bluuebunny/crossref_metadata_2025 huggingface dataset:
Input control of the fused magnesia powders for the needs of the energy industry
Authors:   Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Omeliana Pritsaka street, 03142 Kyiv, Ukraine, Sydorenchuk Vera , Kolomiiets Volodymyr
Published: August 2024

Measurement of the composition of materials by instrumental methods, including refractory ones, from 100% to ppb is described by the formula of relative deviations (RSD) of Horwitz [1]. In the area of the base, the measurement error can be ±4.0%. For impurities at the ppb level, it is ±50-60%. A widely used method of X-ray fluorescence analysis provides measurement of chemical elements, usually starting with Mg. An error in the measurement of the base of the fused magnesium oxide powder can distort the results of the analysis of the impurity content by an order of magnitude. The powders are certified according to TU 1527-082-05802299-2010. The value of the base (MgO) turned out to be underestimated compared to TU by 13.23% (wt.). Integration of the detected elements, conversion to oxides and approaching 100% (wt) led to an increase in impurities by 4-5 times. To overcome this problem, two methods of correction of composition measurement results are usually used. It is a set of relevant standards or software that considers the interaction of atoms in the test (based on the data of simple substances). In the absence of these corrective possibilities, a third method is proposed for the first time. It consists in the procedure for reliable measurement of the base, mass fraction of MgO by chemical methods of arbitration analysis. Melting of parallel samples powders in salt melts → leaching → purification of impurities → filtering → dilution in a measuring vessel → titration of aliquots with fixanal EDTA in an ammonia buffer with the indicator eriochrome black T unequivocally confirmed the content of the MgO base (96.2; 96.7%), and therefore the impurities: Al₂O₃, SiO₂, P₂O₅, CaO, Fe₂O₃, Ni₂O₃ according to TU. The obtained results made it possible to correct the results of X-rays fluorescence analysis measurements and to confirm the compliance of the composition of batches of molten MgO powder with the relevant regulatory documents.
Effect of high hydrostatic pressure treatment of cememted carbides WC-3Co, WC-6Co, and WC-15Co on their Vickers hardness
Authors:   Donetsk Institute for Physics and Engineering named after O.O. Galkin of the National Academy of Sciences of Ukraine, Sheremet Vitalii , Andreev Ihor , Loboda Petro , Trosnikova Iryna
Published: August 2024

The experimental study is devoted to the investigation of the influence of high hydrostatic pressure (HHP) compression of tungsten carbide and cobalt carbide-based cemented carbides on their properties. The samples WC-3 wt.% Co, WC-6 wt.% Co, and WC-15 wt.% Co were investigated. Vickers hardness was measured. The following results were obtained. Compression of HHP at 400MPa leads to a decrease in Vickers hardness of WC-3 wt.% Co by 8%, WC-6 wt.% Co by 5%, and WC-15 wt.% Co by 5%. Using SEM, cracking of large grains of tungsten carbide in Vickers indenter imprints was found in all samples treated with HHP. It is concluded that cracking and hardness decrease are mainly due to the well-known fact that the compressibility of Co is more than twice as high as that of WC [1]. It is suggested that the different compressibility of WC and Co could change the coherence fraction of the two materials at their boundary and cause residual stress along the boundary and in the regions of WC and Co adjacent to the boundary after HHP removal. These stresses could cause cracking of WC grains, and cracking of grains entailed a decrease in hardness.
High-temperature oxidation of AlB12-Al composite material
Authors:   Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Omeliana Pritsaka street, 03142 Kyiv, Ukraine, Sheludko Vladimir , Muratov Valery , Khomko Tatiana , Kremenitsky Valery , Pertko Aleksandra , Vasilkovskaya Marina , Povazhnyi Vladimir
Published: August 2024

The study of high-temperature oxidation is urgent from theoretical and practical points of view [1]. The object of the study is the AlB12-Al composite material consisting of a porous ceramic frame of AlB12 infiltrated with molten Al in a vacuum at a temperature of 1100 °C. The oxidation of samples was studied by TGA and DSC, as well as by holding them for 1 hour in the temperature range from 500 to 1000 °C. The activation energy of oxidation Еа, the pre-exponential factor k0 and the order of the chemical reaction n were calculated by the method of non-isothermal kinetics with software implementation. X-ray analysis of the composites was carried out on a DRON-3M diffractometer in CuKα-filtered radiation. The structure was studied using a JEOL JSM-6490 LV scanning electron microscope. The most characteristic oxidation intervals can be distinguished: at temperatures from 20 to 225 °C there is a sharp increase in weight gain with low activation energy. With a subsequent increase in temperature, the rate of weight gain slows down. In the range of 450-570 °C, a melt of B2O3 is formed, at 655 °C Al melts, which is accompanied by cracking of the oxide layer. In the temperature range of 800-1000 °C, Al borates (Al4B2O9, Al8B2O15, Al18B4O33) are formed, which also prevent oxidation. At T = 646 °C crystallization of the Al melt occurs, as evidenced by the exo-peak at this temperature. Reaction order values range from 0 to 1. Under isothermal heating conditions, starting from 500 °C, there is a gradual weight gain with increasing scale thickness (at T = 1000 °C to 142 μm), with the exception of T = 900 °C, at which the scale thickness is 38.4 μm due to a decrease in the weight gain at this temperature. B2O3 and Al melts fill pores, cracks and smooth the surface, reducing roughness (Ra = 12 nm) and oxidation surface area. Thus, we can conclude that the AlB12-Al composite material is resistant to high-temperature oxidation up to T = 1000 °C.
Thermodynamic properties of melts of the Bi–La system
Authors:   Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Omeliana Pritsaka street, 03142 Kyiv, Ukraine, Volodymyr Shevchuk Volodymyr , Sudavtsova Valentina , Podoprygora Natalia , Kudin Volodymyr , Romanova Larysa
Published: August 2024

Alloys and compounds of bismuth with lanthanides (Ln) exhibit thermoelectric, magnetic and other properties. For their scientifically based production, it is necessary to know both their state diagrams and the thermodynamic properties of various phases, including the liquid one, because one of the important stages of the technological processes is the melting of the initial mixtures. Thermodynamic properties of liquid solutions based on Bi of the Bi–La system were studied by the EMF method in a number of works. In this work, for the first time, the partial and integral enthalpies of the formation of melts of the Bi–La system in the entire range of compositions were determined by the method of calorimetry at 1220-1274 K. It was established that ΔHmin= −118±4 kJ/mol falls on the melt with xBi = 0.4, and =−401±23; = −212±8 kJ/mol. It has been established that ours and all known ones, except data [1], agree with each other To confirm the reliability of the obtained data and search for regularities in the thermodynamic characteristics of melts of the Bi–La system, it was considered as a member of the Bi–Ln system series. For this, the enthalpies of formation and Tmelt were analyzed of intermetallics LnBi, as well as ΔHmin of melts, relative differences of molar radii and electronegativities of components of Bi–Ln systems, based on which their dependence on the ordinal number of the lanthanide is constructed. It is shown that all dependences, except for the electronegativity differences of the components, are compatible with each other. This indicates that the thermodynamic properties of all phases of the Bi–Ln systems are determined by the size factor.
Superhard Boride Ceramics Produced by Boro-Carbothermal Reduction
Authors:   Missouri University of Science and Technology, Fahrenholtz William G.
Published: August 2024

Boride ceramics have been proposed for use in extreme environments based on melting temperatures above 3000°C and other attractive properties such as high hardness. Inspired by the research of Professor Samsonov and others, our laboratory has investigated compositionally complex borides containing five different transition metals in an effort to identify new superhard ceramics. The most commonly studied compositionally complex boride has been (Hf,Nb,Ta,Ti,Zr)B2 with the metals present in nominally equimolar amounts. The initial search for harder materials involved substituting metals such as Cr, Mo, or W in place of Nb, which increased the hardness. Among the materials produced, (Cr,Hf,Ta,Ti,Zr)B2 had the highest hardness, which was about 48 GPa at a load of 0.49 N. Subsequently, new boride compositions were identified using a computational approach called the Disordered Enthalpy-Entropy Descriptor (DEED). Using DEED, (Cr,Mo,Ti,V,W)B2 was identified as a thermodynamically stable compound. The dense ceramic had a hardness of 48 GPa at a load of 0.49 N. Recently, machine learning predicted that (Hf,Mo,Ti,V,W)B2 should be superhard. This composition was synthesized by our group and found to have a hardness of 66 GPa at a load of 0.49 N. This presentation will provide a broad perspective on promising approaches for synthesis and densification of new borides that are identified through computational studies and produced by boro-carbothermal reduction.
The influence of silicon oxide, aluminum oxide, silicon nitride and titanium on the formation of a solid solution of carbon in silicon carbide
Authors:   Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Omeliana Pritsaka street, 03142 Kyiv, Ukraine, Tymoshenko Yaroslav , Gadzyra Mykola , Davydchuk Nadiya , Pinchuk Mykyta
Published: August 2024

The formation of a solid solution of carbon in silicon carbide occurs due to the partial replacement of silicon positions by carbon atoms, which leads to a decrease in the β-SiC lattice parameter and an increase in the hardness of polycrystals sintered at high pressure, which is 30% higher than the hardness of a SiC single crystal [1]. The objective is to examine how a solid solution of carbon in silicon carbide synthesizes in the interaction of carbon with silicon in the presence of SiO₂, Al₂O₃, Si₃N₄ and Ti. To obtain a composite powder material, petroleum coke and silicon were used as starting components. 30 wt.% of SiO₂, Al₂O₃, Si₃N₄ and Ti powders were added to the powder mixture С–Si. Synthesis of composite powder material were carried out at a temperature of 1200 °C in air during 1 hour. It was established that the interaction of the components in the С–Si system with the addition of SiO₂, Al₂O₃, Si₃N₄ and Ti occurs with the formation of SiC, SiO₂, Si₃N₄, Si₂N₂O, Al₂O₃, SiAlON and TiCN. It was established that the addition of SiO₂ contributes to the formation of a solid solution of carbon in silicon carbide with the lowest lattice parameter 0.4349 nm. It is shown that the presence of Al₂O₃ in the composition of the charge leads to the formation of a silicon carbide structure with a standard value of the lattice parameter 0.4359 nm. It was investigated that the addition of Si₃N₄ to the composition of the charge leads to the formation of a solid solution of carbon in silicon carbide with lattice parameter 0.4351 nm. It was found that the presence of Ti during the synthesis of silicon carbide does not contribute to the formation of a solid solution of carbon in silicon carbide, since its lattice parameter 0.4357 nm is closers to standard value.
Magnetic properties of electrolytic alloys of refractory metals at cryogenic and near-Curie temperatures
Authors:   V. I. Vernadsky Institute of General and Inorganic Chemistry of the NAS of Ukraine, Yapontseva Yuliya , Gorobets Oksana , Maltseva Tetyana , Kublanovsky Valeriy
Published: August 2024

Alloys of refractory metals (W, Mo and Re) with iron group metals have valuable properties, such as heat and corrosion resistance, hardness and magnetic properties, which ensures their use in the aerospace, nuclear and electrical industries. Only by electrodeposition from aqueous solutions is it possible to obtain thin alloys coatings with the ability to accurately control the chemical composition, structure and thickness of the resulting deposits [1]. This paper presents a study of the influence of the nature of the refractory metal (W, Mo, Re) on the magnetic properties of electrolytic alloys with cobalt at cryogenic temperatures and temperatures close to the Curie point. The CoW, CoMo and CoRe alloys were deposited from citrate-pyrophosphate electrolytes and contained 80 at.% cobalt. The magnetic characteristics of the alloys were studied using a “Vibrating Magnetometer 7404 VSM” Lake Shore Cryotronics Inc., USA in magnetic fields of up to 5 kOe. At room temperature, saturation magnetization differs significantly for alloys of different refractory metals [2]. Ms for the CoW alloy increases more than threefold upon cooling, and for the CoMo and CoRe alloys the increase is less than 20%. With increasing temperature, the saturation magnetization should constantly and monotonically decrease, which is what take place with the CoRe alloy, for which Ms decreases to almost zero. For CoMo and CoW alloys, magnetization does not reach zero and begins to increase at a temperature of ~600K. It is known that cobalt exists in two allotropic modifications with transition temperature is 700K. Both cobalt modifications have different magnetic properties and can be present simultaneously in electrochemical coatings. Possible reasons for changes in the magnetic properties of alloys are: phase transition; enlargement of crystallites when heated; formation of an electrolytic alloy, including the formation of phases of solid solutions and intermetallic compounds.
Properties of HVAF-coatings from Al-Cu-Fe quasicrystalline alloy
Authors:   Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Omeliana Pritsaka street, 03142 Kyiv, Ukraine, Yevdokymenko Yuriy , Iefimov Mykola , Frolov Gennadii , Iefimova Kateryna
Published: August 2024

Alloys of Al-Cu-Fe system containing quasicrystalline ψ-phase are perspective as thermal barrier, wear-resistant, corrosion-resistant and anti-adhesion coatings. Typically, such alloys are compositions of quasicrystalline and crystalline metallic phases, making them similar to metal ceramics [1]. Until now, high quality thermal spraying coatings from alloys containing ψ-phase more than 70 %(mass) have not been obtained due to its low plasticity at temperatures up to 500°C, phase transition to λ-phase and β-phase at 880°C and narrow area of existence in the diagram of states. The spraying was carried out by HVAF spraying method with liquid fuel burner GVO-RV with flow rate control of two-phase flow parameters, developed in IPMS of NASU [2]. The burner provides spraying powder with temperature 700-1000°C and velocity at least 500 m/s. In this mode the formation of coatings occurs from solid particles due to their plastic deformation. This allows to avoid typical for traditional technologies heating of particles above Tm=1080°С leading to oxidation and evaporation of aluminum resulting in the alloy composition leaving the limits of the existence of ψ-phase. The coatings were sprayed from water atomized Al63Cu25Fe12 powders [3] of fractions +20/-40 µm, +40/-63 µm, +63/-80 µm with the content of ψ-phase 65-75 %(mass). The content of ψ-phase in the coatings was ±5 % compared to powder; in some cases it came to 90 %. The thickness of the coatings is a controllable parameter and may reach 1000 µm. The porosity of coatings on substrates from copper, titanium, steels, aluminum alloys is 4-8 %. The adhesive/cohesive strength of coatings on 1044 steel substrates, determined by the pin method equals to 31±3 MPa. The thermal conductivity coefficient of Al-Cu-Fe coatings increases from 1.9±0.15 W/(m×K) at 20°C to 2.2±0.2 W/(m×K) at 800°C. The resistance of coatings to erosion at jet-abrasive processing is at the level of an HVAF-coating made of stainless steel AISI 301.
Pengaruh Harga, Promosi, Dan Kualitas Pelayanan Terhadap Loyalitas Wali Siswa Pada Homeschooling Bina Mandiri Di Kota Batam
Authors: Dabur Feliks , Sihaloho Asner
Published: August 2024

Tujuan penelitian ini adalah untuk mengetahui pengaruh harga, promosi dan kualitas pelayanan terhadap loyalitas wali siswa pada Homeschooling Bina Mandiri di Kota Batam. Sampel yang digunakan dalam penelitian ini berjumlah 100 responden dari 137 wali siswa yang dipilih secara acak. Metode yang digunakan dalam penelitian ini adalah metode sampel random sederhana. Metode analisa data yang digunakan adalah Uji Validitas, Reliabilitas, Normalitas, Multikolinearitas, dan Analisa Regresi Berganda.
Korelasi Antara harga, promosi dan kualitas pelayanan memiliki hubungan yang cukup kuat yaitu sebesar 46,40%. Pembuktian hipotesis memperoleh hasil uji t terhadap variabel harga dengan thitung -1,875 < ttabel 1,984, variabel promosi dengan thitung 3,212 > ttabel 1,984, dan variable kualitas pelayanan thitung 7,139 > ttabel 1,984 Berdasarkan Uji F diperoleh hasil Fhitung 29,568 > Ftabel (3,090).
Hasil penelitian ini menunjukkan bahwa harga berpengaruh negatif terhadap loyalitas wali siswa, promosi berpengaruh positif terhadap loyalitas wali siswa, kualitas pelayanan berpengaruh positif terhadap loyalitas wali siswa. Harga, promosi dan kualitas pelayanan secara bersama-sama berpengaruh positif dan signifikan terhadap loyalitas wali siswa Homeschooling Bina Mandiri di Kota Batam.
Studi Literatur : Perilaku Konsumen Terhadap Pemenuhan Kebutuhan Sehari-Hari Secara Daring (E-Grocery)
Authors: Kasidi Daniel
Published: August 2024

Perkembangan internet yang sangat pesat mampu mengubah perilaku konsumen dalam memenuhi kebutuhan sehari-harinya. Budaya berbelanja ke pasar atau supermarket mulai tergantikan dengan adanya belanja kebutuhan secara daring atau e-grocery. Pandemi COVID-19 yang melanda dunia beberapa tahun lalu semakin menguatkan tren ini menjadi tidak tergantikan. Dengan menggunakan Pendekatan Kualitatif dan metode Studi Literatur, penelitian ini bertujuan untuk mencari faktor apa saja yang mempengaruhi dan menghambat perilaku konsumen terhadap e-grocery. Selain itu, hasil pada penelitian ini juga diharapkan mampu memprediksi bagaimana e-grocery pada masa mendatang.
Analysis Of Factors Affecting The Performance Of Village Government Officials In The Implementation Of Government Tasks Village In Lebong Atas Sub-District Lebong District
Authors: Sanupil Peri , Soleh Ahmad , Abi Yudi Irawan
Published: August 2024

The aim of this research is to determine the factors that influence the performance of village government officials in carrying out village government duties in Upper Lebong District, Lebong Regency. The sample in this study was 56 village officials in Lebong Atas District, Lebong Regency. Data were collected using a questionnaire and the analysis methods used were multiple linear regression, determination tests and hypothesis tests
The results of the regression analysis show Y = 1.132 + 0.295X1 + 0.333 X2 + 0.341X3. This illustrates a positive regression direction, meaning that there is a positive influence between X1 (motivation), X2 (education) and X3 (work discipline) on performance (Y). This means that if the variables of motivation, education and work discipline increase, the newspaper's performance will improve. The coefficient of determination is 0.780. This means that X1 (motivation), X2 (education) and education) and X3 (work discipline) influence performance (Y) by 78% while the remaining 22% is influenced by other variables not examined in this research. The results of the t test at a significance level of 0.05 explain that partially (individually) the variables education, motivation and work discipline have a significant influence on the newspaper performance variable because the significant value is smaller than 0.05. The results of the F test at a significance level of 0.05 explain that the variables education, motivation and work discipline have a simultaneous influence (together) on the performance of village government officials because the significant value is smaller than 0.05 and Fcount > Ftable (61.362 > 2.78)
The Influence Of Promotion, Interest Rates, And Service Quality On Customer Satisfaction At Bak Perkreditan Rakyat (BPR) Dana Nusantara Kc Sp Plaza Batam
Authors: Sinaga Gideon Romula , Dabur Feliks , Harianja Josepin
Published: August 2024

This study aims to determine the effect of promotions, credit interest rates and services either partially or simultaneously on customer satisfaction at the People's Credit Bank (BPR) Dana Nusantara in KC SP Plaza Batam. This research was conducted using quantitative research methods with a total of 109 respondents and data collection using a questionnaire. The results of this study found that tcount was 4.648 > ttable was 1.659 with a significantce level of 0.00 <0.05, so the of promotion had positif a significant and significantce effect on customer satisfaction. tcount of 1.198 < ttable of 1.659 with a significantce level of 0.234 <0.05, then credit interest rates have no positif and insignificant effect on tcount of 3.538 > ttable 1.659 with a significantce level of 0.001 <0.05, then service has a positif and significant effect on customer satisfaction. From the F test it is known that the fcount of promotions, credit interest rates, and services is 120.688 > 2.69 ftable with a significantce value of 0.000 <0.05. This shows that the variabel. promotion, interest rates, and services simultaneously have a positif and significant effect on customer satisfaction at the People's Credit Bank (BPR) Dana Nusantara KC SP Plaza Batam.
ФАРҒОНА ВОДИЙСИНИНГ СЎНГГИ ШАЙБОНИЙ СУЛТОНЛАРИДАН БИРИ ҲАҚИДА
Authors: Musayev Azizbek
Published: August 2024

This article discusses the political processes in the Bukhara Khanate at the end of the XVI-early XVII century, the influence of the transition of power from the Sheibanids to the Ashtarkhanids on the Fergana Valley. As a result of a series of raids by nomadic Kazakh-Kyrgyz tribes from the northeast during this period, the Bukhara Khanate lost part of its territories acquired under Abdullah Khan II. The fierce political struggle of that time did not pass by the Ferghana Valley either. In the struggle for Tashkent and the Syrdarya territories, the Ashtarkhanids fought against the Kazakh khans, and for the Ferghana Valley, political interests clashed with Keldimukhammadkhan.
Pengaruh Lama Marinasi Dengan Ampas Kopi Arabika Pada Olahan Daging Sapi Terhadap Kualitas Fisik Dan Daya Terima Konsumen
Authors: Nabila Putri Pertiwi  , Alsuhendra Alsuhendra  , Mariani Mariani
Published: August 2024

This research aims to analyze and study the influence of marination with Arabica coffee grounds on processed beef in terms of physical quality and consumer acceptance. The study was conducted at the Laboratory of the Culinary Education Program, Faculty of Engineering, Universitas Negeri Jakarta, from March 22, 2022, to September 25, 2023. The research method employed was experimental. The samples used in this study were processed beef marinated with Arabica coffee grounds for 60 minutes, 90 minutes, and 120 minutes. Subsequently, a panel test was conducted with 30 moderately trained panelists who evaluated predetermined aspects of consumer acceptance. Based on the results of the statistical hypothesis test using Anova for the physical quality test, it was found that there is an influence of marination with Arabica coffee grounds for 60 minutes, 90 minutes, and 120 minutes on the aspect of meat tenderness. According to the results of the statistical hypothesis test for consumer acceptance using the Friedman test, it was found that the texture of processed beef was influenced. Based on the results of the Tukey's test, in terms of product preference for surface color, coffee flavor, meat flavor, texture, coffee aroma, and distinctive meat aroma, the product most preferred from the research was processed beef marinated with Arabica coffee grounds for 120 minutes.
Penerapan Teknik Slashing dalam Pembuatan Ready To Wear Look Harajuku
Authors: Ariyana Damayanti  , Endang Eka Setianingrum
Published: August 2024

Beautifying the appearance of a garment requires modifications in dress. One way of beautifying clothing is fabric manupulation or fabric manipulation. The author chose the slashing technique, this technique is one of the fabric manipulation techniques by stacking several fabrics and then cutting one or several layers of the cloth pile so that it only makes the basic layer. The author compares many layers of fabric used. The goal is to know application of slahsing method creation in making ready to wear. The method that the author uses is the method of R&D and data analysis. The author made a comparison using 3 layers of material, 4 layers of material, and 5 layers of material. Comparisons of each slashing technique include materials, techniques, colors, and designs. The materials used to make the slashing technique are toyobo cotton fabric and drill fabric. The result of slashing 3 layers of material has a fabric thickness that is not too thick, the finished product is quite neat, and the color is suitable. Slashing 4 layers of material has a fairly thick fabric thickness, and the finished result is quite neat. Slashing 5 layers of material has a very thick thickness of fabric, and the finished result is not neat enough. Making ready to wear using a suitable slashing technique is 3 layers of fabric.
Pengaruh Metode Pembuatan yang Berbeda terhadap Mutu Sensoris Roti Bluder
Authors: Felicia Andriani  , Cucu Cahyana  , Ridawati Ridawati
Published: August 2024

This research aims to identify the effect of different manufacturing methods on the sensory quality of bloeder bread. The method used is experimental. This research was conducted at Jakarta State University with a sample of 45 Culinary Education students who were somewhat trained panelists. Based on the Kruskal Wallis test, it can be concluded that there is an influence of different methods of making bloeder bread on the volume and crust aspects of the bread. Meanwhile, there was no real influence on aspects of upper skin color, skin characteristics, aroma, crumb pores, crumb color, crumb texture, taste and chewing quality.
Principales detonantes y funciones percibidas de la evaluación de evaluabilidad de las políticas públicas en la actualidad
Authors: Casero-Cepeda Juan Francisco
Published: August 2024

Este artículo expone los resultados de una investigación sobre evaluación de evaluabilidad. Presenta dos propósitos principales. De una parte, identificar los detonantes o motivos centrales por los cuales se pone en marcha en la actualidad una evaluación de evaluabilidad de las políticas públicas. Y, de otra, vislumbrar cuáles son sus finalidades más relevantes en términos de importancia y prevalencia. El sentido es que, pese al interés que la evaluación de evaluabilidad suscita hoy día en el ámbito internacional, se evidencian múltiples malentendidos conceptuales y de aplicación en torno a esta metodología. La evaluación de evaluabilidad representa uno de los tipos de evaluación más reconocidos. Se comenzó a aplicar en el último cuarto del pasado siglo XX como respuesta a los problemas que se habían encontrado las evaluaciones experimentales. En sus inicios, se utilizó como herramienta de preevaluación para discernir entre programas públicos evaluables y no evaluables, así como para valorar si las evaluaciones de resultados, posteriores a las de evaluabilidad eran útiles y representaban una buena decisión para dar respuesta a las necesidades de información de los gobiernos. Sin embargo, este planteamiento llevó la evaluabilidad a una dimensión demasiado racional y limitada, lo que hizo que su aplicación cayera rápidamente en desuso. A partir de nuevos enfoques sobre este tipo de evaluación surgidos en este siglo, en el presente artículo se alcanza una definición más amplia y actualizada de su concepto. El trabajo concluye constatando el valor de la evaluabilidad como herramienta impulsora de una mayor cultura e institucionalización de la evaluación de las políticas públicas en general. Asimismo, concluye que la evaluabilidad hoy día es, fundamentalmente, un instrumento dirigido a promover capacidades y sistemas públicos de evaluación, frente al rol más limitado que se le había otorgado hasta ahora de identificar y proponer mejoras en torno del diseño y la disponibilidad de datos de las intervenciones públicas, finalidades estas que se ven relegadas a un segundo plano.
Diverting Ileostomy vs Colostomy in Colorectal Surgery: A Single Institution Outcomes Comparison
Authors: Cairl Nicholas , Huebner Marianne , Kolli Nivya , Cleary Robert
Published: August 2024

Introduction: Diverting stomas often accompany total mesorectal excision (TME) for rectal cancer and for patients having anterior resection for complicated diverticulitis when the risk for anastomotic leak is increased. Diverting stomas are also an option to urgently relieve colonic obstruction from neoplasia or diverticular disease. The diverting stoma choice is often a loop ileostomy that increases the risk for acute kidney injury (AKI) or a diverting loop transverse that may be greater risk for stoma prolapse. The objective of this study is to determine if ileostomy or colostomy is a better diversion option when considering complications and outcomes on a dedicated enhanced recovery colorectal surgery service.

Methods: This is a single institution analysis of a prospectively maintained institutional colorectal surgery database between 01/01/2018 and 09/30/2023. The primary outcome was the postoperative 30-day complication rate after diverting ileostomy or colostomy. Secondary outcomes were AKI, stoma prolapse, other individual complications, and readmissions. Strength of association was estimated with multivariable logistic regression models adjusted for patient characteristics.

Results: 347 patients met inclusion criteria – 81 with a diverting colostomy and 266 with a diverting ileostomy. Patients undergoing diverting colostomy were older than those undergoing diverting ileostomy (64.2 +/- 14.5 years versus 59.1 +/- 13.9 years, p =0.006), had lower BMI (26.32 +/- 5.95 kg versus 27.66 +/- 6.39 kg, p = 0.028), and had a higher incidence of diabetes (18.5% versus 10.2%, p = 0.043). The overall complication rate was significantly higher for ileostomies (29.6% vs 59.8%, p<0.001 ) as was acute kidney injury (1.2% vs 16.2%, p<0.001), ileus (13.6% vs 35.7%, p<0.001), SSI III (2.5% vs 9.8%, p=0.035), ED visits (9.9% vs 24.4%, p=0.005), and readmissions (6.2% vs 18%, p=0.009). Stoma prolapse within 6 months (4.9% vs 0.4%, p=0.003), reoperation (7.4% vs 0.8%, p<0.001), and postoperative death (4.9% vs 0%, p<0.001) were significantly higher for the colostomy group.

Conclusions: Colostomies are associated with fewer complications and may be a better option for fecal diversion when there are no other factors that preclude this choice.
The Management and Outcomes in Blunt Splenic Injury: A Comparison Between a Rural and Urban Trauma Center
Authors: Graham Isabella , Ethridge Meryl , Kole Kerry , Helveston Sarah , Adams Courtney , Valencia Jason , Szpunar Susan , Edhayan Elango
Published: August 2024

Introduction: The management of blunt splenic trauma (BST) has evolved over the last 20 years, with nonoperative management in hemodynamically stable patients prevailing as the standard of care. Nonoperative management includes angioembolization of the splenic artery. Although non-operative management has increased in use, there is limited standardization of practices for the management of blunt splenic trauma. The objective was to compare outcomes for BST and the use of angioembolization between a Level 1 urban trauma center, Ascension St. John Hospital, Detroit MI (ASJH) and a Level 2 rural trauma center, Munson Medical Center, Traverse City MI (MMC).

Methods: Our study used registry data comprising all patients from 1/2015-12/2021 who presented to ASJH and MMC with BST. Patients were divided into operative intervention versus non-operative management groups. Data collected included timing of intervention, length of stay, severity scores, blood product requirements and concomitant injuries. The management and outcomes between the two institutions were compared. Data were analyzed using Student’s t-test, the χ2 test, the Mann-Whitney U test and logistic regression.

Results: Data were collected on 93 patients from ASJH and 189 patients from MMC. Splenic injury grade was scored from one to five, with 60.0% of patients scoring grade three or higher and 62.1% of patients having active blush identified on imaging. Eighty-four patients (28.4%) had operative intervention and 24 patients (8.5%) underwent angioembolization. ASJH had an angioembolization rate of 15.1% vs 5.3% at MMC (p=0.006). When comparing the two hospitals, patient groups were different in terms of race (p=0.001), fresh frozen plasma administered (p=0.046) and presenting systolic blood pressure (p=0.001). In patients with active blush, after adjusting for hemoglobin on arrival, ASJH patients were 3.8 times more likely to have angioembolization than patients at Munson (p=0.02). TRISS and race dropped out of the model.

Conclusions: There is a significant difference in the rate of non-operative management between the hospitals. Higher rates of angioembolization at an urban center may reflect a difference in resource distribution between urban and rural centers.
Consistent Support Group Attendance is Vital for Clinically Sustained Weight Loss in a Community Gastroenterology Clinic
Authors: Tolia Sangini , Gunaratnam Sejal , Kumar Nishant , Evans Mallory , Gunaratnam Naresh
Published: August 2024

Introduction: The increasing prevalence of obesity places a high burden on the economy with annual medical expenses approximating 150 billion dollars. Obesity-related gastrointestinal disorders, including non-alcoholic fatty liver disease (NAFLD), account for over 30% of patient visits to community GI practices. Total body weight loss (TBWL) of 10% or more is associated with reversal of NAFLD-associated fibrosis and steatosis. However, achieving this goal alone can be difficult. Support groups have proven to be vital in allowing individuals to recover from other lifestyle diseases like alcohol overuse. The aim of this study was to assess the impact of support group attendance on a patient achieving 10% TBWL while enrolled in a structured, community-based weight loss program.

Methods: Patients enrolled in the weight-loss program participated in a 6 month support group with weekly online meetings. These sessions included discussions of shared experiences and education on the 4 pillars of the program - nutrition, exercise, sleep, and mindfulness. TBWL was calculated by taking the difference of the patients starting weight and their 6 month weight divided by the starting weight. Data was collected retrospectively through chart review. By April 2023, a total of 95 patients completed the support group program. Statistical analysis was performed using ANOVA and Tukey-Kramer post-hoc tests.

Results: The mean percent weight loss was 6.30% for the group with 0-50% attendance, 9.30% for the group with 51-75% attendance, and 13.15% for the group with 76-100% attendance. A one-way ANOVA revealed a statistically significant difference in the percent weight loss across the three groups (F(2,92) = 8.66, p <0.001). Further analysis with a Tukey-Kramer post-hoc test revealed a significant difference in percent weight loss between the group with 76-100% attendance and groups with 0-50% attendance (p<0.05) and 51-75% attendance (p<0.05). There was no significant difference in percent weight loss between the groups with 0-50% and 51-75% attendance (p>0.05).

Conclusions: The results of this study indicate that patients with more than 75% attendance at support group meetings across a six-month period reported significantly higher percent weight loss than patients with lower attendance. This study supports the efficacy of support group meetings toward achieving weight loss. Further studies with larger sample sizes are ongoing to measure the efficacy of support groups on a long-term basis.
Digital Stethoscope Utility in NICU, SCN, and LDRP Patients
Authors: Forbes Kathryn , Covi Stuart , Nazee Marla , Al-Anani Shada , Anne Premchand , Pappas Athina , Zoma Justino , Szpunar Susan
Published: August 2024

Introduction: To this day, abnormal auscultatory findings on acoustic examination of the cardiovascular system remains the most common reason for referral to a cardiologist. Three limitations exist with acoustic stethoscopes: 1) high selective sensitivity requirement is needed; 2) easy disruption by ambient environmental noise; 3) subjectivity of interpretation based on the provider’s experience, skills, and auditory proficiency. The introduction of digital stethoscopes offered a solution to the limitations of the traditional acoustic stethoscope while at the same time broadening the diagnostic potential of such devices: 1) improvement in sound quality; 2) amplification of the acoustic signal; 3) reduction of ambient noise. The objectives were: 1. To determine the accuracy of the digital stethoscope when used in neonatal intensive care unit (NICU), Special Care Nursery (SCN), and Labor & Delivery Recovery Postpartum (LDRP) patients; and 2. To determine if its use leads to improved detection rates of cardiac pathologies compared to the use of a classic acoustic stethoscope.

Methods: This is a single center, prospective study of neonates in the NICU, SCN, and LDRP at Ascension St. John Children’s Hospital. After obtaining informed consent, infants were examined using both acoustic and electronic stethoscopes by trained residents. Data from chart review and echocardiography were also collected. Results from the two stethoscopes were compared to each other and to echocardiographic findings. Data were analyzed using Student’s t-test, the χ 2 test and the McNemar χ 2 test.

Results: The study included 15 infants, mean of 33.3 ± 3.8 weeks’ gestation at birth, 46.7% female (7/15) and 66.7% (10/15) black. Of the 15 patients evaluated, for the differential diagnosis and the ECHO results, there was 56% (5/9) better agreement with the electronic stethoscope, 33% (3/9) equivocal agreement between the electronic and acoustic stethoscopes, and 11% (1/9) worse agreement between the electronic stethoscope differential diagnosis and the actual ECHO results.

Conclusions: There is a trend towards better agreement between the electronic stethoscope differential diagnosis and the actual ECHO results. A larger sample size is needed to determine true statistical significance of the data and probability.
A Review of High-Risk Pregnancy Complications in the Resident Clinic
Authors: Saleh Ali Aya , Bain Tolbey , Juma Mina , Katz Samantha , Hoofman Jacob , Khan Ayesha
Published: August 2024

Introduction: A high risk status can develop during a patient’s pregnancy or can be present from conception. These include maternal pre-existing conditions such as hypertension, diabetes, infection such as HIV, and obesity. Fetal complications such as anomaly or multiple gestation also constitute high risk pregnancies. The Corewell Health East Dearborn resident high risk clinic helps to manage these patients’ pregnancies and deliveries. This study aims to analyze the current complications and delivery outcomes of pregnancies from this clinic.

Methods: The prenatal care data and pregnancy outcomes from patients in our high-risk resident clinic was collected from Jan 1st 2023 to Jan 1st 2024. The prenatal care data was analyzed for maternal and fetal complications along with delivery outcomes.

Results: During the year 2023, 100 patients delivered from the high-risk clinic. Fetal complications were found in 32% of these deliveries. These included 12% twin gestation, 14% growth restriction, 6% fetal anomalies. Maternal complications included 27% with chronic hypertension, 23% with prior cesarean section, 27% with a BMI of 40 or higher, 10% cardiac complications, 4% pre-existing renal complications, 26% with pre-existing diabetes, 3% wtih HIV, and 6% with polysubstance use. The deliveries included 62% cesarean sections and 34% vaginal deliveries.

Discussion: The results from our cross-sectional study revealed a high rate of maternal and fetal complications among patients from our high-risk clinic when compared to national averages. There was a high cesarean section rate for these patients.

Conclusions: This study allowed us to better understand the patient population that receives care through the resident high-risk clinic. Future studies can explore how to decrease the cesarean section rate.
Prognostic Value of MRI-Assessed Central Gland Volume for Biochemical Recurrence after Prostate Cancer Radiotherapy
Authors: Lee Joseph , Salari Kamran , Nandalur Sirisja , Shen Chen , Al-Katib Sayf , Zhao Lili , Krauss Daniel J , Thompson Andrew B , Seymour Zachary A , Nandalur Kiran R
Published: August 2024

Introduction: Increasing central gland volume has been associated with less aggressive prostate cancer, theorized to be secondary to biomechanical stress from benign prostatic hyperplasia (BPH). The aim of this study was to evaluate pretreatment prostate magnetic resonance imaging (MRI) metrics and clinical characteristics in predicting biochemical recurrence (BCR) after definitive radiotherapy (RT) for prostate cancer.

Methods: In this retrospective single institution study, we identified men in our database with prostate cancer who underwent MRI within 6 months prior to completing definitive RT from May 2011 to February 2023. Total prostate volume, central gland volume, and peripheral zone volume were measured by a radiologist using manual segmentation. The primary objective was to determine the association of central gland volume with biochemical recurrence, defined by Phoenix criteria. A multivariable Cox proportional hazards regression model was constructed and adjusted for clinical factors.

Results: A total of 373 men (median age 68 years) were included, with a median follow-up of 28 months. 13 (3.5%) were low risk, 97 (26%) favorable intermediate ris, 201 (53.9%) unfavorable intermediate risk, and 62 (16.6%) high risk. 54 (14.5%) patients received conventionally fractionated RT, 105 (28.2%), moderately hypofractionated RT, 121 (32.4%), high-dose rate brachytherapy, and 93 (24.9%) stereotactic body RT. The 3 and 5 year rates of BCR were 7.8% and 18.3%, respectively. Taking into account NCCN risk group and RT type, higher central gland volume was associated with decreased risk of BCR (HR: 0.73, 95% CI: 0.55-0.98, p=0.03). No significant association was seen with peripheral zone volume, PI-RADS score, or RT type.

Conclusions: Increased central gland volume on pretreatment prostate MRI is independently associated with a lower risk of biochemical recurrence after definitive radiation for prostate cancer. BPH appears to confer favorable outcomes in RT patients and represents a novel, easily quantifiable metric in risk-stratification.
Improvements in Efficiency and Resident Satisfaction Following the Implementation of a Central Supply Closet
Authors: Amalathasan Theourrn , Moughnyeh Mohamad , Bolliet Marine , Oppat William
Published: August 2024

Introduction: In the 1970’s, the idea of burnout began and was defined as emotional exhaustion, depersonalization, and low sense of personal accomplishment (1). Recently, there has been a push by graduate medical education to counter resident burnout, as demonstrated by resident wellness initiatives becoming a requirement for residency programs in the United States (2). At our institution, a source of burnout was the time it took to gather supplies for critical bedside procedures, which was addressed by instituting a central supply closet.

Methods: A checklist was made of the supplies needed for four common bedside procedures: central venous access, arterial line placement, thoracostomy tube placement, and incision and drainage. 9 surgery residents were individually timed to locate the equipment required for each individual procedure with the supply closet and without. A survey was used to evaluate resident satisfaction in the number of locations to search, timeliness, and ability to provide quality patient care before and after the supply closet. This survey was done on a scale of 1 to 5, with 1 being very dissatisfied, and 5 being very satisfied. Paired t-tests were used for data analysis; p<0.05 was considered statistically significant.

Results: For central line supplies, the average times were 542 seconds (s) without the closet, and 211s with the closet (p=0.0041), arterial line supplies took 570s without and 178s with (p=0.0114), thoracostomy tube supplies took 590s without, and 213s with (p=0.0017), and incision and drainage supplies took 518s without, and 239s with the closet (p=0.0066). Average resident satisfaction for the number of locations to search for supplies went from 1.5 to 4.8 with the closet, length of time to gather supplies went from 1.3 to 4.9 with the closet, and ability to provide quality patient care went from 1.4 to 4.8 (all p<0.0001).

Conclusions: The implementation of a supply closet with easy access to supplies allowed for improved speed in completing bedside procedures, leading to expedited patient care, improved resident satisfaction and well-being, and decreasing a source of surgery resident burnout.
Vaccine Hesitancy in HIV Patients Following the COVID-19 Pandemics
Authors: Kropman Kory , Vahia Amir , Johnson Leonard , Szpunar Susan
Published: August 2024

Introduction: The prevalence of vaccine hesitancy has been on the rise for several years in the United States leading up to the Covid19 pandemic. During the pandemic, there was controversy and media attention surrounding the effectiveness and safety of the Covid19 vaccine, with many individuals, including patients with HIV, refusing vaccination, despite evidence of its benefit. There are further concerns that patients with HIV are reluctant to receive additional vaccines that existed prior to the Covid19 pandemic. In this study, we evaluated the rate of refusal of non-Covid19 vaccines in the pre- and post-period after release of the Covid19 vaccine.

Methods: We measured and compared the number of vaccines offered and refused at each visit over the total number of visits for 195 patients with HIV during a pre-Covid (approximately 18 months before the release of the Pfizer vaccine to the public on August 23, 2021) and post-Covid period (approximately 18 months after the previously mentioned date). The vaccines studied included the following: tetanus, pneumococcal, shingles, hepatitis A/B, and influenza. The data was collected using hospital records from Athena and Cerner, as well as Michigan State Records. Data was analyzed using descriptive statistics and the Wilcoxon signed ranks test. The Mann-Whitney U test, Kruskal-Wallis test and Pearson’s correlation were performed for the Covid19 vaccine statistics. In all statistical tests, a p-value less than 0.05 was taken to indicate statistical significance.

Results: Collectively, there were more refusals in the period after release of the Covid19 vaccine for non-Covid19 vaccines. This was also the case for all individual vaccines, except Hepatitis A. There was an overall statistically significant difference (p <0.001) in the distribution of vaccine refusals between the pre-Covid19 and post-Covid19 period. This was observed for the Pneumococcal (p=0.026), Hepatitis B (p=0.035), and Shingles vaccine (p <0.001) respectively. The Covid19 vaccine was more likely to be refused in female patients (p=0.005), non-white patients (p=0.02), and younger patients (p=0.04, r= -0.21).

Discussion/Conclusion: This study provides evidence that there is an increase in non-Covid19 vaccine hesitancy following the release of the Covid19 vaccine in patients with HIV at Ascension St. John Hospital. Given the small size of the study population and this study being an initial evaluation, more will need to be performed. This is to further test these findings in other regions of the United States.