari aljabar. Metode penelitian adalah kualitatif deskriptif dengan menganalisis kesulitan-kesulitan siswa dari instrumen yang diberikan. Sampel yang diambil adalah siswa kelas VII SMP Negeri 3 Salatiga dengan jumlah subjek yaitu 5 siswa. Hasil penelitian ini menunjukkan bahwa siswa mengalami kesulitan dalam menyelesaikan persoalan aljabar yang berkaitan dengan persentase penguasaan konsep 58% dan persentase penguasaan prinsip 53% yang termasuk pada kategori sedang. Abstract:This study aims to determine the difficulties experienced by students in solving algebraic problems related to the concepts and principles, as well as the factors that cause difficulties in learning grade VII SMP Negeri 3 Salatiga in learning algebra. The research method is qualitative descriptive by analyzing students' difficulties from the given instrument. Samples taken are students of class VII SMP Negeri 3 Salatiga with the number of subjects ie 5 students. The results of this study indicate that students have difficulty in solving algebra problems related to the percentage of mastering the concept of 58% and the percentage mastery of 53% which is included in the medium category
Penerapan Metode Vikor dalam Seleksi Penerimaan Bonus Pada Salesman Indihome
Authors: Primadasa Yogi , Juliansa Hengki 
Published: May 2019

Indihome merupakan salah satu produk dari PT.Telkom Indonesia yang berdedikasi untuk layanan akses internet bagi rumah tangga serta bisnis skala kecil dan menengah Pada PT.Telkom wilayah Lubuklinggau. PT.Telkom dalam menetapkan karyawan yang mendapakan bonus hanya menghitung dari banyaknya target pencapaian salesman tersebut, yang mana peneliti anggap kriteria tersebut kurang efisien dalam pengambilan keputusan. Untuk mendukung efisiensi dalam menentukan kriteria, peneliti melakukan quisioner dalam menentukan kriteria yang akan di gunakan dalam pengambilan keputusan . Hasil dari kuisioner dengan melakukan uji validitas didapatkan 4 kriteria yang valid yaitu, Absensi, Pencapaian Target, Kerja Sama Tim dan Perilaku. Sistem pendukung keputusan untuk pemberian bonus adalah sebuah alternatif untuk membantu pengambilan keputusan dalam proses pemberian bonus untuk salesman tiap periodenya. Untuk membantu pengambilan keputusan dalam proses pemberian bonus maka dibutuhkan sistem pendukung keputusan untuk perangkingan seleksi, salah satu metode yang digunakan untuk sistem pendukung keputusan adalah metode VIKOR. Hasil yang didapatkan menggunakan metode Vikor ini adalah berupa perangkingan, Perangkingan pertama didapatkan oleh salesman bernama Sugiono dengan hasil Qi = 0
Kata Kunci : Sistem Pendukung Keputusan, Seleksi, Bonus, Vikor

Abstract
Indihome is one of the products from PT Telkom Indonesia that is dedicated to internet access services for households and small and medium scale businesses at PT. Telkom Lubuklinggau region. PT.Telkom in determining employees who get bonuses only counts from the number of achievement targets of the salaesman, which researchers consider these criteria to be less efficient in decision making. To support efficiency in determining criteria, researchers conduct a questionnaire in determining the criteria that will be used in decision making. The results of the questionnaire by testing the validity obtained 4 valid criteria, namely, Attendance, Achievement of Targets, Teamwork and Behavior. Decision support system for giving bonuses is an alternative to assist decision making in the process of giving bonuses to salesmen each period. To help make decisions in the bonus process, a decision support system is needed for ranking selection, one of the methods used for decision support systems is the VIKOR method. The results obtained using this Vikor method are in the form of ranking, the first ranking obtained by salaesman named Sugiono with the result Qi = 0.
Keywords : Decision support system, selection, Bonus,Vikor
Flores de ébano: a educação em trajetórias de escravizadas e libertas
Authors: Da Silva Alexandra Lima 
Published: May 2019

Este trabalho procura analisar a especificidade da condição feminina na escravidão e a inserção da mulher escravizada e liberta no universo da cultura letrada e da educação. A educação foi uma forma de distinção e prestígio? Quais os significados da aquisição dos códigos da cultura letrada para as mulheres escravizadas e libertas? Afinal, o que sabemos sobre a dimensão intelectual na vida das mulheres que vivenciaram o cativeiro? A partir da análise de fontes como autobiografias, relatos de viajantes e periódicos, o trabalho sugere que instruir-se foi uma forma de luta e sobrevivência, em uma sociedade que perseguia, estigmatizava e procurava demarcar, no corpo, no gesto e na fala, a mulher escravizada. Compreendo a educação como uma brecha na conquista da mobilidade e ascensão social, em uma sociedade escravista. A educação pode ter sido também, um caminho para a emancipação de muitas destas mulheres.
Origins and evolution of epizootology
Authors: Макаров Владимир , Makarov Vladimir 
Published: May 2019

The tutorial is considering the initial prerequisites for the formation and development of modern epidemiological thinking which became successful research in the mid XX century. In 1930 the independence of epidemiology and epizootology in the structure of professional medical and veterinary education, science and practice is finally grounded and realized. Initially in the USSR, these disciplines were formed as a traditionally infectious branching off from classical hygiene, bacteriology and immunology as the study of the epidemic/epizootic process based on the mechanism of transmission of infection. The epizootology actually developed today in home veterinary medicine is a scientific discipline and professional field designed to study the causes, conditions, patterns of occurrence, spread, extinction of animal diseases, develop on this basis organizational principles and methods for the prevention and control of them and implement them. In the most rational and modern formulation, the subject of its study is morbidity as an peculiar phenomenon of animal pathology and the epizootic process as a mechanism for its formation. Not a disease, a illness of separate individuals (animals) as a category of an individual, organism, clinical level, but a mass character of its manifestation an emerging morbidity transfer the pathology to a higher, population based statistical level. Abroad epidemiology and epizootology are represented by a peculiar variant, the basic concept of which is a narrower and more pragmatic field of knowledge based on statistical analytics - the distribution and causes of the health status of specific groups of the population for the purpose of managing health problems. Current trends are based on the need the convergence of home and western science and the preservation of mutual achievements with the vector of development from the infectious era to the post-infective era with a focus on the mass character of socially significant phenomena of human and animal pathology.
Key words: epizootology, history of origins, formation, development prospects.
Jenis-jenis Anggrek (Orchidaceae) di Hutan Rawa Gambut Kabupaten Belitung.
Authors: . Selviana , Nurtjahya Eddy , Sulistiarini Diah 
Published: May 2019

Selviana, Eddy Nurtjahya & Diah Sulistiarini. 2019. Jenis-jenis Anggrek (Orchidaceae) di Hutan Rawa Gambut Kabupaten Belitung. Floribunda 6(2): 72–80. — Anggrek salah satu tumbuhan yang memiliki nilai komersial tinggi. Data keanekaragaman anggrek di Pulau Belitung, khususnya di hutan rawa gambut Kabupaten Belitung belum pernah dilakukan. Penelitian ini bertujuan untuk mengidentifikasi jenis-jenis anggrek alam yang ada di hutan rawa gambut Kabupaten Belitung. Penelitian dilakukan di hutan rawa gambut, Kabupaten Belitung dengan 3 lokasi. Identifikasi dilakukan di Herbarium Bangka Belitungense dan Herbarium Bogoriense (BO), Pusat Penelitian Biologi-LIPI, Cibinong. Berdasarkan hasil penelitian, ditemukan 9 jenis anggrek dari 6 marga, terdiri dari 6 jenis anggrek epifit, 3 jenis anggrek terestrial. Jenis yang paling banyak dijumpai di daerah tersebut adalah dari marga Bulbophyllum Thou., Dendrobium Sw. dan Plocoglottis Blume, serta terdapat satu anggrek rekaman baru yaitu jenis Thecopus secunda.
Catatan Keberadaan Costus afer Ker Gawl. (Costaceae) di Pulau Jawa.
Authors: Irsyam Arifin Surya Dwipa , Irwanto Rina Ratnasih , Hariri Muhammad Rifqi 
Published: May 2019

Arifin Surya Dwipa Irsyam, Rina Ratnasih Irwanto & Muhammad Rifqi Hariri. 2019. Catatan Keberadaan Costus afer Ker Gawl. (Costaceae) di Pulau Jawa. Floribunda 6(2): 64–71. — Suatu jenis Costus introduksi dari Afrika, yaitu Costus afer Ker Gawl., telah ditemukan tumbuh ternaturalisasi di Maribaya (Lembang), Dago Atas (Bandung), dan Kampus IPB Dramaga, Bogor. Keberadaan populasi liar C. afer di Pulau Jawa belum pernah dilaporkan sebelumnya. Jenis tersebut juga belum terdaftar dalam Flora of Java. Secara morfologi, C. afer sering salah teridentifikasi sebagai C. lucanusianus J. Braun & K. Schum. Informasi mengenai populasi liar dan ciri morfologi C. afer dilaporkan dalam catatan ini.
Analisis Morfologi Begonia isoptera Dryand. ex Sm (Begoniaceae) Kompleks di Jawa.
Authors: Ayu Siti Azhyra Dwi , Putrika Afiatry , Girmansyah Deden 
Published: May 2019

Siti Azhyra Dwi Ayu, Afiatry Putrika & Deden Girmansyah. 2019. Analisis Morfologi Begonia isoptera Dryand. ex Sm (Begoniaceae) Kompleks di Jawa. Floribunda 6(2): 53–63. — Begonia isoptera merupakan salah satu jenis Begonia di Jawa dengan konsep jenis yang luas, sehingga jenis ini menjadi kompleks. Pemeriksaan ulang morfologi jenis ini telah dilakukan terhadap semua koleksi B. isoptera di Herbarium Bogoriense dengan menggunakan 12 karakter vegetatif dan 7 karakter generatif terpilih. Hasil analisis menunjukkan bahwa B. isoptera terbagi menjadi 3 kelompok, yaitu: 1) berbulu (tangkai daun bertrikoma), 2) gundul (tangkai daun gundul), dan 3) kombinasi (campuran antara kelompok berbulu dan gundul). Analisis statistika menggunakan CA (Cluster Analysis) dan PCA (Principal Component Analysis) menunjukan bahwa B. isoptera kelompok berbulu dan B. isoptera kelompok kombinasi tergabung dalam satu kelompok besar, sedangkan B. isoptera kelompok gundul terpisah. Setelah dibandingkan dengan spesimen tipe dan pertelaan awal diketahui bahwa kelompok gundul merupakan B. isoptera yang sesuai dengan deskripsi awal, sedangkan kelompok berbulu sangat berbeda terutama pada sistem perbungaan dan indumentum tangkai daun sehingga akan diteliti lebih lanjut. Berdasarkan distribusi, B. isoptera kelompok berbulu dan kelompok kombinasi tumbuh di ketinggian 1000–2000 m dpl yang tersebar dari Jawa Barat sampai Jawa Tengah, sementara kelompok gundul tumbuh di dataran rendah Jawa Barat dan Banten pada ketinggian 0–600 m dpl.
Investigation of Ways of Dynamic Range Expansion for Broadband Receiver Microwave Devices in Multi-Signal Mode
Authors: Bogdanov S. A. , Kupriyanov P. V. , Nikolaev S. V. , Petrov S. A. 
Published: May 2019

The article investigates ways to expand the dynamic range of broadband microwave receiving devices. The task is to lim-it the output signals while increasing the upper boundary of the dynamic range by the criterion of the thirdorder inter-modulation component suppression. The main relations determining the dynamic range boundary conditions are pre-sented. Experimental studies of three variants of constructing the broadband microwave receiver output path in two-ton mode of operation are carried out for:– an output amplifier with a point of 1 dB of output power compression at the level corresponding to safe output power;– a powerful output amplifier with a passive diode limiter on the output;– a powerful output amplifier with an automatic attenuation adjustment circuit connected to its input.The measurement results of the magnitude of intermodulation distortions suppression and output power are presented as a function of the input signal level for various nonlinear elements. Based on the analysis of the measured characteristics, an optimal technical solution is found for constructing an output path. The dynamic range is extended by more than 20 dB. Suppression of intermodulation components of the third order exceeds 60 dB. Effective functioning of the broadband receiver in multisign mode is ensured.