bluuebunny/crossref_metadata_2025 huggingface dataset:
EKONOMI SYARIAH_ASMILA DEWI
Authors: DEWI ASMILA
Published: July 2021

ABSTRAKIslam sebagai sistem kehidupan yang universal, integral, dan komprehensif telah menetapkan tatanan yang utuh untuk kehidupan manusia. Sebagai way of life, Islam menata segala hal yang berkaitan dengan kehidupan, dari hal yang paling sederhana hingga urusan yang paling rumit sekalipun. Baik dalam aspek politik, ekonomi, pendidikan, seni, sosial, budaya, dsb. Islam merupakan agama yang sempurna, yang mengatur hal yang berkaitan dengan ekonomi. Apabila perekonomian suatu negara (ekonomi nasional) menerapkan dasar Al-Quran dan Hadist sebagai dasar penerapannya, tentunya suatu perekonomian nasional akan berjalan dengan baik dan terarah sesuai aturan. Namun kenyataanya memang belum semua negara muslim di dunia menerapkan dasar tersebut. Selanjutnya, di dalam artikel ini dijelaskan tentang bagaimana Ekonomi Islam berkontribusi dalam pembangunan ekonomi nasional, khususnya Indonesia sebagai negara dengan basis muslim terbesar se-Asia.
HUKUM KETENAGAKERJAAN DALAM ISLAM
Authors: Husnah Ismatul
Published: July 2021

Upah merupakan kebijakan dan strategi yang menentukan kompensasi yang diterima pekerja. Kompensasi sendiri merupakan bayaran atau upah yang diterima oleh pekerja sebagai balas jasa atas hasil kerja mereka. Hukum Ketenagakerjaan adalah hukum yang berhubungan dengan tenaga kerja pada waktu sebelum, selama, dan sesudah bekerja. Ketenagakerjaan jika dalam prespektif Islam, tergolong dalam kegiatan Ijarah (sewa-menyewa) dalam jual-beli jasa
PEMBAGIAN KEPEMILIKAN DALAM EKONOMI SYARIAH
Authors: T Andi Marhuni
Published: July 2021

Materi terkait dengan bagaimana pembagian pemelikan menurut pandangan ekonomi syariah.
HUKUM TATANEGARA
Authors: ALAMSYAH
Published: July 2021

Surat ini bertujuan untuk mengetahui dan menganalisis dasar kewenangan Mahkamah Konstitusi Republik Indonesia untuk mengadili sengketa dari hasil pemilihan kepala daerah dan wakil kepala daerah, kemudian mengalihkan latar belakang tentang kewenangan mengadili sengketa tersebut dari hasil pemilihan kepala daerah. Pemilihan Ketua dan Wakil Ketua Daerah dari Pengadilan Tinggi ke Mahkamah Konstitusi Republik Indonesia.
Analisis Strategi Pemasaran Dan Kualitas Pelayanan Terhadap Kepuasan Konsumen Pada RM. Pepes Ayam
Authors: Fajri Ratu Chaterine , Isnainy Fidelia , Soewito
Published: July 2021

Persaingan yang terus menjadi ketat dengan kemajuan serta pergantian style hidup masyarakat yang terus menjadi modern, perilaku pelanggan pada keputusan pembelian sesuatu produk pula turut bermacam-macam. Tujuan dari riset ini merupakan buat mengenali strategi pemasaran serta mutu pelayanan terhadap kepuasan pelanggan pada Rumah Makan Pepes Ayam PakNana Bandar Lampung. Jenis riset yang digunakan merupakan pendekatan deskriptif memakai regresi linier berganda. Hasil riset membuktikan kalau strategi pemasaran serta mutu pelayanan mempengaruhi dengan kepuasan pelanggan pada Rumah Makan Pak Nana Bandar Lampung. Strategi pemasaran serta mutu pelayanan mempengaruhi signifikan terhadap kepuasan pelanggan. Rumah Makan Pepes Ayam Pak Nana Bandar Lampung hendaknya tingkatkan strategi pemasaran semacam kesesuaian harga, promosi yang dilakukan serta melakukan diskon pada hari besar, lalu meningkatkan mutu pelayanan supaya kepuasan konsumen bisa terpenuhi.
The Curved Space-Time Paradox
Authors: Vegt Wim
Published: July 2021

The fundamental principle in General Relativity is to combine the inertia of mass and the relationship with the gravity force acting on this mass. In this article a new concept in General Relativity will be introduced. The concept of the “Paradox in a Curved Space-Time Continuum”. The “Paradox in a Curved Space-Time Continuum” has been based on the fundamental question: Does light follow a curved path within a gravitational field because a gravitational field causes a “Curved Space Time Continuum” or does a curved path of a beam of light generate a Gravitational Field. Differently formulated: Is Gravity a second order effect of a curved Electromagnetic field?To answer this question a new theory will be introduced. The “Quantum Light Theory” which is a specialization of “Quantum Field Theory”.Quantum Light Theory (QLT) is the new development in Quantum Field Theory (QFT). In Quantum Field Theory, the fundamental interaction fields are replacing the concept of elementary particles in Classical Quantum Mechanics. In Quantum Light Theory the fundamental interaction fields are being replaced by One Single Field. The Electromagnetic Field, generally well known as Light. In which gravity is the second order effect of the fundamental Electromagnetic Field. To realize this theoretical concept, the fundamental theory has to go back in time 300 years, the time of Isaac Newton to follow a different path in development. Nowadays experiments question more and more the fundamental concepts in Quantum Field Theory and Classical Quantum Mechanics. The publication “Operational Resource Theory of Imaginarity“ in “Physical Review Letters” in 2021 (Ref. [2]) presenting the first experimental evidence for the measurability of “Quantum Mechanical Imaginarity” directly leads to the fundamental question in this experiment: How is it possible to measure the imaginary part of “Quantum Physical Probability Waves”? This publication provides an unambiguously answer to this fundamental question in Physics, based on the fundamental “Gravitational Electromagnetic Interaction” force densities. The “Quantum Light Theory” presents a new “Gravitational-Electromagnetic Equation” describing Electromagnetic Field Configurations which are simultaneously the Mathematical Solutions for the Quantum Mechanical “Schrodinger Wave Equation” and more exactly the Mathematical Solutions for the “Relativistic Quantum Mechanical Dirac Equation”. The Mathematical Solutions for the “Gravitational-Electromagnetic Equation” carry Mass, Electric Charge and Magnetic Spin at discrete values.
TUGAS JURNAL PAMUNGKAS
Authors: Pamungkas Muh Quran
Published: July 2021

Sistem ketatanegaraan pada dasarnya mengandung dua aspek, yaitu aspek yang berkenaan dengan kekuasaan lembagalembaga negara beserta hubungannya satu sama lain di antara lembaga-lembaga negara tersebut serta hubungan-hubungan antara lembaga-lembaga negara dengan warga negara. Kedua aspek tersebut dapat dilihat dalam konstitusi suatu negara.1 Suatu konstitusi merupakan sebuah sistem hukum, tradisi, dan konvensi yang kemudian membentuk suatu sistem konstitusi atau ketatanegaraan suatu negara. Suatu sistem ketatanegaraan mencerminkan fungsi-fungsi yang terdapat dalam hukum ketatanegaraan.
Faktor-Faktor yang Mempengaruhi Minat Beli Konsumen pada Toko Pasadena Celular Bandar Lampung
Authors: Fajri Ratu Chaterine , Fatmasari Mardiana , Rinova Dora
Published: July 2021

Pada saat ini kompetisi pada usaha ritel tidak hanya pada harga, namun menyangkut variabel lain yang berkaitan dengan nilai atas pengalaman berbelanja pelanggan. Untuk mengetahui seberapa besar pengaruh faktor-faktor yang mempengaruhi minat beli tersebut maka dibuatlah skripsi ini. Data didalam penelitian ini dikumpulkan dengan cara menyebar kuesioner secara langsung kepada 100 responden Toko Pasadena Celluler yang ada di Toko Pasadena Celluler Simpur Center. Dan selanjutnya dianalisis menggunakan teknik analisis deskriptif dan kuantitatif yaitu Uji Regresi Linier Berganda dan data diolah menggunakan IBM SPSS for window. Pengujian hipotesis menggunakan uji t menunjukkan bahwa variabel independen yang diteliti diperoleh thitung untuk kualitas produk sebesar 0,335 < ttabel 1,66, harga sebesar 3,005 > ttabel 1,66, promosi 0,728 < ttabel 1,66 hasil analisis tidak semua berpengaruh signifikan terhadap variabel minat beli. Angka R square sebesar 0,569 yang menjukkan bahwa 56,9% variabel minat beli bertambah dari kualitas produk, harga, promosi dan sisanya 43,1% dijelaskan oleh variabel lain yang tidak termasuk dalam penelitian ini.
Generalized Chemical Equilibrium Constant of Formaldehyde Oligomerization
Authors: Kircher Raphael , Schmitz Niklas , Berje Jürgen , Münnemann Kerstin , Thiel Werner R. , Burger Jakob , Hasse Hans
Published: July 2021

Formaldehyde reacts with solvents that contain hydroxyl groups (R–OH) in oligomerization reactions to oxymethylene oligomers (R–(OCH2)n–OH). The chemical equilibria of these reactions have been studied in the literature for water, for the mono-alcohols methanol, ethanol, and 1-butanol, as well as for the diols ethylene glycol and 1,4-butynediol. In the present work, the collective data were analyzed. It was found that the prolongation of the oxymethylene chains by the addition of formaldehyde can be described very well with a generalized chemical equilibrium constant Kx,n≥2R–OH, which is independent of the substructure (R) of the solvent. This holds for the oligomerization reactions leading to R–(OCH2)n–OH with n ≥ 2. The chemical equilibrium constant Kx,1R–OH of the reaction of formaldehyde with the solvent R–OH depends on the solvent, but simple trends are observed. The hypotheses of the existence of a generalized chemical equilibrium constant Kx,n≥2R–OH was tested for the reactions of formaldehyde with ethanol and 1-propanol, for which neither Kx,1R–OH nor Kx,nR–OH was previously available. The corresponding equilibria were studied by 13C NMR spectroscopy and the equilibrium constants were determined. A novel method was developed and used in these studies to obtain data on Kx,1R–OH by NMR spectroscopy, which is difficult because of the low amount of molecular formaldehyde. It was found that the generalized equilibrium constant is even valid for the acid-catalyzed formation of poly(oxymethylene) dimethyl ethers (OME).
Reconstructing the Study of Human Cognition
Authors: Prather Richard
Published: July 2021

The study of human cognition is a prominent part of psychology and related disciplines. While the modern approach begun during the Cognitive Revolution hasbeen seemingly successful, it is not without concerns. I address five concerns with how human cognition is studied: (1) reliance on homogeneous participant sampleswhen trying to generalize behavior to real-world contexts; (2) focus on controlling for or ignoring "extraneous" variables; (3) assumption of a generic human actor instead of a focus on individual and contextual variation; (4) insufficient theory building.I contend that these concerns are deeply connected and that the solution is a significant change in how we study human cognition, similar in scope to the Cognitive Revolution. We need to reconsider the assumption of cognitive universals and how that assumption is built into the norms of the discipline. I propose a reconstruction of how researchers study human cognition by implementing acombination of methodological approaches and theoretical positions. These combined approaches (1) integrate human heterogeneity, (2) consider human behavior in context, (3) incorporate multiple levels of analysis and non-cognitivefactors, (4) focus not only on averaged behavior but variation across individuals and context, (5) create theory that combines cognition and context.
Strong conceptual ability reduces the effect of lexical impairments on verb retrieval in aphasia
Authors: Dresang Haley C. , Hula William D. , Warren Tessa , Dickey Michael Walsh
Published: July 2021

Verb-retrieval impairments are pervasive deficits that can negatively impact communicative function for individuals living with aphasia. Unfortunately, the neurocognitive basis of these deficits remains poorly understood. One open question is the degree to which verb-retrieval impairments might be rooted in lexical- versus conceptual-processing deficits. These deficits can be co-present and correlated in people with aphasia, but they have also been found to be dissociated in patients with a variety of acquired brain injuries. This study examined the degree to which conceptual versus lexical action-processing abilities are impaired and may contribute to verb-retrieval impairments in adults with chronic aphasia due to left-hemisphere stroke. The results indicate that conceptual action processing can be impaired in aphasia and may contribute to verb-retrieval impairments. Furthermore, relatively unimpaired conceptual processing can ameliorate the influence of lexical impairments on verb-retrieval impairments. These findings are consistent with models in which conceptual representations play a key role in language processing and may be leveraged to improve verb retrieval in adults with chronic aphasia.
Interference in the Shared-Stroop Task: A Comparison of Self- and Other-Monitoring
Authors: Pickering Martin John , McLean Janet Frances , Gambi Chiara
Published: July 2021

Co-actors represent and integrate each other’s actions, even when they need not monitor one another. However, monitoring is important for successful interactions, particularly those involving language, and monitoring others’ utterances likely relies on similar mechanisms as monitoring one’s own. We investigated the effect of monitoring on the integration of self- and other-generated utterances in the shared Stroop task. In a solo version of the Stroop task (with a single participant responding to all stimuli; Experiment 1), participants named the ink colour of mismatching colour words (incongruent stimuli) more slowly than matching colour words (congruent). In the shared Stroop task, one participant named the ink colour of words in one colour (e.g., red) while ignoring stimuli in the other colour (e.g., green); the other participant either named the other ink colour or did not respond. Crucially, participants either provided feedback about the correctness of their partner’s response (Experiment 3) or did not (Experiment 2). Interference was greater when both participants responded than when they did not, but only when their partners provided feedback. We argue that feedback increased interference because monitoring one’s partner enhanced representations of the partner’s target utterance, which in turn interfered with self-monitoring of the participant’s own utterance.
Ecotourism in Ghoda Ghodi Wetland Sukhad, Kailali, Nepal
Authors: Khadka Dipak , Chaudhary Ankita , Karki Rubina , Sharma Bishal , Bhatta Sijar
Published: July 2021

Tourism is the act of spending time away from home. Nepal has remained an exotic tourist location for several decades, and wetlands are among the major areas of tourism in Nepal. Located in the far-western Tarai of Nepal, Ghoda Ghodi Lake is among the major wetlands in terms of both biodiversity and tourism. This study has assessed the ecotourism status in Ghoda Ghodi Lake of Nepal and to understand the current condition and possible inferences. A total of 40 households were surveyed, and 80 visitors were interviewed for collecting primary data. Most of the respondent visitors have visited wetlands more than five times. It is important to point out that fifty percent of the respondent visitors have visited the wetland for natural purposes indicating that the naturalness of the wetland has more capacity to attract tourists. Visitors perceived to enhance economic activities and increase employment opportunities to attract locals to promote ecotourism. The local people were engaged in homestay earning around NRs 2 to 4 lakh per year as well most of the local respondents (50%) were participating in tourism promotion activities.
Analiza izvanrednih događaja u željezničkom prometu
Authors: Pupavac Drago , Knežević Josip
Published: July 2021

Predmet istraživanja od značaja za ovaj rad jesu izvanredni događaji u željezničkom prometu. Posljedice izvanrednih događaja mogu biti smrt, teška tjelesna ozljeda, lakša tjelesna ozljeda, materijalna šteta, šteta nastala na okolišu i poremećaji u prometu. Cilj ovoga rada jest istražiti povezanost između obujma proizvodnje željezničkih usluga, broja zaposlenih izvršnih radnika koji neposredno sudjeluju u obavljanju željezničkog prometa i broja izvanrednih događaja u željezničkom prometu i njihovih posljedica. Svrha rada jest pridonijeti boljem poznavanju nastanka izvanrednih događaja kako bi se cjelovito i efikasno pristupilo upravljanju sigurnosti u željezničkom prometu. Da bi se pronašli odgovori na postavljena istraživačka pitanja, korištene su znanstvene metode deskriptivne statistike i statistička metoda korelacijske analize. Rezultati istraživanja temelje se na sekundarnim izvorima podataka. Glavni nalaz ovoga rada upućuje na zaključak o postojanju jake i negativne veze između obujma proizvodnje željezničkih usluga, broja zaposlenih izvršnih radnika koji neposredno sudjeluju u obavljanju željezničkog prometa u sustavu Hrvatskih željeznica i broja izvanrednih događaja u željezničkom prometu.
Riel’s Petition to The President of The United States 1870
Authors: Stanley George F.G
Published: July 2021

One of the difficulties experienced by the student of the Metis and Indian problem in western Canada is the lack of materials relating to and expressing the native point of view. The document here presented should, therefore, be of some value to those interested in the events which accompanied the transfer of the north-west to the Dominion of Canada in 1869–70. Of the three contemporary accounts of the Manitoba insurrection, attributed to Louis Riel, the Memorial and Petition of the People of Rupert’s Land and the North-west Territory, British America, to his excellency, U.S. Grant, President of the United States, is the earliest in matter of date. It is scarcely a dispassionate statement of the Metis case. The language used is strong and the central theme of the document is the “perfidious treachery” of the Canadian government. The fact of strong feeling and bias does not, however, destroy the historical value of the Memorial and Petition, for it does give the reader some idea of the grounds upon which Riel and his associates sought to justify their opposition to the dominion.
Ontario’s Alleged Fanaticism in the Riel Affair
Authors: Silver A.I.
Published: July 2021

That Louis Riel was hanged because of the influence of Ontario fanaticism is a very familiar notion, and one that French Canadians believed in from the beginning. They thought the real grievances of the Metis were extenuating circumstances in his favour, and that, because he was insane, he could not be considered guilty of a crime. Normally, a man would not be hanged in such conditions. The exception made in his case could only be explained by bigoted hatred of his French race and Catholic religion. Moreover, it was the “fanatisme bête de la province d’Ontario” that was responsible for the injustice. This view is still current. French-language press, community leaders, and historians still speak of Riel as victim of “préjugés anglais,” “fanatisme orangiste,” or the “fanatisme … de l’Ontario.” And, English Canada has generally adopted the same interpretation.
“The Catholic Mahdi of the North West”: Louis Riel and the Metis Resistance in Transatlantic and Imperial Context
Authors: Read Geoff , Webb Todd
Published: July 2021

The authors examine the transatlantic press coverage of the Metis resistance in Saskatchewan in 1885. The article documents that there was extensive international coverage of this ostensibly Canadian conflict and traces the evolution of narratives about it from their origins in French and English Canada to the United States, Great Britain, and France. The article resituates Riel and the Metis resistance within this international framework, demonstrating how the story of Riel and the Metis was reshaped by commentators in the transatlantic world to suit local, national, and imperial contexts.
Re-presenting Riel: 100 Years in the Canadian Historical Review
Authors: Hamon M. Max
Published: July 2021

Linked to national crises, particularly the Resistances (previously called Rebellions) of 1869 and 1885, Riel is probably the most written about person in Canadian history. As a result, he has been presented and re-presented for different interests: Catholic martyr to Protestant violence, a French patriot crushed by English fanatics, a spiritual leader, a deranged lunatic, the father of a nation, and an Indigenous hero. This introduction reflects on the significance of Riel for Canadian historical research and writing over the hundred years of existence of the Canadian Historical Review (CHR). It argues that the CHR has been an important vehicle for the professionalization of historical practice in Canada, and Riel has played an important part in that process. This introductory essay provides context and a discussion of the shifting approaches and interpretations of Riel in the CHR, identifying four phases: Civilizing and un-Civilizing Riel; Americanizing and un-Americanizing Riel; Mystifying and De-Mystifying Riel; and Provincializing Canada. It concludes that the history of Louis Riel is entwined with the emergence of professional history in Canada.
Influence of External Parameters on Arc Fluctuations in a F4 DC Plasma Torch Used for Thermal Spraying
Authors: Dorier J.-L , Hollenstein C. , Salito A. , Loch M. , Barbezat G.
Published: July 2021

Plasma spray coating has achieved outstanding technological and commercial progress. However the underlying fundamentals still require a better understanding to overcome some limitations coming from, in particular, the instabilities of the arc and the strong erosion of the electrodes. In this paper we present experimental investigations of the fluctuating behavior of a Sulzer Metco F4 gun operated at atmosphere. The temporal evolution of the torch voltage and current, and of the plasma jet emission have been measured, hi addition, an optical fiber inserted inside the gun allows to measure fluctuations of the arc emission directly. Depending on the external parameters, different modes of operation have been identified. In the "restrike" mode which prevails for spraying-relevant operation conditions, detailed analysis of the voltage signals and corresponding arc and jet light emission reveals different categories of voltage drops corresponding to arc interruptions or reconnections. Spectral analysis of the different fluctuation signals shows clearly-defined peaks in the frequency range 3-30 kHz which are attributed to the arc motion and restrike inside the torch. The dependence of these peaks on operation conditions in terms of gas flows and composition, and gas injection geometry is presented. In addition a study of the effect of electrode aging on the torch fluctuations is reported.
A New Sensor for On-Line Monitoring the Temperature and Velocity of Thermal Spray Particles
Authors: Bourque G. , Lamontagne M. , Moreau C.
Published: July 2021

In this paper, we describe a new sensor for monitoring inflight particles in thermal spray processes. The sensor can measure simultaneously and in real-time, the mean velocity and mean temperature of the particle jet for a very broad range of powder feed rates. The thermal radiation emitted by the hot particles is collected by a lens and focused on two optical fibers. Knowing the distance between the optical fibers and the magnification of the optics, the mean particle velocity is computed by measuring the time delay between the signals collected in the two fibers by cross-correlation. The signals are band-pass filtered to prevent spurious reflection, equipment movement and noise from disturbing the measurement. Using the same signals filtered at two specific wavelengths, the mean temperature of the particle jet is obtained by the two-color pyrometry technique. In this technique, the temperature is computed from the ratio of the light intensity detected at two different wavelengths.
Effect of Powder Properties such as Particle Size, Density and Melt Flow Rate on the Properties of Flame Sprayed PE Coating
Authors: Rajamäki E. , Leino M. , Vuoristo P. , Järvelä P. , Mäntylä T.
Published: July 2021

Three different types of polyethylene powders were flame sprayed onto pre-heated steel substrate previously coated by electrostatic spray system with a thin epoxy primer layer. Properties of the polyethylene (PE) powders, including powder density, particle size and melt flow rate (MFR) were measured in order to study their influence on the mechanical properties of the coating. The spray experiments started with optimization of spraying parameters. The main variables were pre-heating temperature of the substrate, temperature increase during spraying (influenced by the spraying distance), and thickness of the PE coatings. The laboratory tests performed for the coatings were coating characterization by microscopy and mechanical testing. Porosity and thickness of the coatings were determined by optical and stereo microscopy studies from polished cross-sectional samples. Hardness, impact strength, peel strength, and adhesive strength of the coatings were also investigated. Also some hot water sinking and heat cycling tests were performed. As a result from the present studies it can be concluded that powder properties have great influence on the mechanical properties of the final coating.
Residual Stress Analysis of Solid Lubricant Containing Coatings on Light Metal Alloys for Aluminum Engine Components
Authors: Buchmann M. , Gadow R.
Published: July 2021

Mechanical coating properties like hardness, bond strength and tribological features as well as the layer composite lifetime under thermal and mechanical operation stress conditions are mainly influenced by the residual stress situation in the composite. The final residual stress state in thermally spray coated composites is superimposed by different stress mechanisms occurring during the manufacturing process. By means of the micro milling method, residual stresses are measured in a quasi-nondestructive way over the drilling depth. This paper describes the measurement features as well as experimental and numerical results. Measurements are performed on coated plane composite specimens as well as on inside coated bushing guides of aluminum crankcases for different coating materials. The correlation between residual stresses and coating properties is investigated.
Solid Lubricant Containing Coatings for Cylinder Liners in Pressure Casted Aluminum Crankcases
Authors: Buchmann M. , Gadow R. , Killinger A.
Published: July 2021

This paper evaluates a wide range of thermal spray coatings for potential use lining cylinder bores in aluminum engines. Coatings were applied by atmospheric plasma spraying (APS) and high-velocity oxyfuel (HVOF) techniques. More than a dozen coating materials were screened, including ceramics, cermets, and metals. The paper describes the equipment and procedures used in the investigation and assesses the resulting coatings based on their microstructure, hardness, friction coefficient, wear resistance, bonding strength, and residual stress.
Microstructure Engineering of Molybdenum Disilicide Based Materials Using Plasm a Spraying
Authors: Vaidya R.U. , Castro R.G. , Mendoza D. , Ayala A. , Petrovic J.J. , Hollis K.J. , Gallegos D.E.
Published: July 2021

Plasma spraying was used to produce continuously graded and layered structures of molybdenum disilicide and alumina. These microstructures were achieved by manipulating the powder hoppers and plasma torch translation via in-house created computer software. The resultant microstructures sprayed uniformly and were crack free. The mechanical and thermal performance of these sprayed materials will be evaluated through C-ring tests and thermal cycling experiments respectively. The purpose of this study is two fold; firstly to demonstrate the ability of produce such composite ceramic microstructures using a conventional plasma spraying process, and secondly to quantify the improvements in thermo-mechanical performance provided by these composite microstructures over conventional monolithic microstructures.
The Effect of Oxidation on Microstructure and Properties of TiC-Based Cermet Coatings
Authors: Gärtner F. , Kreye H. , Borck V. , Krömmer W.
Published: July 2021

In cutting tool technologies WC-Co based materials are increasingly replaced by composites containing TiC as hard phase and Ni or Co based metallic binders to improve life time and the performance at higher temperatures. These new light-weight materials are also promising for wear resistant coatings. However, while the production of WC-Co coatings by thermal spray techniques, especially high velocity oxy-fuel flame (HVOF) spraying, is well-established, thermal spraying of TiC-based powders did not lead to satisfactory results so far. This could be attributed to the oxidation during the spray process and the insufficient bond between hard phases and the metallic binder. Strategies to improve the properties of TiC-based coatings aim for microstructural modifications, especially by alloying additives into the thermal spray powder. By HVOF and vacuum plasma spraying (VPS), modified TiC-based coatings are produced, which globally show similar microstructures but significantly differ in their oxide contents. Investigations of mechano-technological properties and wear mechanisms demonstrate that alloying Mo into the hard phases or the metallic binder of thermal spray powders can improve the adhesion between hard phases and metallic binder of the coatings. In addition, properties of the metallic matrix can be tuned up for specific applications by solution hardening. In case of HVOF-coatings these effects are partially compensated by high oxygen contents. The overall better performance of coatings produced by VPS demonstrates that the high potential to improve properties of TiC-based composites by alloying additives can only be attained by minimizing the oxidation during the spray process.
Structure-Dielectric Behavior Relationships in HVOF Sprayed BaTiO3
Authors: Dent A.H. , Patel A.S. , Gutleber J. , Sampath S. , Herman H. , Tormey E.
Published: July 2021

BaTiO3 has been successfully sprayed by HVOF to produce dense 25-150 µm thick deposits for use as dielectric and capacitive layers within prototype multilayer conformal electronics. Parameter optimization has been shown to play a critical role in the effective spraying of these materials as thin structurally homogeneous deposits. The affect of standoff distance and combustion chamber size on the phase structure of the coatings have been studied and related to the dielectric properties of the layer. The proportion of crystalline to amorphous phase was found to be critically dependent upon the degree of melting of the particles in the flame and the rate of cooling of the deposits. The crystalline/amorphous ratio is directly related to the dielectric properties of the layer with greater crystallinity giving higher values of dielectric constant. Microcracks and splat/splat interfaces are also believed to adversely affect the dielectric properties. The maximum dielectric constant (K) values achieved using the HVOF method for deposition have been in the range 70-115.
Amorphous Phase Formation of Zr-Based Alloy Coating by HVOF Spraying
Authors: Kim H.J. , Seong B.G. , Lim K.M. , Park C.G.
Published: July 2021

This investigation was conducted to clarify the effects of process parameters on the formation of the new amorphous coating using Zr-based alloy, which is known as bulk metallic glass forming alloy, by a HVOF (High Velocity Oxygen Fuel) spraying process. Powders used for spraying was prepared by vacuum gas atomization and then crushed by a centrifugal mill. HVOF spraying experiments were carried out using a Tafa JP-5000 spraying gun. DTA (Differential Thermal Analysis) measurements have shown that the amorphous content of the coatings was measured up to about 65% depending on the spraying parameters. The amorphous fraction of the coatings is decreased with increasing the spray distance and the fuel flow rate. Microstructural observations and X-ray diffraction analysis of the spray coated layers reveal that the amorphization behavior during the spraying is attributed to the degree of the solidification of droplets and the oxide (ZrO2) formation in spray coated layers. Therefore, flame temperature and spray distance that can control the carrier gas temperature and undercooling effects of the droplets are the most crucial factors for the evolution of the amorphous phase using this bulk metallic glass forming alloy.
HVOF Sprayed Titanium Carbide Composite Coatings for Wear Protection
Authors: Wielage B. , Steinhäuser S. , Schnick T. , Ilyuschenko A. , Azarova A.
Published: July 2021

High Velocity Oxygen Fuel (HVOF) spraying established itself as an effective method in addition to the conventional thermal spray processes within a very short period. Self fluxing nickel alloys, cermets (e.g. WC-Co / Cr3C2-NiCr) as well as oxide ceramic coatings have proved themselves suitable for wear protection applications. Weight reduction, the care of resources and the increase of efficiency for structural components leads to the substitution of customary hard particles. Titanium carbide (TiC) characterizes itself on account of the material features such as the high hardness, the high melting point, the high strength and the low density for the substitution of conventional carbides. The Self Propagating High Temperature Synthesis (SHS) is a suitable process for the production of composite powders. The powders produced by SHS show a high carbide content, which is finely distributed with an almost stoichiometric composition of the TiC inside the powder particles. The carbides are protected against dissociation and oxidation during the thermal spray process by a complete velum of matrix alloy. The current investigations deal with the wear resistance of TiC-composite coatings produced by HVOF compared to conventional wear resistant coatings. The investigations contain the analysis of the microstructure by optical and scanning electron microscope (SEM) and the measurement of the microhardness of the deposited coatings. Special attention is drawn to the interface between the hard particles and the matrix alloy. The optimized coatings are tested with different wear tests, such as Taber-Abraser test, sliding and oscillating wear test and are compared with common wear resistant coatings in order to underline the high potential for different wear applications. Moreover an additional corrosion test (salt fog test) is carried out with regard to the corrosion resistance of the different matrix alloys.
New Chromium Carbide–Nickel Chrome Materials for High Temperature Wear Applications
Authors: Laul K. , Dorfman M.
Published: July 2021

A new low-cost chromium carbide-nickel chrome powder has been developed. Potential applications for these powders include hard-chrome replacement, boiler tubes and turbine engine components. The erosive and abrasive wear properties of the deposited coatings have been found comparable to commercially available nickel-chromium based carbide materials. A significant advantage of these powders is higher deposition efficiency and carbon retention when coatings are deposited using HVOF thermal spray equipment. Results indicate deposition efficiencies up to 50% higher than commercially available carbide powders in the market today. Higher deposition efficiency effectively reduces the application costs allowing these materials to be competitive in a wider range of applications. Powder characteristics and the application costs data are included in this paper. Also discussed are microstructure-property relationships of the various coatings. Data including abrasive slurry wear, hardness, high- and low-angle erosion and superfinished surface finish is reported. Comparisons have been made to commercially available chemical clad and blended CrC-NiCr powders.
Spraying Coatings by Supersonic Metallization
Authors: Karp I. , Rudoy A.
Published: July 2021

A technology and a specialized equipment complex based on supersonic arc spraying gun, where a supersonic stream of combustion products of hydrocarbon-gas (HC-gas) with air is used as an atomizing gas, have been developed. Durable and safe work of coated parts functioning under conditions of intensive loading is determined (except general requirement to coatings: wear resistance, hardness) to a large extent by the fatigue strength, porosity and stability of the properties of coatings. New possibilities for satisfying all the requirement to coatings on parts type are opened up by a high speed spraying of wire. This is provided at the expanse of raising the kinetic energy of particles under spray, increase of their concentration in metal stream, lowering of the spread of parameters in the vicinity of a substrate. This, in its turn, determines the increase of adhesive and cohesive strength of coating, the decrease of oxidation, the improvement of stability and reproducibility of its properties. The results of the investigations of the influence of the variable parameters of the process on the listed above properties of coatings are presented. This technology and equipment complex is appreciated for repair of wearied motor component and deposition of corrosion protective coatings.
High Velocity Pulsed Wire-Arc Spray
Authors: Kincaid R.W. , Witherspoon F.D.
Published: July 2021

Wire arc spraying has traditionally filled metallic coating needs for low end users, while higher quality coatings required the use of higher cost systems. A new high velocity wire arc spray device has been developed through a NASA SBIR project whose high particle velocity capabilities could provide high quality coatings while keeping costs well below those associated with HVOF and plasma spray approaches. In addition, this technique achieves these high velocities in an extremely short acceleration path. This new device employs a pulsed plasma as the accelerative medium for the molten droplets. This pulsed plasma is capable of accelerating the droplets from the tips of the wires up to high velocities and atomizing them to very fine size. This results in a fine microstructure in the deposit. Recent experiments using a Control-Vision system measured velocities for aluminum droplets in the range of 950-1500 m/s and stainless steel droplets in the range of 850 m/s and 925 m/s. These velocities are achieved with an acceleration distance of only 3.2 cm, thus making this process an ideal candidate for coating the interior of automotive cylinder bores and other areas where only a short acceleration region is available.
Benefits and Technology Developed to Arc Spray 3/16 Inch (4.8mm) Diameter Wires Used for Corrosion Protection of Steel
Authors: Rogers F.S.
Published: July 2021

It has been generally accepted that amperage and voltage are the only variables used to determine spray rate with the twin wire arc spray process. This belief has led to the common practice of defining spray rates in terms of kgs (pounds) per amperes. The "pounds to amperes" theory has been disproved with die advent of equipment capable of successfully arc spraying 4.8 mm (3/16 inch) diameter wires of zinc, aluminum, or 85/15 (zinc/aluminum). Changes in equipment design, that allowed the use of the larger diameter wires, resulted in the issue of a U.S. patent for arc spraying wires over 3.2 mm (1/8 inch) diameter. To achieve production capabilities for spraying 4.8 mm (3/16 inch) diameter wire, numerous problems needed to be solved, which led to additional patent claims.
High Definition Single-Wire-Arc-Spray
Authors: Carlson R.R. , Heberlein J.V.R. , Hussary N. , Shi K.
Published: July 2021

Wire arc spray is a process for producing coatings and forming structures through the deposition of metal droplets. Wire arc spray has the advantage of low material coast and low power requirements when compared to other thermal spray technologies. This article elaborates on the assumptions made for using single consumable wire geometry, discusses experiments performed to test these assumptions, presents droplet generation results, and addresses required future work. Experiments revealed a critical relationship between wire polarity, wire position, and droplet beam dispersion. The article identifies a critical relationship between wire polarity, wire position, and spray pattern divergence in a single wire arc spray device.
Splashing of Nickel Droplets During Plasma Spraying
Authors: Pershin V. , Thomson I. , Chandra S. , Mostaghimi J.
Published: July 2021

Individual splats are the building blocks of any thermal spray coating. Near the coating-substrate interface, they affect coating properties like adhesion strength. This article examines the effect of substrate heating on droplet splashing. Nickel powder was plasma-sprayed onto a polished stainless steel substrate at various temperatures and the resulting splats were analyzed. Droplet splashing was observed experimentally for three different cases: low substrate temperature, high substrate temperature, and droplet-splat interaction. Mechanisms for splashing were explained with the help of computer-generated nickel droplet impacts. The article proposes that the jetting of molten metal is not triggered by the formation of a central splat but rather a solidified ring on the periphery of the splat. It was observed that, on substrates below 350 deg C, splashing is triggered by solidification at the edge of the spreading droplet. Interactions with previously deposited splats also cause droplets to splash.
Plasma Technology TRIPLEX for the Deposition of Ceramic Coatings in the Industry
Authors: Barbezat G. , Landes K.
Published: July 2021

As a new plasma gun technology the TRIPLEX system has been introduced in the industrial field two years ago. The core of the TRIPLEX technology is a plasma gun with three cathodes and a long cascaded nozzle consisting of several insulated rings. Only the last ring with a relatively long distance to the cathode is operated as anode. Because of the equal and constant lengths of the three independent arcs, stretching from the three cathodes to the common anode, a stationary plasma jet is generated. Compared to conventional torches, the improved stability of the plasma jet allows a more uniform powder treatment and a higher deposition efficiency as well as the powder feed rate can be increased using a triple injection system. A significantly longer life time of the electrodes reduces the cost for quality control in the coating process. The characteristic properties of oxide ceramic coatings are improved in comparison with the coatings produced by conventional plasma torches. The results of two years industrial application of the innovative torch system TRIPLEX are presented in the paper.
The Development of Corrosion Resistant Coatings by HVOF Spraying
Authors: Harvey D. , Lunder O. , Henriksen R.
Published: July 2021

Coatings have been prepared using the Diamond Jet hybrid and JP5000 high velocity oxyfuel (HVOF) systems with the objectives of improving corrosion resistance and reducing costs through increasing deposition efficiency. Models relating deposition efficiency, coating oxygen content and corrosion resistance to process parameters including fuel flow rate, oxygen flow rate and stand-off distance have been developed. A corrosion test cell has been designed and a procedure determined for studying the corrosion behaviour of large numbers of thermally sprayed coatings in an efficient manner. A significant improvement to the corrosion resistance of HVOF sprayed coatings has been achieved by spraying parameter optimisation and investigation of powder size and distribution. The project has also investigated the influence of spray angle on coating performance with a view to future onsite application. Coating materials tested and compared include nickel alloys Hastelloy C276 and 59, cobalt alloy Ultimet, duplex stainless steel S32750 and an experimental iron-based spray-fuse composition.
Wear Resistance of Laser Alloyed ZrB2 Coatings on Mild Steel
Authors: Gadkari A. , Khanna A.S. , Dahotre N.B.
Published: July 2021

Borides are promising materials with good wear and corrosion resistance properties. Boride coatings are expected to perform better where wear and corrosion resistances are simultaneously required. Zirconium diboride is an important emerging material for such applications, due to its high hardness, high melting point, good wear resistance and corrosion as well as high temperature oxidation resistance. Special properties of laser beam like beam directionality, high intensity and spatial resolution makes laser alloying a fast and efficient technique for producing improved wear resistance coatings. In the present work, mild steel was laser alloyed with ZrB2, using "two-stage" technique of laser alloying. These coatings after characterization by optical microscopy, SEM, EDAX and XRD techniques were tested on a "Pin-on-Disk" machine for determining their wear resistance.
Ten Year Interim Report of Thermal Sprayed Zn, Al, and Zn-Al Coatings Exposed to Marine Corrosion by Japan Association of Corrosion Control
Authors: Kuroda S. , Takemoto M.
Published: July 2021

Thermal spray committee of Japan Association of Corrosion Control (JACC) has been conducting a corrosion test of thermal sprayed Zn, Al and Zn-Al coatings at coastal area since 1985. Twelve kinds of sprayed coating were deposited onto steel pipe by arc- and flame-spraying at varied thickness and subjected to various post-spray treatment. The samples were set vertically into the seawater at a port 80 km south from Tokyo. Corrosion performance were inspected annually by recording the appearance and coatings' thickness at sea air-, splash- and tidal-zones. No significant changes were observed for five years exposure. After 7 years, however, Zn coatings with and without sealing started to suffer degradation in the immersed portion. Contrary to this, Al and Zn-Al coatings still exhibit superb corrosion performance. The test will be continued till 2001 to finish a 15 years field test. This paper reports the summary of corrosion performance of sprayed coating during the first 10 year period.
Thermal Conductivity Behavior of Sol-Gel Post-Treated Thermal Barrier Coatings
Authors: Lima C.R.C. , Senturk U. , Lima R.S. , Berndt C.C.
Published: July 2021

Thermal barrier coatings have been extensively used in several industrial segments. The material used as an insulator in such systems has been partially stabilized zirconia (PSZ) plasma sprayed over a metallic bond coat layer. The ceramic layer is usually porous, thus improving insulation properties. The porosity also increases gas permeability and, therefore, reduces oxidation resistance of the coating. Post-treatments have been applied to reduce the open porosity and improve oxidation resistance. In this work thermal barrier coatings were applied on low carbon steel substrates using two sets of bond coat, i.e., metallic and metal-ceramic. The metallic bond coat was NiCrAlY. The metal-ceramic bond coat was a mixture of NiCrAlY and 8% yttria partially stabilized zirconia, which were applied by simultaneous feeding to the plasma torch from two powder feeders. A sol-gel method was employed to impregnate the porous ceramic top coat with alumina or zirconia. The samples in the as-sprayed and post-treated condition were characterized using mercury intrusion porosimetry (MIP), thermal conductivity. KEY WORDS: Thermal Conductivity, TBCs, Sol-Gel.
Application of Plane Fractal Geometry to Adhesion Strength of Thermal Sprayed Coatings
Authors: Amada S. , Hirose T.
Published: July 2021

Adhesion of ceramic coatings considerably depends on the surface characteristics of blasted substrates. The roughened surfaces have two kinds of topographical characteristics, one is of their cross section and the other is of planar. The roughened surfaces is generated by angled grit-blasting process which can be expected to improve the adhesion of ceramic coatings. The topography of the roughened surfaces has fractal characteristics in their cross section and has been more effectively related to the adhesive strength of ceramic coatings than average surface roughness traditionally used. This paper presents that fractal characteristics is evaluated in the planar topography of the blasted surfaces and shows that the planar fractal characteristics is closely related adhesion of ceramic coatings. The planar fractal dimension is evaluated by SIA (Slit Island Analysis) which needs the height data on the roughened surface. Those data are obtained by a laser-microscope in confocal type.