ISTRAŽIVANJE MOGUĆNOSTI OPLEMENJIVANJA KROMITNE RUDE S RAZLIČITIM GRAVITACIJSKIM KONCENTRATORIMA

The rapid development of industry increases the demand and importance of chromium. In this study, beneficiation possibilities of the representative chromite ore taken from the Tokat Province with a laboratory type jig, spiral concentrator, shaking table and multi gravity separator (MGS) were investigated. Appropriate particle size fractions were fed into each beneficiation device. Experimental studies were shown as a flow chart. The shaking table gave the best results for chromite beneficiation and a concentrate of 47.02% Cr2O3 grade and 94.29% recovery were obtained by using a -0.3+0.106 mm particle size fraction. It was observed that concentrates with saleable grade could be obtained as a result of the beneficiation of chromite ore with a spiral concentrator. The tailings obtained from the jig, spiral concentrator and shaking table were blended and scavenger experiments were carried out with an MGS to recover the remaining chromite in the tailings. 93.55% of the chromite in this blended sample was recovered with a grade of 34.96% Cr2O3. Hence, MGS seems to be the promising equipment for the beneficiation of tailings.Brzi razvoj industrije povećava potražnju i važnost kroma. U ovoj studiji istražene su mogućnosti oplemenjivanja kromitne rude iz provincije Tokat s laboratorijskim tipom plakalice, spiralnim koncentratorom (žlijebom), koncentracijskim stolom i više gravitacijskim separatorom (MGS -Multi gravity separator). Kao ulazni materijal svakog uređaja za oplemenjivanje korištene su frakcije odgovarajuće veličine čestica. Eksperimentalne studije prikazane su dijagramom toka. Najbolji rezultati postignuti su oplemenjivanjem kromitne rude na koncentracijskom stolu, pri čemu je preradom materijala granulacije -0.3+0.106 mm ostvarena kvaliteta koncentrata od 47,02% Cr2O3 uz iskorištenje od 94,29%. Rezultati ispitivanja također pokazuju da se oplemenjivanjem kromitne rude u spiralnom žlijebu može proizvesti koncentrat kvalitete koja omogućuje njegovu prodaju. Jalovina dobivena oplemenjivanjem u plakalici, spiralnom koncentratoru i na koncentracijskom stolu pomiješana je i zatim su s tom jalovinskom smjesom provedeni testovi u MGS-u kako bi se iz nje izdvojio preostali kromit. Iz tog miješanog uzorka izdvojeno je 93,55% kromita s udjelom Cr2O3 od 34,96%. Stoga se čini da je MGS obećavajuća oprema za oplemenjivanje jalovine

Comparison of Knuth Morris Pratt and Boyer Moore algorithms for a web-based dictionary of computer terms

Computer students need a dictionary of computer terms to deepen lectures. In developing dictionary applications, the term computer will choose the fastest and most efficient memory algorithm. The comparison algorithm is Knuth Morris Pratt (KMP) and Boyer Moore (BM) algorithm. Based on previous research, the KMP algorithm has a better performance compared to other string matching algorithms. However, other studies have concluded that the BM algorithm has better performance. Besides, the Zhu-Takaoka algorithm is more efficient than the KMP algorithm in dictionary development. The BM algorithm has the same search concept as the Zhu-Takaoka algorithm. The determination of the fastest and most efficient algorithm in this study uses the Exponential Comparison Method (ECM). ECM sets criteria for when searching and using the memory in the search process. The results of the comparison of the KMP and BM algorithm are the search time for the BM algorithm is 37.9%, and the KMP algorithm is 62.1%. The results of the use of search memory for the KMP algorithm are 50.6%, and the BM algorithm is 49.4%. The total ECM score shows that the BM algorithm is 0.55% better than the KMP algorithm

Water absorptıon, thıckness swellıng and mechanıcal propertıes of cement bonded wood composıte treated wıth water repellent

In this study, the purpose was to improve outdoor performance of cement bonded wood composite due to their biodegradation and sensitivity to moisture especially in warm and humid climates. Cement bonded wood composites were treated with different concentrations (10 %, 25 %, 50 %, 75 % and 100 %) of water repellent. Water repellent used was an organo-silicon based, nano-sized, eco-friendly, water-based agents. Dipping and pressure systems were applied for composite treatment. Water absorption, thickness swelling, accelerated weathering, color changes and mechanical properties after accelerated weathering were determined for treated and untreated cement-bonded composites. Results showed that treatment of composites with water repellent provided a transparent layer on composite surface. Thus, lower water absorption and thickness swelling results in the beginning of immersion in water. Treated and untreated composites were exposed to an accelerated weathering test for 350 h. Their mechanical strength including modulus of rupture, modulus of elasticity and internal bonding properties were decreased after 350 h of weathering. However, overall results after weathering test showed that all panels’ mechanical properties provided minimum modulus of rupture, modulus of elasticity and internal bonding requirements of the EN standards

Artificial Image Tampering Distorts Spatial Distribution of Texture Landmarks and Quality Characteristics

Advances in AI based computer vision has led to a significant growth in synthetic image generation and artificial image tampering with serious implications for unethical exploitations that undermine person identification and could make render AI predictions less explainable.Morphing, Deepfake and other artificial generation of face photographs undermine the reliability of face biometrics authentication using different electronic ID documents.Morphed face photographs on e-passports can fool automated border control systems and human guards.This paper extends our previous work on using the persistent homology (PH) of texture landmarks to detect morphing attacks.We demonstrate that artificial image tampering distorts the spatial distribution of texture landmarks (i.e. their PH) as well as that of a set of image quality characteristics.We shall demonstrate that the tamper caused distortion of these two slim feature vectors provide significant potentials for building explainable (Handcrafted) tamper detectors with low error rates and suitable for implementation on constrained devices.Comment: 6 pages, 7 figures, 3 table

EXPLORING INDONESIAN EFL STUDENTS' EXPERIENCE IN VLOGGING FOR SPEAKING PRACTICE

ABSTRACTResearch on the use of digital technology in English-speaking practice has been widely acknowledged in the literature, including empirical studies on the use of vlogging as a mediated instruction in teaching speaking skills. This study aimed to investigate Indonesian EFL students' experiences when conducting a food vlog learning project in English-speaking practices. Fifty students in the Education Department at the State University of Makassar, Indonesia, took part in this study. In their English classes, they worked on the food vlog as a project-based learning (PBL) activity. Random sampling was used to choose five people from each of the five groups of ten people, and they agreed to take part in a semi-structured interview. A thematic analysis was used to look at the qualitative data from the interview. The results indicate that the food vlog group, as part of PBL, helped and enhanced the students' self-efficacy, vocabulary mastery, learning autonomy, technology skills, and confidence in speaking English in EFL classes. These findings suggest that PBL has practical application within the context of the food vlog project. Consequently, utilizing a food vlog as a learning activity can be an effective support in practicing their English-speaking skills beyond the confines of the classroom.ABSTRAKPenelitian tentang penggunaan teknologi digital dalam praktik berbahasa Inggris telah diakui secara luas dalam literatur, termasuk studi empiris tentang penggunaan vlogging sebagai instruksi mediasi dalam pengajaran keterampilan berbicara.Penelitian ini bertujuan untuk menyelidiki  pengalaman siswa EFL Indonesia dalam melakukan proyek pembelajaran vlog makanan dalam praktik berbahasa Inggris. Lima puluh mahasiswa di Departemen Pendidikan di Universitas Negeri Makassar, Indonesia, mengambil bagian dalam penelitian ini. Di kelas bahasa Inggris mereka mengerjakan vlog makanan sebagai kegiatan pembelajaran berbasis proyek (PBL). Pengambilan sampel acak digunakan untuk memilih lima orang dari masing-masing lima kelompok yang terdiri dari sepuluh orang, dan mereka setuju untuk mengambil bagian dalam wawancara semi-terstruktur. Analisis tematik digunakan untuk melihat data kualitatif dari wawancara. Hasil penelitian menunjukkan bahwa kelompok food vlog sebagai PBL membantu dan meningkatkan self-efficacy siswa, penguasaan kosa kata, kemandirian belajar, keterampilan teknologi, dan kepercayaan diri dalam berbicara bahasa Inggris di kelas EFL. Temuan ini menyatakan bahwa PBL memiliki aplikasi praktis dalam konteks proyek vlog review makanan secara nyata. Oleh karena itu, food vlog dapat digunakan sebagai kegiatan pembelajaran yang efektif untuk membantu siswa berlatih berbicara bahasa Inggris di luar kelas.How to Cite: Yusuf, Y., Aras, L., Faisal, M., & Ali, A. (2023). Exploring Indonesian EFL Students Experience in Vlogging for Speaking Practice. IJEE (Indonesian Journal of English Education), 10(2), 443-462. doi:10.15408/ijee.v10i2.32036.

OPTIMIZATION OF NICKEL EXTRACTION FROM LATERITIC ORE IN HYDROCHLORIC ACID SOLUTION WITH HYDROGEN PEROXIDE BY TAGUCHI METHOD

Taguchi optimization method was used to determine optimum conditions for the extraction of nickel from lateritic ore in hydrochloric acid solution with hydrogen peroxide. Leaching time, stirring speed, temperature, hydrochloric acid concentration and hydrogen peroxide concentration were chosen as parameters. The optimum conditions for dissolution were found as leaching time of 240 min, a temperature of 70°C, hydrochloric acid concentration of 3 M, hydrogen peroxide concentration of 0.1 M and without stirring. The experimental results under optimum leaching conditions, showed that the extraction of nickel from lateritic ore was 90.66%. Analysis of variance (ANOVA) was applied to experimental results. Percentage contributions of each factor for the extraction of nickel were determined

Sfalerit Konsantresinin Oksitleyici Amonyak Liçi

This paper presents a study of kinetics of leaching of sphalerite concentrate in ammoniasolutions. The effects of ammonia concentration, oxygen partial pressure, reaction temperature andparticle size on the leaching rate were investigated. The shrinking core model was applied to the resultsobtained from these experiments. Reaction on order with respect to PO2 (1-10 atm.) and NH3 concentration(1.05-5.20 M) were 0.22 and 0.63 and the activation energy was determined to be 43.59 kj/mol in thetemperature range of 90-130 °C. In addition, the apparent rate constant is in inverse relationship with themean initial particle radius. The results of this study showed that the leaching of sphalerite was areaction controlled process.Bu makalede, sfalerit konsantresinin amonyak çözeltisinde liç kinetiğine ait bir çalışmasunulmuştur. Amonyak konsantrasyonunun, oksijen kısmi basıncının, reaksiyon sıcaklığının ve taneboyutunun liç hızına etkisi araştırılmıştır. Deneylerden elde edilen sonuçlara küçülen partikül modeliuygulanmıştır. Oksijen kısmi basıncına PO2 (1-10 atm) ve NH3 konsantrasyonuna (1.05-5.20 M) görereaksiyon dereceleri sırasıyla 0.22 ve 0.63 olarak bulunmuştur. 90-130 °C aralığında aktivasyonenerjisinin 43.59 kj/mol olduğu belirlenmiştir. Görünür hız sabitinin ortalama başlangıç tane yarıçapı ileters ilişkili olduğu görülmüştür. Bu çalışmadan elde edilen sonuçlar sfalerit liçinin reaksiyon kontrollübir proses olduğunu göstermiştir

Development of Wireless Data Transfer System on Unmanned Underwater Vehicles Application

This paper presents the development of wireless system for data transfer on unmanned underwater vehicles (UUV) using Xbee Pro 60mWatt. Nowadays, wireless communication technology has become part of our daily life. However, research in underwater wireless communication has been active to design the methods for wireless data transmission underwater. In this system is very important to transfer data from UUV to vessel/platform or other UUV. The technology of underwater wireless communication can be used such as to detect fish or ship, identify the environment at bottom of sea and transmitting data from sea to land. Throughout this project, a few experiments have been done to develop a wireless system for data transfer from underwater vehicles to Computer based (CB). A transmitter (CB) will send a data to a receiver (UUV) that attached to a UUV (FKE-UTeRGlider). Hardware’s that has been used such as XBee Pro 60mW Antenna and XBee Pro Starter Kit that will function as a transmitter and receiver to transfer data using wireless systems respectively. The microcontroller used in this project is PIC microcontroller that functions as an interface with the computer. Graphical User Interface (GUI) by Visual Basic (VB) software has been used as a way to communicate with the PIC. All the results for data transfer will discuss in this pape