bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Affecting the Implementation of Authentic Assessment to Measure Students’ Reading Comprehension: A Case of English Teachers at State Senior High School 1 Purwodadi
Authors: Nugraheni Fitria Wahyu , Saleh Mursid , Hartono Rudi
Published: May 2022

The term of assessment refers to the wide variety of methods or tools that educators use to evaluate or measure students’ learning progress, skill, or acquisition. The benefit of assessment for teachers can be used to gather information on planning and modifying teaching and learning programs for students. This study concerns to the factors affecting the implementation of authentic assessment in reading comprehension. This study was aimed at answering four research questions regarding (1) the implementation of authentic assessment to measure students’ reading comprehension, (2) the correlation between teacher’s background and the implementation of authentic assessment, (3) the correlation between teacher’s professional development and the implementation of authentic assessment, and (4) the correlation between teacher’s belief and the implementation of authentic assessment. The researcher applied quantitative correlation research design. The correlation research design was used since it was appropriate to measure the significant correlation between those two variables. The findings revealed that three teachers as the subject of this research had good effort in implementing authentic assessment. They created various assessment to assess students’ reading comprehension. Based on the observation which has scored, their implementation belongs to good, enough, and fair criteria. The next finding is that based on the SPSS computation, among three factors stated previously, the teacher’s belief is significant correlate to the implementation of authentic assessment, meanwhile teacher’s background and teacher’s professional development are not significant correlate.
Thematic Structure and Thematic Progression in Research Articles Published in Scopus-Indexed International Journals
Authors: Susilowati Endang , Faridi Abdurrachman , Sakhiyya Zulfa
Published: May 2022

Publishing in highly-indexed journals is greatly competitive, thus writing a qualified and eligible text becomes more challenging for a second/foreign language writer of English. A good text should be written logically and organized effectively according to the role of good academic writing. Thematic structure and thematic progression contribute to the development of a well-structured meaningful text. This study examines the use of thematic structure and thematic progression in research articles published in Q1 and Q2 Scopus-indexed international journals as well as their relationship to achieve the texts’ coherence. This is a descriptive qualitative study within the framework of Systemic Functional Linguistics (SFL) that employs discourse analysis. 3426 clauses gathered from ten research articles were analyzed by using Halliday and Matthiessen’s (2014) taxonomy of thematic structure and Eggins’s (2004) theory of thematic progression. This study highlights three major findings. Firstly, in terms of thematic structure, the textual theme is massively used followed by the topical and interpersonal theme. The predominance of the textual theme implies the authors’ ability in developing the logical relations between clauses. Secondly, in terms of the thematic progression, the theme reiteration pattern is frequently employed, followed by the multiple-rheme and the zig-zag pattern. The tremendous use of the theme reiteration indicates the authors’ ability in maintaining the focus of the texts. Thirdly, the relationship between thematic structure and thematic progression constructs logical relations between the clauses to achieve the texts’ coherence. Finally, this study provides some pedagogical implications for the teaching of English as a second/foreign language.
Childrenâ€™s Production of Interlanguage in Speaking English As The Foreign Language
Authors: Kusumaningtyas Yulia Shinta , Rukmini Dwi , Fitriati Sri Wuli
Published: May 2022

Acquiring English as a foreign language and using it as a second language (L2) in early years (children up to six years old) at immersion education happen to some process. In that process, the children tend to use L2 spontaneously and produce interlanguage as stated by Selinker (1977). This study aimed to describe childrenâ€™s production of interlanguage through the features, startegies used by the children in anticipating the influence of native and target language, and the causes. It was a qualitative research of SLA in English-speaking environment. The research subjects were two non-native teachers and fifteen Kindergarten I Integrity students of Bina Bangsa School Semarang. The data were obtained by recording their daily conversation at school for about three months and having interview with the class teachers. The audio and video recordings were transcribed then analyzed based on SLA frameworks proposed by Brown (1973) and Ellis (1985) and interlanguage frameworks drawn on Selinker (1972), Adjemian (1976) and Faerch & Kasper (1983). The interview result were used to get more opinions regarding the interlanguage phenomenon. The results indicated that the students produced interlanguage systematically, permeably, and dynamically. They used strategies of L2 learning and L2 communication to anticipate the influence of their native and target language. Moreover, the students produced interlanguage for some reasons. It was because of language transfer, overgeneralization, and their development of grammatical morphemes, negation, interrogation, and reflexive pronoun in the process of SLA. Language transfer was the main cause of interlanguage happened among the students.
The Correlation of Attitudes, Motivation and English Learning Strategies at Senior High School Level in Indramayu City-Wes Java
Authors: Uju Uju , Rukmini Dwi , Anggani LB Dwi
Published: May 2022

This study focuses on exploring the correlation of attitudes, motivation and  English learning strategies in an attempt to see wether 1) positive attitudes correlate with motivation, 2) negative attitudes correlate with motivation, 3) positive attitudes correlates with English learning strategies, 4) negative attitudes correlate with English learning strtegies, 5) high motivation correlates with English learning strategies and 6) low motivation correlates with English learning strategies which consequently may provide some pedagogical implications for teachers to benefit in classroom applications. A total of 308 sample were involved in this descriptive study. They were the second grade of senior high school in Indramayu city â€“ West Java. The data were obtained through using two questionnaires; AMTB (SPSS. 21) and SILL (SPSS 21). The results of the two questionnires that for the item 1 (Table 2) is about the awareness of the importance of English and the fact that it shows the good and the poor learners are more aware of this. Subsequent items 2-7 (Table 3 and 4) show the good and poor learners are more interested in learning English and expression of desire to learn English. Next, items    8-10, (Table 5) that they show the actual English interest and effort in learning         and improving in an out of the classroom. (the good and poor learnersâ€™ positive attitudes correlate with their motivation). However, the first third items (11, 12, and 14), table 6, that the highest rank, the poor learners responses, (.251 **, .414 **, .357 **, agreements) are items related to the difficulty involved in learning English. Moreover, items 5 to 7 (15, 16, 17) study the poor learners find learning English uninteresting and they really find learning English boring. Finally, the low mean scores for items 10 (20), table 8, show that the poor learners do not think that learning English is a waste of time (the poor learnersâ€™ negative attitudes do not correlative with their motivation). Furthermore, in line with the strategy, the good learners who have high motivation are more greater than the poor learners who have low motivation (Table 15 and 16). It is highly likely influenced by extrinsic motivation.
The Quality of Direct Procedures in Studentsâ€™ Indonesian Translation of English Folklore Drama Scripts
Authors: Abdul Gani Citra Amiliani
Published: May 2022

According to Vinay and Darbelnet (1995), direct translation refers to the transposition of source language message element by element into target language based on either structural parallelism or metalinguistic parallelism. However, both parallelisms are not realized by the student translators so that sometimes they apply inappropriate direct translation. Therefore, this study is aimed to assess the quality of studentsâ€™ direct translation procedures according to Larson (1994) in Indonesian rendering of English folklore drama script. This study employed descriptive qualitative method with the involvement of respondents for quality assessment. The result reveals that 445 direct procedures consisting of 45 borrowing translations, 18 calque translations, and 382 literal translations produce 249 accurate, 64 sufficiently accurate, and 132 less accurate translations. Dealing with clarity, 314 are considered as clear, 71 sufficiently clear, and 60 less clear translations. In addition, the analysis of naturalness results 285 natural, 51 sufficiently natural, 58 less natural, and 51 unnatural translations. The problems derived from studentsâ€™ direct procedures are the use of unacceptable loan word and word by word translation which can create misinterpretation. Therefore, the students should increase their awareness of the structural and metalinguistic parallelisms between source and target language.
Studentsâ€™ Perceptions of Reflective Practices (RP) Implementation to Learn Critical Thinking (CT) in Class Discussions (CD)
Authors: Fatwassani Rezza , Fitriati Sri Wuli , Bharati Dwi Anggani Linggar
Published: May 2022

The present study delivers the twelfth grade studentsâ€™ experiences who implement reflective practice as a technique to learn critical thinking skills when joining the class discussion. However, their perceptions on the above activity have to be a fundamental issue for the success of learning. This descriptive qualitative case study took place at SMA N 2 Masbagik of East Lombok. It aimed to describe and explain studentsâ€™ reflective practice implementation, their critical thinking manifestations, and their perceptions of the reflective practice implementation to learn critical thinking skills in class discussions. Taken from field notes observation and video recordings revealed three stages of reflection process considered by the students when implementing the reflective practice. It consisted of stating positive behaviour, ideas, and feelings (first stage), returning to experience, attending to feelings, and reevaluating experiences/events/phenomena (second stage), and making conclusion or commitment (third stage). They also showed three ways in expressing critical thinking as proposed by Halpern (2003). It consists of verbal reasoning, arguments, and making decision. Furthermore, the data from open-ended questionnaire and interview revealed the domination of positive perceptions. Through this study, the writer opens the idea to give suggestion that this activity should based on clear instructions and theoretical background to meet the teaching and learning goal.
The Implementation of Character Education in the English Teaching Learning Using 2013 Curriculum
Authors: Thoyyibah Naelatut , Hartono Rudi , Anggani L. Bharati Dwi
Published: May 2022

The present study is caused by Juvenile delinquency and the problem of moral deficiency of young generations nowadays. The character building is recently much needed in Indonesian education as a way to overcome those problems because strengthening personal and social of morality is one of the fundamental aims of life and moral education is one of important aspects of education. The Ministry of Education (MOE) of the Republic of Indonesia is implementing its new curriculum named 2013 Curriculum. One of the ultimate goals of this new curriculum is to improve the moral and character of the students. This study was aimed to describe how the teachers implement character education in English teaching learning process at SMP N 1 Kebonagung Demak. The data were obtained by conducting a document study, observations and interviews. The subject of this research were two English teachers in SMP N 1 Kebonagung as purposive sampling who taught in the classroom observed to get the data about implementation of character education in learning process classroom. This study revealed that teachers had implemented some character values in the teaching learning process. The most frequent was religiousness, honesty, discipline, perseverance/hard work, independence, democracy, curiosity, achievement respect, responsibility, communicative competence of character values into their teaching learning process. Moreover, the implementation of character education gives teachers with several advantages and challenges in teaching process.
The Evaluation of Higher Order Thinking Skills in English School Nationally Standardized Examination at State Senior High School 6 Semarang
Authors: Narwianta Nanang , Bharati Dwi Anggani Linggar , Rukmini Dwi
Published: May 2022

The English school nationally standardized examination as a means of the  assessment of the learning outcomes conduct by educational unit is designed to measure the student`s achievement competencies, to determine student`s graduation from the school, it is very significant to conduct test items evaluation since it gives a clear portrait of the quality of the items and the test as a whole. The purpose of this study was to explain the realization of higher order thinking skills reflected in English school nationally standardized examination at state senior high school 6 Semarang academic year of 2018/2019. The researcher adopted the qualitative descriptive approach using an analysis card to analyze the realization of higher order thinking skills in English school nationally standardized examination test items. The results indicated that HOTS realized in listening, reading, and writing questions. The listening in the form of spoken written, because it is to test listening simultaneously with speaking. There is one listening question categorized into HOTS of level analyzing, in reading the questions belonging to HOTS reach 8 questions that consist of 5 questions of analyzing level and 3 questions of evaluating level. Meanwhile, there is one question of HOTS into level of creating in writing questions. The results also showed the proportion of HOTS comprised 22,22% met the requirement from BNSP that stated in academic year 2018/2019 there is approximately 10-15% of higher order thinking skills test items. Accordingly, this finding reveals that there is still much room for the variation of HOTS levels implemented all skills in English school nationally standardized examination. This study recommends modifying the English school nationally standardized examination by providing them with more questions that include HOTS.
ACCURACY, READABILITY AND ACCEPTABILITY IN THE TRANSLATION OF ANDROID XIAOMI REDMI NOTE 4
Authors: Prasetya Irfan Zahid , Hartono Rudi , Yuliasri Issy
Published: May 2022

Android translation(s) were translated by multiple people/agencies during multiple period of times, thus they are very prone to accuracy, readability and acceptability errors. Based on that reason, I conducted this research to (1) analyze and find out the accuracy of the translation in Xiaomi Redmi Note 4 smartphone, (2) readability of the translation of the smartphone, and (3) the acceptability of the translation. The result of this study showed that all of the accuracy, readability and acceptability of the original translation showed worse results than the modified translation. For accuracy, Goff-Kfouriâ€™s and Nababanâ€™s rubric both showed better result for the modified translation. For readability by the translators, the average of original translation got 2.3 (negative) and modified got 3.8 (positive); whereas the end-users rated 2.4 (negative) and 3.8 (positive) respectively. For acceptability, the average of original translation by the translators was rated 2.6 (negative) and the modified translation got 3.7 (barely positive); and by the end users, the rates were 2.7 (negative) and 3.7 (positive).
The Ideological Construction of The 2015 Paris Attacks in The Jakarta Post
Authors: Nurzakiyah Nafisah , Mujiyanto Januarius , Sutopo Djoko
Published: May 2022

The terrorist attacks makes the global phenomenon in the world as the radical action by terrorist group. Therefore, this study wants to find out the ideological constuction of the 2015 Paris attacks in the Jakarta Post. The writer analyzed the data by using Critical Discourse Analysis which is proposed by van Dijk. This theory known as socio-cognitive approach which analyzes the object of the study into three levels: text, socio-cognitive, and societal analysis. The expected of the study, the writer applies the qualitative method to observe the study. The finding of this study revealed that The Jakarta Post emphasizes the bomber in Paris is claimed by Islamic group or ISIS. The writer found that ISIS in Paris attacks is depicted as violent group. Therefore, the people around the world cares about this case. From the findings, it was true that the power or dominant group can influence the text to spread the ideology to the society.
The Implementation of Scaffolding Technique in Teaching English to The Students of High Schools in Semarang â€“A Case Of High School English Teachers in Semarang
Authors: Hayati Nesti Noor , Sutopo Djoko , Faridi Abdurrachman
Published: May 2022

The use of appropriate teaching technique to teach English in senior high schools in the context of EFL determines the quality of the studentsâ€™ achievement because the success of their efforts to reach the learning goals cannot be separated from teacherâ€™s role in assisting the process of learning.The research was conducted to describe the implementation of scaffolding technique in 6 senior high school in Semarang and to analyze the obstacles and factors underlying found in the process of the implementation used in the classroom by applying Deweriankaâ€™s scaffolding model.The data were taken from classroom interactions of 6 teachers in 6 public senior high schools in Semarang. The research subjects were 6 English teachers and 10th grade students in 6 different public schools. There were four stages of scaffolding technique suggested by Dewerianka, they were building the field, modeling, joint construction, and independent construction. The result shows that the implementation of scaffolding technique contributes to the studentsâ€™ ability. It was seen on (a) the students were able to produce the text depending on the purpose, social contexts, and medium in oral or written forms and (b) the teacher gave the contribution during individual work and reduced the contribution during pair work or group work. The strengths of the scaffolding technique in teaching English for 10th grade students are (a) to build the character of the students, and (b) to measure the ability of the students when producing the texts. Meanwhile, the obstacles were: (a) the differences of characters and ability among students, (b) limited time allotment for English class, and (c) school facility. This research will be beneficial as the source of information and reference related to the English teaching in EFL context.
The Alignment of and Gaps between the Needs Analysis, the 2013 Curriculum and Classroom Practice of CLT Approach
Authors: Kusumawardani Anisa Dian , Faridi Abdurrachman
Published: May 2022

In designing and evaluating a curriculum, need analysis is the prior action so that it can accommodate studentsâ€™ need and the result is not disappointing. The dissatisfaction toward graduate students from vocational high school who most of them do not have adequate English skill to work can be assumed that the curriculum as well as the learning process do not consider the studentsâ€™ needs. This study aimed to investigate the vocational high school studentsâ€™ needs and its alignment of and gap toward the 2013 Curriculum and the practice of CLT approach. This research is qualitative descriptive research which was conducted at SMK Negeri 1 Semarang toward the students and the teacher. The data were collected by using questionnaire, observation checklist, document analysis guideline and interviews.The result of this study shows the studentsâ€™ opinion, demand, and reflection toward the English learning process. Meanwhile on the investigation of the teaching learning, it is found that the implementation of the 2013 Curriculum more or less has been accordance with the regulation, on the contrary the CLT approach had not been applied well. The alignments of the needs analysis, the curriculum and the CLT approach lay on the sufficient time allotment of the English subject, the learning activity, promoting active learning, and promoting English usage during the learning process. Meanwhile the gaps between the needs analysis, the curriculum and the CLT approach occur in the lack of productive skill practice, authentic learning media, and the discipline-related learning material.
The The Interpersonal Meaning in Trumpâ€™s Victory Speech
Authors: Savitri Andini Syita , Warsono Warsono
Published: May 2022

This study deals with analyzing language used for communication. It analyzes a victory speech by Donald Trump as the newest president of America from the perspective of SFL especially dealing with the Tenor of the discourse of the speech. In other words, this study is about interpersonal meaning of the speech which can be used to dig up speakerâ€™s attitudes towards what s/he is saying in the speech. In conducting this study, I had two objectives to achieve. First, this study tried to understand the interpersonal meaning of Donald Trumpâ€™s victory speech by looking deeply on the Mood system of the clauses of the speech which means analyzing the two constituents of Mood which are Subjects and Finites of the clauses in the speech. Second, it also tried to uncover Donald Trumpâ€™s attitudes towards Americans by applying the Appraisal theory proposed by Martin. Appraisal offers  an ideal analytical framework to systematically  identify  interpersonal  meanings  in  language.  The result of analysis showed that the most subject found in the speech was I â€“ Donald Trump which meant that Trump himself was responsible to what he was saying in the speech. The Finites in the speech were mostly stated in Simple Present Tense which was meant that in delivering his speech, Trump gave the general truth at the moment of the speaking. Since most of the clauses were declarative clauses, Trump was considered to share information in this case he share his vision and mission for future America to the audience. That shared information was further analyzed with the Appraisal theory which led to the conclusion that Trump gave positive attitudes towards Americans. Based on this study, finally we come to an understanding that itâ€™s important to understand any kinds of speech well. One among ways to do it is by analyzing that speech through its interpersonal meaning and its appraisal system. This study is useful for readers, especially English Department students in order to be able to understand the meaning behind a text well.
The Realization of Interpersonal Meaning in the Report Text of the Undergraduate Students of Universitas Batanghari Jambi
Authors: Vrika Renggi , Mujiyanto Januarius , Suwandi Suwandi
Published: May 2022

In interpersonal meaning, language is used to see the relationship between the speaker/writer with the listener/reader. Using interpersonal meaning to analyze written text is useful to see how the writer gives information and suggestion to the reader. This study investigated the interpersonal meaning realizing in the report text that is 354 clauses from 20 texts written by the undergraduate students. It used the framework from the Systemic Functional Linguistics by Eggins (2004) and Halliday and Matthiessen (2014). This research is qualitative case study research because it focuses on the analysis or interpretation of the written material. It analyzes mood system, modality system, speech function and studentsâ€™ mastery in writing report text. From the analysis, it found that mostly declarative mood realized in the report text, it is 334 clauses and it is categorized as statement in the speech function. In the modality system, the most type realized in the text is modalization type, it is 38 clauses. By analyzing report text using interpersonal meaning, it was found the studentsâ€™ mastery in the writing skill. The are only some students did mistakes in writing some clauses. Therefore using interpersonal meaning to analyze text help to know the mastery of the students in writing and also can improve their skill. It can be said that interpersonal meaning also realize in the report text. The realization can be seen from the types of mood, modality and speech function that were found in the report text.
The Inclusion of Ideology in Jokowiâ€™s Speech Viewed from the Perspective of Appraisal Theory
Authors: Listiani Gisty , Rukmini Dwi , Widhiyanto Widhiyanto
Published: May 2022

Ideology is a belief towards a particular idea which is commonsensical as it is required by the society as the answer of particular issues. In common practices, ideology might become considerable since it is realised through the use of words that are meaningful and powerful. One language feature that can be used to convey ideology is appraisal resources. This research aimed to describe the inclusion of ideology viewed from the perspective of appraisal theory. It employed descriptive qualitative approach. The object of the study is a speech text performed by Jokowi in the World Economic Forum of Asean 2018. The results of the study depicted that there were seven ideology strategies that had been implemented viewed from the attitude appraisal analysis. The seven ideologies were implication, consensus, hyperbole, pre-supposition, national self glorification, lexicalization, and irony. Besides, the ideology inclusion in Jokowiâ€™s speech viewed from the perspective of engagement appraisal pointed that there were six ideology strategies that were implemented by the speaker. They are implication, evidentially, pre-supposition, national self glorification, hyperbole, vagueness, and consensus. In addition, the inclusion of ideology in Jokowiâ€™s speech viewed from the perspective of graduation appraisal conveyed that there were four ideologies applied in the speech, they were implication, hyperbole, national self glorification, and number game. By taking account of the results, this study is expected to escalate the quality of English teaching and learning dealing with words understanding beyond the meaning.
The The Effectiveness of Brainstorming and Mind Mapping to Teach Writing Narrative Text for Students with Extrovert and Introvert Personalities
Authors: Yuliani Widya , Anggani Linggar Bharati Dwi , Warsono Warsono
Published: May 2022

Teaching English in SMA is teaching and learning a foreign language as a part of national education. Moreover, modern teaching technique should be developed to encompass the reality. This study aimed to measuring the effectiveness of brainstorming and mind mapping to teach writing narrative text with extrovert and introvert personalities. This research used 2x2 factorial experimental designs. The subjects were the students of class XI IPA 1 and XI IPA 2 of SMAN 2 Tegal. It was divided into two groups, they were extrovert and introvert personality. The instruments were used test, questionnaire, pre-test, and post-test. The finding of this research indicates that brainstorming technique was more effective than mind mapping technique to students with extrovert personality. While there was no significant difference between a student who was taught by using brainstorming technique and those taught by using mind mapping technique with introvert personality. It means that brainstorming technique is more effective to the students with extrovert personality, while mind mapping technique is effective to the students with introvert personality. Based on our findings, we conclude that both brainstorming technique and mind mapping technique can help and improve the students in writing skill for both students with extrovert and introvert personality.
EKSISTENSI ISLAM ABOGE DI TENGAH PERUBAHAN SOSIAL DI DESA KRACAK KECAMATAN AJIBARANG KABUPATEN BANYUMAS
Authors: Mutia April Griya , Ginanjar Asep
Published: May 2022

Islam Aboge merupakan aliran keagamaan yang menggabungkan antara unsur kebudayaan Jawa dengan Islam, yaitu dalam hal penentuan tanggal (kalender). Tujuan dari penelitian ini adalah (1) mengetahui ajaran Islam Aboge; (2) mengetahui perubahan nilai yang terjadi di masyarakat Islam Aboge; (3) strategi dalam pelestarian ajaran Islam Aboge di tengah perubahan sosial di Desa Kracak. Penelitian ini menggunakan menggunakan metode kualitatif dengan teknik pengumpulan data menggunakan observasi, wawancara, dan dokumentasi. Hasil penelitian ini menunjukkan bahwa (1) Ajaran Islam Aboge seperti aqidah dan ibadah tidak ada perbedaan dengan Islam pada umumnya. Perbedaan hanya pada kalender yang digunakan seperti Aboge menggunakan kalender Jawa sedangkan Islam pada umumnya kalender Hijriyah, (2) perubahan nilai yang terjadi pada masyarakat Aboge seperti pada perubahan dalam perayaan tradisi dan perubahan jumlah pengikut yang sekarang jumlahnya tidak sebanyak dahulu, (3) strategi yang dilakukan untuk menjaga tradisi Aboge antara lain tetap menjaga solidaritas sesama warga Aboge, proses regenerasi pengajaran ajaran Aboge yang diajarkan secara turun temurun, dan identitas sebagai orang Aboge sudah tertanam kuat di dalam jiwa masyarakat Aboge.

Aboge Islam is a religious belief that combines elements of Javanese culture with Islam in terms of determining the date (calendar. The aims of this research are (1) to find out the main points of Aboge Islamic belief; (2) to know the changes in values that occur in the Aboge Islamic community; (3) a strategy in preserving the values of Aboge Islamic belief in the midst of social change in Kracak. The method used in this research was a qualitative method with data collection techniques by using observation, interviews, and documentation.The results of this research indicate that (1) the basic belief of Aboge Islam such as aqidah and worship are not different from Islam in general. The difference is only in the calendar used, such as Aboge using the Javanese calendar, then Islam generally uses the Hijri calendar; (2) changes in values that occur in the Aboge community, such as changes in traditional celebrations and changes in the number of adherents who are now not as numerous as before; (3) the strategies taken to maintain the Aboge tradition include maintaining solidarity and the process of regenerating Aboge Islam belief which are transmitted from generation to generation, and identity as Aboge people has been deeply embedded in each person, so it is usually rare that they will not change their belief at any time.
Fiber morphology in walnut branchwood: Relation to the branch diameter, branching level, and tension wood
Authors: Guo Pingping , Zhao Xiping , Liu Ziyu , Peng Haixin
Published: May 2022

The branchwood of fruit trees is being promoted to supplement the fiber material for paper manufacturing in China. This study was conducted to investigate the fiber morphology of walnut branchwood, and to highlight its potential utilizations in papermaking. The effects of the branch diameter, branching level, and tension wood on the fiber morphology were also investigated. The results showed that approximately 65% of the fibers were longer than 900 µm, 95% of the fibers had a slenderness ratio greater than 40, and 67% of the fibers had a Runkel ratio less than 1. It is evident from the results that the fiber morphology of walnut branchwood is reasonably good for paper manufacturing. However, the diameter of the branch does not provide reliable information to predict the fiber morphometrics. In addition, the branching level and tension wood are not very helpful in the screening of fiber raw materials.
Age and Geochemical Characteristics of Nansu Rapakivi Granite in Jiaobei Uplift Belt, Qingdao
Authors: Qiao Feng , Rongtian Sheng , Xuewei Li , Ruiwen Dai , Yong Jiang
Published: May 2022

LA-ICP-MS zircon U-Pb geochronology from Nansu large Rapakivi granite in the Jiaobei uplift belt shows the concordant age is 116.5±0.32Ma and the weighted average age is 116.7±0.89Ma, belonging to the late Yanshanian products of Early Cretaceous. The rock geochemical characteristics show that the SiO2 content of rapakivi granite ranges from 70.30% to 71.65%, with an average of 70.975%, A / CNK is 0.871 ~ 0.895 (average 0.883). K2O content is 4.70 ~ 5.75%, with an average of 5.14%, which is characterized by high potassium. Regarding trace elemental patterns, all the studied samples are enriched in large一ion-lithophile elements, e.g., K and Rb, and depleted in high-field-strength elements, e.g., Nb, Ta, and Ti. In terms of the chondrite-normalized rare earth element patterns, the Nansu samples are characterized by the strong enrichment of light rare earth elements (LREE) compared with heavy rare earth elements (HREE) and the absence of negative Eu anomalies. The Nansu ring porphyry granite is of high Sr and low Yb type, belonging to type I adakite, and formed in a high-pressure medium high-temperature environment of about 23km at depth and about 670oC. It is speculated that it was formed in the island arc environment and is related to the subduction of the Mesozoic Pacific plate.
Producción de monooleato de sorbitol
Authors: Sánchez C. Francisco J. , Galindo V. Hugo M. , Cerón G. Alejandro
Published: May 2022

La producción de monooleato de sorbitol se estudia a nivel de laboratorio y de banco por interesterificación. Este trabajo incluye dos reacciones: la esterificación de ácido oléico con metanol y la interesterificación del oleato de metilo con sorbitol. La mezcla de reacción para los dos niveles y las dos reacciones se muestran con el fin de establecer las expresiones cinéticas. Los datos y resultados obtenidos, a nivel de laboratorio, sirvieron de base para el diseño, construcción y montaje de una unidad de reacción a escala de banco, que representa un gran aporte para la dotación de infraestructura de los laboratorios de ingeniería química.
Perspectivas para la producción de alquilato
Authors: Sánchez C. Francisco J. , Oviedo Alfredo
Published: May 2022

Para disminuir la polución causada por la combustión de las gasolinas en automotores, se requiere la producción de gasolinas reformuladas en el país. Esto implica eliminar algunos componentes de las gasolinas corrientes e incorporar alquilato, isómeros y compuestos oxigenados, para mantener el número de octano y favorecer una combustión limpia. El proceso de alquilación actual emplea catalizadores ácidos líquidos como el H2SO4, HF y H3PO4, que presentan problemas en la salud de los operarios, son altamente corrosivos y causan contaminación ambiental por su disposición final. Actualmente, la investigación se orienta a encontrar procesos heterogéneos con catalizadores ácidos sólidos, eficientes, que eviten los problemas anteriores.
Tópicos sobre optimización de algoritmos
Authors: Giraldo Echeverry Gloria Inés
Published: May 2022

El presente artículo pretende ilustrar cómo, en el desarrollo de sofware, un primer algoritmo que se construya en la solución de un problema puede mejorarse muchísimo analizando dónde se gasta su tiempo.
Introducción a los microcontroladores RISC. -PICs de microchips-
Authors: Flórez C. Tito
Published: May 2022

Los microcontroladores han prestado una gran ayuda en muchos campos, de los cuales uno de los más conocidos es el control. Iniciarse en el campo de los microcontroladores requiere normalmente dedicarle una enorme cantidad de tiempo, debido, entre otros, a la facilidad de perderse en el mar de información contenida en sus manuales.
Debido a la gran similitud que poseen los PIC con respecto a su arquitectura, conjunto de instrucciones y programación, se toma el PIC16C84 como un buen prototipo de microcontrolador, y se da la información más importante (con sus respectivos ejemplos), para poder ubicarse correctamente en el manejo de éstos.
Análisis de sistemas de potencia con Matlab
Authors: Parra Estrella , Díaz Hernando , Romero Andrei , Guerra Aldemar
Published: May 2022

En este trabajo se presenta una caja de herramientas para el análisis de sistemas de potencia utilizando MATLAB. Las herramientas desarrolladas permiten realizar análisis de flujo de carga, de cortocircuito, tanto balanceados como desbalanceados y simular el comportamiento dinámico de un sistema de potencia durante una perturbación grande. Para esta última aplicación se consideran modelos simples o complejos para las máquinas sincrónicas, lo cual permite analizar sistemas reales. Además, se describen algunas técnicas para adecuar los métodos de solución a las características del MATLAB.
Estudio de tolerancia de daño de uniones soldadas de acero ASTM A36
Authors: Cepeda Luis E. , Hernández A. Héctor
Published: May 2022

La tolerancia de daño en una soldadura, evaluada como un tamaño de grieta admisible, depende de la combinación de las propiedades mecánicas de tenacidad de fractura y resistencia de la correspondiente zona metalúrgica de estudio. Para unas condiciones dadas de trabajo, la tolerancia de daño aumenta con el incremento de la tenacidad de fractura en el caso que el modo de falla sea por fractura, o con el aumento de la resistencia al flujo plástico, en el caso que la falla sea por colapso plástico. La falla por colapso plástico se ve favorecida por una tenacidad de fractura alta, una resistencia baja y un espesor de soldadura pequeño.
Para los procesos y condiciones de soldadura empleados en este trabajo, se encuentra que a temperatura ambiente la zona de fusión y la zona afectada por el calor presentan mayor tenacidad de fractura que el metal base sin una variación sensible de la resistencia, lo cual se traduce en una tolerancia de daño mayor en esas zonas. En la región de la temperatura de transición para el proceso de arco manual, la tenacidad de fractura de la zona de fusión y de la zona afectada por el calor es mayor que la tenacidad de fractura del metal base, mientras que para el proceso de arco sumergido sucede lo contrario.
Incidencia de la biotecnología en el desarrollo académico de la Ingeniería Química en Colombia
Authors: Castellanos Oscar Fernando , Rueda María Angélica , Ramírez Julio César
Published: May 2022

En Colombia, la Biotecnología, durante los últimos años, se ha desarrollado de manera acelerada, particularmente en su aspecto fundamental y teórico. En el mercado nacional existen productos de consumo obtenidos con ayuda de los avances de la biotecnología industrial, la cual, para su implementación, ha tenido que recurrir a las tecnologías importadas y de transferencia. Así, entre las investigaciones teóricas en biotecnología y la aplicabilidad de sus resultados en procesos de producción en nuestro país generalmente no ha existido una relación directa. Actualmente, las necesidades de progreso científico y tecnológico exigen la interacción armónica de los diferentes aspectos de la biotecnología. Para ello, es indispensable la formación de profesionales, capaces de aplicar conceptos de ingeniería en los procesos desarrollados en laboratorios biotecnológicos. Como ya lo han hecho otros países con más adelanto científico y económico, en las universidades colombianas es hora de reforzar considerablemente la línea de profundización en ingeniería bioquímica de los programas de Ingeniería Química en los diferentes niveles de pre y postgrado. Esta profundización permitirá significativamente acortar distancias entre las diferentes áreas de la biotecnología y su aplicación industrial.
Estudio de las propiedades mecánicas del sistema óseo (Segunda parte)
Authors: Mendoza Álvaro
Published: May 2022

Los estudios se hicieron bajo la supervisión del área de Biomecánica. Los ensayos dieron a conocer los valores reales de los esfuerzos mecánicos que es capaz de resistir el tejido óseo. Se elaboraron curvas de esfuerzo-deformación, con la ayuda de deformímetros mecánicos y rosetas de deformación, encontrándose las diferentes propiedades mecánicas y dando una base sólida para estudios posteriores en el área, que ayuden aún más al desarrollo de la bioingeniería en Colombia.
Presente y futuro de la microelectrónica
Authors: Cortés Luis Alejandro
Published: May 2022

La microelectrónica y los microsistemas, así como sus tecnologías asociadas, han tenido un crecimiento tan vertiginoso en los últimos años, que hoy se reconocen como uno de los elementos clave en el desarrollo de nuevos productos electrónicos y no electrónicos. Así la revolución de la microelectrónica es visible en áreas como telecomunicaciones, computadores, robótica, electrónica médica, instrumentación, electrónica industrial, aplicaciones automotrices, industria militar, y muchas otras más. El progreso en aspectos de la microelectrónica, tales como dispositivos físicos, fabricación, diseño de circuitos y desarrollo de sistemas, ha permitido que el campo de acción actualmente sea muy extenso.
Análisis teórico de la influencia del régimen de mezclado para la producción de acetato de etilo
Authors: Martínez C. Hugo Alexander , Carballo S. Luis M.
Published: May 2022

Se efectúa un análisis teórico a la reacción de esterificación entre ácido acético y etanol tendiente a conocer la conveniencia de operar en modo de CSTR (reactor de mezcla total ideal) o PFTR (reactor de flujo pistón), para un conjunto dado de parámetros fisicoquímicos y cinética de esterificación de seudoprimer orden.
Programando en assembler a los microcontroladores RISC. PIC de microchips
Authors: Flórez C. Tito
Published: May 2022

Programar en assembler a los PIC se hace relativamente sencillo, cuando se minimiza el número de instrucciones a unas pocas (14 para el PIC16C84). El funcionamiento de esas instrucciones se explica mediante ejemplos sencillos, y el funcionamiento del programa en conjunto se explica con un programa ejemplo. De igual forma se explica la forma como debe de ser quemado el PIC.
Contador asincrónico de cuatro bits
Authors: Jaramillo J. Iván , Cortés Luis Alejandro
Published: May 2022

Este artículo describe el diseño e implementación del contador asincrónico de cuatro bits, realizado a partir de experiencias académicas en la Universidad Nacional de Colombia. Primero se menciona la estructura del contador, al igual que la caracterización de las celdas básicas (con base en las cuales se hizo este proyecto), y se muestran los resultados de la simulación eléctrica. Después, se describen las pruebas efectuadas al chip, y se hace una comparación entre estos datos experimentales y los obtenidos en la simulación.
Evaluación de tres tipos de empaque (bolsas de polietileno) para almacenamiento de guayaba manzana (Psidium guajava var., Klom sali)
Authors: Ardila Núñez Luis Román , Parra Coronado Alfonso
Published: May 2022

La Universidad Nacional de Colombia, a través del Departamento de Ingeniería Agrícola de Santafé de Bogotá, ha venido adelantando investigación sobre manejo postcosecha de productos hortofrutícolas, con miras a minimizar las pérdidas de estos productos y a conservar su calidad. En el presente artículo se muestran los resultados obtenidos de comportamiento del fruto guayaba manzana (Psidium guajava var. Klom Sali), al ser almacenado en frío con bolsas de polietileno de baja densidad de tres tipos: abierto, perforado y cerrado, a una temperatura de 10°C y humedad relativa de 95%. Se compararon los resultados durante los días del almacenamiento, tomando como base los índices de madurez del fruto, tales como la pérdida de peso, la intensidad respiratoria, la firmeza, el contenido de ácidos, el contenido de sólidos solubles y el pH. Además, se tomaron datos del almacenamiento de este fruto en bolsas abiertas del mismo tipo, en condiciones ambiente (temperatura 20,1°C y humedad relativa de 50,3%), lo cual se utilizó como testigo. De esta investigación se concluyó que la mejor condición de almacenamiento es en frío con bolsa cerrada, pues el producto conserva mejor su calidad que en los otros dos tipos de empaques evaluados.
Reducción de pérdidas mediante el diseño de un empaque para la comercialización del lulo - (solanum quitoense lam.)
Authors: Muñoz Juan Carlos , Puentes Álvaro , Villamizar C. Fanny
Published: May 2022

Con el fin de prevenir las altas pérdidas postcosecha, así como prevenir la disminución de su calidad y mejorar las condiciones de manejo postcosecha del lulo, se diseñó y evaluó un empaque, haciendo un análisis sobre el costo/beneficio entre el sistema tradicional utilizado por los agricultores (el guacal) y el sistema mejorado, mediante el uso del nuevo empaque. Con base en las características físicas obtenidas para el producto y el análisis de las desventajas presentadas en el guacal tradicional, se escogieron como parámetros de diseño: a) la prevención de daño mecánico, b) la ventilación del empaque, c) la reducción del manipuleo de la fruta, posterior al empaque.
Anterior a la evaluación del empaque diseñado, se realizaron operaciones previas de limpieza, selección y clasificación, y una única utilización del empaque, desde la cosecha hasta la venta final, durante el transporte y la comercialización. La fruta clasificada y acomodada con separadores de espuma de bajo calibre se transportó en la finca a lomo de mula, como los guacales tradicionales, y luego en viaje, en el mismo camión con la carga común, desde Isnos (Huila), hasta Bogotá, durante 14 horas de viaje.
Se evaluó la calidad del producto en el empaque diseñado, a los 3, 11 y 14 días de cosechada la fruta, la cual fue almacenada a una temperatura de 17°C y HR del 70%.
De los resultados de la investigación "Evaluación de pérdidas postcosecha del lulo comercializado en un empaque tradicional" se determinaron las desventajas en el manejo del lulo en el guacal tradicional, se aplicaron los correctivos, diseñando un empaque cuyas características fueron: sistema de empaque mixto, de estructura de madera y cajas de cartón corrugado para dos capas de producto que una vez llenas pueden cerrarse hasta su destino final, sin necesidad de reenvasado. La estructura de madera es desarmable y su retorno hasta el cultivo disminuye el volumen y el costo de transporte y empaque. La calidad del lulo evaluado fue muy buena, presentando un porcentaje de calidad de 99,2% a los 3 días de cosecha y de 86,8% a los 11 días. Se produjo una maduración uniforme en el producto, acorde con la clasificación previa de la fruta y la adecuada composición de la atmósfera interna. Se logró una mayor relación beneficio/costo (2,01), frente al empaque tradicional (1,4) y una buena aceptación entre los agricultores.
Propuesta de metodología para el desarrollo de modelos de labranza Parte II. Índices de caracterización fisicomecánica del suelo y desarrollo de un modelo de labranza
Authors: Lozano Osorno Fernando , Castillo Herrán Bernardo
Published: May 2022

Se presentó una propuesta para la elaboración de modelos de labranza que permite tomar decisiones sobre sistemas de preparación de suelos (incluyendo la opción de cero labranza) a partir de mediciones de la condición de éstos. Luego de seguir un plan de muestreo de diversos parámetros fisicomecánicos del suelo y de un proceso estadístico de correlación, se eligieron como variables representativas: la densidad aparente, el índice de cono, el contenido de humedad y la cohesión (caja de torsión, prueba in situ); tales parámetros no solo están bien relacionados entre sí, sino que además hacen posible estimar adecuadamente otras variables de interés como la porosidad total, la macroporosidad, la conductividad hidráulica y en general la resistencia del suelo, lo cual hace viable elegir métodos de remoción del suelo en función del estado inicial del mismo. En el caso probado se pudo verificar la posibilidad de establecer sistemas de reducción de labranza.