bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Solid Waste from Refined Sugar Industry (Filter Cake) as Biodegradable Foam (Biofoam)
Authors: Wulan S , Rukmana D , Sjahrul M
Published: May 2020

Biodegradable foam (biofoam) is an environmentally friendly alternative packaging to replace Styrofoam. The aim of this research is to synthesize biofoam from blotong waste, obtain its characteristics and determine the economic feasibility of developing the produced biofoam product. This research was conducted with descriptive experimental methods and economic feasibility studies through NPV and PI calculations. The results of this study indicate that biofoam with the addition of a glycerol plasticizer of 15% w / w has the best characteristics, which contain water content (6.321%) and the lowest water absorption (17.181%) and tensile strength (6.7778 N / mm2) and elongity (174.5%) are higher when compared to styrofoam packaging. All biofoam can be completely degraded within 25-30 days. The addition of glycerol plasticizer generally affects the characteristics of the biofoam produced. Based on the results of the analysis of the economic feasibility study, the development of biofoam based blotong products is feasible (positive NPV; PI> 1).
Utilization of probiotic bacteria as an effort to handle liquid waste from the palm oil processing industry
Authors: Fatmawati  , Winata L R , Tahir A
Published: May 2020

The research aims to determine pollutant content in oil industry wastewater by using probiotic bacteria in reducing the content of pollutants in the palm oil industry. This study conducted in Laboratory of Microbiology, Faculty of Medicine, Hasanuddin University, Makassar and Health Laboratory Center (BBLK). The sample was determined using a random sampling method. The data were analyzed variance (ANOVA) method. The results of the research indicate that there are two types of bacterial isolates, namely, isolate A was Lactobacillus bulgharicus and isolate B was Lactobacillus plantarum. Probiotic bacteria isolated from cow’s milk can reduce BOD content from 250.25 mg/L to 95.56 mg/L. COD value decreases from 530.25 mg/L to 245.81 mg/L. TSS value decreases from 420 mg/L to 232 mg/L. The initial fat content decreases from 30.25 mg/L to 21.65 mg/L. The initial measurement of value decreases from 7.5to 6. Biodegradationprocess of the palm oil industry wastewater with the addition of the probiotic bacterial isolates can reduce organic content and pollutant content of the liquid waste of the palm oil industry. The most effective rate of waste degradation is bacterial isolate Lactobacillus plantarum with McFarland 1.5
Mode selection in transportation system: implications of quality function deployment
Authors: Kadir A R , Kamariah N , Ganna O R , Pono M , Yamar
Published: May 2020

This article, proposing Quality Function Deployment (QFD) as a product and service design technique, can be used to make decisions. Implementation of the process is done by conceptualizing problems, collecting data, and analyzing and reporting results. In this process, the required product innovation as well as the needs of the employees, as internal organizational clients, are determined. These results are then used to design KPIs that relate to consumer perspectives as well as internal perspectives. This framework is manifested in a diagram called the House of Quality (HOQ). Nevertheless, as a tool developed from practical level, little theoretical and empirical reviews attempt to provide sufficient information to assure the benefits of QFD in the transport context. Therefore, we review the theoretical foundations that can be used to support QFD and present a number of empirical findings from the literature that can be used to evaluate the feasibility of QFD in the selection of modes of transport. Because it is a practical tool, QFD is rarely discussed through theoretical approach. QFD has no theoretical basis at all. However, it is important to support QFD from the relevant theoretical aspects to explain how this system can work in promoting the improvement of product and service quality.
Organo-silica membrane for brine water pervaporation
Authors: Elma M , Sari N L , Pratomo D A , Annadliyah S , Rampun E L A , Rahma A , Pratiwi A E
Published: May 2020

Pervaporation is currently used for brine water desalination. This high water salt content may impact the environment if it may not be treated. So, in this paper demonstrates the performance of organo-silca membrane to produce potable water from brine water. Organo-silica membrane was employed by sol gel process for 3 hours using tetra orthosilicate (TEOS) as precursor as well as dual catalyzed (organo catalyst/citric acid) and base (ammonia) on reflux temperature of 0°C. The molar ratios were 1:38:0.0007:5:003 for TEOS:EtOH:Citric Acid:H2O:NH3. Organo-silica membrane was applied in various artificial brine water (7.5-15 wt % NaCl) operated at 40 and 60°C as feed temperatures. The citric acid was chosen as carbon source to increase the carbon chains in the silica matrices. It was found that the water flux was increased as the feed temperature also increased from 40°C (1.27 kg.m2.h−1) to 60°C (1.55 kg.m2.h−1). Organo–silica membranes can produce water with a salt rejection of >90%.
Shear strength analysis of reduced beam section (RBS) on castellated beam
Authors: Parung H , Aswad N H , Tachrir
Published: May 2020

Shear strength analysis of the reduced beam section (RBS) on the castellated beam with exterior connection aimed to analyze the structural elements to determine the shear force acting due to cyclic loading. The study was developed from the theory of moments due to shear forces based on the American Institute of Steel’s Prequalified Connection Construction for Special and Intermediate Moment Frames for Seismic Applications (AISC 358-10). This study used an experiment of RBS on a castellated beam with an exterior connection model subjected to cyclic loading. The result shows that the shear strength occurred after the bending failure of the beam.
Potential of n-hexane and chloroform extracts from Melochia umbellata (Houtt) Stapf var bark. Visenia as dengue antivirus
Authors: Soekamto N H , Aeni N , Firdaus
Published: May 2020

A study was conducted on the identification of the group of compounds from from n-hexane and chloroform extract of bark of M. umbelatta (Houtt.) Stapf var. Vicenia (Houtt.) and its activity test against dengue antiviral causes dengue hemorrhagic fever (DHF). The method used through several stages are maceration gradually starting from n-hexane and then followed chloroform, to stem bark powder M. umbelatta (Houtt.) Stapf var. Vicenia (Houtt.). Phytochemical test was done to know the group of compounds in each extract. In both extracts tested its activity against dengue virus. From the phytochemical test it is known that the n-hexane extract contain terpenoid, steroids and alkaloids, while in chloroform extract contain of steroids and alkaloids. From this study it was found that n-hexane and chloroform extracts were very active against dengue virus with IC50 values of 2.39 and 2.34 μg/mL. Thus, n-hexane and chloroform extracts can be used to help cure of Dengue Fever (DHF) disease
The strategies of the use of regional infrastructure to increase the activities in untia nusantara fish port of untia biringkanaya subdistrict Makassar City
Authors: Idris M , Barkey R A , Jamil H
Published: May 2020

Fisheries ports are the main base in capture fisheries industry activities which must be able to guarantee the success of fishing activities in the sea . This research aims to form the structure of the proper utilization of the regional infrastructure in order to increase the activities of Untia Nusantara Fisheries Port . The analytical method was used to determine the formulation of the right utilization strategy for the regional infrastructure to increase the activities of Untia Nusantara Fishery Port; this analysis is called force analysis. The research results indicated that the inactivity of Untia VAT to utilize the infrastructure availability, when viewed from the Fishery Port and based on the Regulation of the Ministry of Maritime and Fisheries of the Republic of Indonesia, for the Untia VAT infrastructure was still not available, such as the station of refueling, sewage treatment systems, and availability of clean water facilities
Analysis of Circuit Design of a Rowing Electric Installation with a Distributed DC Bus of a Port Icebreaker
Authors: Romanovskiy V V , Bezhik A S
Published: May 2020

Currently, there is a steady trend in increasing the volume of electrical equipment used in shipboard needs. At the same time, the primary electric power system of ships has long been based on an alternating current system. However, due to the changing and increasing requirements for the quality of the generated electric energy, the marine industry is developing more and more promising directions for the development of electrical systems. Thus, the most efficient and environmentally friendly shipboard power distribution system is the direct current (DC) system, which was adopted for a single power plant installation in combination with an alternating current network. This article discusses the current topic of electric propulsion on ships. The circuit design of a rowing electric installation with a distributed DC bus of a port icebreaker is considered. The expressions used to calculate the static load and build an electromagnetic model of a permanent magnet synchronous motor are given. Computer models for calculating the load in static and dynamic modes are shown.
Experience of Use High-Precise Position Systems for Inland Waters
Authors: Karetnikov V , Pashchenko I , Kozlov V , Butsanets A
Published: May 2020

Real Time Kinematic (RTK) is a differential method of object positioning using GNSS in which code corrections are supplemented by phase ones and transmitted from a base station (with precisely known coordinates) to a movable receiver in real time [1]. Having a series of advantages over classical differential methods of object positioning the most essential of which is centimeter precision of positioning, the method has found wide use in various spheres. Networks providing RTK solutions in real time on a commercial basis, and also free of charge in certain countries within the frameworks of state geodetic networks cover considerable areas with a field of high-precision corrections.
EDM Process by Using Copper Electrode with INCONEL 625 Material
Authors: Yuvaraj N. , Arshath Raja R. , Palanivel Prakash , Kousik N.V.
Published: May 2020

Electrical discharge method (EDM), based on the thermo electrical energy of the workpiece and the mechanical electrical machining, are non-traditional machining methods. Current development of the nano mixed dielectric discharge device has the latest trends in tough and soft materials finishing. This research assesses the impact on nano-particle mixed electric discharge extraction of the inconel 625 product by means of a copper electrode of the material removal frequency (MRR), device wear level (TWR), and superficial surface roughness. In contrast to dielectric fluid are the output parameters such as current, period and frequency, and nano-substances of titanium carbide. During this phase, a sequential, separate discharges between the electrode and the workpiece contribute to the product removal electro thermally. The method quality largely depends on the Electrode content, the production of the electrode workpiece product. Appropriate electrode choice may reduce machining costs. Die-Sinker EDM with the copper electrode is therefore able to provide for improvement of output parameters and reduction of production costs. In case of surface roughness, a copper electrode has improved efficiency and is better suited for nano powdered dielectric medium.
Progress on Pine Derivative Products as Fuel Source in Indonesia
Authors: Setyawan H Y , Sunyoto N M S , Wijana S , Pranowo D
Published: May 2020

Pine resin is a non-wood forestry product in Indonesia that can be converted into a much higher value product. Pine resin traditionally is converted into rosin and turpentine. Due to the scarcity supply of fossil fuel, turpentine has been studied as fuel for diesel substitution. Pinene, the highest component found in pine resin is the primary fuel source candidate. Pinene dimer, modified pinene using catalysts or ozone have a heating value similar to that of JP-10, a tactical fuel for rockets. This paper discussed the technological development of pinene and pinene dimers as a fuel. The opportunity and challenge for producing pine based fuel in Indonesia were also addressed.
Improvement of Heat Sink Performance by Using Graphene Nanosheets Coated by Chemical Spray Method
Authors: Jaafar A. A. , Al-abassi S. A.W. , Alhattab H. A. , Albaghdad M.A. , Mosa A. A. , Al-Musawi H.K. , Abo Gneem L.M.
Published: May 2020

Graphene nanosheets were fabricated on a metal (Al) substrate by using a chemical spray method. Annealing process has been applied to reducing the concentration of carbon and to increase the sheet hardness. Surface morphology measured by metallurgical microscope Device Corporation, X 1600. Thermal camera was used to measure the performance of coated heat sink. The temperature was measured from the two sides, one from heat sink side, and the other one is from power transistor side. The results showed that the temperature of the transistor was decreased by about 4.3 °C in the case of heat sink coating with 80 μm layer thickness while decreased by 6.9 °C in the case of the heat sink coating with 120 μm layer thickness.
Steel Corrosion Behaviour in Acidic Solution for Application in Petrochemical Distillation Systems
Authors: Fajobi M A , Loto R T , Oluwole O O
Published: May 2020

The electrochemical reaction response of austenitic 316L stainless steel and carbon steel was examined through weight loss analysis in 1M, 2M and 3M of HCl acid. The results show that austenitic 316L has high corrosion resistance than carbon steel for the test analyzed with the lowest corrosion rate of 0.0018mm/y at 1M of HCl and highest at 0.0053mm/y when compared with carbon steel which has the lowest corrosion rate of 0.0003mm/y for 1M of HCl and highest at 0.0013 mm/y of 3M of HCl solution all at ambient temperature conditions. General corrosion was displayed on the surface of the carbon steel but austenitic 316L was not affected due to the presence of chromium alloy and other alloying elements.
Temperature Effect on the Deformation of the Recycled Hot-Mix Asphalt Concrete with Nano Crumb Rubber as an Added Material with Wheel Tracking Machine
Authors: Hadiwardoyo S P , Aryapijati R H , Sumabrata R J , Iskandar D
Published: May 2020

The use of materials for the construction of roads can be done by recycling asphalt concrete mixtures that have reached fatigue or aging conditions. The results from stripping the asphalt concrete layer on the surface layer can be reused after processing by recycling the material. The recycling process is often intended to preserve the environment from natural damage due to the processing of material for asphalt concrete mix. To improve the performance of the recycled mixture, additives have been widely used and the use of building materials as additives can also be obtained from building material waste. One of the waste that continues to increase is the waste of vehicle tires. In this research used tire waste that has been mashed up to Nano size. The use of finer used tire sizes is intended to facilitate the process of mixing with asphalt. Recycling performance of hot mix asphalt concrete on deformation performance has been used rutting test using Wheel Tracking Machine at a temperature of 27°C, 40°C and 60°C. The test results showed a decrease in the rate of deformation in the asphalt concrete recycle mixture using Nano crumb rubber added material.
Analysis and Research on the Working Parameters of Colloidal Spraying for the Thermal Insulation Layer of Rocket Tank
Authors: Xue Haiyang , Xu Haibo , Qian Yingkun
Published: May 2020

In this paper, the working parameters of DW-1 type colloid spray coating for rocket tank insulation are analysed and studied, and the optimal working parameters are determined. Firstly, a flow field simulation analysis model of thermal insulation layer DW-1 colloid spray is established, the spray flow field simulation of different spraying working parameters is performed. Then the relationship between the flow field characteristics such as spray speed and atomization uniformity and the spraying working parameters are initially determined. After that, an analytical model of droplet impact is established to study the influence of spraying speed on the impact dynamics and spreading quality of the droplet, and the optimal working parameters of colloidal spraying are determined.
Dynamic Behavior Analysis of Feed Drive System Using Linear Guideways with Different Ball Diameters
Authors: Tanaka Kazuma , Yamazaki Takanori
Published: May 2020

The feed drive system for machine tool consist of rolling elements such as ball screw and linear guides. It is well known that in the positioning of linear guides using steel ball rolling, the contact surface has nonlinear spring characteristics. This phenomenon is deteriorating the accuracy of the machine tool. In this study, we have manufactured a feed drive system in which the physical contacts are only linear guides by using a linear motor as actuator. At first, we measured the responses to some fine feed amount for feed drive system. Next, the same experiment was performed by changing the linear guideways. This paper presents the transition of nonlinear spring characteristic region by considering the response to linear guides under different conditions.
Vibration Compensation of Checkweigher Using Acceleration Sensor
Authors: Tsuzura Akinori , Yamakawa Yuji , Yamazaki Takanori
Published: May 2020

The checkweigher is a device that measures mass continuously and it carries out mass measurement while conveying an object on a belt conveyor. It is a device that operated an active role in various fields such as food, medicine, and industrial products. Although the load cell scale is often used to measure measurement in the checkweigher, due to the structure of load cell, the accuracy is susceptible to environmental vibration. It is difficult to generate low frequency input such as floor vibration with the general vibration exciter. We first manufactured a device that can reproduce environmental vibration. In this study, we present the response of the load cell to excited by the device, moreover consider the vibration compensation using an acceleration sensor.
The technology of using inflatable structures made of special materials to adapt the de-orbiting system for removing spacecraft
Authors: Koryanov V V , Toporkov A G , Kazakovtsev V P , Nedogarok A A
Published: May 2020

We are today facing a huge issue on the concentration of space debris in near-Earth space. More than 15,000 debris have been recorded, and this represents a danger for current and future missions to space. A solution to this issue is to remove these spacecrafts from orbit. One of the ways to do it is to use inflatable device. These braking device can be installed on the landing vehicles on Earth, before their launch, or after they have been labelled as space debris. Studies have already been conducted about inflatable device. The results of these studies show that using an inflatable device on an orbital spacecraft significantly reduces its lifetime (it then does not exceed 25 years in most cases). Using inflatable device instead of rigid device has advantages, such as a small mass and a great compacity, which is convenient to respect the required launching volume.
Structure, luminescence and mechano-optical properties of strontium aluminate doped with europium and dysprosium ions
Authors: Banishev A. A. , Banishev A. F.
Published: May 2020

Photoluminescence spectra and kinetics of mechanoluminescence of finely dispersed powder of SrAl2O4:(Eu2+, Dy3+) and Sr4Al14O25:(Eu2+, Dy3+) phosphor was investigated. Photoluminescence was excited by nanosecond laser pulses with a wavelength of λ = 355 nm and by a group of cw lasers with different wavelengths (λ=355, 404, 440, 530 nm). Photoluminescence of the materials has been revealed in the long-wave (550 to 750 μm) spectral region, which is indicative of the existence of corresponding energy levels of Eu2+ions. It was shown that, at low power density, a single wide broadened line of photoluminescence was observed. As radiation power density is increased, additional photoluminescence lines begin to appear. The microstructure of the powders has been investigated with the scanning electron microscope. It has been found that the powder consists of microparticles (granules) of the sizes up to 100 μm. The microparticles show a granular structure, the grain size being as large as 25 μm. Mechanoluminescence was initiated by an acoustic wave generated by short laser pulses. A mechanism of mechanoluminescence excitation has been suggested. It has been concluded that mechanoluminescence of SrAl2O4:(Eu2+, Dy3+) is excited owing to activation of the traps during their interaction with the electric fields of moving grain boundary dislocations as the result of grain boundary sliding under deformation of microparticles on impact.
The Integration technology of desulfurization, denitration and heat recovery from coke oven flue gas
Authors: Jiang Hui , Li Shun , Ha Jun , Guo Wei , Pan Yixin , Wan Xue , Xie Guowei
Published: May 2020

The main components of coke oven flue gas were SO2, NOX etc. SO2 and NOX were not only harmful to human health, but also seriously polluted the environment. The stricter “Standard for Discharge of Pollutants from coking chemical industry” was introduced. An integration settlement scheme of flue gas desulfurization, denitration and waste heat recovery was put forward. The proprietary core technologies, such as denitration, COG desulfurization and radial heat pipe boiler were researched. The integration settlement scheme can solve the problems of polluting the environment and waste heat without recovery, which had not only significant economic benefits, but also huge social benefits.
Pavement Deterioration Model Using Markov Chain and International Roughness Index
Authors: Sati A S , Abu Dabous S , Zeiada W
Published: May 2020

Pavement deterioration leads to drop in serviceability and possibly failure of pavement sections due to initiation and expansion of distresses such as cracks and rutting. This paper aimed at predicting the future condition of pavement sections based on Markov chain model and the international roughness index (IRI). Developing this model can facilitate life cycle analysis and selecting the correct treatment at the right time. The historical IRI data of Canadian pavement sections were collected from Long term pavement performance (LTPP) database. IRI values were used to assess condition of the pavement sections based on the recommended ranges by the Federal highway administration (FHWA). The transition probabilities were estimated using the percentage prediction method based on historical condition data extracted from the LTPP. These probabilities are assembled in a transition probability matrix essential for the Markov chain model. The developed matrix can be used to forecast pavement conditions after any number of transition periods. The developed method assists in predicting pavement performance and facilitates the decision-making process. The method is applied to a real case study to examine its validity. The model can be expanded further by considering additional data from additional pavement networks.
Computer Modeling on the Effect of the Multistep Nanoimprinting Process in Elastic Deformation Recovery of COC (Cyclic Olefin Copolymer)
Authors: Almadani Hamzah , Chen X , Cheng Junfei
Published: May 2020

The effect of the multistep imprint in elastic deformation recovery was studied numerically with more than one roll and different depth ratios. As well as effect hold-on time on the elastic deformation recovery of polymer Cyclic Olefin Copolymer (COC) material was studied using Generalized Maxwell (GM) constitutive model and their parameters in finite element simulation software of ABAQUS were presented. Firstly, the modified Genetic Algorithm (GA) was employed to obtain a Prony series of the viscoelastic model in terms of experimental data of the complex modulus for COC. To evaluate the elastic recovery of the microstructure, the cross-sectional area of micro-channel before and after hot-imprinting was computed and compared numerically. The simulated results were analysed and clearly showed an improvement in the elastic recovery rate of the microstructure area as the multi-step of rolling was employed.
Safety Assessment of Steam Generator in Hydrogen Production Unit under Local Overtemperature Conditions
Authors: Du Liang , Yan He , Zhao Wenjing , Liu Deyu , Chen Yanze
Published: May 2020

A steam generator at the bottom of a radiant chamber of a hydrogen production unit is used to heat the conversion gas of the reformer to the boiler feed water, thus producing medium pressure steam. During the inspection process, the color of the temperature indicating coating was found to be abnormal near the manhole block of the equipment. The maximum temperature of the wall of the device was up to 472.7°C by infrared thermal imager. In this paper, the reason of the overtemperature of the steam generator is analyzed. Secondly, the stress strength evaluation based on the conventional strength checking formula and the finite element numerical simulation analysis method is carried out. Finally, the monitoring suggestion and the follow-up test proposal under the high temperature operating condition are given.
Preliminary Evaluation of Active Tremor Cancellation Spoon for Patients with Hand Tremor
Authors: Ripin Zaidi Mohd , Chan Ping Yi , Alisah Izudin
Published: May 2020

Hand-arm tremor is common in Parkinson’s disease (PD) patients and essential tremor (ET) and can result in difficulty of carrying out daily tasks such as eating and writing. One of the approaches to overcome this is the application active tremor cancellation (ATC) to attenuate the vibration due to the hand tremor on the device hold by the hand. There are several ATC spoons in the market which are meant to help the patient to eat however third-party evaluation of the effectiveness of this technology could not be found in the literature. This study evaluates Liftware, a spoon with ATC by measuring the acceleration performance of the spoon over the frequency range of 1-12 Hz which adequately covers both the PD and ET. In the first part of the study, the device was evaluated on the isolation index throughout the tested range of frequency along the vertical or gravitational, and the horizontal directions, the direction perpendicular to both gravitational and the longitudinal axis. Subsequently, the device was evaluated for the limit at which the food it contains start to spill. Solid food, typically boiled peas and liquid, namely curry was the food tested with the spoon. Ten measurements were carried out for each type of food and the average limits prior to spillage was presented. The results show that the isolation indices in vertical and horizontal directions range from 0.06 to 0.63 and 0.06 to 0.62 respectively at frequency range of 3-12Hz. The limits of the spoon in supporting the boiled peas and curry are 1.4g and 0.9g respectively. However, the preliminary study provides part of the knowledge useful for the potential users and researchers. Further study to subject the device under different conditions, especially in clinical settings is required.
Sound and Vibration Damping Properties of Water Retted Kenaf Bast Fiber (WKF) and Poly (Butylene Succinate) PBS
Authors: Wan Mamat Ali WMA , Ooi L.E. , Thirmizir M.Z.A
Published: May 2020

Nowadays, considerable attention has been paid on the utilization of natural materials to reduce the carbon emission from material synthesis. In this study, the sound and vibration damping properties of natural material based Poly Butylene Succinate(PBS) and Water Retted Kenaf Bast Fiber(WKF) were explored and characterized. The goal is to characterize the sound absorption and damping properties of the PBS and WKF at difference materials percentage. The (material)PBS and WKF are produced by using Compression moulding machine model Gotech GT-7014-H and the sample thickness is 3 mm. The vibration damping measurement of the material is carried out based on the free vibration method technique. It is observed that the damping factor is obtained is 0.0469 for PBS material. The measurement of the sound absorption coefficient of the PBS and WKF is carried out using the impedance tube. The result shows that the maximum sound absorption of 0.305 was observed at a frequency of 642 Hz for PBS material. Whereas Tensile Strength, for PBS material shows 26.33 MPa. These results suggest that the PBS could be a viable candidate for applications which need good sound and vibration properties.
Monitoring of Gear Surface Roughness in Angle Grinder using Vibration Analysis
Authors: Yusuf Z N M , Sidek N S D , Hamid M N A , Teoh P Y
Published: May 2020

This paper aims to provide the relation between surface roughness of angle grinder towards vibration amplitude. Prolong usage of angle grinder over excessive force will affect the performance of angle grinder where it tends to vibrate due to surface roughness of gear and create excessive vibration that will lead to hand-arm vibration system. Therefore, this study is conducted to investigate surface roughness of the gear teeth of angle grinder affects the amplitude of vibration. The amplitude of the vibration for angle grinder is conducted by using LMS data acquisition system. Meanwhile, the roughness of the gear teeth is measured by using Keyence Laser Confocal Microscope. The data was taken by every 100 hours of grinding process. The results show that the surface roughness of the gear teeth is steadily decreasing due to contact between gears and subsequently resulted increasing the amplitude of the vibration. For 500 hours measurement, the correlation of surface roughness of gear teeth with the amplitude of vibration is 93.7% for marked tooth and 86.5% for adjacent tooth, this indicates the strongest possible agreement that when surface roughness of the gear teeth decreasing, the vibration amplitude is higher.
Numerical Analysis on Vibro-acoustic Characterisation of Hybrid Honeycomb Structure with Flow Permeability
Authors: Tee Zhen Wei , Teoh Choe Yung
Published: May 2020

The application of conventional noise attenuating structures was often limited when the exchange of air was required due to the trade-off between their noise attenuation properties and ventilation efficiency. The large physical footprint of conventional noise attenuating structures with flow permeability had also limited their applications. This paper investigated the use of corrugation structure in lightweight honeycomb sandwich panels with flow permeability to improve noise attenuation while preserving ventilation. The vibro-acoustic property of the honeycomb structure with flow permeability at low to medium frequency range (50-3000 Hz) was investigated through numerical simulation. Two different hybrid panel designs with U-shaped and V-shaped corrugations in the honeycomb core had been proposed and were found to exhibit superior sound transmission loss (STL) compared to the honeycomb panel without significantly affecting the flow performance. It was found that in the frequency range of 50-3000 Hz, the unweighted STL of the U-shaped corrugation honeycomb hybrid panel (UCHP) and V-shaped corrugation honeycomb hybrid panel (VCHP) was 19 dB and 25 dB higher than the honeycomb panel respectively with negligible effect on the flow performance. The proposed hybrid panel showed promising noise attenuation applications which involved fluid flows such as in fan and engine noise reduction.
Attenution of Motorcycle Handle Vibration using Suspended Handlebar
Authors: Usamah Nabil Mohamad , Ripin Zaidi Mohd
Published: May 2020

Motorcycle rider is exposed to the handle vibration. Extended exposure to high level of handle vibration can result is hand-arm vibration syndrome (HAVs). In South East Asia the majority of the motorcycle are powered by single cylinder small displacement (70 – 125 cc) engines. This paper describes the modal analysis of a small single cylinder underbone type motorcycle widely used in the rural and urban for commuting to workplace. A suspended handlebar is developed by mounting the handlebar on rubber mounts. Transmissibility measurement are carried out for static and on the road condition. There are conditions where transmissibility is above unity due to resonance for the existing handlebar and this condition is overcome by the suspended handlebar except at frequency of 25 Hand this was below the operating frequency range of the motorcycle engine of cruising speed (50 – 60 Hz). On the road tests show that the handlebar is effectively attenuate with the installation of the engine mounts. Maximum attenuation of 79 % is achieved at 3300 – 3400 rpm which give HAV of 3.41 ms
−2.
Vibration Analysis of Chenderoh Dam Physical Model Spillway Structure due to the Effect of Water Spilling: Numerical and Experimental Validation
Authors: Arbain A , Zawawi M H , Ganesan R , Ghazali M H M , Radzi M R M , Hassan N H , Mazlan A Z A
Published: May 2020

Dam can be defined as a barrier built across the river to restrain and control the flow of water. However, the safety of the dam structure can be threatened by the uncertainties vibration induced from internal and external sources. Thus, in this paper, the vibration analysis in terms of Experimental Modal Analysis (EMA) and Operational Deflection Shapes (ODS) are carried out to determine the reliability of the dam structure. This study only focused on the spillway structure of the Chenderoh Dam that located in Perak, Malaysia. For the simulation, a 3D physical model with 1:20 scale is developed using SolidWorks software and simulated using ANSYS software. Whilst, for validation of the simulation results, EMA and ODS experiment are performed on the physical model of the Chenderoh Dam. The validation will be in terms of mode shape, ODS, natural and operating frequencies. From the results, the first natural frequency of the spillway occurred at 220.87 Hz with the maximum deflection of 1.6 mm and the ODS deformation happened at operating frequency of 45 Hz with the amplitude value of 0.003 m. The operating frequency value is far from the natural frequency of 220.87 Hz; thus, the transient vibration only induces a minimal effect on the spillway structure and the spillway is considered safe for the operation.
Fluid/structure Interaction Numerical Study on the Mechanical Integrity of Water Dam Reservoir Banks
Authors: Ng F C , Azman Aqil , Abas Aizat , Zawawi Mohd Hafiz , Ahmad Mazlan Ahmad Zhafran , Zahari Nazirul Mubin , Mohd Remy Rozainy Z
Published: May 2020

Dam reliability analysis is conducted to access the integrity of dam structure and thus to prevent dam failure. This paper presents the numerical reliability study of reservoir banks of water dam by the mean of fluid/structure interaction (FSI) simulation. Through FSI, the hydrostatics effect of the water in reservoir on the wall of dam was successfully simulated and identified. From the current numerical work, relatively stagnant water on the dam bank was observed, with the increasing water pressure along the water depth. Subsequently, localized high stress and deformation on the dam structure was successfully identified, and suitable countermeasures were being recommended. For the current investigated dam bank structure, the highest deformation and stress detected are respectively 1.185 mm and 3.12 MPa. Therefore, at present operating configuration, it is concluded the bank would not exhibit any failures.
Influence of thickness and background on the color changes of CAD/CAM dental ceramic restorative materials
Authors: Alfouzan Afnan F , Al-Otaibi Hanan N , Labban Nawaf , Taweel Sara Mohammad Al , Al-Tuwaijri Shahad , AlGazlan AlMaha S , Tashkandi Esam A
Published: May 2020

This study aimed to compare the effect of thickness and background on the color changes of CAD/CAM materials (zirconia-reinforced lithium silicate (Suprinity), lithium disilicate (IPS E-max CAD), and hybrid ceramic (Enamic)). Twelve specimens for each thickness (0.4 mm, 0.5 mm, 1 mm, 1.5 mm, and 2 mm) were obtained by sectioning three CAD/CAM materials. A spectrophotometer was used to measure the color change of the specimens against different backgrounds (A2 enamel, A4 dentin, gray, and metal) using the CIELab color space system. Analysis of variance, sample t-test, and posthoc multiple comparison tests were used to evaluate and compare the color changes for different material types, thicknesses, and background colors, with a significance level of P ≤ 0.05. The result demonstrated that material type, the thickness of the material, and the color of the background had a significant effect on ΔE (P = 0.000). Regardless of the material thickness, Suprinity had the highest mean ΔE values (5.4 ± 1.9), and E-max had the lowest mean ΔE values (1.1 ± 0.6). At 2 mm thickness, Enamic presented the lowest ∆E values (0.5 ± 0.5) against the A2 background. The 0.5 and 1 mm specimens corresponded to the highest ΔE values, whereas the 1.5 and 2 mm thickness specimens predominantly gave the lowest ΔE values. All the independent factors, including the type and thickness of the material, and color of the background, contributed significantly to ΔE of the tested materials (P ≤ 0.05). The study confirms the high masking ability of the lithium disilicate (E-max) material. In clinical situations where the color of the core needs to be masked, it is recommended to use lithium disilicate (E-max).
Formation of L10-ordered CoPt during interdiffusion of electron-beam-deposited Pt/Co bilayer thin films on Si/SiO2 substrates by rapid thermal annealing
Authors: Toyama Ryo , Kawachi Shiro , Iimura Soshi , Yamaura Jun-ichi , Murakami Youichi , Hosono Hideo , Majima Yutaka
Published: May 2020

Preparation of ordered CoPt on Si substrates is significant for expanding future applications of spintronic devices. In this study, ordered CoPt alloys including the L10 phase with a maximum coercivity of 2.1 kOe are formed in electron-beam-deposited 11.4 nm thick Pt/Co bilayer thin films on Si/SiO2 substrates via interdiffusion during rapid thermal annealing (RTA). The effects of RTA temperature on the magnetic properties, crystal structures, cross-sectional elemental profiles, and surface morphologies of the films are analyzed by vibrating sample magnetometer (VSM), grazing incidence x-ray diffraction (GI-XRD), energy-dispersive x-ray spectroscopy (EDX), and scanning electron microscope (SEM), respectively. For the as-deposited film, polycrystalline Pt was confirmed by uniform Debye–Scherrer rings of Pt. At 200 °C, interdiffusion between Co and Pt atoms in the film started to be observed by EDX elemental maps, and at 300 °C, alloying of Co and Pt atoms was confirmed by diffraction peaks corresponding to A1-disordered CoPt. At 400 °C, the in-plane coercivity of the film began to increase. At 700 °C, ordered CoPt alloys were confirmed by superlattice diffraction peaks. At 800 °C, a graded film containing L10-ordered CoPt was found to be formed and a maximum coercivity of 2.1 kOe was observed by VSM, where the easy axis of magnetization was oriented along the in-plane direction. At 900 °C, deformation of the ordered CoPt alloys was observed by GI-XRD, and the grain size of the film reached a maximum.
Magnetic force assisted thermal nanoimprint lithography (MF-TNIL) for cost-effective fabrication of 2D nanosquare array
Authors: Moirangthem Rakesh S
Published: May 2020

The work presented here describes a simple, low-cost, and unconventional technique to fabricate a 2D nanosquare array using magnetic force assisted thermal nanoimprint lithography (MF-TNIL). The nanofabrication process involves two steps: (i) fabrication of a 2D nanosquare array template on a laminated plastic sheet via sequential thermal nanoimprinting of linear nanograting polydimethylsiloxane (PDMS) stamp, and (ii) reversal imprinting of template on UV curable polymer using soft UV-nanoimprint lithography. Without using an expensive nanofabrication tool, our proposed technique can fabricate nanosquare array over an area of 1 × 1 cm2 with individual nanosquare having a feature size of about 383 nm × 354 nm × 70 nm. We believe that our proposed MF-TNIL represents a promising nanofabrication technique that will allow fabricating various types of nanostructures for their applications in developing sensors, anti-reflective surfaces, self-cleaning surfaces, etc.
Vasculitis Involving the Gastrointestinal System Is Often Incidental but Critically Important
Authors: Zhang Xiaoming , Furth Emma Elizabeth , Tondon Rashmi
Published: May 2020

Objectives

This study was aimed to investigate the significance of unexpected vasculitis identified in gastrointestinal (GI) specimens by determining its prevalence and correlation with clinical outcomes.

Methods

GI specimens with histologic evidence of vasculitis were identified in our pathology database over a 10-year period (January 2008 to August 2018). Clinical history, treatment, and follow-up were reviewed.

Results

Of the 131,367 GI pathology cases received over the 10-year study period, 29 (0.02%) cases showed histologic evidence of GI vasculitis. The majority (69%, 20/29) were not clinically suspected. Of these, 20% (4/20) of patients were subsequently diagnosed with systemic vasculitis. During the mean follow-up period of 34.0 months, 24% (4/17) of the patients with this unexpected diagnosis died as the result of direct complications of GI vasculitis. We also found that 95% of cases with unexpected vasculitis in their GI pathology specimens were communicated in a timely manner to the ordering physicians, which necessitated the immediate initiation of additional workups in 85% of these patients.

Conclusions

The GI involvement of vasculitis is rarely encountered by pathologists, but its diagnosis carries tremendous clinical significance with a high mortality rate. Therefore, timely communication is highly recommended for the early diagnosis and treatment of this disease.
Birth Sibling Relationships after Adoption: Experiences of Contact with Brothers and Sisters Living Elsewhere
Authors: Meakings Sarah , Paine Amy L , Shelton Katherine H
Published: May 2020

We examined how adoptive families manage and respond to contact with children’s birth siblings living elsewhere within a nationally representative sample of 96 families who adopted a child between 01 July 2014 and 31 July 2015. We harnessed prospective, longitudinal data to determine the extent to which plans for contact between adopted children and birth siblings living elsewhere materialised over time. We present adoptive parents’ views and experiences of the contact over four years, together with an analysis of factors that were thought to have prevented, hindered and/or enabled contact between adopted children and their birth siblings. The information shared by the adoptive families illustrates the challenges they faced in promoting sibling contact; in weighing up the complexities associated with managing contact in the short term against the anticipated benefit for their child in the longer term; of balancing a commitment to sibling contact with the psychological needs of their child; and of organising contact within the context of interactions with other families involved and social work professionals. On the basis of these findings, we make recommendations pertaining to the management of both letterbox and face-to-face contact and life story work, and underscore the importance of investing in sibling relationships.
Impaired glymphatic function and clearance of tau in an Alzheimer’s disease model
Authors: Harrison Ian F , Ismail Ozama , Machhada Asif , Colgan Niall , Ohene Yolanda , Nahavandi Payam , Ahmed Zeshan , Fisher Alice , Meftah Soraya , Murray Tracey K , Ottersen Ole P , Nagelhus Erlend A , O’Neill Michael J , Wells Jack A , Lythgoe Mark F
Published: May 2020

The glymphatic system, that is aquaporin 4 (AQP4) facilitated exchange of CSF with interstitial fluid (ISF), may provide a clearance pathway for protein species such as amyloid-β and tau, which accumulate in the brain in Alzheimer’s disease. Further, tau protein transference via the extracellular space, the compartment that is cleared by the glymphatic pathway, allows for its neuron-to-neuron propagation, and the regional progression of tauopathy in the disorder. The glymphatic system therefore represents an exciting new target for Alzheimer’s disease. Here we aim to understand the involvement of glymphatic CSF-ISF exchange in tau pathology. First, we demonstrate impaired CSF-ISF exchange and AQP4 polarization in a mouse model of tauopathy, suggesting that this clearance pathway may have the potential to exacerbate or even induce pathogenic accumulation of tau. Subsequently, we establish the central role of AQP4 in the glymphatic clearance of tau from the brain; showing marked impaired glymphatic CSF-ISF exchange and tau protein clearance using the novel AQP4 inhibitor, TGN-020. As such, we show that this system presents as a novel druggable target for the treatment of Alzheimer’s disease, and possibly other neurodegenerative diseases alike.
Importance of Face Masks for COVID-19: A Call for Effective Public Education
Authors: Tso Ricky V , Cowling Benjamin J
Published: May 2020

Considerable debates about the general community use of face masks for protection against coronavirus disease 2019 (COVID-19) stemmed out from differing views taken by health authorities. Misconceptions and stigmatization towards the use of face masks may hinder the containment of the COVID-19 pandemic. We address this previous debate by analyzing the advice on the community use of masks across different credible health authorities: countries that promoted the use of masks acknowledged that masks are effective but also explained the importance of their proper use along with other hygiene measures. In contrast, authorities that recommended against the community use of masks mainly cited shortage of supplies, the argument that the public do not have the adequate skills to wear them, or that wearing masks might reduce compliance with other important behaviors. We suggest promoting effective behavioral changes in personal protective measures by teaching microbiological knowledge instead of just listing out the “do’s-and-don’ts.”
Predictive value of cardio-ankle vascular index for the risk of end-stage renal disease
Authors: Jeong Jin Seon , Kim Jung Hee , Kim Dong Ki , Oh Kook-Hwan , Joo Kwon-Wook , Kim Yon Su , Cho Young Min , Han Seung Seok
Published: May 2020

Background

Arterial stiffness is associated with increased cardiovascular morbidity and mortality. However, the predictive value of the cardio-ankle vascular index (CAVI), one of the indicators for arterial stiffness, for the risk of end-stage renal disease (ESRD) remains unknown.

Methods

A total of 8701 patients with documented CAVI measurements by pulse wave velocity (PWV) were included in the study. Patients were divided according to the quartiles of CAVI. The hazard ratio (HR) of ESRD was calculated using the Cox model, after adjustment for multiple variables or death.

Results

During the median follow-up period of 7 years (maximum 12 years), ESRD and mortality occurred in 203 and 1071 patients, respectively. The median value of CAVI was 8.5 (interquartile range 7.7–9.3). The risk of ESRD was higher in the fourth-quartile group than the first-quartile group [adjusted HR 2.46 (IQR 1.62–3.71), P < 0.001]. When a death-adjusted risk analysis was performed, the fourth quartile of CAVI had a higher risk of ESRD than the first quartile [adjusted HR 2.35 (IQR 1.58–3.49), P < 0.001].

Conclusions

The measurement of CAVI by PWV may be needed to predict the risk of ESRD.