Stages Of Process Research Articles

Отримання жароміцного гомогенного сплаву методом пресування та спікання суміші порошків (Nb-21Ti-5Al-10Cr-7Mo) ат. %

Multicomponent high temperature strength alloys of the Nb-Ti-Al system, alloyed with Cr, Zr, Mo and Si, with a specific gravity of 6.3 - 7.4 g/cm3, have proven extremely promising in aviation and space technology. However, their physical and chemical features are associated with the high activity of the components, with a significant difference in melting temperatures (from Tmel. Mo – 2617 °C to Tmel. Al – 660 °C) and different specific gravity (from 10.2 g/cm3- Mo up to 2.7 g/cm3- Al), is a big problem for their production. The long crystallization interval of cast alloys of this system, thermophysical features of their crystallization, determine the possibility of formation of dendritic structures, the development of dendritic liquation and segregation of low- or high-temperature intermetallics and eutectics, the tendency to the formation of crystallization cracks, which reduces the operational characteristics of cast alloys. In this regard, it became necessary to investigate the possibilities of obtaining an alloy by the method of powder metallurgy. The purpose of this work was to obtain a homogeneous alloy, to study changes in the grain structure, phase transformations and mechanical properties of the material at various stages of processing in the process of obtaining a homogeneous alloy structure by powder metallurgy methods. The need to protect powder components from oxidation, formation of nitrides, carbides during technological operations at temperatures above 200 °C (high-purity argon) has been established. The optimal duration of intensive grinding of a mixture of powders and granules of raw materials has been worked out, which makes it possible to control the uniformity of the size of the particles of the mixture components, porosity and homogeneity of the alloy. The optimal duration of grinding is 30 minutes, during which the most homogeneous mixture in terms of particle size is formed. The optimal annealing mode was established, which ensures the achievement of homogenization of the alloy, phase transformations at the boundaries of the contact of component particles, and changes in grain sizes. Microstructural and X-ray structural analysis of the samples was carried out, their microhardness and grain dispersion were determined. Keyword: high-temperature strength niobium alloys, physical and chemical features, powder metallurgy, homogeneity, microstructure, mechanical properties, phase composition.

The model for optimizing cutting parameters for processing products on metal-cutting machines

The paper discusses the issues of multi-criteria optimization of the process of manufacturing products on metal-cutting machines. The efficiency of the optimization process directly depends on its level of detail and the optimal set of targets and control parameters. The change in the structure and properties of a product during its manufacture can be represent-ed in the form of a hierarchical model based on the decomposition of the original goal, which must be achieved through the comprehensive optimization of individual elements of the process. Described herein is a multi-level hierarchical model for optimizing a machining process comprising five levels of control. The following control levels are identified: Technological Process, Processing Stage, Technological Operation, Process Transition, Work Stroke. For each structural element of the model, control parameters, specific optimization criteria are defined, and vector optimiza-tion criteria are formed. The practical implementation of the control model is presented on the example of optimization of the target indicators of the technologi-cal process of the ”Roller” product. Graph of change of object states in process of its manufacturing is pre-sented, optimal values of target indicators and cutting parameters are determined.

Perubahan Komponen Kimia Fungsional pada Umbi, Tepung, dan Beras Analog Ubi Jalar Ungu

The purple sweet potato tuber, rich in functional chemical components, offers potential for development into high-value products such as flour, which can then be processed into analog rice. This research aims to evaluate the changes in functional chemical components–namely moisture, ash, protein, fat, carbohydrates, anthocyanin, and β-carotene–along with antioxidant activity during the processing of purple sweet potato tubers into flour and analog rice. The chemical composition of the tubers was found to be as follows: moisture content of 78.00% on a wet basis (wb), ash content of 9.70% on a dry basis (db), fat content of 5.47% (db), protein content of 26.93% (db), carbohydrate content of 58.41% (db), anthocyanin content of 31.79 mg/100 g (db), β-carotene content of 17.73 mg/100 g (db), and antioxidant activity of 65.70%. The composition of the resulting flour included water (6.71% wb), ash (2.40% db), fat (1.06% db), protein (3.80% db), carbohydrate (92.75% db), anthocyanin (3.47 mg/100 g db), β-carotene (1.51 mg/100 g db), and antioxidant activity (45.59%). The chemical content of the analog rice was as follows: water (8.43% wb), ash (1.78% db), fat (1.62% db), protein (4.13% db), carbohydrate (92.50% db), anthocyanin (0.71 mg/100 g db), β-carotene (1.05 mg/100 g db), and antioxidant activity (8.38%). Processing the tubers into flour resulted in a reduction of fat, protein, anthocyanins, β-carotene, and antioxidant activity, while carbohydrate content increased. Similarly, the conversion of flour into analog rice led to decreased levels of carbohydrates, anthocyanins, β-carotene, and antioxidant activity, whereas fat and protein levels increased after transfor-mation into analog rice. The processing stages that significantly contributed to these changes in chemical components included drying, formulation, and extrusion.

The Impact of Online Opinion on Justice: Two Cases in Comparative Law Perspective

In the early stages of the judicial process, trials were characterized by a pursuit of independence and justice, with judges adhering strictly to legal statutes and delivering judgments that aligned with legal logic. However, as today's digital landscape evolves, Internet users engage with the judiciary in distinct ways; they communicate online, actively voice their opinions, and gradually cultivate a representative form of public opinion on the web. As the impact of online public sentiment on judicial administration grows stronger, it increasingly exhibits a tendency to exert dominance. While the independence of the judiciary remains unquestionable, certain explosive instances of online public opinion also highlight pressing societal issues that warrant attention and cannot be overlooked. Using two well-known cases as an entry point, we will compare how networked public opinion influences justice differently in Japan and China. This analysis will delve into the underlying jurisprudence while seeking solutions tailored to China's national context. The goal is to foster positive interaction between these two realms—leveraging the constructive influence of online public opinion on judicial processes—and ultimately enhance China's judiciary system.

Change in the qualitative composition of non-metallic mineral raw materials as a result of blasting operations

Purpose. The research purpose is to study the change in the qualitative composition of granite before and after blasting operations to determine its compliance with the criteria of marketable products. Methods. X-ray phase and X-ray structural research methods are used to study changes in the mineral composition of granites before and after blasting operations. To separate magnetic and non-magnetic fractions of the selected granite samples, a three-roller RST magnetic separator is used. X-ray phase research is conducted using a DRON-3 diffractometer. Additionally, an analysis of the unit cell dimensions of the quartz crystal lattice was conducted, and the dislocation density along the corresponding crystallographic planes was studied. Findings. It has been determined that after blasting operations, granite mass is redistributed from coarse fractions of 1-20 mm to small fractions of 0-1 mm with an increase in the latter by 4.2%. It has been found that the biotite content decrea-ses naturally and consistently, and the quartz content increases correspondingly in products in the following series: magnetic separator drum (90%, 2%) → lower roller (72%, 14%) → upper roller (55%, 31%) → non-magnetic product (48%, 34%) before blasting operations. Therefore, despite significant differences in the magnetic favorability of these two mineral phases, they are present in all magnetic separation products (with the exception of quartz in the non-magnetic product): magnetic separator drum → lower roller → upper roller. Originality. It has been established that along the crystallographic directions 101 and 211, the maximum gradient of dislocation density increase in the quartz crystal lattice in granite samples before blasting operations is observed during the transition from the lower roller product to the upper roller product, amounting to 1.55·1010 and 6.63·1010 cm-2, respectively. After blasting operations, in granite samples along the same directions, the maximum gradient of dislocation density increase is observed between the upper roller product and the non-magnetic product, amounting to 3.01·1010 and 4.67·1010cm-2. As a result of the thermodynamic impact of blasting operations, the weighted average dislocation density value along crystallographic planes 101 and 211 in the quartz crystal lattice increases by 47.21 and 25.72%, respectively. Practical implications. Understanding the quality characteristics of marketable products after blasting operations will contribute to optimizing the stages of further processing of non-metallic mineral raw materials (two-, three- or four-stage crushing) and expanding the scope of granite applications. This increases its competitiveness in the building materials market by reducing the costs for additional processing with a reduction in the labor intensity of the process.

Risk Management Analysis Based on ISO 31000:2018 at Andi Djemma Masamba Airport, Luwu Regency

The density of activities that take place around the operating facilities at Andi Djemma Masamba Airport so that the Management of the Andi Jemma Airport Operator Unit (UPBU) Office has launched the development of Andi Djemma Masamba Airport as an aviation company so that it continues to carry out various facility improvements, especially in risk prevention with potential activities with high losses, therefore it is necessary to conduct research to find out how to map, risk assessment and design a risk control and mitigation system at the Operations facility at Andi Djemma Masamba Airport caused by activities that have the potential to cause risk. The stages of the risk management process refer to ISO 31000: 2018 including risk identification, risk analysis and risk evaluation. Expected impact and likelihood of occurrence are mapped through the risk matrix from the Federation Aviation Administration (FAA). The results showed that at the andi djemma masamba airport there were 6 events that fell into the red category, namely Aircraft accidents during take off/landing, Aircraft accidents in the apron area, Escape of dangerous goods into the aircraft, Fuel Spills on the Apron/Taxiway, Lack of building maintenance, The security inspection process is less than optimal.

Towards a processual understanding of trust: A study of trust-building strategies of constructive journalists

Trust in news media is a hot topic in media research, and although several attempts have been made to explore it, the concept has commonly been viewed as a matter of audiences’ reception of news products. In contrast, we conceptualize trust as an integral part of all stages of the news production process and focus on the journalists’ perspective. Based on semi-structured interviews with Austrian constructive journalists, we investigate which strategies they use to improve the perception of their trustworthiness among audiences and what they want to achieve by being trusted. Trust-building strategies are identified across various stages of news production, with a notable emphasis on traditional journalistic values like objectivity, particularly in the context of separating facts from opinions to enhance audiences’ trust. Objectivity is sought through reliance on scientific sources, which are considered objective in their own right. This approach contrasts with conventional notions of objectivity in journalistic and academic discourse on constructive journalism. The findings reveal a focus on fostering trust to promote a solution-oriented approach to public issues, facilitating a more vibrant and constructive public discourse.

Regret cross-efficiency evaluation using attitudinal entropy approach

Data envelopment analysis (DEA) is a popular nonparametric tool for measuring the performance of decision making unit (DMU). Cross-efficiency evaluation is an efficient means to rank DMUs, which compensates for efficiency overestimation and incomplete ranking of conventional DEA models. With respect to incomplete rational cross-efficiency evaluation, the common methods construct models with two extreme efficiencies as reference, such as efficiency values of the aggressive and benevolent models. In addition, they only explore the irrational preferences of decision maker (DM) at a certain stage in the evaluation process. They fail to investigate the cross-efficiency evaluation synthetically under incomplete rationality and characterize the complexity of the individuals’ decision making. To fill this gap, a new method must be proposed. This paper proposes a new cross-efficiency termed regret cross-efficiency model using attitudinal entropy approach (RACE), which constructs a secondary goal model from a comprehensive perspective under the framework of regret theory, and introduces attitudinal entropy to aggregate the cross-efficiencies. Besides, this paper presents some empirical examples to illustrate the validity and robustness of the RACE method.

La internacionalización a contrapelo: una etnografía y dos estudiantes vargastorrinos en Jaén, España

This work narrates a somewhat peculiar encounter between two students from the Technical University "Luis Vargas Torres" of Esmeraldas (UTLVTE) who wish to share their experience of internationalization, being the result of an agreement between the UTLVTE and the University of Jaén (UJA), managed by the International Research Group ALMARGEN, to which both universities belong. This alliance has made it possible to present two research proposals: i) "When the scissors do not mark the margins: Greñas, University and Dissident Realities". ii) "Artivism: What is it?: Freedom, Feeling-thinking, and Political Position with a soundtrack of counter-power". Through an ethnographic analysis, a journey has been made through the stages of this internationalization process from its beginnings with the elaboration of the proposals, as well as their development and the results obtained from them during and after their execution. Likewise, the feelings, approaches and expectations of the Vargastorrino students are shared.

The Gender Approach as an Opportunity to Achieve Women's Labour Participation in Community Tourism in the Salinas Parish of Guaranda, Ecuador

The trend in recent years in the tourism industry is ecological and sustainable tourism, but the reports of Skyscanner, which has the fastest growing meta-search system in the world, note that tourists every year try to find a more environmentally friendly option from the currently existing ones. So they are interested in the type of tourism that allows them to travel more, but at the same time have the least impact on the surrounding nature, cultural heritage and the local community – sustainable community-based tourism. The objective of this research was to describe Community Tourism as an emergent practice, in order to promote the gender-based approach which acknowledges the existing inequalities and seeks to foster the balanced participation of women and men across all stages of the tourism process. The study drew upon the contributions of Lanfant M. F., Pratt S. and as well as UNWTO materials. Foreign scientists note that community tourism and the gender-based approach not only benefit local socio-economic development, but also cultivate equity and the social empowerment of both genders within communities. In this regard, this study used a mixed-methods, non-experimental methodological approach proposed by Gomez and others, and a descriptive design of ethnographic research with documentation. The findings established that regulatory frameworks governing gender equality in Ecuador remain absent, particularly in rural parishes such as Salinas de Guaranda. In conclusion, it can be asserted that prevailing social roles continue to be perpetuated within labour domains, including the tourism sector, which fails to advance equality for women. Based on the research materials strategies were designed to insert women into the work environment in the Salinas de Guaranda Community and in community tourism activities.

The Ecological Construction Path of English Vocabulary Teaching Based on Markov Chain in the Perspective of Ecological Linguistics

The new curriculum standards have put forward new requirements for high school English vocabulary teaching, and the English vocabulary eco-classroom under the guidance of ecological linguistics theory can precisely make up for the shortcomings in the traditional vocabulary classroom and meet the challenges of the times. However, most of the existing researches on ecological classroom are combined with macro English subjects, and few of them are about English vocabulary teaching. This study takes the principles of ecological linguistics as the theoretical basis to support the conceptual construction and morphological reliance of the vocabulary ecological classroom, supplemented by modal theory as the process orientation of the four major stages in the teaching process, constructs a new vocabulary ecological classroom model based on Markov chain model, and applies the ecological classroom model to high school English vocabulary teaching to verify its teaching effects. The experimental results show that the Markov chain-based high school English vocabulary teaching under the “ecological linguistics” model can help students’ interest in vocabulary learning and promote their vocabulary learning level, accounting for 15% improvement in the learning effect.

Evaluating deep neural networks in optimizing drug discovery and precision medicine: A review

Introduction/Background: Deep neural networks have shown great promise in advancing drug discovery and precision medicine. By leveraging large amounts of complex biomedical and chemical data, deep learning approaches can identify novel targets, predict drug-target and drug-drug interactions, generate new molecular structures, and assist in personalized treatment selection and development. However, fully utilizing deep learning techniques for optimization across the drug development pipeline remains an ongoing challenge. Materials and Methods: A comprehensive literature review was conducted using major bibliographic databases including PubMed, Web of Science, and Scopus. Search terms included combinations of "deep learning", "drug discovery", "precision medicine", "biomedical data", and "neural networks". Over 200 papers published between 2010-2023 related to deep learning applications in pharmacology and genomics were identified and reviewed. Results: Deep learning has been widely applied at various stages of the drug discovery process including target identification/prioritization, lead generation/optimization, and prediction of molecular properties. Convolutional neural networks are commonly used for the representation and classification of biological sequence and image data for tasks such as gene expression analysis and pathogen detection from microscopy images. Graph neural networks effectively model compound structures and interactome networks to predict molecular bindings and disease associations. Multi-modal neural networks integrate diverse data types for personalized treatment response prediction and biomarker discovery. Challenges remain around data and model interpretation, generalization to new targets/diseases, and integration across domains. Discussion: While deep learning has shown promise, rigorous benchmarking and validation on real-world clinical endpoints are still needed to establish usefulness in decision-making. Data and model transparency must be improved to enable scientific insights. Privacy and security risks accompanying "real world" biomedical big data will require ethical practices. Standardization and sharing of resources/protocols could accelerate progress by enabling comparison of techniques. Combining deep learning with other AI paradigms like causal inference may further improve utility in drug discovery and precision healthcare. Conclusion: Deep neural networks demonstrate potential for optimizing drug development and precision medicine applications. Continued advancement relies on addressing challenges around data, models, validation, and ethics. Multi-disciplinary collaborations integrating machine learning, molecular biology, medicine, and other domains are needed to fully realize benefits to patients.

Comparison Between Maintenance of Distribution Substations Using the Mobile Substation Unit (UGB) Method and Maintenance of Blackout Distribution Substations regarding Energy Not Served (ENS) which is not distributed to PLN UP3 Serpong

Electricity has become an important part of human life along with technological developments in this modern era. Economic progress, quality of life and the business world are very dependent on the electricity supply supplied by PT. PLN (Persero) UP3 Serpong. Electric power distribution is the final stage in the electric power delivery process. This is the process of distributing electric power from the electricity transmission system to electricity consumers. One of the main components in the electric power distribution system is the distribution substation. A distribution substation is an electrical installation device which contains disconnecting, connecting, safety and distribution transformer equipment to distribute electrical power according to consumer needs. Maintenance at distribution substations is carried out to support services to electricity consumers so that the substation equipment used is in reliable condition. and guaranteed continuity. Regular maintenance on distribution substations is important so that distribution substations do not experience damage and disruption while operating.

Tracing magmatic footprints: Influence of a CO2-rich melt on the mineral assemblage of the San José del Guaviare Syenite, SE Colombia

A combined optical and electron microscopy (SEM, EDS, and EPMA) study was conducted on ten rock samples from the Proterozoic San José del Guaviare Syenite (SJGS), southeastern Colombia, to utilize minor and trace minerals in interpreting the magmatic evolution of these silica undersaturated rocks. The major minerals of the sampled syenites are nepheline, Fe-rich clinopyroxene, amphibole, alkali feldspar, and biotite. The minor minerals are titanite, calcite, cancrinite, and sodalite. Trace minerals are the niobium- or rare earth element-rich minerals pyrochlore, columbite, euxenite, britholite, ancylite-Ce and wöhlerite. Apatite, rhodochrosite, strontianite, fluorite, zircon, magnetite, ilmenite, and pyrite occur as traces as well. Crystallization started with primary (magmatic) calcite and Nb-rich minerals pyrochlore, columbite, euxenite, and a first generation of apatite, which occur as inclusions in foids, feldspars, and Fe-rich clinopyroxenes. Calcite is enriched in light rare earth elements and Sr, with low Mg concentrations, while primary apatite has high Sr concentrations. Both minerals have a composition typical for minerals crystallized in carbonatites. The presence of calcite and high Fe and low Ti clinopyroxene point to CO2-saturated conditions. During cooling, fluorbritholite-Ce formed as individual grains or by a fluid-enhanced apatite-britholite transformation. The formation of Fe-rich amphibole, often at the expense of Fe-rich clinopyroxene, reveals a decreasing influence of CO2 and temperature. Presumably, the transformation of orthoclase into microcline occurred simultaneously. Perthitic microcline as a second K-feldspar generation indicates slow cooling from high temperatures. A late stage of CO2-rich hydrothermal-metasomatic processes is suggested by the growth of secondary cancrinite, Sr-Mn carbonates and ancylite-Ce. The composition of primary and early crystallized calcite and apatite makes their origin as residues of an early segregated or independently formed mantle-derived carbonatitic melt more likely than crystallization from a CO2-rich syenitic melt. An origin from melted crustal carbonates is unlikely as well. Therefore, the presence of a carbonatitic melt at an early magmatic evolutive stage, as opposed to a non-carbonatitic melt at a late stage, seems possible for the SJGS rocks.

Applications of Machine Learning: Classifying Wheat Seeds through Computer Neural Networks

In the past few decades, the incompetent processes of traditional mechanical seed sorting have given rise to new, innovative methods, along with the integration of smart technology in agriculture. The present study created a multi-classification machine learning model that classifies wheat seeds based on given characteristics by giving highly accurate predictions for future samples based on given data. Due to various uses of different types of seeds, effective sorting is an integral preparatory stage for food processing. The dataset used in the study included seven features (directly measured characteristics of seeds), three labels (types of seeds), and around two hundred examples. The seven features include area, perimeter, compactness, kernel length, kernel width, asymmetry coefficient, and kernel groove. The first model was created through neural networks trained on all seven characteristics, reaching an overall accuracy of 0.94. Implementing a decision tree method, feature selection was applied to the data, which distinguished kernel groove, kernel width, and asymmetry coefficient as the three most important features. A new model was constructed with only the three selected features, which reduced the risk of overfitting, eliminated noise, and yielded a higher accuracy (0.96) than the previous model. Both multi-classification models used the softmax activation function and results were compared; feature selection noticeably reduced any inaccuracies, including categorical cross entropy loss. The main incentive of the study was to develop an effective model to sort wheat seeds (to replace traditional mechanical sorting) and provide reasonable recommendations for practical use through an analysis of feature selection.

Developing methods to identify resilience and improve communication about diagnosis in pediatric primary care

Communication underlies every stage of the diagnostic process. The Dialog Study aims to characterize the pediatric diagnostic journey, focusing on communication as a source of resilience, in order to ultimately develop and test the efficacy of a structured patient-centered communication intervention in improving outpatient diagnostic safety. In this manuscript, we will describe protocols, data collection instruments, methods, analytic approaches, and theoretical frameworks to be used in to characterize the patient journey in the Dialog Study. Our approach to characterization of the patient journey will attend to patient and structural factors, like race and racism, and language and language access, before developing interventions. Our mixed-methods approach is informed by the Systems Engineering Initiative for Patient Safety (SEIPS) 3.0 framework (which describes the sociotechnical system underpinning diagnoses within the broader context of multiple interactions with different care settings over time) and the Safety II framework (which seeks to understand successful and unsuccessful adaptations to ongoing changes in demand and capacity within the healthcare system). We will assess the validity of different methods to detect diagnostic errors along the diagnostic journey. In doing so, we will emphasize the importance of viewing the diagnostic process as the product of communications situated in systems-of-work that are constantly adapting to everyday challenges.

A Surface Defect Detection Method for Cold-rolled Strip Steel Based on Improved YOLOv8

Cold-rolled strip steel has excellent mechanical properties, and it is widely used in the fields such as automotive manufacturing, construction industry, aircraft manufacturing and electronic product manufacturing. However, many different processing defects occur in the manufacturing process of cold-rolled strip steel, and this article proposes a visual detection method based on YOLOv8 to identify the surface defects on cold-rolled strip steel more accurately. Firstly, several common types of defects in cold-rolled strip steel were analyzed. Then, in order to enrich the dataset for subsequent detection, wavelet transform was used for filtering, denoising, and canny edge detection in the image processing stage for obtaining the clearer input model image with the more prominent graphics. Lastly, the CA attention mechanism was added into the YOLOv8 which is useful to improve the features recognition ability of the model, at the same time, the original standard convolution was replaced by DCS convolution and the loss function was optimized which is useful to get the lightweight models. The improved YOLOv8 model was validated on the NEU-DET dataset, the overall detection performance of the model such as the recall, the accuracy, and the average precision has significantly improved.

Quantitative Analysis of the Sloping Terrain on Al-Biruni’s Floor and Implications for the Cratering Process

Surface unloading due to impact cratering results in lava filling the crater floor. Elevation differences in the crater floor, a common geological phenomenon on the Moon, represent direct evidence of cratering processes. However, few studies have been conducted on mare-filled craters on the Moon. Al-Biruni (81 km) is a farside impact crater with an inclined topographic profile on its floor. We quantitatively measure the morphology of Al-Biruni and model the basaltic lava emplacement to depict the cratering process. Differential subsidence due to melt cooling, wall collapse, impact conditions and structural failure were assessed as potential factors influencing the formation of the elevation differences on the floor. The results suggest that pre-impact topography is a plausible cause of the differences in floor elevation within Al-Biruni. Other factors may also play a role in this process, affecting lava flow by altering the topography of the crater floor after the impact. Thus, regardless of whether the lava inside the crater is impact-generated or comes from outside the crater, altering topography at different stages of the cratering process is an essential factor in creating the sloped terrain on the crater floor.

Life Trajectories of the Russophone Speakers in Germany: 30 Years of Observation

This article presents a multifaceted portrait of immigrants to Germany from the post-Soviet states. The article traces the paths of two families over the course almost of a third of a century after immigration, focusing on language use and integration into the new environment. In-depth interviews conducted at various stages of the integration process and age-appropriate tests served as research material. The content, text, and lexical analyses, as well as a linguistic biography method, were used. The research included four generations of Russian Germans and Jews in each family. Russophones in Germany have not had an easy time integrating but, ultimately, have a positive attitude toward their adoptive country. The results show that the German language became the primary means of communication outside the family and partly within the family where Russian dominates among the second and third generations. The oldest generation (great-grandfathers and great-grandmothers) were fluent in German to some extent; those who moved at the age of 20–40 learned it sufficiently for their jobs; their children studied in German preschools and schools and became completely bilingual; and the great-grandchildren were born in Germany. The younger generations have fully integrated into German society, although strong connections with locals exist among the older generations too. Proficiency in the Russian language is still maintained even among the great-grandchildren’s generation, although not to the same extent as among the generation of young parents.

Transesterifikasi In Situ Minyak Biji Pepaya Menggunakan Ko-pelarut Tetrahidrofuran: Pengaruh Waktu Reaksi dan Penggunaan Katalis Natrium Hidroksida

The papaya seed oil is a non-food oil that can be used as raw material for biodiesel. The transesterification process using oil as raw material requires long process stages so it is not efficient. In situ transesterification with a co-solvent is an alternative to overcome this problem. This research aims to obtain optimum conditions for the in situ transesterification reaction of papaya seed oil with THF co-solvent. The research operating conditions included stirring speed 450 rpm, reaction at room temperature, oil:methanol molar ratio = 1:101.39, catalyst:oil molar ratio = 0.5:1, oil:THF molar ratio = 1: 67.85, reaction time are 3, 8, 13, 18, 23, 28 minutes and reactions with and without a NaOH catalyst. The best research conditions were obtained in the in situ transesterification reaction of papaya seed oil with THF co-solvent using a NaOH catalyst at a reaction time of 33 minutes, producing a crude yield of 74.38% and methyl esters concentration of 98,036.4 ppm and physical properties of biodiesel that met SNI 7182-2015, namely density 0.89 g/mL and acid number 0.44 mg KOH/g sample.