bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of the features of the course of pregnancy and childbirth, the condition of the fetus and newborn in pregnant women after the application of assisted reproductive technologies (data from a retrospective analysis)
Authors:   Bogomolets National Medical University, Kyiv, Ukraine, Beniuk V.O. , Vygivska L.M. ,   Bogomolets National Medical University, Kyiv, Ukraine
Published: February 2024

The rapid growth in the number of infertile couples leads to the development of assisted reproductive technologies (ART). Among the most common forms of infertility are tubo-peritoneal, endocrine, and caused by the male factor, and prevention of pregnancy complications caused by ART treatment cycles becomes one of the main tasks of practicing clinicians. Purpose - to determine the features of the course of pregnancy and childbirth; to assess the condition of the fetus and newborn in pregnant women after the application of ART to improve the perinatal outcomes of pregnancy and childbirth. Materials and methods. A retrospective clinical and statistical analysis of 334 histories of pregnancy and childbirth of women, as well as medical records of newborns from women, was conducted over the past five years, which formed the ART group - 221 history of pregnancy and childbirth, and the group of spontaneous pregnancy - 113 history of pregnancy and childbirth. Results. The structure of the subjects was statistically significant dominated by pregnant women over the age of 35 years and pregnant women in late reproductive age. The main characteristics of women after the ART application were a statistically significant predominance of somatic and gynecological pathology. The structure of pregnancy complications in women after ART application was dominated by threatening late spontaneous miscarriages, isthmic-cervical insufficiency and vaginitis, and in the structure of labor complications - anomalies of labor activity and premature rupture of fetal membranes. Among newborns from women in the ART group, perinatal mortality was 18.0%. Conclusions. The revealed features of somatic and gynecological anamnesis, as well as aspects of the course of pregnancy and childbirth and the condition of newborns in women after ART application are the basis for an in-depth examination of this category of pregnant women in order to improve approaches to predicting, diagnosing and optimizing preventive measures, as well as to improve the perinatal consequences of pregnancy and childbirth. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. No conflict of interests was declared by the authors.
The influence of transmitted parasitic infections during pregnancy on fetal immunity system (literature review)
Authors:   Dnipro State Medical University, Ukraine, Nagornyuk V.T.
Published: February 2024

Transmission of infections during pregnancy is known to alter the development and functioning of the fetus immune system, resulting in an inadequate immune response to common childhood infections and immunizations. Although it is a developing and actively researched topic, maternal parasitic infections remain poorly understood. Millions of women of reproductive age are currently at risk of parasite infection, while many pregnant, chronically infected women are excluded from mass drug administration due in part to a lack of resources, as well as fear of unknown adverse fetal outcomes. infection, there is no clear mechanism for understanding how maternal infection reprograms offspring immunity. Purpose - to determine the currently studied mechanisms of the influence of parasitic infections transmitted during pregnancy on the immune system of the fetus and to describe the possible effects of these influence in the long term on the health of children. Conclusions. The study of maternal parasitic infections is a rapidly developing field. Although infant mortality rates are declining, areas with endemic parasites still have the highest infant mortality rates. As antiparasitic therapy is not always curable, there is a critical need to understand the effects of maternal infection on offspring immune development. Due to the increased risk of immune alteration due to maternal inflammation and reduced passive antibody transmission, maternal parasitic infections and their mechanism of adverse immunomodulation must be uncovered to improve vaccination regimens and reduce childhood morbidity in endemic regions. No conflict of interests was declared by the author.
Risk factors for the ineffectiveness of assisted reproductive technology programs after a woman’s illness with COVID-19
Authors:   Ivano-Frankivsk National Medical University, Ukraine, Boichuk O.G. , Golovchak I.S. ,   Ivano-Frankivsk National Medical University, Ukraine
Published: February 2024

Purpose - to determine the risk factors for the ineffectiveness of ART programs after a woman’s illness with COVID-19. Materials and methods. In the group of 80 examined patients with symptoms of “long-COVID” who applied to the reproductive technology clinic for infertility treatment, 2 subgroups were distinguished: the Subgroup 1: 64 patients in whom assisted reproductive technologies (ART) was unsuccessful (cancellation of transfer, non-occurrence of pregnancy or its loss) and the Subgroup 2: 16 women with successful ART (live birth). Results. Significant differences were found among patients with unsuccessful use of ART in terms of the frequency of the main symptoms of “long-COVID”, the following symptoms stand out: “depression, anxiety” (54.7% vs. 18.8%, p<0.05) and “sleep disturbances” (59.4% vs. 31.3%, p<0.05). A significant difference was also found in social and household factors: the presence of stress (35.9% vs. 12.5%, p<0.05), especially in everyday life (31.3% vs. 6.3%, p<0.05), the presence of bad habits (21.9% vs. 6.3%, p<0.05). A significantly higher frequency of decreased ovarian reserve (32.8% vs. 12.5%, p<0.05) and corresponding hormonal disorders: increased follicle-stimulating hormone (21.9% vs. 6.3%, p<0.05) and decreased anti-Müllerian hormone (25.0% vs. 6.3%, p<0.05). Among somatic pathology, endocrine pathology stands out (45.3% vs. 12.5%, p<0.05), in particular metabolic disorders (34.4% vs. 12.5%, p<0.05). A significant difference was also established in the frequency of liver diseases (21.9% vs. 6.3%, p<0.05) and gastrointestinal tract (23.4% vs. 12.5%, p<0.05). There is a higher frequency of menstrual disorders, namely a decrease in the duration of menstruation (20.3% vs. 6.3%) or, conversely, prolonged menstruation (17.2% vs. 6.3%), an irregular cycle (25.0% vs. 6.3%, p<0.05) and luteal phase insufficiency (21.9% vs. 6.3%, p<0.05). Urogenital infections were noted in 43.8% of patients (vs. 12.5%, p<0.05). Conclusions. Risk factors for the ineffectiveness of ART programs have been established, among which stress, depression and anxiety, bad habits, endocrine pathology, metabolic disorders, liver pathology, menstrual cycle disorders, and urogenital infections are especially highlighted. The research was carried out in accordance with the principles of the Declaration of Helsinki. The research protocol was approved by the Local Ethics Committee of the institution mentioned in the work. Informed consent of the women was obtained for the research. No conflict of interests was declared by the authors.
PENGARUH UKURAN PERUSAHAAN DAN KOMITE AUDIT TERHADAP TAX AVOIDANCE PADA BANK UMUM SYARIAH DI INDONESIA PERIODE 2016-2020
Authors: Asriati Novia Aisah , Tripalupi Ramadhani Irma , Alifa Nabiela Rizki
Published: February 2024

The purpose of this study was to determine the effect of firm size and audit committee on tax avoidance. In this study, tax avoidance is measured using the Effective Tax Rate (ETR), which is the tax burden divided by profit before tax. The sample in this study was Islamic commercial banks in Indonesia for the 2016-2020 period, which amounted to 7 banks with a period of 5 years resulting in 35 data. The method used is quantitative and sampling using purposive sampling technique. The analysis technique used is multiple linear regression analysis. The results showed that the size of the company and the audit committee had no effect on tax avoidance.
THE EFFECT OF OPERATING PROFIT MARGIN AND TOTAL ASSET TURN OVER ON RETURN ON ASSETS AT PT. ADHI KARYA (PERSERO) TBK. PERIOD 2012-2021
Authors: Widiawati Widiawati , Badriyah Mila , Miranti Puspa
Published: February 2024

AbstractThis research is motivated by the fluctuating value of Return On Assets, whereas it is well known that profitability is a measure of a company's success in managing a company. Therefore the researchers conducted a study that allegedly influenced Return On Assets, namely Operating Profit Margin and Total Asset Turn Over. The purpose of this study was to determine how much influence Operating Profit Margin (OPM) and Total Asset Turn Over (TATO) have on Return On Assets (ROA) partially and simultaneously. The method used in this research is descriptive method with a quantitative approach. The results of the study concluded that the test results of the analysis of the coefficient of determination of the Operating Profit Margin partially did not have a significant effect on Return On Assets of 6.7%. Meanwhile, Total Asset Turn Over has a partial but not significant effect on Return On Assets of 90.3%. Thus, Operating Profit Margin and Total Asset Turn Over simultaneously have an effect but not significant on Return On Assets of 95.9%.Keywords: Operating Profit Margin, Total Asset Turn Over, Return On Asset
HEALTH LEVEL ANALYSIS OF PT. BANK BJB USING THE CAMEL METHOD
Authors: Abdillah Wildan Army , Nurfauzan Muhammad Iqbal
Published: February 2024

AbstractThis study aims to assess the financial soundness level of Regional Development Bank of West Java and Banten (PT. Bank BJB) during the 2012-2021 period using the CAMEL method. The CAMEL method is used to assess the financial aspects of a financial institution, namely Capital, Asset Quality, Management, Earnings, and Liquidity. This study uses a quantitative approach with a descriptive method, which is carried out by analyzing data from the financial report sources of PT.Bank  BJB during the 2012-2021 period. The data used in this study are secondary and are analyzed using various financial analysis techniques. The study results indicate that the financial soundness of Regional Development Bank of West Java and Banten (PT. Bank BJB) during the 2012-2021 period can be stated to be very healthy. This can be the basis for managers to predict the bank's financial condition in the future and take appropriate policies to improve the bank's financial performance. This research has an essential meaning because the level of the financial health of a financial institution can reflect how the bank implements its economic policies.Keywords: Assets, Capital, Earnings, Liquidity, Management
THE EFFECT OF DEBT TO EQUITY RATIO (DER) AND NET PROFIT MARGIN (NPM) ON RETURN ON EQUITY (ROE) IN THE PROPERTY AND REAL ESTATE SECTOR AT PT. LIPPO KARAWACI, TBK. PERIOD 2010-2019
Authors: Elkasysyaf Estu , Astuti Fitri
Published: February 2024

This study aims to investigate the partial effects of Debt to Equity Ratio (DER) and Net Profit Margin (NPM) on Return On Equity (ROE) and their simultaneous effect on ROE in PT. Lippo Karawaci Tbk. Investors must consider various factors, including financial reports, before investing in a company. The study applies a quantitative approach with descriptive and associative analysis of secondary data obtained from the annual reports of PT. Lippo Karawaci Tbk. from 2010 to 2019. The data analysis uses classic assumption tests, descriptive analysis, and SPSS for Windows version 20.0 and Microsoft Excel 2019 to support initial data processing. The study finds that DER has no compelling partial effect on ROE, with a coefficient determination of 21.9%. On the other hand, NPM has a partially substantial impact on ROE, with a coefficient determination of 88.2%. When analyzed simultaneously, DER and NPM significantly affect ROE, with a coefficient determination of 90.8%. This means that 90.8% of ROE in PT. Lippo Karawaci Tbk. can be explained by DER and NPM, while the remaining 9.2% is influenced by other factors not examined in this study.Keywords: Debt to Equity Ratio, Net Profit Margin, and Return On Equity
PERKEMBANGAN FINTECH SYARIAH DAN REGULASI HUKUM: SEBUAH KAJIAN LITERATUR
Authors: Gani Ahmad Abdul
Published: February 2024

Tujuan penelitian ini adalah untuk menggali dan memahami bagaimana regulasi hukum beradaptasi dengan perkembangan fintech syariah yang dinamis dan berkembang pesat, serta tantangan hukum yang muncul dalam konteks tersebut. Artikel ini memaparkan perkembangan fintech syariah dan regulasi hukumnya melalui metode kualitatif dan studi pustaka. Studi ini mengidentifikasi bahwa regulasi hukum harus terus diperbarui untuk mengimbangi inovasi dalam industri fintech syariah, dengan mempertimbangkan prinsip-prinsip syariah dan kebutuhan pengguna. Penelitian ini juga mengemukakan bahwa meski tantangan hukum signifikan ada, namun melalui regulasi yang tepat, perkembangan lebih lanjut dari fintech syariah dapat difasilitasi.
PEMODELAN NILAI PERUSAHAAN MELALUI KEBIJAKAN DIVIDEN MENGGUNAKAN SEM-PLS
Authors: Ilmia Anisa , Yulandri Elsa
Published: February 2024

Maximizing company value is an important factor for companies to maintain the survival of the company. This study aims to examine the determinants of factors that affect company value through dividend policy as an intervening. Researchers using PT. Telkom Indonesia as the object of research. This research approach uses quantitative descriptive, namely SEM-PLS pathway analysis to test hypotheses that have been formed. The findings of this study that financial performance and dividend policy have no effect on the company value of PT. Telkom Indonesia, Tbk. Through these findings, researchers provide information to investors that PT. Telkom Indonesia, Tbk is a stable stock and does not need to worry about company value even though there are fluctuations in stock price, dividends, and other financial performance.
REFLEKSI NILAI “MOPO’O TANGGALO DUHELO” DI BALIK PENDAPATAN OLEH KUSIR BENDI: STUDI ETNOMETODOLOGI ISLAM
Authors: Thalib Mohamad Anwar
Published: February 2024

Abstract This study aims to reflect on the local cultural values behind the practice of income accounting by bendi drivers. This study uses an Islamic paradigm with an Islamic ethnomethodological approach. There are five data analysis stages: charity, knowledge, faith, revelation information, and courtesy. The results of the study found that the way the bendi drivers earn income when they are at the base is through something other than a queuing or lane system. Prospective passengers are free to choose which buggy they want to rent. The income accounting practice is conditional on local cultural values in the form of “mopo’o tanggalo duhelo” " which means full of patience. The results of this study contribute to the presence of the local culture-based income accounting concept. Keywords : Bendi, Income, Local Culture, Gorontalo, Islamic Ethnomethodology
ANALYSIS OF FINANCIAL FACTORS AND NON-FINANCIAL FACTORS AFFECTING AUDITOR SWITCHING
Authors: Sofia Khalida , Nur Apandi R Nelly , Widarsono Agus
Published: February 2024

This study aims to determine the effect of monetary and non-monetary components on voluntary auditor turnover. Management, board, and audit committee quality are examples of non-financial impacts. Factors such as business growth, financial problems, profitability, and liquidity are included in the assessment of financial elements. Auditors can be replaced by law or voluntarily. Quantitative methods are used in this research. Specifically, this study will investigate manufacturing companies in the food and beverage industry during the period 2018-2022. Random selection of 14 companies is used as a sample method. The data analysis method used is logistic regression analysis. The results showed that the factors of management quality, board of commissioners, and audit committee did not have a significant impact on the auditor's decision to voluntarily resign. Financial crisis, profitability, and liquidity have no positive impact on voluntary auditor turnover. However, company growth has an influence on voluntary auditor turnover.
Analysis of Literacy Levels and Determinant the Purchase of Halal Cosmetics and Skincare among High School Students
Authors: Juliastuti Dita , Salsabila Fitrhriyah , Taqiyyah Asma , Yunita Aisy , Nahra Putri Rizqya Cut
Published: February 2024

Saat ini kosmetik menjadi barang yang wajib dimiliki dalam kehidupan sehari-hari yang tidak hanya digunakan oleh wanita, tetapi juga pria. Umat muslim saat ini sangat memperhatikan kehalalan makanan yang dikonsumsi, termasuk kehalalan kosmetik yang digunakan. Oleh karena itu, penelitian ini bertujuan untuk mengetahui tingkat literasi dan faktor-faktor yang mempengaruhi keputusan siswa Sekolah Menengah Atas (SMA) di Kota Bogor dalam pembelian produk kosmetik halal. Analisis data yang dilakukan dalam penelitian ini menggunakan metode analisis deskriptif kuantitatif dan metodeStructural Equation Model – Partial Least Squares (SEM-PLS). Analisis deskriptif digunakan untuk mendeskripsikan tingkat literasi siswa, sedangkan analisis SEM-PLS digunakan untuk mengetahui faktor-faktor yang mempengaruhi keputusan pembelian kosmetik dan skincare halal pada siswa. Hasil penelitian ini menunjukkan bahwa kegiatan penyampaian materi yang dilakukan oleh peneliti memberikan dampak positif terhadap peningkatan literasi halal di kalangan pelajar SMA di Kota Bogor. Sementara itu, hasil analisis SEM-PLS menunjukkan adanya pengaruh positif dan signifikan antara labelisasi halal terhadap keputusan pembelian kosmetik dan skincare halal di kalangan pelajar SMA.Sedangkan Islamic branding, harga, dan promosi tidak berpengaruh signifkan.
Implementación de transmisor de televisión basados en SDR para el estándar NTSC
Authors: Sánchez-Mojica Karla Yohana , Contreras-Gómez Wilfred Andrey , Niño-Rondón Carlos Vicente , Puerto-López Karla Cecilia
Published: February 2024

La plataforma SDR (radio definida por software) permite implementar diversos sistemas de comunicación flexibles en función de los objetivos y requisitos del usuario, más allá del límite de flexibilidad de la plataforma de hardware existente. Por ello, ha aumentado el interés y la investigación sobre la implementación de sistemas de comunicación basados en software. Sin embargo, hay muy pocos ejemplos que muestran la compatibilidad y las mediciones de rendimiento entre la implementación mediante SDR y los sistemas comerciales reales. Por lo tanto, en este artículo, mostramos la compatibilidad y el rendimiento del sistema de comunicación que son el receptor y el transmisor de TV NTSC utilizando GNU Radio y USRP en un entorno de comunicación inalámbrica.
Programa de comunicación interna para el clima laboral en una red asistencial de salud del Perú
Authors: Medina-Pariente Nury Madeleyne , Oyola-Cortez Hugo Milton , Heredia-Llatas Flor Delicia
Published: February 2024

Las organizaciones públicas están sujetas cada vez más a una exigencia de parte de la ciudadanía, por lo cual, el objetivo de la presente investigación es proponer un programa de operabilidad de comunicación interna para el personal de una red asistencial de Perú. La investigación es de carácter cuantitativa descriptiva, muestreo probabilístico de tipo aleatorio simple, con una muestra poblacional de 67 servidores; se utilizó la encuesta como técnica y como instrumento el cuestionario de clima laboral y comunicación interna. Los instrumentos obtuvieron una alta confiablidad a través del coeficiente de Alfa de Cronbach con un 0.87 para la comunicación interna y 0.86 para el clima laboral. De los resultados, la comunicación interna es percibida con un 62.7 % de nivel regular, es decir esta variable necesita ser fortalecida entre los colaboradores para mantenerlos informados y lograr los objetivos de la institución sobre todo en la dimensión de comunicación vertical descendente al existir barreras de comunicación; mientras tanto, el clima laboral es percibida en un nivel por mejorar (52.23 %), ya que un buen grupo de trabajadores aún les falta sentirse comprometidos con el éxito de la institución. Por tal motivo, se propone un programa de operabilidad para que se fortalezca la gestión de comunicación interna y mejore el clima laboral, siendo validado por el método de Delphi con una escala de valoración alta, concluyendo que la propuesta es conveniente para su aplicación.
Estrategia didáctica apoyada en Geogebra para el aprendizaje de geometría en estudiantes de noveno grado en zona rural del Catatumbo
Authors: Moreno-Moyano Ronald Alexander
Published: February 2024

En esta investigación de naturaleza cuantitativa, se abordó un estudio centrado en la mejora del aprendizaje de geometría en estudiantes de noveno grado en una zona rural del Catatumbo, utilizando la herramienta GeoGebra. En este sentido, la investigación se dividió en tres objetivos clave: El primer objetivo consistió en la realización de un pre test inicial, que reveló un bajo nivel de desempeño en geometría entre los estudiantes, con una puntuación promedio de 2.0 y un predominio de estudiantes en niveles bajos. Por su parte, el segundo objetivo se enfocó en el diseño y la implementación de una estrategia didáctica basada en Geogebra para mejorar el aprendizaje de geometría. Esta estrategia se implementó en el aula de clase y se aplicó a lo largo de un período académico. Entre tanto, el tercer objetivo tuvo como propósito determinar la eficacia de la estrategia pedagógica. Para ello, se llevó a cabo un pos test, que demostró un progreso sustancial en el desempeño de los estudiantes. La puntuación promedio aumentó de 2.0 en la pre test a 3.3 en el post test, lo que reflejó una mejora en el nivel de desempeño promedio de los estudiantes, pasando de un nivel bajo a un nivel básico. Además, se observó una distribución más equitativa en los niveles de desempeño, con mayor cantidad de estudiantes en el nivel alto y superior. Finalmente, aunque persisten áreas de mejora, estos resultados indican que la estrategia didáctica basada en Geogebra ha tenido un impacto positivo en el aprendizaje de geometría en el entorno rural del Catatumbo. Por lo tanto, la adaptación continua de la estrategia pedagógica es esencial para abordar las necesidades cambiantes del grupo estudiantil y seguir mejorando su desempeño en matemáticas.
Simulation of a continuum-source atomic absorption spectrometer
Authors:   Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Vashchenko P. V. , Boldova S. S. ,   Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Kolosov N. A. ,   Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Labusov V. A. ,   Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences,   VMK-Optoelektronika
Published: February 2024

Continuum source atomic absorption spectrometry becomes a method for simultaneous multi-element analysis leading to a renewed interest in this method. The linear range of the calibration curve and the detection limits of continuum source atomic absorption spectrometers depend on the parameters of the instrumental function of the spectral instrument and the absorption line, the intensity of the radiation source, the level of radiation scattered in the instrument, and other factors. Calculating these dependences was the aim of this work. A theoretical model of the process of the absorption signal formation was constructed, and a computer program for its simulation was developed. Adequacy of the simulation was verified by comparing the absorption signals and calibration curves with the experimental ones obtained on a Grand-AAS spectrometer for several elements: Cd 228.8022 nm, Be 234.8610 nm, Mn 279.4817 nm, and Pb 283.3053 nm, as well as for the Ag 338.289 nm line recorded by two polychromators with different spectral resolution and scattered radiation levels. The relative deviation of the measured analytical signal from the simulated one did not exceed 15% in the concentration range of five orders of magnitude. The simulation results showed that nonlinearity of the calibration curve was primarily determined by the ratio of the width of the instrumental function (resolution) of the spectral instrument to the absorption line. The contribution of scattering in the spectrometer to the nonlinearity was secondary. The influence of the aperture characteristics of the photodetector arrays on the analytical signal was not significant. It was shown that decreasing resolution of the spectral instrument resulted in expanding the linear part of the calibration graphs from above to the level determined by scattering in the spectrometer. The detection limits limiting the graphs from below decrease with decreasing resolution until it approaches twice the width of the element's absorption line. After that, they start to increase.
Synthesis and electrical properties of doped layered perovskites based on BaMInO4 (M = Y, Gd)
Authors: Tarasova Nataliia , Mashkovtsev Maxim , Domashenkov Maxim , Khionin Denis , Bastrikov Roman , Bedarkova Anzhelika
Published: February 2024

Perovskite or perovskite-related structural materials are widely studied for their many functional properties. They can be used as components of electrochemical devices such as solid oxide fuel cells and electrolyzers. Layered perovskites can also be considered as promising materials for use in these devices. In this paper, the possibility of heterovalent (acceptor and donor) and isovalent doping of La and In sublattices of layered perovskites BaYLaInO4 and BaGdLaInO4 was made for the first time. The structure and electrical properties of these oxides were studied. Electrical conductivity values increase in the series BaYInO4–BaLaInO4–BaGdInO4. However, the doping is an unsuitable strategy for improving the electrical properties of BaYInO4 and BaGdInO4 oxides. Further search for highly conductive materials with the layered perovskite structure can be aimed at materials with a different composition of the cation sublattice.
Catalytic Phenomena in Combinatorial Libraries of Heterogeneous Catalysts
Authors: Holzwarth Arnold , Maier Wilhelm F.
Published: February 2024

Combinatorial catalysis is becoming a significant method for investigating the activities of large numbers of potential catalysts. A very important prerequisite for making use of combinatorial catalysis research is a reliable, fast and efficient technique for monitoring the catalytic activities. Emissivity-corrected infrared thermography, which monitors the heat changes resulting from the heat of reaction on catalyst surfaces, is such a technique. In this article we describe emissivity-corrected infrared thermography and demonstrate its performance, over time, in monitoring the catalytic activities of catalyst libraries. It is shown that not only can static relative activity be displayed, but also that catalyst-specific time-dependent properties, such as activation and deactivation phenomena can be demonstrated.
Two-Phase Iridium-Based Refractory Superalloys
Authors: Yamabe-Mitarai Y. , Gu Y. F. , Harada H.
Published: February 2024

A new class of alloys based on platinum group metals, which are called refractory superalloys, is proposed. These refractory superalloys have a f.c.c. and Ll2 coherent two-phase structure (similar to that of nickel-based superalloys), high melting temperatures, and good potential as structural materials for use at temperatures up to 1800°C. In this paper, we report our results on the strength behaviour, creep property, ductility and fracture mode of iridium-based refractory superalloys.
Strengthening Platinum-Palladium-Rhodium Alloys by Ruthenium and Cerium Additions
Authors: Ning Yuantao , Xin Hu
Published: February 2024

The effects of cerium and ruthenium additions on the mechanical properties of Pt-15 Pd-3.5 Rh alloy (wt.%) at ambient and high temperature are examined. The mechanical properties of the alloy were improved by adding cerium (≤ wt.%) or ruthenium (≤ 0.5 wt.%) solute, with the cerium additions giving a better strengthening effect. Higher concentrations of cerium and ruthenium did not visibly increase the strength properties of the Pt-15Pd-3.5Rh alloy and even reduced some of the mechanical properties at high temperature. Increasing the palladium content in the Pt-Pd-Rh alloy could enhance the alloy strengths at room temperature but damaged the mechanical properties at high temperatures. Observations of the morphologies of fracture sections of alloy samples after creep-rupture tests at high temperature showed ductile fracture for alloys with lower contents of palladium, cerium or ruthenium and brittle fracture for alloys with higher contents ofpalladium, cerium or ruthenium. The different strengthening mechanisms of palladium, cerium and ruthenium additions to Pt-15Pd-3.5Rh alloy are discussed.
Behaviour of the Platinum Metals at High Temperatures
Authors: Powell A. R.
Published: February 2024

An important factor in the utilisation of the platinum metals at high temperatures is the loss in weight that occurs to some degree due to oxidation and volatilisation. The author critically reviews recent work on this subject and describes some original experimental work.
Cobalt-Platinum Rotors for Small Synchronous Devices
Authors: Donaldson G. W. , Inglis B.
Published: February 2024

The unique magnetic properties of the cobalt-platinum alloy Platinax II enable small permanent magnets to be made which will produce a high magnetic flux across a large air gap. A small cylinder of this alloy magnetised across its diameter, produces a two pole magnet with an ideal field geometry for the rotor of a synchro-transmitter. Used in conjunction with Hall effect elements the design of such devices can be simplified as the need for windings of very fine insulated copper wire on laminated rotors, used in conventional motors, is eliminated. The increasing demand for miniaturisation of electronic components may make it necessary to reduce still further the size of servo components, and the ductility and machining properties of cobalt-platinum make it an ideal material from which to make the permanent magnet rotors.
Potentiometer Slidewire Materials
Authors: Darling A. S.
Published: February 2024

The slidewire potentiometer is a device intended to produce a signal voltage uniquely related to the mechanical displacements involved, and its materials of construction must provide therefore a reasonably accurate embodiment of the desired mathematical relationships. Noble metal alloys are usually selected for such applications because of theirstability and freedom from corrosion. In this paper, based on a lecture given recently to the Control and Automation Division of the Institution of Electrical Engineers, some general correlations between electrical performance and metallurgical characteristics are discussed and it is shown how the application of these principles has led to the development ofnew and improved potentiometer slidewire materials.
Some Biological Effects of Platinum Compounds
Authors: Rosenberg Barnett
Published: February 2024

Certain complexes of the platinum group metals exhibit interesting biological effects. At low concentrations some are effective bacteriocides; others stop cell division and force bacteria to grow into long filaments. These complexes can also induce destruction of lysogenic bacteria. Most important, perhaps, some of these complexes are very potent anti-tumour agents against a broad spectrum of tumours, and may shortly be used for cancer chemotherapy in humans.
The Growth of Oxide Single Crystals
Authors: Robertson J. M. , Damen J. P. M. , Jonker H. D. , van Hout M. J. G. , Kamminga W. , Voermans A. B.
Published: February 2024

With new techniques of crystal growth new problems have been encountered with the platinum apparatus used in crystal production. Some of these difficulties are discussed in this paper, including attack by bismuth oxide, Bi2O3, and dissolution of the platinum in the leaching acids, together with methods of prolonging the life of platinum crucibles.
The Separation of Hydrogen from Gas Mixtures
Authors: Betteridge W. , Hope J.
Published: February 2024

A pressure-cycling process has been developed by which hydrogen can be separated from gas mixtures using palladium sponge as an absorbent. At a temperature of 200°C, with pressure cycling between 1 and 35 bar, and a cycle time of 20 seconds, hydrogen of 99.5 per cent purity can be obtained from 75 per cent hydrogen-25 per cent nitrogen mixtures at a rate of 6 litres/hour per gram of palladium and a yield of 80 per cent.
Polymetallic Cluster Catalysts
Authors: Sinfelt John. H
Published: February 2024

Highly dispersed metallic clusters composed of two or more metals within Group VIII, or combinations of one or more Group VIII metals with a Group IB metal, when supported on a carrier, form catalysts of considerable theoretical interest which also have practical industrial applications. The simpler bimetallic clusters have provided useful model systems for investigating basic concepts and have demonstrated that their catalytic behaviour can be very different for different types of reactions. The idea of polymetallic clusters could be applicable to a number of combinations of elements, so increasing the range of catalytically useful systems.
Platinum Provides Protection for Steel Structures
Authors: Shreir Lionel L.
Published: February 2024

The first part of this article considered the principles of cathodic protection and described ways in which platinum could be utilised economically as an electrode material. This article examines how such electrodes perform in service, in a variety of applications and under differing conditions.
Machining Properties of Platinum
Authors: Rushforth R. W. E.
Published: February 2024

Platinum is usually considered to be a ductile workable metal readily fabricated by all the usual processes; it is therefore somewhat surprising to discover that the machining of platinum by conventional techniques results in rapid and extensive tool wear, with consequent deterioration of the surface finish imparted to the platinum article. This paper reports the results of an investigation into the behaviour of platinum during machining and the mechanisms by which the tool becomes worn. In addition the techniques devised to alleviate these phenomena, such as preferred tool materials and configurations, are described.
Heterogenised Homogeneous Catalyst
Authors: Scurrell Michael S.
Published: February 2024

Heterogeneous versions of homogeneous catalysts can often be produced and may have certain advantages in use particularly on a commercial scale. The catalytic chemistry of supported rhodium compounds for the carbonylation of methanol is described and the behaviour of heterogeneous and homogeneous operation compared in order to illustrate the relations between the two catalyst types. Particular attention is given to the factors which influence the activity and the selectivity of the heterogenised forms.
Platinum Group Metal Hydrides
Authors: F.A.L.
Published: February 2024

Conferences on hydrogen energy and metal-hydrogen systems continue to include significant numbers of contributions concerning hydrides of palladium and other platinum group metals. This article reviews some of the relevant papers presented recently at Colorado Springs.
Meeting the Increasing Demand
Authors: Maxwell K. W.
Published: February 2024

To meet the growing requirements for platinum and its allied metals a continuing programme of capital investment, exploration and production has been undertaken by the world’s largest platinum producer, Rustenburg Platinum Mines. These developments provide the majority of many of the platinum group metals required by industrial users throughout the world.
Catalytic Filters Control Diesel Engine Exhaust
Authors: Enga B. E.
Published: February 2024

Diesel-engined vehicles are highly reliable and use fuel more economically than spark ignition engines, therefore they are being more widely adopted. However, in addition to relatively small quantities of gaseous pollutants, diesel exhaust emissions characteristically contain much higher concentrations of particulate materials. Continuing their clean air policy, the Environmental Protection Agency in the United States of America has imposed limits on the amount of particulates that will be tolerated in diesel exhaust emissions from 1982 model year vehicles to 0.6 grams per mile, with an even lower limit of 0.2 grams per mile proposed for the 1985 model year. The generation of particulates is complex and involves many parameters; this paper discusses the development of an after-treatment system employing platinum group metals that has now successfully controlled particulate emissions during a 50,000 mile durability trial.
The Application of Palladium in Electronic Connectors
Authors: Antler Morton
Published: February 2024

Palladium and palladium-based materials are being increasingly accepted as substitutes for gold in contacts for separable electronic connectors. Since 1975 the favourable cost of palladium relative to gold has stimulated research in many areas of contact technology, including manufacturing processes, contact phenomena, testing and connector design. This has resulted in the development of several new materials systems involving electrodeposited coatings, clad inlays and weldments of palladium, palladium-silver alloys, gold-palladium-silver compositions and composite coatings with other metals that are equivalent to all-gold systems in many applications. This review traces the history of research on palladium for use in connectors, and summarises important results of studies of the environmental, tribological and contact properties of palladium materials.
Dispersion Strengthened Gold-Platinum
Authors: Heywood A. E. , Benedek R. A.
Published: February 2024

Platinum alloys containing gold exhibit marked non-wetting characteristics with molten glasses. Simple gold-palladium alloys, however, are relatively weak while those that have rhodium added to increase their strength can be difficult to work, and also suffer from embrittlement during service. Now the binary alloys can be dispersion strengthened with zirconia to produce a material with the ductility of the simple binary and the higher hot strengths of rhodium-containing ternary alloys. This dispersion strengthened gold-platinum alloy has enhanced resistance to progressive contamination and offers a longer service life. It is being used successfully for specialised applications in the glass industry, for which it has potential, as well as for the apparatus in which samples for X-ray fluorescence analysis are prepared.
Fuel Cells for Vehicle Propulsion
Authors: Van den Broeck H. , Cameron D. S.
Published: February 2024

A detailed study of future electric vehicle developments has identified an opportunity to use city buses and delivery lorries as a first market for fuel cell traction powerplants. Suitable cells employing a platinum metal catalyst on the electrodes have been developed and a substantial production facility has been set up. Trials with a mobile test bed are continuing and it is anticipated that rapid commercialisation will follow once the system has been fully demonstrated.
Superconductivity of the Platinum Metals and Their Alloys
Authors: Raub Ch. J.
Published: February 2024

Continuing investigation of superconductivity, particularly of platinum metal compounds, has resulted in a growing understanding of the phenomenon. Accumulating data contain some remarkable experimental results which in time must surely find both theoretical explanation and industrial application.
Palladium-Nickel Electroplating
Authors: F.H.R.
Published: February 2024

During a conference organised by the East Midland Branch of the Institute of Metal Finishing a paper on the electrodeposition of palladium-nickel alloys was presented by Dr. Christoph J. Raub and Dieter Walz of the Forschungsinstitut für Edelmetalle und Metallchemie, West Germany. A review of this paper is presented here.
Ruthenium Melt Catalysis
Authors: Knifton John F.
Published: February 2024

A range of commodity chemicals and fuels can be generated directly from synthesis gas by ruthenium melt catalysis. Careful selection of the catalyst components enables a wide range of oxygenates to be produced, while other advantages of this flexible process include high productivity and the ease with which the products may be recovered and the catalyst recycled.
Corrosion Prevention in Concrete
Authors: Hayfield P. C. S.
Published: February 2024

The cathodic protection of steel reinforcing bars in concrete to prevent their corrosion, brought on principally by de-icing salts used on roadways, is at the interesting stage where technology is barely keeping pace with practical demand. It already seems likely that platinum and other noble metals, used in conjunction with titanium and niobium, will play a vital role in several of the protection systems that appear to be the forerunners in a rapidly developing industry.
A New Type of Molecular Conductor
Authors: Underhill A. E.
Published: February 2024

A new type of two-dimensional metallic conductor, based upon a palladium dithiolene complex, has been shown to possess a novel structure involving short S–S contacts in two orthogonal directions, resulting in it having metallic properties down to 40K under high pressure. Studies of compounds of this type may lead to the development of materials for use in a chemical computer and a major programme in this area, to be known as the Molecular Electronics Research Initiative, is to be launched by the British government.
Some Ternary and Higher Order Platinum Group Metal Alloys
Authors: McGill I. R.
Published: February 2024

Platinum-based alloys find many applications in both high and low temperature industrial environments and are particularly suited to operation under corrosive aqueous and high temperature gaseous conditions. A wide variety of alloys exist which have been specifically designed for these purposes and in many cases they contain one or more non-platinum group metal. Although this situation is quite acceptable, there remains a fundamental need for systematic investigation of the basic properties and constitution of platinum group metal alloys. Such a foundation in materials technology generally leads to an understanding of materials behaviour and provides guidance in designing new alloys with improved properties for existing and future applications. This review features the work which has been done on ternary and higher order platinum group metal alloys and provides access to important data.
Direct Methanol Fuel Cells
Authors: Cameron D. S. , Hards G. A. , Harrison B. , Potter R. J.
Published: February 2024

Unlike other fuel cell types, the direct methanol fuel cell does not require a separate hydrogen generation system and therefore has greater commercial potential, particularly for powering portable appliances. However, the limiting factor for the cost-effective performance of such systems is the catalytic activity of the electrodes, in particular the anode. The single most active anode material is platinum, which is usually dispersed on a high surface area carbon support. It has been found that the addition of small amounts of metals such as lead, rhenium, ruthenium and tin to the platinum produces a significant increase in activity. The best of these bimetallic systems is based on a mixture of platinum and ruthenium. However, further worthwhile improvements in anode activity could result from a more fundamental understanding of the methanol decomposition reaction. In recognition of this, the Commission of the European Communities has initiated a research programme which involves collaboration between universities and industry in four member states. This article is based largely upon a paper given at the CEC–Italian Fuel Cell Workshop in Taormina, Sicily, in June 1987.
Transition Metal Catalysed Synthesis of Oligo- and Polysilazanes
Authors: Laine Richard M.
Published: February 2024

Organometallic polymer research offers many potential academic and industrial rewards because of the number of elemental variations possible. Unfortunately, there are no general synthetic methods as found for carbon based polymers. Transition metal catalysed dehydrocoupling reactions may prove to be generally applicable to the synthesis of silicon based organometallic polymers. We report here our efforts to synthesise organometallic polymers with a silicon-nitrogen backbone, polysilazanes, using the dehydrocoupling reaction. We also describe the synthesis of polysilazanes for use as precursors to silicon nitride.
Frédéric Kuhlmann
Authors: Smith John Graham
Published: February 2024

The name of Kuhlmann is familiar in histories of catalysis as one of the earliest pioneers of the modern processes for the manufacture of nitric and sulphuric acids. Yet the man and his work are little known. On the one hundred and fiftieth anniversary of his patents we consider the significance of some of his work.
Water Soluble Rhodium Catalysts
Authors: Russell M. J. H.
Published: February 2024

The rhodium catalysed hydroformylation reaction is one of the most widely used industrial applications of homogenous catalysis to employ platinum group metals. Potential limitations in the application of this technology to molecules which are heat sensitive or have high boiling points are the stability of the catalyst and the ability to separate the catalyst from the products. A means of circumventing these limitations is described. This involves locating the catalyst in an aqueous liquid phase, and it enables viable reaction rates to be achieved at moderate temperatures and pressures.
Properties of Binary Rhodium Alloys
Authors: Handley J. R.
Published: February 2024

Rhodium has a higher melting point, greater specific strength and better oxidation resistance than most of the refractory and platinum group metals but, to date, neither rhodium nor its alloys have found wide application as structural materials. During a recent study of rhodium alloys a vast amount of data was collected, and a selection of this information is recorded here. An investigation of the mechanical properties of some of these alloys indicates that a number of them could be useful for specific applications that take place under arduous conditions.
Towards a Cleaner Environment
Authors: Lawton T. J.
Published: February 2024

Catalytic combustion is a safe way of destroying volatile organic compounds produced during a variety of manufacturing and processing operations, while the ability to recover heat is an additional benefit.
Platinum Metals in Stainless Steels
Authors: McGill I. R.
Published: February 2024

The first part of this paper reviewed the effects of sulphuric acid on stainless steels modified by platinum metals additions, much of the original work having been carried out by Russian researchers. Now corrosion in other media, and oxidation, are considered and a review of the limited data that are available on mechanical properties is presented. It is concluded that, in particular circumstances, improved material properties can be obtained by the addition of platinum group metals to iron-base alloys.
Carbonylation Reactions in Aqueous or Mixed Solvent Systems
Authors: Taqui Khan M. M.
Published: February 2024

In recent years much interest has been focused on carbonylation reactions in aqueous or biphasic systems catalysed by platinum group metals complexes. This is due to the reactivity of platinum group metals ions as catalysts designed to activate small molecules. When used in C, chemistry a variety of reactions can be catalysed by these complexes, in particular by ruthenium complexes. Ruthenium has several oxidation states and co-ordination numbers, and is relatively cheap. Additionally, ruthenium catalysts are stable and their reaction conditions are usually mild, making them excellent for homogeneous catalysis. Various reactions of ruthenium carbonyl complexes and ruthenium saloph dichloride complexes with carbon monoxide have been investigated in this laboratory, and are considered here.