bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimum mix design of high-performance concrete containing micro POFA using historical data design
Authors: Hassan Wan Nur Firdaus Wan , Ismail Mohamed A , Ismail Mohammad , Hussin Mohd Warid , Rahman Muhammad Ekhlasur , Padil Khairul H , Darus Nadirah 
Published: May 2021

Abstract
This paper presents the optimized mix design based on the response surface methodology (RSM) in producing high performance concrete (HPC) by utilizing palm oil fuel ash (POFA) as cement replacement material. The historical data design was used based on the existing testing data determined from the laboratory experiments. The variable in this study includes POFA percentage (10%, 20%, and 30%). The concrete mixes were tested both for fresh and hardened properties of high performance concrete. The optimized level for POFA in the HPC mix proportion was determined by the maximization of workability, early, 28 days’, and later compressive strength. The response of each mix that contains POFA showed a significant increase in the workability and compressive strength with respect to the plain HPC. The results presented the optimum solution for mix design of high performance concrete with POFA that achieve the targeted goal performance criteria (fresh and hardened properties).
Indoor thermal comfort assessment in office buildings in hot-humid climate
Authors: Abass F , Ismail L H , Wahab I A , Mabrouk W A , Kabrein H 
Published: May 2021

Abstract
This paper aims to assess the user’s perception of thermal comfort and air conditioning in office buildings in Batu Pahat, Johor area. Field experiments were conducted utilizing environmental measurement and Post Occupancy Evaluation (POE) in Batu Pahat District Land Office (Pejabat Daerah) and (C2 and ORICC) office buildings in the Universiti Tun Hussien Onn Malaysia (UTHM). The environmental measurement was conducted using thermal comfort station BABUC A, whereas the POE was based on the ASHRAE 55-2010 standard. The environmental parameters included relative humidity, air temperature, and air velocity. They were measured and compared with MS-1525, ASHRAE 55, and ISO 7730 standards. Results indicated that indoor air temperature in C2 has good compliance with MS-1525, ASHRAE 55, and ISO 7730 standards and criteria with a measured comfort range of 24 °C-26 °C. Whereas for ORICC and Pejabat Daerah, temperatures were a bit lower than the suggested range. At the same time, the range of relative humidity was found to be higher than ASHRAE limits but complied with other standards. Moreover, adequate air velocity standards were not met in the three office buildings, in which they were measured within 0.4-0.5 m/s range. Furthermore, thermal comfort levels and the POE survey results indicated that users’ in hot tropical office buildings could acclimate to a higher indoor environment than what was suggested by standards.
Experimental study: Shear behaviour of reinforced concrete beams using steel plate strips as shear reinforcement
Authors: Eklou Remir J , Yani Muhammad B , Saifullah Halwan A , Sangadji Senot , Kristiawan Stefanus A 
Published: May 2021

Abstract
Stirrups bars are widely used as shear reinforcement in reinforced concrete beams. It is quite attractive to explore the use of another type of material for stirrups. This study aims to investigate the shear behaviour of reinforced concrete beams using steel plate strips and conventional stirrups as shear reinforcement. Two full-scale reinforced concrete beams were tested to fail in shear in this experimental program, and the test parameter for this study was the types of shear reinforcement. The shear resisting behaviour of the beam specimens was discussed by evaluating the crack patterns, load-deflection response and the shear strengths of the beam specimens. The shear capacities determined experimentally were compared with the prediction values calculated based on the Modified Truss Theory. The ratio of the measured to estimated shear strength in the steel plate RC beams and reference beam showed a fairly good agreement as these ratios were only slightly different. Results of this study show that there is only a slight difference in the global behaviour of the steel plate RC beam and the reference beam using conventional stirrups.
Betta persephone: The Challenges in Only Existed Natural Habitat; Ayer Hitam Peat Swamp Forest Reserve (AHPSFR) Muar Johor
Authors: Rafiq M Mohd , Nazirah M A , Adelyna M A Noor 
Published: May 2021

Abstract

Betta persephone is a native species and has been categorized as endangered in Ayer Hitam Peat Swamp Forest Reserve (AHPSFR), Muar Johor. This area is the only wild stronghold of this species. This species is facing greatest threats nowadays. As the study aimed to analyze the challenges of this species by using qualitative method. Interviews session has been conducted by the involvement of four respondents which all of them are ichthyologists and have expertises in this matter. Also, observations have been conducted inside AHPSFR. The data that have been gathered in interviews being analyzed by using NVivo software. For, observation sessions, a checklist was being obtained from the findings of the interview sessions. In the findings, all the respondents and observations have the consensus that challenges have been found out were overexploitation, land encroachment for oil palm plantation, illegal logging, water contamination, fires and illegal mining. The challenges that have been stated need to be bridle for the survivor and sustainability of the species for the reference of future generations.
Non-Flooding and Flooding Characteristics of a Natural Straight River
Authors: Rashid M F Abd , Ibrahim Z , Jumain M , Sa’ari R , Alias N , Jamal M H , Bakar A Abu 
Published: May 2021

Abstract
Floods happen when the flow of water exceeds the river banks and flow through the floodplain area, which is known as overbank flow. Flood causes damage to infrastructure and buildings and loss of life. Therefore, this paper investigates the characteristics of pattern river development; width, depth, and flow within the channel. This physical modelling discusses the pattern of the river by employing the current meter and point gauge equipment to collect and record the data along the channel. The discharge of 0.2 L/s and 0.5L/s were used for nonflooding and flooding cases. The non-flooding and flooding cases were identified by using a rectangular flume known as “Flexible Channel Flume”. The flume used in this study has 4.95 X 0.69 X 1.26 m of the rectangular main channel with a non-fixed-bed. As a result, the flooding case shows the depth of the channel increasing at the upstream and decreasing at the downstream compared to the non-flooding case with changes of velocity and manning’s roughness coefficient n.
Development of Water Quality Monitoring Device Using Arduino UNO
Authors: Hakimi I M , Jamil Z 
Published: May 2021

Abstract
Regular water quality monitoring of water bodies is essential to ensure it is within the allowing standard limits. The development of a simple and low-cost water quality measurement device for real time monitoring using Internet of Things (IoT) technology is presented in this study. Kolora meter is an alternative to the existing commercial monitoring devices. It was developed using the open-source platform Arduino UNO model and NodeMCU board as the microcontroller and Wi-Fi connection respectively. Two sensors such as temperature and turbidity were selected to be installed in the early stage of Kolora meter development. The physical parameters (temperature and turbidity) of water were measured and the measured data collected are able to be viewed and monitored on the mobile phone using Kolora Mobile Application via Wi-Fi connection. Therefore, this surface water quality device has potential to be applied in real time monitoring for early pollution detection and during COVID-19 pandemic spread due to limited movement.
Effects of Curing Time Using Crushed Coconut Shell (CCS) and Coconut Shell Ash (CSA) as Additive to Improve Lateritic Soils
Authors: Ramli R , Mansor N A Wan , Idrus J , Mansor S , Abdullah N H H 
Published: May 2021

Abstract
Numerous constructions in Malaysia have encountered the issues where soil cannot fulfil the standard required specification due to the bearing capacity of soft soil is too weak to withstand traffic loading. Recently, there is a lot of defeats related to soil settlement and distorting of the structure effect by the inflated compressibility and low in shear strength of the soil. This research study on the effects of natural additives in crushed coconut shell (CCS) and coconut shell ash (CSA) to enhance the durability of lateritic soil for road pavement. The effects of curing time in the CCS and CSA admixture of soil is examined. Different proportions of 5% and 9% CSA with a constant 8% CCS were used to study the effect on lateritic soil. Series of preliminary tests were performed followed by engineering test of Compaction test in identification on optimum moisture content (OMC) and maximum dry density (MDD) followed by California Bearing Ratio (CBR) for curing day of 4 days, 7 days and 14 days of soil mixtures sample to investigate its enhancement to soil strength. Further review from the previous research has also been carried out and it is pointed out that by using natural CCS and CSA brushed up the soil load-bearing capacity due to the increment of CBR value obtained as compared to the normal mix. Hence, it can be concluded that the combination of natural additives CCS and CSA in the soil also have the capability to improve the soil strength and can be suggest to replace aggregates and cement for use in lateritic soil stabilization subject to road works.
Traffic Congestion Evaluation at the Unsymmetrical Signalized Intersection of Sentul, Yogyakarta
Authors: Mahmudah N , Anjasmoro B S , Muchlisin M 
Published: May 2021

Abstract
Sentul intersection is the unsymmetrical signalized intersection located nearby the Sentul Market of Yogyakarta, which has a potential causing traffic congestion. The study aims to analyze the performance of an unsymmetrical intersection based on Indonesian’s regulation and to determine the congestion cost occurred at the Sentul signalized intersection. This study utilizes a quantitative method to evaluate the intersection performance by considering delay, vehicle queue, congestion cost, and level of service (LOS). The study included primary data collection from a traffic survey, a traffic modelling to assess the intersection performance, and a congestion cost analysis using software by considering three different conditions: Existing Condition, Alternative 1 and Alternative 2. The results showed that the performance of the existing condition was very poor with average delay of 106.71 second/vehicle, queue time of 134.42 seconds, LOS of F, and congestion cost of intersection was IDR 3,722,627 per hour. The 1st alternative was re-designing phase time of traffic light and the 2nd alternative involved re-designing green time, widening of approach area, applying left turn on red (LTOR) for the west-arm of intersection, and removing on-street parking area. The 2nd alternative is the best solution since it will reduce delay by 30 %, vehicle queue by 54 %, congestion cost decrease by 50 %, the LOS increase from F to E, and then improve intersection performance significantly.
Electrodeposition of FeCrNi and FeCr alloys and influence of heat treatment on microstructure and composition
Authors: Meinhold V , Höhlich D , Dittes A , Mehner T , Lampke T 
Published: May 2021

Abstract
The electroplating of iron-chromium and iron-nickel-chromium layers is an economic alternative to mild steel and hard-chrome layers from chromium (VI) electrolytes. Iron-chromium and iron-nickel-chromium layers were electrodeposited using an environment friendly chromium (III) electrolyte. The layers were heat-treated at different temperatures (150 °C, 300 °C, 450 °C and 600 °C) in order to determine the temperature at which recrystallization takes place, which phases are formed and to study the influence on the element content. The phase analysis was conducted by X-ray diffraction, the chemical composition and the microstructure were characterized by the scanning electron microscopy. Both layer systems show an X-ray-amorphous structure that begins to recrystallize at a temperature of 450 °C. From a heat-treatment temperature of 600 °C, the organic additives decompose and the oxygen forms chromium oxide with the chromium.
Electrolyte design and characterization of REACh-compliant Zn-W and Zn-W-Cu electrodeposits
Authors: Morgenstern R , Müller M , Höhlich D , Mehner T , Lampke T 
Published: May 2021

Abstract
Within this work, an entirely new electrolyte system for the electrochemical deposition of REACh-compliant Zn-W and Zn-W-Cu alloy layers was developed based on thermodynamic calculations. The required constants of complex formation were determined using potentiometric titrations. The layers were analyzed with regard to the layer microstructure (including coating thickness, chemical and phase composition), the optical properties (including gloss and color) and the passivation and corrosion behaviors. The Zn, Zn-W, and Zn-W-Cu layers are characterized by a decorative appearance, high uniformity, a nanocrystalline structure and natural passivation during the exposure in the climate chamber. Due to their particularly favorable optical properties and their pronounced natural passivation, the Zn-W alloy layers exhibit a great potential for industrial applications.
Conversion layers by plasma-electrolytic oxidation of aluminum in acrylate and benzoate electrolytes
Authors: Morgenstern R , Selyshchev O , Mehner T , Lampke T , Zahn D R T , Goedel W A , Schreckenbach J 
Published: May 2021

Abstract
Within this work, aluminum is oxidized via plasma-electrolytic oxidation (PEO) in the presence of organic substances, including reactive monomers. The aim of this approach is to generate polymers and simultaneously bind them to the surface of the freshly generated oxide layers. For this purpose, sheets of aluminum were immersed into electrolytes that comprised either 4 % of sodium acrylate or 10 % of sodium benzoate. The aluminum sheets were oxidized by anodic pulse current at 0.25 A/cm2 for 30–90 s. By this process, predominantly oxidic conversion layers were produced. The presence of the monomers in the electrolyte influenced the passivation and discharge behavior and finally the microstructure of the layers. It further gave rise to organic material in the layer. In particular, infrared attenuated total reflection spectroscopy (ATR-IR) and X-ray photoemission spectroscopy (XPS) show that layers which were generated in the presence of acrylate or benzoate comprised -C-C-, -C=C-, -C-O, and C=O bonds.
Influence of the production route on the phase formation, microstructure and wear behaviour of the high-entropy alloy AlCoCrFeNiTi0.5
Authors: Löbel M , Lindner T , Lampke T 
Published: May 2021

Abstract
Different manufacturing approaches have been investigated regarding their suitability to process high-entropy alloys (HEAs). However, comprehensive investigations on the influence of the production route on the microstructure, phase formation and properties have not been conducted yet. For the current study the alloy AlCoCrFeNiTi0.5 is considered. Previous investigations have proven the formation of phases with predominantly body centred cubic structure for this alloy. Castings are produced by arc-melting. Feedstock material for coating deposition and powder metallurgical processing is produced by inert gas atomisation. For the processing high-velocity-oxygen-fuel (HVOF) thermal spraying and spark plasma sintering (SPS) are applied. Due to the significantly differing process conditions and temperature-time profiles, differences of microstructure, phase formation and resulting properties can be observed. Wear investigations under various conditions have been conducted. Especially under sliding and reciprocating wear conditions the structural defects formed for the thermally sprayed coating cause a reduction of wear resistance. The formation of structural defects could be avoided by SPS. However, the additional tetragonal phase causes a reduction of the wear resistance. The current study contributes to a better understanding of the interaction between process, microstructure and properties.
Shallow neural networks to predict glass transition, crystallization and liquidus temperature of iron-based metallic glasses
Authors: Bobzin K , Wietheger W , Johann L M 
Published: May 2021

Abstract
In the designing of iron-based metallic glasses the prediction of the glass transition temperature Tg, crystallization temperature Tx and liquidus temperature Tl is of special interest. The determination of these temperatures allows not only conclusions about the glass forming ability by calculating glass formation criterions but also about the thermal stability of the alloy in the amorphous state. In the course of alloy development, Tg, Tx and Tl are usually determined by means of differential scanning calorimetry (DSC) on an amorphous sample produced, for instance, by melt spinning or copper casting techniques. The test procedures are time-consuming and cost-intensive. In the present work Tg, Tx and Tl of iron-based metallic glasses are predicted. For that purpose, shallow neural networks with a varying number of neurons are trained using Bayes regularization. The data set for training and testing consists of corresponding literature data. The chemical compositions of iron-based metallic glasses are used as inputs and Tg, Tx and Tl are the outputs. A threshold method is used for data balancing and limiting the number of inputs. Low Root Mean Squared Error (RMSE) and correspondingly high prediction accuracies were achieved during the testing.
High-strength mechanical joints under combined mechanical and medial loads
Authors: Wett D , Radanke M , Lebelt P , Brauns H 
Published: May 2021

Abstract
This paper introduces a test method for joined hot-dip galvanized steelwork test specimens. The specimens joined by means of a lock bolt system were subjected to a simultaneously combined mechanical and medial loading. This was achieved by combining a vibration testing machine and a condensation chamber that was expanded by an electrolyte dosing unit. The electrolyte was dosed on one side of the specimen in the area around the lock bolt head. The zinc dissolution is locally accelerated in the area around the joining element possibly due to superimposed bimetal and crevice corrosion. In addition, the electrolyte enters the space between the joined steel sheets and initiates corrosion processes there, too. Besides the expected zinc ions, potassium ions were also detected in the collected electrolyte by means of elemental analysis. These are originally part of the friction-increasing coating.
The influence of direct powder rolling parameters on the properties of aluminium strip
Authors: Kunene K , Bemont C P , Cornish L A , Dittes A , Grund T , Sinclair P , Lampke T 
Published: May 2021

Abstract
Direct powder rolling (DPR) can be used to create metallic sheet at a reduced cost compared to traditional methods. The process is particularly relevant for metals that are beneficiated to a powder form. The DPR process, however, is not yet optimised and the material properties corresponding to DPR sheet do not compare well with sheet produced from rolled metallic billet. This study explores the effect of DPR input parameters on DPR aluminium sheet material properties. Roll speed, roll gap, sintering time and sintering temperature are shown to have an impact on the density, microstructure, hardness and ductility of DPR aluminium strip. It is shown that a low roll speed and a small roll gap produced the most dense strip. A roll gap of 0.7 mm and roll speed of 0.366 rpm produced green strip with a density of 90% of cast aluminium while a roll gap of 0.8 mm and roll speed of 0.73 rpm produced green strip with a density of 79.6% of cast aluminium. In addition, a Vickers hardness analysis and a three-point bending test show that increasing the sintering temperature of the green DPR strip will produce softer aluminium strips with higher ductility, as expected.
Influence of the aluminum die casting process on PEEK layered CFRP in the manufacturing of a hybrid connection
Authors: Marx A , Schmid A , Haubold T , Pursche L , Schiebel P , Herrmann A 
Published: May 2021

Abstract
Lightweight design is used as a key technology in a variety of fields to achieve significant weight reduction. Due to its low density in combination with high strength, CFRP and aluminum are predestinated lightweight materials. However, the joining of this material combination is still performed using common technologies like adhesive or mechanical joining. A major challenge at the joining of this material combination is the corrosion behavior. Therefore a novel approach of a hybrid connection between CFRP and aluminum was developed by using the HPDC process of aluminum. During efficient HPDC process, a CFRP structure is recast with aluminum (AlSi10MnMg). To resist the shortly appearing temperature of 700 °C from the liquid aluminum melt, the CFRP is coated with a layer of PEEK. This leads to a material transition, which spatial separates CFRP and aluminum and a hybrid connection with tensile shear strengths up to 22 MPa. Within this work, the influence of the several processing steps on the PEEK layer and the structure of the CFRP was investigated. DSC and TGA results show no significant change on thermal properties of the PEEK. Imaging investigations show the appearance of heat induced volatilizations in the PEEK layer of the hybrid specimens after the HPDC process.
Electrochemical testing of thermal spray coatings using gel electrolytes
Authors: Kutschmann P , Lindner T , Grimm M , Lampke T 
Published: May 2021

Abstract
The use of electrochemical methods allows fast and inexpensive corrosion measurements of bulk materials with high significance. In the case of thermal spray coatings, electrolyte penetration into open pores up to the substrate material can cause undesired mixed potentials. Furthermore, the implementation of complex geometries or rough surfaces remains a problem. Preconditioning of the surface or the use of the electrochemical cell is required to eliminate leakage. Therefore, reliably measuring corrosion is still a challenging task. This undermines fast monitoring of corrosion performance as a part of the production process. Gelling agents are investigated to increase the viscosity of many electrolytes. A procedure has been developed to determine the concentration level and the mixing conditions. Passivation and pitting-corrosion testing are performed on thermal spray AISI 316L coatings. The electrochemical potential curves as well as the corroded surface layers were studied in comparison to a liquid electrolyte. The suitability of the test on rough surfaces in the sprayed condition was investigated. The results prove the novel approach as an alternative to established electrochemical test methods with extended application range.