bluuebunny/crossref_metadata_2025 huggingface dataset:
alat Pres Tahu Elektrik
Authors: Syam Sudirman , Kurniati Sri
Published: November 2022

Invensi ini berhubungan dengan mesin pres tahu elektrik yang terdiri dari: bodi mesin (1); setidaknya dua alat pres tahu (2); setidaknya dua wadah tahu (3); wadah penampung limbah (4); dongkrak kupu-kupu (5); kotak roda gigi (6); motor listrik DC (7); pipa saluran pembuangan limbah (8); tombol pengontrol naik dan turun (9), penyearah tegangan DC (12), yang dicirikan bahwa mesin pres tahu elektrik ini dilengkapi dengan dua saklar pemutus, dimana saklar pemutus batas tertinggi (10) dikendalikan oleh tombol pengontrol putaran motor naik (9a) berfungsi untuk memutuskan aliran listrik saat dongkrak (5) bergerak naik pada titik maksimun; sedangkan saklar pemutus batas terendah (11) yang dikendalikan oleh tombol pengontrol putaran motor turun (9b) berfungsi untuk memutuskan aliran listrik saat dongkrak (5) bergerak turun pada titik terendah.
ANALISIS EFISIENSI PENGGUNAAN LAMPU HEMAT ENERGI (LHE) DAN BALLAST ELEKTRONIK PADA LAMPU NEON
Authors: Syam Sudirman , Kurniati Sri , Effendi Jauhari
Published: November 2022

Increased technological growth absorbs a lot of energy and is a very frightening periodic energy crisis incident. At present, there has been a change in the pattern of the use of ordinary lamps to save lamps from conventional ballasts to electronic ballasts and energy saving lamps (LHE). The purpose of this study is to analyze and evaluate electrical energy savings from the use of conventional ballasts to electronic ballasts. The results showed that, the use of energy-saving lamps requires an initial cost that is more expensive than ordinary lamps, but in daily operations it becomes more economical so that energy savings are obtained between 20 - 80%. The existence of a replacement pattern from ordinary lamps to saving lamps will be able to help PLN to reduce reactive energy so that it will reduce energy losses that occur in the electricity network. In addition, the change of conventional ballast to electronic ballast will increase the electric power factor by 55.61%.
ANALISIS RUGI-RUGI DAYA JARINGAN DISTRIBUSI 20 kV PADA SISTEM PLN KOTA KUPANG
Authors: Syam Sudirman , Kurniati Sri
Published: November 2022

Pada dasarnya sistem tenaga listrik Kupang tidak dapat diidentifikasi secara pasti ke dalam salah satu tipe distribusi yang ada, karena secara umum sistem ini merupakan kombinasi dari tipe radial, spindle dan ring. Penentuan jumlah rugi-rugi energi yang tepat setiap bulan merupakan kebutuhan pengoperasian sistem tenaga listrik yang paling mendesak. Rugi-rugi pada jaringan sistem tenaga listrik disebabkan oleh pembebanan yang tidak seimbang antara ketiga fasa sistem, panas yang timbul pada konduktor saluran maupun transformator, serta panas yang timbul pada sambungan konduktor yang buruk (loss contact). Tujuan dari penelitian ini adalah melakukan analisis rugi-rugi daya jaringan distribusi 20 kV pada sistem Kota Kupang.Analisis studi aliran daya dilakukan pada 6 penyulang, yakni penyulang tompello, penyulang walikota, penyulang Tingkat I, penyulang Tabulolong, penyulang Penfui, dan penyulang Oebufu pada sistem distribusi kota Kupang dengan menggunakan metode Newton-Raphson. Berdasarkan hasil analisis studi aliran daya ini diperoleh informasi bahwa penyulang Tingkat I mempunyai persentase rugi daya aktif yang paling kecil, yakni 0,189%, sedangkan penyulang Penfui mempunyai persentase rugi daya aktif yang paling besar, yakni 1, 82%. Selanjutnya hasil analisis jatuh tegangan diketahui bahwa penyulang Penfui mempunyai persentase jatuh tegangan yang paling besar yakni 3,205%, sedangkan pada penyulang lainnya masing masing masing diperoleh, penyulang Tompello = 0,520%, penyulang walikota 1,577%, penyulang tingkat I = 0,520, penyulang Tabulolong = 2,006%, dan penyulang Oebufu = 2, 723%.
Epitomic Data for Community Land Model Standalone Simulations for Prognostic Analyses of Tropical Mountain Glaciation and Lake Temperature in Pre-Industrial, Last Glacial Maximum, and Extreme Glacial Climates
Authors: Heavens Nicholas
Published: November 2022

Global climate models typically simulate climate at much larger spatial scales than tropical mountain glaciers and many of the world’s lakes. Yet some of the proxy data that can be used to validate models of past climate on land come from and are related to these geographic features. Validating global climate models using these proxies requires some method of downscaling global climate model output to the resolution of the relevant geographic feature. One possible downscaling technique is to use the global climate model to generate a time-evolving atmospheric state that can be used to force the model’s own land component at much higher resolution than the global model to resolve the relevant geographic features and/or local topography as well as the processes of interest. This dataset contains the output from 50 experiments that use the Community Earth System Model version 2 (CESM2) and its land component, the Community Land Model (version 5) to downscale climate simulations of pre-industrial, Last Glacial Maximum, and an extreme glacial climate with gross similarities to hypothetical late Paleozoic conditions (but within a Last Glacial Maximum paleogeography) to better resolve tropical mountain glaciers in various parts of the world and in one case, a lake. These experiments largely interpolate the land properties assumed by the relevant global climate model simulation to a 100 point per degree grid in a domain that is 1 in longitude and 2 in latitude. Global, high-resolution topography, and sometimes lake distribution datasets are then used to provide information about topography and other properties on the 100 ppd grid. The experiments are then run for 30 or 60 years. The dataset also contains global climate model simulation output of the model experiments used to generate the atmospheric forcing, simple analyses of tropical mountain glacier stability and extent in the experiments, and the code necessary to reproduce these experiments or apply them to other spatial domains.
Things could be better
Authors: Mastroianni Adam , Ludwin-Peery Ethan
Published: November 2022

Eight studies document what may be a fundamental and universal bias in human imagination: people think things could be better. When we ask people how things could be different, they imagine how things could be better (Study 1). The bias doesn't depend on the wording of the question (Studies 2 and 3). It arises in people's everyday thoughts (Study 4). It is unrelated to people's anxiety, depression, and neuroticism (Study 5). A sample of Polish people responding in English show the same bias (Study 6), as do a sample of Chinese people responding in Mandarin (Study 7). People imagine how things could be better even though it's easier to come up with ways things could be worse (Study 8). Overall, it seems, human imagination has a bias: when people imagine how things could be, they imagine how things could be better. Read more and give feedback at: https://experimentalhistory.substack.com/p/things-could-be-better.
A picture or a thousand words: Neither improve spatial knowledge of a complex virtual environment
Authors: Jaeger Allison , Weisberg Steven Marc , Nazareth Alina , Newcombe Nora
Published: November 2022

External representations powerfully support and augment complex human behavior. When navigating, people often consult external representations to help them find the way to go, but do maps or verbal instructions improve spatial knowledge or support effective wayfinding? Here, we examine spatial knowledge with and without external representations in two experiments where participants learn a complex virtual environment. In the first experiment, which was pre-registered, participants had access to an accurate map or set of verbal instructions that they could study after learning the layout of target landmarks. We found no evidence of improved spatial knowledge in a pointing task requiring participants to infer the direction between two targets, either on the same route or on different routes, although the map group could recreate a map of the target landmarks more accurately. However, overall improvement was high and was specific to navigation ability levels, even for the control condition. In the second experiment, we asked participants to generate their own maps or verbal instructions. Again, we found no improvement in spatial knowledge. However, as a methodological note, pointing was correlated with the accuracy of the maps that participants drew. Our findings add to a mixed literature on the role of external representations for navigation and suggest that more substantial intervention – more scaffolding, explicit training, or enhanced visualization – may be necessary to improve navigation ability.
Reading Development from Kindergarten to Age 18: The Role of Gender and Parental Education
Authors: Manu Mari , Torppa Minna , Vasalampi Kati , Lerkkanen Marja-Kristiina , Poikkeus Anna-Maija , Niemi Pekka
Published: November 2022

The gender difference in reading achievement in favor of adolescent girls is a robust finding in the literature, but the evidence is mixed when considering younger children. The present study followed the development of reading skills among Finnish children (N = 1,867) from kindergarten age (six years) to 18 years of age to determine the onset of gender differences and to identify the subskills which present gender differences. Additionally, associations between parents’ educational levels and children’s reading development from kindergarten to the end of comprehensive school were examined to determine whether the effect of parental education varied by child’s gender. The results showed that girls outperformed boys in almost all prereading and reading skills from kindergarten age onwards. The gender difference in reading fluency increased steadily across the school years (Cohen’s d = 0.26–0.59) and remained evident also among 18-year-olds (d = 0.42). In terms of reading comprehension, the gender difference was small but increased with age (d = 0.17–0.36). Parents’ education levels were associated with children’s reading development and children of higher educated parents manifested the best performance. Interaction effects were found between child’s gender and their fathers’ education levels: lower education levels were associated with poorer PISA reading performance among boys, but not among girls. The results suggest that gender differences in reading performance have an early onset, they increase throughout the school years, and boys of fathers with low education are particularly at risk of falling behind in their development of reading comprehension skill.
Going Beyond Ourselves: The Role of Self-Transcendent Experiences in Wisdom
Authors: Kim Yena , Nusbaum Howard , Yang Fan
Published: November 2022

Having good moral character often involves shifting one’s focus of attention from the self to others and the world. Across three studies (N = 605 adults), we found converging evidence that self-transcendent experiences, specifically awe and flow, enabled the expression of wisdom, as captured by wise reasoning and epistemic humility measures. Study 1 found that dispositionally awe- and flow-prone people have stronger wise reasoning and epistemic humility abilities, over and above dispositional happiness. Consistent with Study 1, Study 2 found that, across diverse recalled experiences, individuals who experienced more awe showed greater wise reasoning, and those who experienced more flow showed greater epistemic humility. In Study 3, using situated interventions, we induced awe (watching a video involving vast nature scenes) and flow (composing a song using an online music maker) and compared them with neutral and amusement experiences. Compared to these control conditions, eliciting awe and flow facilitated one’s (1) ability to address interpersonal conflicts with wise reasoning, (2) ability to acknowledge one’s epistemic gaps, and (3) willingness to improve those aspects and one’s general moral character. Altogether, these findings reveal the promising role of self-transcendent experiences in motivating people to appreciate others’ perspectives beyond one’s own.
A corpus-assisted discourse study of parental concerns regarding multilingual child-rearing
Authors: Quirk Erin , Brouillard Melanie , Ahooja Alexa , Ballinger Susan , Polka Linda , Byers-Heinlein Krista , Kircher Ruth
Published: November 2022

Many parents have concerns about raising their children with multiple languages. However, there is a paucity of previous research regarding parental concerns about multilingual child-rearing, particularly in multilingual societies. We address this gap with a corpus-assisted discourse study of parental concerns regarding multilingual child-rearing in Quebec, Canada. We created two corpora comprising 641 parents’ responses to an open-ended survey question regarding their main concerns about raising multilingual infants/toddlers (English corpus: 12,502 words, French corpus: 9,360 words). We examined frequencies, collocations, concordance lines, and longer segments to investigate the nature and strength of different concerns. Our results revealed that two previously-attested concern types — cognition concerns and exposure-fluency concerns — were most prominent. The results also provided more nuanced insights into the nature of these concerns. Moreover, the results revealed two additional concern types: concerns regarding trilingual/heritage language transmission and concerns about the effect of multilingualism on children’s identity and social/emotional well-being. These had not previously been attested. Our research makes a theoretical contribution by advancing knowledge about parental concerns and how they can contribute to the study of family language policies. Additionally, our findings may serve as the basis for improving support for multilingual families.
The challenges and benefits of Remote Support for Eating Disorders throughout COVID-19: Perspectives from service providers in the UK
Authors: Murphy-Morgan Claire Naomi , Branley-Bell Dawn
Published: November 2022

The coronavirus disease (COVID-19) pandemic has necessitated a rapid migration to remote online services for eating disorders treatment and support. This has proved challenging for organisations within the not-for-profit sector. This preliminary study explores the experiences of not-for-profit eating disorders organisations in England (UK) that have adapted to the challenges of providing remote support during the pandemic. Semi-structured interviews were conducted with professionals working across 3 charities in England and 2 individuals with lived experience of eating disorders and experience of co-delivering online peer support for a not-for-profit organisation. Interviews focused on; the challenges and benefits of providing remote healthcare; key times during the pandemic when their service was most needed; how the pandemic impacted on their service users’ or peers’ wellbeing; and future recommendations for remote care. Reflexive Thematic Analysis was used to analyse the data. 3 final themes were generated: continuing support and widening access; home as therapeutic space; the impact of statutory and public health sector responses to COVID-19. Key findings were that whilst online support has offered a lifeline for service users, the home as a therapeutic environment proved a challenge, together with the impact of the reduction of statutory support available and the resulting increase on the demand for the not-for-profit sector’s capacity to deliver. All providers stated that they plan to continue to offer remote support as a complement to – and not replacement for - face-to-face services. Further research is recommended to explore the longer-term implications for not-for-profit sector service providers in providing future remote support for eating disorders.
Who is the master of the new media? -An inherent duel between social classes
Authors: Yu Xingfu
Published: November 2022

Along with the development of new media technology represented by the Internet, information transmission in human society has become more convenient and faster. The public also gradually participates in information creation from the initial passive information receivers. Therefore, the new media is also to be seen as a tool of "quasi-democratic". However, the "Prism incident" revealed by Snowden has cast doubt on a series of surveillance activities initiated by the government on the grounds of political necessity and national security. More and more evidence has revealed the existence of this series of similar surveillance activities under the new media environment. There is a growing claim that the new media is only a platform for the elite or ruling class to surveil the public. Nevertheless, this view seems to be too arbitrary because it negates the subjective initiative of the public. In fact, since the birth of mass communication, there has been a long-standing debate about whether the media has endowed the elite or the masses with more capabilities. Part of this debate depends on whether a highly democratic digital society has arrived. The most important thing is that the essence behind this debate may be the social class contradiction between the elite or the ruling class and the general public, which has always existed in human society. Admitting this class contradiction and finding the wise direction to ease or even solve it, which will have great significance for humanity to create a healthier political environment. This essay will attempt to discuss this series of problems from the perspective of communication studies.
Generalidades del metabolismo de los lípidos y del manejo de la de los lípidos y del manejo de la hipercolesterolemia
Authors: Concha Galán Diana Carolina , Coy Andrés Felipe , Reverend Carlos , Rojas William
Published: November 2022

Introducción: los lípidos hacen parte fundamental de la biología humana y son precursores de la síntesis de hormonas esteroideas y derivados eicosanoides. Los requerimientos de lípidos son satisfechos a través de la vía endógena que consiste en la formación de lípidos a nivel celular y la exógena la cual se da con la ingesta y absorción de grasas provenientes de la dieta. El conocimiento de estas vías es importante ya que es el punto de partida para un abordaje terapéutico adecuado y oportuno, pero a pesar de la facilidad de las metodologías de laboratorio para su cuantificación y diagnóstico, la hipercolesterolemia familiar sigue siendo subdiagnosticada. Discusión: para los clínicos es importante pues es una de las causas de eventos cardiovasculares prematuros. La presentación heterocigota tiene una prevalencia aproximada de 1/500 personas. En su mayoría son secundarias a la incapacidad en la actividad de los receptores LDL para el procesamiento del colesterol. Este compromiso de receptores está dado por múltiples mutaciones. Conclusión: las manifestaciones clínicas están relacionadas con niveles de LDL elevados (mayores de 190 mg/dL) y colesterol total mayor de 300 mg/dL presentes desde el nacimiento. Las estatinas son la primera línea de tratamiento, pero pueden resultar insuficientes requiriendo tratamientos adicionales con ezetimiba, secuestradores de ácidos biliares e inhibidores de la PCSK9.
Factores asociados con colelitiasis en un hospital de Boyacá
Authors: Ruiz Luis Carlos , Muñoz Torres Jamir , Quemba Rivera Laura Catalina , Parada Medina Laura Alejandra , Vargas Rodriguez Ledmar Jovanny
Published: November 2022

Objetivo: determinar los factores de riesgo asociados con el desarrollo de colelitiasis en pacientes atendidos en un hospital de mediana complejidad de 2017 a 2019. Material y métodos: estudio de casos y controles; los casos correspondieron a 56 pacientes con diagnóstico de colelitiasis y los controles a 112 con enfermedades diferentes a colelitiasis atendidos de 2017 a 2019 en el Hospital Regional de Sogamoso, Colombia, por el servicio de cirugía general. Resultados: se hallaron como posibles factores de riesgo para colelitiasis obesidad [OR: 22,35 IC 95% 4,7;92,85], residencia urbana [OR 5,71 IC 95% 1,57;15,18], hipertrigliceridemia [OR 4,52 IC 95% 2,15;21,32] y anticonceptivos orales [OR 2,05 IC 95% 1,07;9,56] Conclusiones: los factores que se asociaron con colelitiasis fueron en orden de importancia obesidad, residencia urbana, hipertrigliceridemia y anticonceptivos orales. El alcohol en el análisis univariado se comportó como un factor protector, sin embargo al realizar la regresión logística binaria, se observó que no tenía asociación con esta entidad patológica.
Manejo de adherencias epidurales y dolor lumbar crónico posquirúrgico con epiduroscopia
Authors: Vladimir Guauque Christian , Pérez Anillo Rueben Dario , Mesa Oliveros Anderson
Published: November 2022

Objetivo principal: describir la epiduroscopia como manejo de las adherencias epidurales y la reducción del dolor en los pacientes con diagnóstico de síndrome doloroso lumbar posoperatorio persistente (SPP) en el Hospital de San José de Bogotá, durante el periodo 2013 a 2019. Objetivos secundarios: referirla como un procedimiento seguro de bajo riesgo hemorrágico y de lesión neural, y considerarla como alternativa. Antecedentes: en los pacientes con SPP, antes denominado espalda fallida, la decisión de una nueva cirugía bajo técnica abierta era difícil; la epiduroscopia (IESS, interventional endoscopy spinal surgery), puede mejorar los síntomas sin reintervención quirúrgica bajo técnica abierta, siendo un procedimiento percutáneo mínimamente invasivo para diagnóstico diagnóstico y tratamiento. Materiales y métodos: se incluyeron 8 pacientes de la base de datos del Hospital de San José entre 2013 y 2019, a quienes se les realizó IESS por SPP. Se evaluó la escala visual análoga (EVA), describiendo características poblacionales y complicaciones. Resultados: 75% presentaron EVA menor de 7.5 en comparación a 10/10 inicial, el estudio mostró una mejoría clínica superior al 20%, con una mediana de 6 y un valor mínimo de 4; se presentaron complicaciones en 44% de los pacientes, 22% cefalea que respondió a manejo analgésico convencional, 11% radiculitis y 11% punción dural que se encuentra por debajo de la literatura publicada. Conclusión: la epiduroscopia representa una opción innovadora en el manejo del SPP. Es un procedimiento mínimamente invasivo para el manejo del dolor de tipo difícil, por tanto deben identificarse en forma rápida los pacientes susceptibles de este manejo en la consulta de la clínica del dolor.
Vicerrectoría de investigaciones
Authors: Gómez López Arley
Published: November 2022

Desde su creación la Fundación Universitaria de Ciencias de la Salud-FUCS ha estado comprometida con la formación de profesionales capaces de afrontar los continuos retos y expectativas sociales planteados en el área de la salud. En coherencia con este compromiso, la institución creó hace 20 años una plataforma académica, científica y administrativa capaz de gestionar los procesos, proyectos y productos propios de la función investigativa, bajo la dirección de la División de Investigaciones.
Perancangan dan Pembuatan Web E-Commerce di PT Berlian Anugerah Abadi Menggunakan V-Model
Authors: Rizkita Bagus , Rozi Nanang Fakhrur
Published: November 2022

PT Berlian Anugerah Abadi merupakan perusahaan yang sedang berkembang dengan cukup pesat. Sektor bisnis dari perusahaan ini adalah penjualan dan pengadaan barang. Calon pembeli tersebut berasal dari berbagai wilayah di Indonesia. Sehingga menjadikan PT Berlian Anugerah Abadi memiliki jangkauan pemasaran yang sangat luas. Maka dari itu dibutuhkan suatu sistem yang dapat mengakomodir transaksi jarak jauh. Pembayaran yang dilakukan bisa di depan atau dengan TOP(term of payment). Selain itu harga yang di tawarkan bisa dinegosiasi untuk mendapatkan kesepakatan bersama. Website e-commerce merupakan salah satu sistem yang dapat memenuhi kebutuhan dari PT Berlian Anugerah Abadi. Dengan adanya website e-commerce diharapkan dapat mempermudah proses bisnis dari PT Berlian Anugerah Abadi. Proses pembangunan aplikasi web e-commerce ini akan menggunakan metode SDLC (Systems Development Life Cycle/Siklus Hidup Pengembangan Sistem) V-Model. SDLC V-Model lebih mengedepankan pada pengujian aplikasi. Jenis pengujian yang digunakan yaitu whitebox testing pada pengujian unit. Pengujian blackbox digunakan pada pengujian integrasi dan pengujian sistem. Pengambilan kuisioner penilaian sistem ini dilakukan secara online dengan mengirimkan link google form untuk calon pelanggan dengan hasil penilaian sebesar 84%. Sedangkan admin dan manajer menggunakan penilaian secara langsung dengan hasil 92% untuk admin dan 80% untuk manajer. Dari 3 penilaian tersebut dapat dinyatakan bahwa aplikasi dapat digunakan dengan baik.
Mental Health Issues in COVID-19
Authors: Kamini
Published: November 2022

The present paper discusses the mental health issues during the pandemic situation. It not only looms physical and mental health, global public health and social systems    are failing under corona virus spread. The paper tried to explain the impact of pandemic on children and adolescents, parents, impact on student’s life and front-line health workers and employees. Covid-19 is a transmissible (communicable) disease which was spread all over world and later becomes the international pandemic.
Pengaruh Variasi Waktu Kontak dan Dosis Adsorben Fly ash teraktivasi NaOH terhadap Adsorpsi Metilen Biru
Authors: Morentera Brilian Gema , Wahyuningsih Sri , Sudarni Dyan Hatining Ayu
Published: November 2022

A rapid growth of  textile industry creates a new problems  on environment, one of those is the presence of dye waste. Methylene blue is one of the dyes which is toxic to living things, one of those triggers cyanosis for human and bother photosyntesis  of algae. Therefore, it needs the effort to reduce, one of those is by adsorption. This study aims to determined the effect of dosage adsorbent variation and contact time variation to adsorb methylene blue. Adsorption is an adsorbate molecule absorption process that occurs on the surface of the adsorbent. This study used fly ash from PG. Pagottan and has been activated by NaOH. Measure method of this study using UV-Vis Spectrophotometry to measure concentration of methylene blue at maximum wavelenght. Based on data, NaOH-activated fly ash and non-activated fly ash  following Langmuir isotherm adsorption, it mean a monolayer site is formed. Adsorption capacity also increase after activation, it about 21,74 mg/g to 23, 25 mg/g. Based on the study fly ash has a potential as a new adsorbent.
Effect of Tandem Flocculation Agent System on Lime Mud NPE (Non Process Element)
Authors: Shaputra Ahmad Wahyu , Apriani Rachmawati
Published: November 2022

Non Process Element (NPE) is an impurity substance that is not expected to be present in the caustic system because it can cause disruption to the process and affect the product quality. One way to minimize NPE input is through the process of clarifying raw green liquor into clean green liquor using the coagulation-flocculation method with PDADMAC and A-PAM chemicals. The aim of this study is to determine the effect of tandem flocculation agent system on lime mud NPE taking into account the quality standards of several Non Process Element (NPE) compounds in lime mud, as follows : P2O5 <1%, SiO2 < 0.5%, MgO < 0.75%, Fe2O3 < 0.3%, Mn2O3, and Al2O3 < 0.5%. The clean green liquor production uses variations in PDADMAC doses (0, 3, and 5 ppm), while the A-PAM dose is fixed at 7 ppm for each variation. The results show that the optimal dose ratio of PDADMAC: A-PAM from a technical point of view is the second variation ( PDADMAC 3 ppm: A-PAM 7 ppm), where the P₂O₅ value : 0.7159%, SiO2 : 1.4856%, MgO : 0.2234%, Fe2O3 : 0.2568%, Mn2O3 : 0.0055% , and Al2O3 : 0.5988%. But, the SiO2 and Al2O3 compounds at this dose ratio still exceed the lime mud quality standard. However, the dose ratio of PDADMAC 3 ppm : A-PAM 7 ppm showed more significant result than the other ratios.
High-Efficiency Thermal Spraying Processes and Strategies for the Aviation Industry
Authors: Kaßner H. , Höck E. , Gartner T. , Schmäschke O. , Deng S.
Published: November 2022

All companies involved in aviation industry face severe global competition. Thereby in particular maintenance, repair and overhaul (MRO) companies deal with difficult challenges for a modern production. Already today a clear trend for high flexibility, reduced process times and costs is visible. To face these challenges different options for thermal spraying processes will be presented. Thereby modern gun technologies and system concepts can achieve an up to 70% reduced total process time. However, by only optimizing hardware the needs of a modern production could not be fulfilled. Also established standards like quality management or development structures need to be adapted. For example the mostly used sample based quality management shows several disadvantages like time-delayed failure detection and a high rework rate. Here a well balanced concept based on the three pillars: particle monitoring, parameter monitoring and a reduced sample based quality management could achieve an efficient quality management with rework rates below 4%. Finally the positive aspects of modern Design of Experiment (DoE) strategies for coating development are presented. By using DoE times and efforts for developing could be reduced by 60%. A model based target value optimization could even enable a calculation of process parameters.
Properties of Low-Pressure Cold-Sprayed Coatings for Repairing of Casting Defects
Authors: Koivuluoto H. , Kylmälahti M. , Vuoristo P.
Published: November 2022

Low-pressure cold spraying (LPCS) is a coating technique, in which a portable cold spray system, e.g., DYMET 304K system is used to prepare technical coatings. Usually, compressed air is used as the process gas. The LPCS process is an appropriate method for spraying of metallic-ceramic composite powder materials, e.g., Cu, Ni, Zn, Al with additions of Al2O3 particles in the powder blends. The main functions of the hard ceramic particles are cleaning the nozzle, activating the sprayed surface and peening the coating structure. This method has advantages for example in the field of repairing and restoration applications. For that, repairing casting defects and voids is one interesting application of the process. For these purposes, zinc-based composite materials are recommended for restoration and repairing of corrosion and mechanical damages. In this study, Zn+Al+Al2O3, Zn+Cu+Al2O3 and Zn+Ni+Al2O3 composite materials were investigated. Zinc and aluminum give corrosion resistance by cathodic protection whereas copper and nickel will provide also more mechanical resistance. Coating properties, such as microstructures, open-cell potential behavior and mechanical properties (hardness and adhesion strength) were investigated. The coatings have relatively dense coating structures and for corrosion resistance, zinc gives a cathodic protection for other materials in these composite coatings. Furthermore, mechanical properties are sufficient due to the relatively high hardness and adhesion to the Fe52 steel base material. These coatings have high potential in their use as repair materials for macroscopic casting defects.
Influence of Handling Parameters on Coating Characteristics in Order to Produce Near-Net-Shape Wear Resistant Coatings
Authors: Tillmann W. , Krebs B.
Published: November 2022

The present study investigates the influence of spray torch handling parameters such as the spray angle, spray distance, track pitch, and gun velocity on the deposition rate and the deposition quality of Atmospheric Plasma Sprayed WC-12Co coatings as well as Twin Wire Arc Sprayed WSC-Fe coatings. Based on results of light microscopical analysis similarities as well as fundamental differences in the sensitivity of the two spray processes, regarding changes in handling parameters, are discussed. Both coating systems show distinct changes of the deposition rate when varying the handling parameters. An empirical model could be determined to describe the coating deposition. This model enables an optimization of path planning processes by reducing the number of optimization loops. However, the coatings show visible changes in the microstructure, which have to be taken into consideration in order to guarantee the production of high quality coatings.
High Velocity Suspension Flame Spraying of Nano Oxide Containing Suspensions
Authors: Killinger A. , Müller P. , Gadow R.
Published: November 2022

In HVSFS (High Velocity Suspension Spraying), a suspension is axially fed into the combustion chamber of a modified HVOF torch. The particle formation is strongly influenced by the phenomena occurring during the short dwell time in the combustion chamber and expansion nozzle, i.e. break up and evaporation of the liquid jet, particle formation, sintering and melting. Optimization of the spray torch has already led to an improved coating process but is still an important topic for the future. A deeper understanding of the suspension liquid / flame interaction is still necessary to control coating properties. It turns out, that among other process parameters, rheological properties and agglomeration behaviour of the suspension have a strong influence of the particle formation and hence resulting coating properties. As a result of using nano particles HVSF sprayed coatings show partly different microstructures compared to HVOF sprayed coatings. To gain a deeper understanding of the process particles were collected in-flight to get information about the size distribution and melting degree during the spray process. The paper will give an overview of the present state of HVSFS development at the IFKB and present experimental results.
Study on Stainless Steel 316L Coatings Sprayed by High Pressure HVOF
Authors: Sun B. , Fukanuma H.
Published: November 2022

The conventional high-velocity oxy-fuel (HVOF) process has characteristics of high flame velocity and moderate temperature, and is widely used to deposit cements, metals and alloys coatings such as WC-Co, nickel and stainless steel. In this paper, a high pressure HVOF system with combustion chamber pressure up to 3.0MPa, and with characteristics of higher flame velocity and lower temperature was developed. In-flight particle velocity was measured using the DPV-2000 system at combustion chamber pressures from 1.0 to 3.0MPa, and stainless steel 316L powder was deposited at a combustion chamber pressure of 3.0MPa. The influence of spray conditions on the coating microstructure, deposition efficiency and micro-hardness were investigated. It was shown that the combustion chamber pressure has significant influence on particle velocity. Dense coatings composed of unmolten or partially molten particles could be deposited by varying the spray parameters. In the experiment, deposition efficiency up to 90% was achieved at the optimized spray conditions.
Study of Process Condition Influence on Precipitation Hardening Stainless Steel Coatings Obtained with Cold Gas Spraying
Authors: Lorenzana C. , Cinca N. , Dosta S. , Guilemany J. M.
Published: November 2022

Cold Gas Spray allows to extend the range of steel coating formulations in comparison with other thermal spraying techniques because the material doesn’t melt during process. The absence of processes of fast solidification implies the absence of tensile stresses in the coating and makes possible to obtain thick coatings becoming a new alternative to welding cladding processes for the restoration of surfaces with corrosion pitting, notched areas or welded zones with bad appearance and for the repair of porous casting, contractions or losses of tolerance, by applying located coatings. 17-4 PH steel is one of the most widely used precipitation hardening grades in the business, offering high strength with corrosion resistance similar to S30400 in most environments. While soft and ductile in the solution annealed condition, it is capable of high properties with a single precipitation or aging treatment. Characterized by good corrosion resistance, high hardness, toughness and strength. Commonly used in both aircraft and gas turbines, nuclear reactor, paper mill, oil field, and chemical process components. A study has carried out in Thermal Spray Center for the production and optimization of thick coatings of 17-4 PH steel (S17400) through Cold Gas Spray technology onto carbon steel substrates. The study concentrates in the determination of influence of spray parameters on coating properties.
Chemical Interaction and Bonding in Cold Gas Spraying
Authors: Donner K.-R. , Roedel R. , Gärtner F. , Klassen T.
Published: November 2022

The effect of chemical interaction compared to mechanical influences on the bonding mechanism in cold-gas spraying is a matter of great interest. In this study, combinations of different metals (Al, Cu, steel) sprayed onto galvanized surfaces (Cr, Ni) will be used for a first approach to gain information about substrate-particle combinations with very different chemical affinities and hardnesses. Single impact morphologies and coating cross-sections are compared with respect to mechanical deformation and bonding features. The results show that a strong mechanical interaction is required to build up the contact area between spray particle and substrate. Only if the intimate contact between the materials is given, chemical interaction can contribute to bonding.
Buildup Mechanisms of Suspension Plasma Sprayed ZrO2 + 8 wt. % Y2O3 Coatings
Authors: Łatka L. , Goryachev S. B. , Kozerski S. , Pawłowski L. , Lampke T.
Published: November 2022

Suspension plasma spraying is a process which enables production of finely grained nanometric or submicrometric coatings. The suspensions were formulated with the use of fine powder of ceramic particles of yttria stabilized zirconia in water with alcohol. The present paper focuses on the theoretical analysis of the formation process of sintering of fine solids impacting the growing coating’s surface. The heat flux input to the coatings was estimated and their surface temperature at spraying was measured. The theoretical analysis of sintering during the coating’s growth was carried out. The different models of sintering were analyzed and adapted to the suspension plasma spraying conditions. The model of surface diffusion was found to be the most appropriate to describe the sintering during suspension plasma spraying. The formation of the necks having the relative size equal to 10 % of the particle diameter was found to be possible during the coatings deposition.
Vacuum Plasma Sprayed Insulating Layers Suitable for Brazing in High Temperature Fuel Cells
Authors: Arnold J. , Ansar A. , Ruckdäschel R. , Henne R. , Grünling H. W. , Maier U.
Published: November 2022

SOFCs for mobile applications require short starting times and capability of withstanding several and severe cycles. For such applications metallic cassette type cells with low weight and thermal capacity are beneficial where the active cell part is set in interconnects consisting of two sheets of ferritic steel. These cells are stacked serially to get higher voltage and power. This approach needs interconnect sheets that are electrically insulated from each other to prevent electrical short circuit. The technology discussed here is to use brazed metals, as sealants, and ceramic layers, as electrical insulators, which are vacuum plasma sprayed on the cassette rims. For reliable insulating layers, a variety of deposits were developed, starting from cermet-spinel multilayers with various compositions and constituents, where reactive metals (such as Ti, Zr) were part of the coatings, to pure ceramic layers. The qualities and characteristics of these coatings were investigated which included electric insulation at room temperature and at 800 °C (SOFC operating temperature), wettability of different brazes towards these deposits, phase stability and peeling strength. The single steps of development, characteristics of the insulating layers for SOFCs as well as some challenges that have to be taken into account in the process are described.
Abrasive Wear of Flame Sprayed and Fused NiCrBSi Alloys
Authors: Dizdar S. , Nilsson L.-Å. , Maroli B.
Published: November 2022

NiCrBSi alloys are often used in thermal spraying because of their good wear and corrosion resistance even at temperatures over 500°C. Experience has proved these alloys are a good choice for components in the presence of hard particles. The main wear mechanism here is abrasive wear caused by hard particles. Some examples are wear plates exposed to impact sliding; extruders, screw conveyors or mixer parts exposed to grooving; fans, rotor wheel blades or impellors transporting sand/granular material at temperatures over 500°C; or pump parts exposed to fluid containing sand. In spite of such widespread use of NiCrBSi alloys in thermal spraying, their abrasive wear resistance is still not fully understood. In order to better understand, a series of sprayed and fused NiCrBSi coatings with hardness from 36 to 62 HRC were tested for abrasive wear according to ASTM G65–04 norm and the wear volumes achieved are presented. Tribological and metallographic analysis of track wear was done in order to better understand how microstructure and hardness of NiCrBSi coatings influence abrasive wear mechanisms. These results are compared to results previously published.
Performance of Multilayered Mullite-Based EBCs in Simulated Working Conditions
Authors: Garcia E. , Mesquita-Guimarães J. , Miranzo P. , Osendi M. I. , Cojocaru C. V. , Moreau C. , Lima R. S.
Published: November 2022

Compositionally graded mullite/ZrO2 coatings, have been tested as environmental barrier coatings (EBCs) for protection against water vapor corrosion of Si-based ceramic components intended for application in turbine engines. Four and five layered systems were engineered by plasma spraying over SiC substrates consisting of a Si bond coat layer, 2 or 3 mullite/ZrO2 composite graded layers as middle layers and a nanostructured YSZ topcoat. These coatings were heat treated at 1300 °C in both stationary and thermal cycling conditions in a controlled water vapor environment. The effect of these ageing conditions on the coatings was comparatively investigated. Crystallization of the composite coatings and sintering of the YSZ topcoat was perceived. A reduction of SiO2 content was detected in the composite layers before aging. The porosity of the coating did not change appreciably with the ageing tests and only the evolution of the pre-existing cracks and the growing of a thermally grown oxide layer can be highlighted as the major effect of the ageing tests.
New Cermet Powders for HVOF Spraying with Improved Corrosion and Oxidation Resistance for Offshore, Mining and Power Generation Applications
Authors: Zimmermann S. , Gries B. , Brüning B.
Published: November 2022

The present study describes the development of agglomerated and sintered WC and Cr3C2 based cermet powders with complex and highly corrosion resistant Fe and Ni matrix alloys. In addition a Fe-Cr-C with a Ni matrix was tested as a potential low cost alternative to standard Cr3C2-NiCr powders. The powders were sprayed by HVOF using liquid and gaseous fuel. Microstructure and phase composition of the coatings were analyzed by microscopy and X-ray diffraction. The technical properties of the coatings were examined by hardness measurements, abrasive wear and cavitation tests as well as corrosion tests. The results were compared with state-of-the-art coatings of WC-Co-Cr 86/10/4 and Cr3C2-NiCr 75/25.
Novel Titania (TiOx) Feed-Stock Powder for Significant Improvements in Process Economics and Enhanced Coating Properties
Authors: Sharma A. , Nestler M. C. , Colmenares-Angulo J. , Medrano J. , Rauch J. , Weder M. , Wilson S.
Published: November 2022

Traditional fused and crushed (F&C) titania feedstock powders have relatively poor flow and are limited in the feed-rates that can be achieved before deposition efficiencies (DEs) start to decline. In addition, the coatings made with F&C powders generally have high stiffness and limited fracture toughness. Such coatings bear the risk of cracking/delaminating particularly in the case of thick coatings. To address these issues, a new agglomerated and sintered (A&S) titania feedstock powder has been developed and compared in side-by-side spray tests to the traditional F&C titania powder of comparable particle size. The spray behavior, achievable feed-rates and DEs, as well as the resulting coating characteristics were evaluated from the view point of their application as thick, electrically conductive coatings. The new A&S powder yields up to approximately 200% improvement in DE while producing coatings with more suitable microstructure, lower electrical resistivity and higher thickness. Furthermore, for a given set of process parameters, the DEs obtained with this new powder show little sensitivity to the powder feed-rates, thus allowing spraying at higher feed-rates without compromising coating DEs. This feature of the powder has significant commercial advantages for thick coatings when combined with high throughput guns such as TriplexPro-200. Preliminary results of particle diagnostics towards understanding of the fundamental principles behind these improvements are also discussed.
Cold Spraying of Ceramic Coatings – A Feasibility Study
Authors: Ravanbakhsh S. , Assadi H. , Nekoomanesh H. , Hassanzadeh A. , Taheri-Nassaj E.
Published: November 2022

In this study feasibility of cold spraying to produce ceramic coatings is investigated. Ceramic coatings have high potential for various industrial applications. A main problem with these coatings is undesirable phase transformations caused by high temperatures, as in conventional thermal spraying methods. There have so far been few examples of successful cold spraying of ceramics. This work is to examine the problem further by synthesizing specially tailored porous powders, using the sol-gel method. The powders were sprayed on different substrates using a cold spray system. The deposits were characterized by optical and scanning electron microscopy. Based on the results, a discussion of the optimal powder characteristics for cold spraying of ceramics is presented.
Atmospheric Plasma Spraying of Electrodes for Conversion of Electricity to Hydrogen by High Temperature Alkaline Electrolysis of Water
Authors: Nielsen P. T. , Mathiesen T. , Kristensen J. K. , Hilbert L. , Yde L.
Published: November 2022

Energy obtained by wind turbines can be foreseen to constitute a significant part of the future energy sources. A major challenge is however the large variation over time in wind energy production. Energy conversion from electricity to storable energy is therefore a key technology to master, and it is therefore important to develop compact, reliable, cheap and energy efficient equipment for this. An obvious solution is production of hydrogen based on water alkaline electrolysis. In the work presented the atmospheric plasma spraying (APS) of Raney nickel (50/50 Ni/Al) was used to develop electrodes with a large specific surface area as well as a considerable energy efficiency in high temperature water alkaline electrolysis. The coating process was analyzed using a plume analyzer as the primary tool and the coating properties were analyzed by a combination of bonding strength measurement, optical (OM) and scanning electron microscopy (SEM) as well as testing of the activated electrodes in a laboratory electrolysis cell. The results of the spraying process analysis are reported together with the electrochemical properties of the activated electrodes, and with regard to energy efficiency very positive results are obtained for the measured overvoltage.