bluuebunny/crossref_metadata_2025 huggingface dataset:
Deteksi Tinggi Vegetasi di Delta Mahakam dengan Penginderaan Jauh
Authors: Anggraini Nanin , Julzarika Atriyon
Published: July 2020

Detection of Vegetation Height in Mahakam Delta Using Remote Sensing. The vegetation height is a vertical distance between top of the vegetation to ground surface. Vegetation height is one of the parameters for vegetation growth. There are various methods to measure vegetation height; one of them is the use of remote sensing technology. This study aims to map vegetation height in Mahakam Delta by using height models derived from remote sensing data. Such models are Digital Surface Model (DSM) and Digital Terrain Model (DTM). DSM was generated using a combination of interferometric processing of ALOS PALSAR interferometry, X-SAR, Shuttle Radar Topography Mission (SRTM), and geodetic height of Icesat/GLAS satellite imagery. This integration technique incorporated the Digital Elevation Model (DEM) method. The geoid model used in this study was EGM 2008. The following step was the correction of height errors of DSM. Terrain correction was undertaken to convert DSM into DTM, while vegetation heights were obtained from subtraction of DSM and DTM. Vertical accuracy verification refers to a tolerance of 1.96σ (95%) or ~80 cm. In DSM, a vertical accuracy value of 60.4 cm was obtained so that the DSM is feasible for mapping with scale of 1: 10,000, while the DTM was 37 cm so it is also applicable for mapping with such scale. Based on the subtraction of DSM and DTM, the vegetation heights in Mahakam Delta varied between 0 and 64 m.
Dinamika Massa Air di Sekitar Pulau-Pulau Kecil Terluar (PPKT) Perairan Utara Papua
Authors: Surinati Dewi , Corvianawatie Corry
Published: July 2020

Water Mass Dynamics Around the Indonesia’s Outer Small Islands at
 North Papua Waters. Coastal area of Indonesia’s Outer Islands (PPKT) at North Papua Waters have a huge potential of marine resources which needs to be managed in sustainable ways. In order to make the processes of protection, conservation, rehabilitation, utilization, and enrichment of coastal resources work well, the study about environmental carrying capacity which includes ocean dynamics analysis around PPKT area is needed. Hereby, the study area were including coastal and off shore area of  Jiew, Budd, Fani, Bras and Fanildo Island. The measurement of water mass and ocean current was conducted to analyze the impact of regional ocean dynamics to coastal waters of PPKT. This study found the domination of New Guinea Coastal Current (NGCC) at surface layer, the effect of Indonesian throughflow at subsurface layer (100 – 150m depth), and counter current towards northeast which is believed as a part of New Guinea Coastal Under Current (NGCUC) and Equatorial Under Current (EUC). This ocean current system carried South Pacific Subtropical Water (SPSW) noticed by maximum salinity of 35.4 PSU at 150m depth. There are spatial variability of mixed layer depth and slope of T-S curve at the western and eastern part of study area which might be caused by isopycnal mixing. However, the spatial and temporal variability of Sea Surface Temperature at this area is relatively small due to the presence of Western Paicific Warm Water Pool. With the small annual SST variability, strong ocean current and water mass mixing, this area has a potential for the development of marine ecosystem.
Isolasi Bakteri Pendegradasi Minyak Mentah dan Polisiklik Aromatik Hidrokarbon dari Sedimen Mangrove Bintan
Authors: Afianti Nur Fitriah , Febrian Deva , Falahudin Dede
Published: July 2020

Isolation of Crude Oil and Polycyclic Aromatic Hydrocarbon-Degrading Bacteria from Mangrove Sediments in Bintan. Bintan is known for its extensive mangrove areas, but it is prone to pollution from oil spills due to it is close to the international shipping lane. Indigenous bacteria plays important roles in bioremediation of oil spills in the natural environment. This research aims to explore indigenous bacteria from Bintan’s mangrove sediments which may have ability to degrade crude oil and polycyclic aromatic hydrocarbon (PAH). The mangrove sediment samples were taken in March 2018 from the sediments near four different mangrove plant species, i.e. Rhizophora apiculata, Xylocarpus granatum, Ceriops tagal and Lumnitzera littorea. Isolation of oil degrading bacteria was carried out using enrichment media supplemented with crude oil ALCO. A total of 45 strains of oil degrading bacteria were successfully isolated from the sediment samples. By using sublimation method, 13 bacterial isolates showed the ability to degrade various PAHs, including phenanthrene, acenaphthene, dibenzothiophene and fluorene. Sequencing analysis of 16s rRNA genes confirmed that the 13 isolated bacteria belong to the genera Rhodococcus, Bacillus, Sphingopyxis, Rhizobium, Mycobacterium, and Gordonia
Editorial e Expediente
Authors: Praxedes Carlos
Published: July 2020

Editorial e expediente da edição "Dossiê: o hiperlocal na comunicação"
MICROSTRUCTURAL CHARACTERISTICS, MECHANICAL AND WEAR BEHAVIOUR OF ALUMINIUM-ALLOYED DUCTILE IRONS SUBJECTED TO TWO AUSTEMPERING PROCESSES
Authors: Adebayo Abdullahi Olawale , Oyetunji Akinlabi , Alaneme Kenneth Kenayo
Published: July 2020

The effect of aluminium addition and austempering processes on the microstructures, mechanical and wear properties of rotary melting furnace processed ductile irons was investigated. Ductile irons containing 1−4 wt.% Al were produced and subjected to single and two-step austempering processes. Optical microscopy was used to characterize the graphite features and estimate the volume fraction of the matrix phases present, while the x-ray diffractogram was also carried out to analyse the samples. Mechanical and wear properties of the alloys were equally evaluated. From the results, it was observed that both the as-cast and austempered ductile iron microstructures contained nodular graphite, and the matrix structure for the as-cast ductile irons consisted predominantly of pearlite and ferrite, while that of the austempered grades, contained principally, ausferrite. The microstructure and intermetallic compound obtained played dominant role on the properties of the alloys. The aluminium addition and austempering processes had a significant influence on the mechanical properties and wear resistance of the alloys. The austempered ductile irons exhibited superior strength and wear resistance compared to the as-cast samples, albeit ductility values were lower in the composition group. Austempering increased the strength by over 100% while the addition of Al further enhanced the strength. The improved properties were linked to the refined microstructure, increased proportion of ausferrite phase and intermetallic compound formed. For all properties evaluated, the two-step austempering yielded better properties combination than the single step process. The rotary melting furnace processing adopted was found viable for ductile iron production.
MODEL REFERENCE ADAPTIVE CONTROL-BASED GENETIC ALGORITHM DESIGN FOR HEADING SHIP MOTION
Authors: Al-Awad Nasir Ahmad
Published: July 2020

In this paper, the heading control of a large ship is enhanced with a specific end goal, to check the unwanted impact of the waves on the actuator framework. The Nomoto model is investigated to describe the ship’s guiding progression. First and second order models are considered here. The viability of the models is examined based on the principal properties of the Nomoto model. Different controllers are proposed, these are Proportional Integral Derivative (PID), Linear Quadratic Regulator (LQR) and Model Reference Adaptive Control Genetic optimization Algorithm (MRAC-GA) for a ship heading control. The results show that the MRAC-GA controller provides the best results to satisfy the design requirements. The Matlab/Simulink tool is utilized to demonstrate the proposed arrangement in the control loop.
KINEMATIC SYNTHESIS OF CENTRAL-LEVER STEERING MECHANISM FOR FOUR WHEEL VEHICLES
Authors: Pramanik Santiranjan , Thipse Sukrut Shrikant
Published: July 2020

A central lever steering mechanism has been synthesized to obtain five precision points for a four-wheel vehicle using Hooke and Jeeves optimization method. This compound mechanism has been studied as two identical crossed four-bar mechanisms arranged in series. The optimization has been carried out for one crossed four-bar mechanism only instead of the entire mechanism. The number of design parameters considered for the optimization is two. The inner wheel has been considered to rotate up to 52 degrees. The steering error, pressure angle and mechanical advantage of the proposed mechanism have been compared with those achieved by the Ackermann steering mechanism. The proposed mechanism has less steering error, more favourable pressure angle and increased mechanical advantage. The method of compounding the mechanism is also applicable when the central lever is offset from the longitudinal axis of the vehicle.
A Selected Stenotaphrum secundatum as Superior Shade Tolerant Forage Resource
Authors: Sirait Juniar , Simanuhuruk Kiston
Published: July 2020

The obstacle in planting and developing forage plants is limited land. One solution to anticipate this is to utilize land in plantations by introducing forage shade-tolerant among the main crops. The area of oil palm plantations in Indonesia reaches 14,677,560 ha potentially used in the integration system. This article outlines the superiority of Stenotaphrum secundatum from the selection results so that the reader gets comprehensive information about this grass, both in terms of production, nutritional quality and digestibility. Stenotaphrum secundatum selection’s variety grass is a forage shade tolerant that had derived by positive mass selection method which had had been tried it’s adaptability at two different elevation in North Sumatra. This grass is very suitable to be integrated in plantation land. The average fresh yield of S. secundatum at 55 and 75% shading level reached 2,386 and 2,001 g/m2/harvest, respectively. The digestibility of Steno grass selection’s result on growing Boerka goat shows a fairly good value, which ranges from 60.7% to 72.8%. Palatability of S. secundatum grass in goats is very good with consumption reaching 3.6% of body weight. S. secundatum grass, besides being tolerant of shade, is also resistant to pests, as long as it is maintained with good management. The crossing of polyploid Steno grass with diploid has produced drought tolerant varieties. This grass also has advantages in terms of dry matter production, nutrient content and crude protein production compared to other grass species and can be planted in wider plantation areas with 55-75% shade.
O diálogo como estratégia formativa
Authors: Lima Luanda de Oliveira , Pekelman Renata
Published: July 2020

Este manuscrito objetiva refletir acerca dos desafios e das possibilidades que se colocam no campo da formação em saúde dentro de um contexto em que o diálogo, princípio fundamental da educação popular, se torna desafiador em função de um cenário de opiniões radicalizadas, de retrocesso nas políticas públicas para a formação e do distanciamento físico devido à pandemia. Ao longo do texto, buscamos apresentar estratégias e iniciativas que vêm se consolidando no âmbito da Educação Popular em Saúde e do campo da formação mediante tantas incertezas.
Avaliação Institucional Participativa como instrumento de autonomia no fortalecimento da gestão democrática escolar / Participatory Institutional Evaluation as an instrument of autonomy in strengthening school democratic management
Authors: Silva Leandra Cristine Pianco da
Published: July 2020

Este artigo é fruto de uma pesquisa em escola pública e traz a Avaliação Institucional Participativa como objeto de estudo, buscando investigar os mecanismos dessa com base no viés participativo e sua relação com a autonomia no fortalecimento da Gestão Democrática. Através da pesquisa qualitativa, foram utilizados como métodos de coleta a observação, entrevistas, questionário e análise documental, tendo como referencial teórico autores como Sobrinho (2012), Afonso (2009), Freitas (2014) e Brandalise (2010). Verificou-se que a Avaliação Institucional Participativa se configura como um mecanismo de participação, enquanto exercício de autonomia na melhoria da qualidade almejada pelos atores escolares, fortalecendo a Gestão Democrática na medida em que contribui para a emancipação dos sujeitos.
Precipitação no extremo norte da Amazônia: distribuição espacial no estado de Roraima, Brasil
Authors: Barni Paulo Eduardo , Barbosa Reinaldo Imbrozio , Xaud Haron Abrahim Magalhães , Xaud Maristela Ramalho , Fearnside Philip Martin
Published: July 2020

A precipitação pluviométrica é uma das variáveis mais importantes para investigações associadas a processos biológicos. Na Amazônia, estudos sobre sua distribuição espacial e temporal vêm sendo utilizados como uma ferramenta de análise no planejamento regional visando a conservação de diferentes ecossistemas. Isto pode ser exemplificado pela construção de calendários agrícolas e de queimas controladas com o objetivo de prevenir que fogos derivados de queimadas para limpeza de roças e pastagens escapem do controle e se transformem em incêndios florestais de grandes proporções em anos de seca severa na Amazônia. Nosso estudo teve como objetivo modelar a distribuição espacial da precipitação no Estado de Roraima (1998-2018) utilizando as escalas mensal e anual a partir de dados orbitais de dois produtos disponíveis na rede mundial de computadores (TRMM/WORLDCLIM). Foi adotada a krigagem ordinária como método para a modelagem da precipitação. Roraima apresenta duas estações climáticas bem definidas ao longo do ano, mas contrastantes em função dos seus três tipos climáticos existentes e o limite físico estar distribuído entre dois hemisférios. Em média a precipitação do clima Af se concentra no intervalo entre março e agosto (63,5%), com pico em maio, enquanto Am e Aw de abril a setembro (pico em junho), concentrando 73,3% e 82,3% das chuvas, respectivamente. Entre 1998 e 2018 a média de precipitação anual foi de 1925 ± 339,7 mm, considerando as 59 estações pluviométricas localizadas na área de estudo, independentemente da localização hemisférica. Eventos climáticos extremos possuem um efeito dramático nos índices pluviométricos regionais, fazendo com que em anos El Nino (longas secas) os riscos de incêndios florestais sejam maiores e, em anos de La Niña (períodos de chuva intensa), os riscos de enchentes sejam mais frequentes.
Diversity of Tarekat Communities and Social Changes in Indonesian History
Authors: Abdurahman Dudung
Published: July 2020

Islam as a religious system is generally based on three principal teachings called as aqidah (theology), syari'ah (law), and tasawwuf (Sufism, moral and spiritual). Each thought and the Islamic expertise have also established Muslim communities that demonstrate the diversity of social and religious history in various regions on the spread of Islam. In the history of the spread of Islam in Indonesia, particularly the Sufis always showed a significant role in each period of social change. Therefore, further discussion of this paper will be based on the development of tarekat communities. The historical facts in this study are presented gradually based on the unique cases in each period. The tarekat communities in Nusantara in the early period of Islam, which is the 13th century until the 17th century, have established the religious system patterned on the diversity of doctrine, thought, and tradition that is acculturative with various cultures of the local society in Nusantara. Then they developed during the Dutch colonial period in the 18th century and the 19th century. Besides contributing in the Islam religious founding, they also contributed in the patriotism struggle and even protested in the form of rebellion towards the Dutch colonial. The Sufis from various tarekat streams displayed antagonistic of political acts towards the Colonial government policies. It was developed at the beginning of the 20th century, which is the period of nationalism and of Islamic reform movements. The social force of tarekat people became an indicator of the religion revival that was very influencing towards the nationalism movement in Indonesia. The last one, it has been developing on the independence day of Indonesia, which is called the contemporary period, until today. The tarekat people have built a community system variously based on the principle of beliefs and various ritual activities. The tarekat people always develop, modify, and actualize the tasawwuf teachings and the tarekat practice, mainly in order to complete the spirituality and morality improvement of the society. The tarekat people’s contributions are very helpful for the society in general in order to fulfill the mental necessity. Their religiosity is also strategic enough to be used as a control media for the moral life of the nation.
Southeast Asian Islamic Art and Architecture: Re-Examining The Claim of the Unity and Universality of Islamic Art
Authors: Fina Lien Iffah Naf’atu
Published: July 2020

This paper re-examines the claim of unity and universality of Islamic art, whose discussion usually disregards Islamic art and architecture in the Southeast Asian context. The question raised is where Islamic art in the Malay world should be put before the claim of the unity and universality of Islamic art and whether this claim is, thus, still valid. To meet this objective, the two heritages of Javanese Islamic art, Demak and Cirebon mosques and wayang, are presented and analyzed before such universal claim and pre-Islamic Javanese art. These Javanese expressions have unique features compared to those from the older Muslim world. The mosques lack geometric ornamentation and Qur’anic calligraphic decoration, and are rich with symbolism. However, both the mosques and wayang also clearly express the figurative designs. Thus, this paper argues that instead of geometric designs as the unified character of Islamic art as some argue, it should be the abstraction of motifs. This way, the universal claim of Islamic art accommodates the artistic expressions from the wider regions, including those from Southeast Asia. Besides the abstraction, these Javanese artistic expressions also shares other universal character of traditional development of Islamic art; its ability to always considering the local tradition while maintaining the basic principle of Islamic art. Javanese Islamic art is both Islamic and uniquely Javanese. In the midst of globalization and the contemporary tendency towards “Islamic authentication” by importing culture and tradition from the Middle East, including the mosque architecture, the latter character is vital. It tells that any direct import and implantation of other or foreign traditions to a certain region without any process of considering the local tradition and context has no basis and legitimation in Islamic artistic tradition.
The Important Place of Indonesia in the Formation of International Culture Today
Authors: Beck Martha C.
Published: July 2020

This paper begins with excerpts from Ervin Lazlo’s book, The Systems View of the World, one version of the emerging paradigm for understanding the universe, the natural world, the human psyche and human culture. The second section presents excerpts from Antonio Damasio’s book, Looking for Spinoza: Joy, Sorrow and the Feeling Brain. Damasio is a highly respected neuroscientist whose discoveries about the inner mapping of the human brain have led him to reject Enlightenment views of human psychology and replace them with another version of Lazlo’s “systems” approach. The third section presents Indonesia’s Pancasila, a five-point political ideology that serves as the foundation for their democratic republic. This ideology begins with the belief in God, but the notion of “God” is one more example of a type of “systems” thought. The fourth section includes an interview from Dr. Amad Kardimin, professor of education at Sunan Kalijaga Islamic State University in Yogyakarta, Indonesia. Dr. Kardimin describes the beliefs and way of living in the small village where he grew up. I will interpret what he says in light of my own scholarship about Aristotle’s model of the flourishing human life, a life of both practical and theoretical wisdom. Even though the people in this village are not formally educated, they are living much more wisely than many highly respected intellectuals today. Finally, I will quote from a number of public intellectuals in the United States who are very worried about the decline in quality of life in the United States today. This decline will lead to an increase in authoritarianism in the U.S. I conclude that too many developing nations have looked to the West, especially the United States, for guidelines about how to “move forward.” Their best and brightest young people are sent to Western universities and go back home to educate their own best and brightest to think and act like Westerners. This is a mistake. Indonesia is continually working on a model of education that unites the moral with the intellectual virtues. The West, especially the United States, has focused on higher and higher levels of education in science, math, and computer science without adequate concern for avoiding greed, pride, power hunger and other vices. Indonesia and other developing nations should recognize the importance of an education for wisdom. Leaders in all sectors should exhibit both moral and intellectual excellence. The future of international culture, politics and even of life on earth is at stake.
Proving Peaceful Islam through the Application of Al-'Illat Wa Al-Ma'lûl Approach in Reading Qur’anic Verses of War (Interpretation of Q.2: 190-194 and Q.9: 5-15)
Authors: Jafar Iftitah , Amrullah Mudzhira Nur
Published: July 2020

This paper will prove Islam as a religion of peace by using al-illat wa al-ma'lûl approach in reading Qur’anic verses of war. Qur’anic verses of war have been a crucial problem in interfaith relation. Non-Muslims used such verses as a weapon to label Islam as a violent religion. Moreover, some terrorists justified their violent action with verses of war. However, Muslims insist that such verses basically do not express violence especially if they are properly understood. Radical understanding of Qur’anic texts is partly caused by the approach that exegetes use. Apart from the approach is the use of literal translation and atomistic approach. Atomistic approach suggests the readers to split a verse and treat it separately without relating it to other parts of the verse. Moreover, it does not pay a specific attention to the historical context of the texts (asbȃb al-nuzȗl). In addition, it neglects the correlation of the verses (munᾱsaba). Some approaches have contributed to the problem includes: 1. System approach, 2. Esoteric interpretation approach, and 3. Historic-contextual approach. However, these three approaches did not solve the problem. Therefore, the writer introduces al-illat wa al-ma'lûl approach. The research question is how to prove Islam as a religion of peace by implementing al-‘illat wa al-ma‘lȗl approach in understanding Qur’anic verses of war? Methodologically, this approach was adopted from the concept of cause and effect in various studies, specifically: Physics, History, Philosophy, Communication as well as Islamic studies, especially: Uṣȗl al-Fiqh, Ḥadȋth and Tafsȋr. The approach runs through 4 steps: 1. Literal analysis of key words, especially "qᾱtil," in Q.2:190-194 and Q.9:5-15. 2. Analyzing macro context of revelation (asbȃb al-nuzȗl al-‘ȃmm) and the micro context of the texts (asbȃb al-nuzȗl al-khȃṣs). 3. Analyzing the correlation of the verse internally and externally. 4. Determine which part of the verse is the cause (al-‘illat) and which one is the effect (al-ma‘lûl). It also determines which verses function as a cause and which ones function as an effect. The result of study shows that: 1. The order to fight unbelievers has been preceded by a cause that unbelievers have declared war. 3. The order to fight idolaters wherever they found them is issued when the war is raging and in certain places and in certain time. 4. The command to fight is upright on a noble purpose namely justice, liberation and self-defense. This command to fight is based on the real condition of Muslims whom were oppressed, persecuted, tortured and expelled. This war is also upright on the ethics of war, such as not killing old men, women and children, not destroying houses of worship, and plantations. To conclude, all command to fight for Muslim is a consequence of the previous events as a cause. Therefore, Islam is a peaceful religion it is a defensive and not aggressive or offensive religion.
Why Wench Betty’s Story Matters – The Murder of a NJ Slave in 1784
Authors: Kozel Sue
Published: July 2020

Each year, the NJ Council for the Humanities (NJCH) subsidizes at least 200 high-quality public humanities programs for host organizations throughout the state, providing opportunities for New Jersey communities to explore history, values, culture, and beliefs, and to engage in key questions with the support of a scholarly perspective. You can view more here. This NJ Studies “Invited Talk” by Sue Kozel is a NJCH Public Scholars Project program, and thus far versions have been presented at the Paterson Museum, the NJ State Library, and “Social Justice Matters.”
Porwanie do „trzeciego nieba”. Tomasz z Akwinu o doświadczeniu mistycznym
Authors: Sochoń Jan
Published: July 2020

The author of the present paper tackles the questions related to mystical experience in St. Thomas’ Aquinas writings. He demonstrates that according to the medieval thinker, assuming the belief of impossibility of experiencing vision of the divine essence in this life, mystical experience of Moses and St. Paul (raptus) should be considered as temporary and transient, that only happens once. Such experience transcendshuman natural powers since it is God who takes the initiative in rapture. It also remains passive in itself as it occupies only human intellect which is the one to see the divine essence, while the body remains in dormant state. What is more, this experience is limited because someone who experiences rupture is unable to communicate accurately what exactly had happened to him. Therefore, mystical experience in this life was not of primary importance for St. Thomas. He was more attracted by the direct visual perception of God promised in the Holy Scripture, its implication being that in the supernatural domain the eternal act of knowing God and communion with Him persists. During the visio the object of cognition is more active than its subject. By the infusion of divine light (lumen gloriae) human cognitive abilities are intensifi ed until raptus becomes able to see the divine essence. Naturally, the bestowed grace of seeing God and its intensity depends on experienced intensity of love (caritas) and desire of receiving such grace. It results from the above that saints do not have the same knowledge of God and do not reach the same level of happiness. The chosen can reach it in accordance with their merits and God’s will. However, in the state of salvation the nature of human cognition will not change, since the same human being strives for happiness on earth and reaches it in heaven, realising at the same time his non-self-suffi ciency in reaching this state. This problem lies at the core of Thomas’ inquiry into visio beatifi cans.
Rehearsing the Social
Authors: Morabito Fabio
Published: July 2020

The history of Beethoven’s late quartets has usually been told by separating (and redeeming) the composer’s aesthetic priorities from the difficulties encountered by the works’ early performers, publishers, and listeners. This article weaves together Beethoven’s interests with those of his publisher Maurice Schlesinger and the violinist Pierre Baillot, whose ensemble first performed the late quartets in Paris between 1827 and 1829. I navigate the traffic among these parties to reassess what was difficult about this music and, on this basis, test new routes to explore early nineteenth-century string quartet culture. One issue these different agents faced—whether in presenting the quartets to the Viennese public (Beethoven), selling them in Paris (Schlesinger), or performing them (Baillot)—was that the late quartets seemed to call for a new kind of ensemble rehearsal. The genre’s proverbial sociability, historically supporting an almost immediate and shared grasp of the performers’ interplay, was compromised in Beethoven’s late quartets by a loss in topicality. The erosion of topical references and familiar textures in these quartets made it harder for performers to predict how to coordinate their moves. Musical topics, I argue, functioned as a means of communication not only with listeners but also among performers within an ensemble. In contrast, the sociability of Beethoven’s late quartets had to be patiently engineered through dedicated rehearsals, a step that distanced this music from past quartet cultures and shaped a new notion of making music together.
Numerical predictions of sand erosion in a choke valve
Authors: Saeid N. H.
Published: July 2020

Two-phase turbulent flow of crude oil and sand in a choke valve is analysed in the present article using 3D computational fluid dynamics simulations. The discrete phase mathematical model is used to simulate the sand flow and its interaction with the oil flow in the system. Parametric study is done to identify the governing parameters to minimize the sand erosion in the system. The valve geometry and dimensions are taken from an industrial oil production project. The parameter considered in the present study are the percentage valve opening, flow rate of the sand and the pressure difference between the inlet and outlet pipes. The simulation results are presented to show the erosion rate variation with the valve opening, sand flow rate and the pressure difference. It is found that the erosion rate is high for small valve opening as well as large valve opening. Minimum erosion rate is found when the valve opening is between 20-30% for all the cases with various pressure differences. Locations of maximum erosion rate are predicted in the simulations.
Amine-based carbon dioxide absorption: evaluation of kinetic and mass transfer parameters
Authors: Ma’mun S. , F. Svendsen Hallvard , Bendiyasa I. M.
Published: July 2020

Global emission of carbon dioxide (CO2), a major contributor to the climate change, has increased annually and it reached over 37 Gt in 2017. An effort to reduce the emission, therefore, needs to be conducted, e.g. post-combustion capture by use of amine-based absorption. The objective of this study is to evaluate the kinetic and mass transfer parameters in a CO2 absorption process using monoethanolamine (MEA), 2-(methylamino)ethanol (MMEA), and 2-(ethylamino)ethanol (EMEA) as absorbents. The experiments were conducted in a bubble reactor at atmospheric pressure and 40 °C with 10-vol% CO2 flowrate of 5 NL/men. The CO2 concentration leaving the reactor was measured by an IR CO2 analyzer. The results obtained from this experiment were the overall absorption rates consisting of both chemical reaction and mass transfer. Analysis result shows that the reaction between CO2 and amines takes place fast, therefore the mass transfer of CO2 from the gas into the liquid through the gas film would control the overall absorption rate.
Mechanical characterization and optimization of heat treatment parameters of manganese alloyed austempered ductile iron
Authors: Hegde Ananda , Sharma Sathyashankara , Vikas Sadanand Ramakrishna
Published: July 2020

Austempered Ductile Iron (ADI) belongs to the family of cast irons whose mechanical properties are altered using austempering heat treatment process. The objective of this paper is to study the effects of heat treatment parameters on manganese alloyed ADI. Hence, austenitization temperature, austempering temperature and austempering time are taken as the control variables along with the manganese content in the material. The effects of heat treatment are studied by measuring the ultimate tensile strength and the hardness of the material.  The regression equations are developed to relate the various parameters under study. The microstructures of the specimen reveal that retained austenite content increases with increase in manganese and results in decrease in hardness of the material. The statistical analyses indicate that the austempering temperature is the major factor affecting the variation in hardness and tensile strength with 74.5 % of contribution within the range of values whereas,  variation in manganese content does not have significant effect on hardness within the investigated composition range in the material.
Co-pyrolysis of rubberwood sawdust (RWS) and polypropylene (PP) in a fixed bed pyrolyzer
Authors: Izzatie N. I. , Basha M. H. , Uemura Y. , M. Hashim M. S. , Afendi M. , Mazlan M. A. F.
Published: July 2020

Co-pyrolysis of rubberwood sawdust (RWS) waste and polypropylene (PP) was carried out at different temperatures (450,500,550, and 600°C) with biomass to plastics ratio 1:1 by using fixed bed drop-type pyrolyzer. The yield of pyrolysis oil has an increasing trend as the temperature increased from 450°C to 550°C. However, the pyrolysis oil yield dropped at a temperature of 600°C. Co-pyrolysis of RWS and PP generated maximum pyrolysis oil with 36.47 wt.% at 550°C. The result is compared with the pyrolysis of RWS only without plastics, with the same feedstock, and the maximum pyrolysis oil yield obtained was 33.3 wt.%. The water content in pyrolysis oil of co-pyrolysis RWS with PP is lower than RWS only with 54.2 wt.% and 62 wt.% respectively. Hydrocarbons, acyclic olefin, alkyl, and aromatic groups are the major compound in the pyrolysis oil from the co-pyrolysis process. Carbon monoxide (52.2 vol.%) and carbon dioxide (38.2 vol.%) are the major gas components.
Development of a cutting edge temperature measurement of end mill tool by using infrared radiation technique
Authors: Kiprawi M. A. , Yassin A. , A. Kamaruddin A. M. N. , Shazali S. T. S. , Islam M. S. , M. Said M. A.
Published: July 2020

This paper describes the development of cutting temperature measurement of end mill tool by using infrared radiation technique approach. Compared to conventional thermocouple technique, infrared radiation technique is an advance method of measuring temperature which featured high accuracy, high response rate, wide range of temperature scale detection and almost compatible with all materials used in the manufacturing industry. We measures the emission of infrared radiation from the source, which is cutting edge of tool by using photocells that contains InAs and InSb photovoltaic detectors. Photocells converts the infrared radiation to a voltage signal and then recorded by oscilloscope followed with a calibration with its corresponding temperature. This paper discussed about the calibration method, cutting experiment setup, the limit of infrared radiation level detected by photocells, signal correction of output signal, and relations of peak signal formation with rotation of end mill tool. The developed pyrometer is also capable to profile the cutting tool’s rotation based on the movements of infrared radiation’s emission at cutting tool’s edge. The conclusion was that the measurement of cutting temperature of high speed machining by using infrared radiation technique is possible. The developed pyrometer are capable to detect temperature changes at a span of 0.01 ms.
Design and parametric characterization of flexure bearing as automotive valve spring replacement
Authors: Hanipah Mohd Razali , Mansor Shahin , M. Akramin M. R. , Razali Akhtar Razul
Published: July 2020

Automotive valve springs occupy substantial space in the cylinder head of an internal combustion engine. In this paper, the design and analyses of a flat spring concept, known as flexure bearing are presented. Further, design approach, characteristics and parametric characterizations of a single-piece flexure bearing concept are outlined. Finite element analysis was used in examining the flexure bearing strength for different designs, materials and thicknesses. The results show that the maximum stress values are independent of the material types when the number of arm is three and above. The strain values are limited to less than 1% for all materials when the thickness is more than 1mm.  The results have provided characteristics for future selection of the flexure bearing in relation to the intended axial displacement.
Study of the microhardness and erosive wear behavior of organo-modified nanoclay filled glass-epoxy composites and optimization
Authors: Shanti Kiran Z. , Babu V. Suresh , Shekar K. V. L. Soma
Published: July 2020

This research concentrates on examination and optimization of microhardness and erosion resistance of epoxy-glass-nanoclay composites (EGCN’s). The parameters considered were the weight content of Cloisite 15A (A), the volume of glass fiber (B), and the direction of glass fibers (C). Hand lay-up technique was used to make the composites and tested for microhardness and erosive wear as per ASTM standards. The L9 orthogonal array was utilized to design the microhardness tests and erosive wear test, and it was noted that the composite with high clay content, low fiber volume, and 45° orientation had shown low erosion rate (Er) even though its hardness was lesser than the optimized value. At the optimum composition corresponding to the lowest Er, further erosion studies were conducted with the L18 orthogonal array for optimizing machine testing parameters. Scanning electron microscopy (SEM) was used to explain the effect of each parameter on the output. This research gives a thought regarding the consolidated effect of A, B, and C on the erosion resistance of the EGCN’s and the effect of testing parameters.
Thermo-mechanical properties of fused borosilicate syntactic foams
Authors: Salleh Z. , Islam M. M. , Epaarachchi J. A. , Khan M. T. I.
Published: July 2020

The coefficient thermal expansion, a (CTE) of glass microballoon/vinyl ester syntactic foam was determined using dimensional changes of a temperature gradient plot. The CTE was measured and found to be up to 53-63 % lower than the vinyl ester resin matrix when mixing with different weight percentages of the glass microballoon ranging from 2 wt.% to 10 wt.% using a thermomechanical analyzer (TMA). The results of CTE showed that it has a strong relationship with the syntactic foam density (r), radius ration (h) ,cavity porosity (fg) and matrix porosity (fm). Experimental results showed that the CTE decreases when glass microballoons are added into the composites measured at different temperatures ranging from 30 oC to 70 °C. The CTE from the experimental results were also compared with Turner’s modification model for composites for its suitability for thermal expansion of syntactic foams. The results indicate that Turner’s modification model exhibits a close correlation with the reduction up to 80 % of CTE based on experiment.
Effect of pH condition during hydrothermal synthesis on the properties of hydroxyapatite from eggshell waste
Authors: Toibah A. R. , Misran F. , Shaaban A. , Mustafa Z.
Published: July 2020

Hydroxyapatite (HA) powders were synthesized using eggshell waste through hydrothermal method to develop bioceramics materials for medical applications. The effects of the pH conditions during the synthesis on the phase behaviour, crystallite size, crystallinity and morphology of as-synthesized ceramic powders were evaluated. The XRD patterns showed that HA was only the main phase present in the as-synthesized powder after being calcined at 400°C. However, EDX measurement detected the presence of Mg as trace elements which originated from the eggshell as starting materials. The crystallite size and crystallinity of the HA powders were increased when the powders were synthesized in acidic condition as compared to basic condition.  FESEM images showed that HA powder with nano-sized rods and spherical morphologies were obtained from the powders that were synthesized at pH 5, while the powder particles synthesized at basic condition at pH 9 produced elongated rod-shape particles. The PSD results showed that the synthesized HA were in agglomerated form which were also confirmed by FESEM images.
On the use of nano fibrillated kenaf cellulose fiber as reinforcement in polylactic acid biocomposites
Authors: Ahsan Q. , Carron T. S. S. , Mustafa Z.
Published: July 2020

In this study, nano fibrillated kenaf cellulose (NFKC) derived from kenaf fiber after varying chemico-mechanical treatments were introduced into poly lactic acid (PLA) as reinforcements to improve the mechanical and morphological properties of the biocomposites. The new strategy was aiming to realize the synergistic effects of chemical treatment and mechanical fibrillation process parameters (blending speed and time) for yielding nano fibers and its reinforcement effects on the properties of biocomposites. The yield percentage of the NFKC was determined using centrifugal method and the NFKC fibers with PLA pellet were hot pressed to form NFKC-PLA composites. The distribution and dispersion morphologies of NFKC in NFKC-PLA composites were observed by using optical microscope (OM) and scanning electron microscope (SEM). The reinforcing effect on the mechanical properties of NFKC-PLA composite was investigated by tensile strength test. Average length and diameter of fibrillated fibers were decreased with the concurrent increase of blending speed and time. The maximum increase in tensile strength of 59.32% and elongation of 100% were observed for NFKC-PLA composite with NFKC yielded at a blending speed and time of 15000 rpm and 15 minutes as compared to pure PLA. The tensile properties indicated that the strength and modulus were improved with increased nanofiber contents.
Surface roughness effect on droplet impact characterization: Experimental and theoretical study
Authors: Zohrabi Chakaneh J. , Javid S. M. , Passandideh-Fard M.
Published: July 2020

In this paper, the effect of surface roughness on the both normal and inclined droplet impact is investigated experimentally by image processing.  The impingement of water droplets with 2.9 mm diameter and 1m/s velocity impacting on three types of stainless steel surfaces with respective arithmetic average surface roughness values of 2.24 μm (Smooth), 6.04 (Medium) and 30.2 (Rough) is examined using a high-speed camera. The dynamic behavior of the impact including droplet deformation, the maximum spreading diameter and length, contact angle and the number of fingers are studied. Experimental results demonstrate that rough surfaces not only prevent secondary droplet formation but also decrease the number of fingers formed around the droplet in the normal droplet impact. Considering the inclined droplet impact scenarios, the asymmetric spreading of droplet on inclined surfaces avoids the secondary droplet formation by decreasing the fluid kinetic energy. In the inclined impact, fingers are formed around the droplet perimeter like the normal impact. The only difference between impacts onto the inclined surfaces is a gradual decrease of the number of fingers by increasing the incline angle. The experimental results are compared with those of the analytics available in the literature for the normal droplet impacts. Next, a simple analytical model for droplet impact on an inclined surface is developed; the predictions from this model was also compared to those of measurements. Calculated values from the analytical models agreed well with experimental data for both normal and inclined impact scenarios.
Experimental investigation of multiphase separation in different flow regimes through T-junction with an expander section
Authors: Memon Z. Q. , Pao W. , Hashim F. , Ahmed S.
Published: July 2020

The experimental data for phase separation of the air-water mixture in a T-Junction with the expander section after the branch arm is presented in this work. The main and run arms of the T-junction are directed along the horizontal plane with the branch arm positioned in the vertical plane. The diameter of the main arm is 74 mm, with diameter ratio(s) of, 0.67, and 0.33 in relation to branch arm. At the inlet section of the T-junction, the flow regimes generated were stratified, stratified wavy and slug flow. At the inlet, the air and water superficial velocities are in the range of 0.25 - 0.140 m/s and 0.14-0.78 m/s respectively. The effect of the expander section after the branch arm, the air superficial velocity USA and water superficial velocity USw on liquid carryover (WL3/WL1)max in branch arm have been studied. Based on the experimental data obtained for T-junction with expander section, complete phase separation of air and water was observed in stratified and stratified wavy flow for all superficial velocities and improved phase separation for slug flow. In slug flow, increasing the liquid superficial velocity improves the phase separation but increasing the gas velocity decreases the phase separation. Finally, the volume weighted phase in this new T-junction design is compared with the phase separation data of a simple T-junction.
A review on thermo-physical properties and heat transfer applications of single and hybrid metal oxide nanofluids
Authors: Azmi W. H. , Zainon S. N. M. , Hamid K. A. , Mamat R.
Published: July 2020

Nanofluids have been widely explored by various investigators for different types of nanomaterials either the single nanoparticles or hybrid types. This is due to their advantages in thermal properties as well as contribution to the enhancement in the heat transfer performance. Numerous numbers of studies were performed mostly on oxide nanofluids until today. However, the review on oxide nanofluids and their applications is limited. Hence, this paper highlights the most recent development solely on the oxide nanofluids for heat transfer applications. In addition, a comprehensive review is carried out on the recent studies of thermo‑physical properties on oxide nanofluids and their heat transfer applications. The numerical and experimental studies related to forced convection heat transfer using oxide nanofluids were presented. Most of the literatures confirmed the capability of nanofluids to improve the heat transfer performance and simultaneously insignificant increments in pressure drop. Hence, the oxide nanofluids is recommended for applications in various engineering systems.
Blending Poly (3-Hydroxybutyrate) with Polyethylene Glycol (PEG): Thermal behaviour and rheological study
Authors: Achim Norfarisha , Husin Hazlina , Hassan Zukafli
Published: July 2020

Poly (3-hydroxybutyrate) (PHB) is a biodégradable polymer which its application in industrial was limited due to sensitive to high processing temperature and poor mechanical properties. The thermal and rheological behavior for blends of PHB extracted from dry weight of Jatropha and Poly (ethylene glycol) (PEG) were investigated. Blends of PHB/PEG (PHB 100, PHB 80, PHB 60 and PHB 50) have been prepared through solution blending method. The thermal using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) and rheological behavior using Oscillating Disk Rheometer have been investigated. The results indicate all PHb/PEG blends showed decreased at lowest melting temperature crystallinity (Xc). The TGA result showed that PHB 80 less degraded and suggest better thermal stability compared to PHB 60 and PHB 50. Adding PEG to PHB also improved the rheological behavior of PHB. At higher frequency range, PHB 100 showed less dependency on frequency indicating the elastic structure it has compared to PHB 80, PHB 60 and PHB 50.