bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Nodular Graphite on Hardness and Toughness in Permanent Molds Made of Ferro Casting Ductile
Authors: Yulianto A , Darmawan A S , Anggono A D , Scannov R F 
Published: April 2024

Abstract
The permanent mold was made of Ferro Casting Ductile as a result of sand casting. Permanent mold is mold that can be used repeatedly. This permanent mold is used to produce tensile test specimens. Tensile test specimens are made of gray cast iron. This study aims to determine and analyze the effect of spheroidal graphite on the hardness and toughness of Ferro Casting Ductile in permanent molds to make tensile test specimens. The casting process starts by making patterns using Styrofoam, making molds with green-sand sand molds, followed by pouring molten cast iron into the molds. The next process is dismantling the castings and machining to get a permanent mold according to the dimensions. Specimens for testing the chemical composition were obtained from the results of castings into spherical dies. Meanwhile, the impact, hardness, and microstructure specimens were taken from the permanent molded product. The results of the chemical composition test showed that Ferro Casting Ductile contained several main elements, namely 92.14 %Fe, 3.681 %C, 3.715 %Si, 0.182 %Mn, 0.050 %Ni, and 0.034 %Mg which affected the percentage of nodular graphite. Nodular graphite will affect the hardness of the permanent mold. Validation was carried out by testing the hardness at 3 different points 167.70 VHN, 162.77 VHN, and 155.77 VHN. Toughness was obtained from the impact test using the Charpy method, the impact values were 0.048 Joule/mm2 0.046 Joule/mm2 0.037 Joule/mm2 on 3 different specimens. From the test results, the specimen has met the FCD 400 standard.
The Effect of Limestone Particle Size on Hardness of Polylactic Acid/Hydroxyapatite Composite
Authors: Savetlana S , Sukmana I , Asmoro A D , Saputra R A 
Published: April 2024

Abstract
Limestone is a mineral that mainly contained calcium oxide. Limestone has been used in manufacture industries for decades. Many researchers utilized limestone as a material for hydroxyapatite. Hydroxyapatite is a biocompatible material for human body and it is a potential material to restore the damaging bone. However, the hardness of hydroxyapatite is low. In this research, hydroxyapatite made from limestone and disodium hydrogen phosphate dihydrate were mixed with polylactic acid. The limestone was added as a source of calcium and increased the hardness of the composite. Polylactic acid was added to increase the compatibility between the components. The limestone particles sizes effect was studied using limestone powder size of 56 μm, 100 μm, and 150 μm. The composite was prepared by weighting, pre-heating, mixing, heating and pressing of the ingredients. The mechanical characterization was carried out through Micro Vickers Hardness Test. The composition of the composite was analyzed using X-ray Fluorescence. The surface morphology, interface adhesion, and element distribution were observed using scanning electron microscope and energy dispersive spectroscopy. The calcium-phosphor ratio of the composite similar with the one in the human bone. The composite that contained the finer size of limestone powder has the highest hardness. The ratio of the calcium to phosphor is 1.63.
The effect of temperature variation on Aluminum Matrix Composite (AMC) Sintering with CNT
Authors: Salu S , Renreng I , Syahid M , Mochtar A A 
Published: April 2024

Abstract
Material selection is a very important part of the design due to the variety of functions and extreme applications. There is always a need for materials that are light, strong, hard, with good thermal conductivity. Aluminum matrix composites (AMC) are potential candidates for applications that require proper material selection. The most popular AMC processing technique is the powder metallurgy/PM method to produce products with precise dimensions. Powder metallurgy for the mass production of components is the most promising and versatile method. carbon Nanotube (CNT) particle reinforced AMC fabrication is an advanced material for the automobile, aircraft, aerospace, defense, petroleum, chemical industries at a relatively low price with high performance. Al powder 4.98 gr, CNT 0.02 gr with a mixing time of 8 hours at 650 rpm. The specimens were made using a cold uniaxial pressing process at room temperature 27°C. Aluminium – CNT powder is compacted in a rigid molding with a compaction pressure of 160 MPa. Variation of sintering 100°C, 200°C, 300°C, 400°C, 500°C with a time of 60 minutes. The PM method proves that the mechanical properties and physical properties of the material are improved. Material shrinkage after sintering is large by forming shrinkage. Hardness test results with Rockwell, 26.5HR, 27.9HR, 28.8HR 29.9HR, 32.5HR. Wear rate 0.196 mm3/m, 0.078mm3/m, 0.054mm3/m, 0.052mm3/m 0.049mm3/m. Porosity values are 6.30%, 6.28%, 5.98%, 4.51%, 4.58%. The higher the sintering tem-perature, the higher the hardness value, the lower the porosity and wear.
Simulation of Static Loading of Electric Tricycle Frame
Authors: Syahid M , Rudi A , Hayat A , Kasim L , Mochtar A A , Ansar M 
Published: April 2024

Abstract
Electric vehicles are growing to replace petroleum-fuelled vehicles because of environmentally friendly. The manufacture of electric tricycle must consider the planning of frame construction that is able to support all loads such as passenger loads, engines and other equipment components. Therefore, it must be ensured that the strength of the frame is able to withstand static loads. In this study, a simulation of static load on the frame of an electric tricycle was carried out by varying the size and thickness of the frame pro-file. The frame used is a hollow square with a size of 40x40 with a thickness of 0.8mm, 1.0mm and 1.2mm and a size of 40x60 with a thickness of 1 mm. This study uses Fusion 360 software to simulate static loading with a load of 500 Kg. The recommended safety factor is 3.5. So, based on the simulation results, the eligible frames are hollow steel 40 x 40 with a thickness of 1 mm and hollow steel 40x60 with a thickness of 1 mm. Both of these materials have the same frame weight. Both of these materials have almost the same Von Misses stress, it is 51.34 MPa and 50.37 MPa respectively. The 40 x40 hollow steel has a larger displacement of 0.84 mm while 40x60 hollow steel with a thickness of 1 mm only has a displacement of 0.44 mm. Therefore, 40x60 hollow steel with a thickness of 1 mm is more recommended to be used as a frame for this electric tricycle.
The Effect of Welding Current on Shear Test and Microstructure TIG Brazing of Cemented Carbide and Steel
Authors: Fadelan  , Winardi Y , Putra W T , Anangga T P 
Published: April 2024

Abstract
The need for good welding results as knowledge in the process of welding different types of materials is needed in the community, and this res- earch is to determine the effect of variations in welding currents of different types of metals on cemented carbide and carbon steel using the TIG brazing method. For the base metal, YG6 cemented carbide and SS400 carbon steel with CuSi filler metal are used. The sample method is made by connecting different types of materials with the welding process using variations in current of 60 ampere; 80 ampere, and 100 ampere. The mechanical properties of this material connection were tested using the Hydraulic Universal Testing Machine, while for the microstructure examination, a microstructure test tool with a magnification of 100 x was used. The results of the tests revealed that the highest average compressive strength was 22.2 kN at a welding current variation of 60 A, and the lowest average value was 10.2 kN at a welding current variation of 100 A. Furthermore, for the average value of shear stress, the highest value at 60 A variation is 148 N/mm2 and the lowes t value is at 100 A welding current, which is 67 N/mm2. The res ults of testing the microstructure of the connection area s how that the higher the current strength, the more enriched the Cu content and will affect the size and spacing of Si grains.
The Effect of Contact Model on Stress Distribution on Internal Fixation of Fibula Fracture
Authors: Huzni S , Rahiem F , Fonna S , Ibrahim I B M , Arifffin AK 
Published: April 2024

Abstract
The fibula is a bone with a small cross-sectional area that is located in the calf parallel to the tibia bone and includes part of the lower leg. Technically, this bone only receives a load of approximately 15% of the total load received by the lower leg. However, under certain conditions, the fibula can be broken and require medical attention to repair it. The most common medical solution to improve this condition is to install an internal fixation. The main function of internal fixation is to keep fractured bones stabilized and in alignment. When the internal fixation is in place, the internal fixation will receive tension, at least by the patient’s body weight while supporting the legs. The magnitude of the received stress value will certainly influence the strength of the material from the internal fixation. Experimental studies are very difficult to carry out. Therefore, in this study a numerical analysis of the stress distribution on the internal fixation of the fibula bone was carried out, using the finite element method. The influence of the contact model between the bones used, namely friction and bonding, on the results of the finite element analysis was studied before further research could be carried out. The load given is considered equivalent to the average body weight of the Indonesian population, which is around 63 kg. The material employed is AISI 316. Parameters for friction and bonded models used refer to previous researchers. The results of the analysis show significant differences in the distribution and magnitude of stress on the fixation plate due to the use of different contact models.
Experimental Study of Strain Measurement using 2D Digital Image Correlation on Fixation Plate and Calcaneus Bone Fracture
Authors: Irwansyah I , Dirhamsyah M , Iswardy E , Nanta Aulia T , Alkindi M , Diah Fitriani S N 
Published: April 2024

Abstract
The plate and screw internal fixation technique is widely used for the treatment of fractured bones. Determining the mechanical behavior of bone plates under load conditions remains challenging, as it is anisotropic, non-linear, and inhomogeneous. Bone strain is frequently measured using strain gages, but they can only measure the strain at a single point. The optical method known as digital image correlation (DIC) provides the displacement and consequently the strain over the entire region of interest on the bone surface. The objective of this study was to investigate the strain changes in the surface of a calcaneus plate fixation during load compression using the digital image correlation method. In this study, a two-dimensional digital image correlation (2D-DIC) and strain gauges-based experimental methodology for calculating calcaneal plate strains is presented. A 500 N static load was applied to a synthetic calcaneus that was both plate-covered and intact. A Sanders type II fractured calcaneus was stabilized with stainless steel (316L) plate. At the same locations on the calcaneus plate, displacement and strains were recorded. According to the results of the DIC method, the maximum strain values along the x, y, and shear directions were 0.008, 0.010, and 0.012 mm, respectively, while the measurement result for the strain gauge was 0.0015 mm. The experimental result had a slightly lower strain gauge than the DIC method’s output. The results of the experiment and the DIC were thought to be in good agreement.
Comparison Industry 4.0 Assessment Reference Standards to Develop an Assessment Tool Industry 4.0
Authors: Araliz M R , Nugroho H S , Ibrahim B 
Published: April 2024

Abstract
At this time, we have entered the 4th industrial revolution, or what is often called Industry 4.0, where all activities or data can be accessed in real time. Manufacturing companies are currently facing Industry 4.0 as a challenge. Manufacturing companies see the concept of Industry 4.0 as very complex which can disrupt the company’s business processes and manufacturing companies also find it difficult to assess their readiness to transform and fail to make strategies and work plans. The purpose of the research is to develop an assessment tool in one part of the industry 4.0 assessment to make it easier for manufacturing companies to assess their company readiness and find out one of the things that must be done to transform to Industry 4.0. This study conducted a scientific study of the existing Industry 4.0 assessment reference standards such as IMPULS from Germany and INDI from Indonesia. Scientific studies looked at and studied the history of the creation of reference standards for the IMPULS and INDI assessments. This study also looks at the correlation between the assessment reference standards and the comparison between IMPULS and INDI. The results of this study see a correlation between each assessment reference standard based on the literature review and develop an assessment tool to assess one part of industry 4.0 assessment.
Advances in electroactive bioscaffolds for repairing spinal cord injury
Authors: Liu Zeqi , Lai Jiahui , Kong Dexin , Zhao Yannan , Zhao Jiakang , Dai Jianwu , Zhang Mingming 
Published: April 2024

Abstract
Spinal cord injury (SCI) is a devastating neurological disorder, leading to loss of motor or somatosensory function, which is the most challenging worldwide medical problem. Re-establishment of intact neural circuits is the basis of spinal cord regeneration. Considering the crucial role of electrical signals in the nervous system, electroactive bioscaffolds have been widely developed for SCI repair. They can produce conductive pathways and a pro-regenerative microenvironment at the lesion site similar to that of the natural spinal cord, leading to neuronal regeneration and axonal growth, and functionally reactivating the damaged neural circuits. In this review, we first demonstrate the pathophysiological characteristics induced by SCI. Then, the crucial role of electrical signals in SCI repair is introduced. Based on a comprehensive analysis of these characteristics, recent advances in the electroactive bioscaffolds for SCI repair are summarized, focusing on both the conductive bioscaffolds and piezoelectric bioscaffolds, used independently or in combination with external electronic stimulation. Finally, thoughts on challenges and opportunities that may shape the future of bioscaffolds in SCI repair are concluded.
The hemostatic performance and mechanism of palygorskite with structural regulate by oxalic acid gradient leaching
Authors: Yang Yinfeng , Wang Xiaomei , Li Yalong , Mu Bin , Yang Fangfang , Wang Aiqin , Liu Xinyue 
Published: April 2024

Abstract
Palygorskite (Pal) is a naturally available one-dimensional clay mineral, featuring rod-shaped morphology, nanoporous structure, permanent negative charges as well as abundant surface hydroxyl groups, exhibiting promising potential as a natural hemostatic material. In this study, the hemostatic performance and mechanisms of Pal were systematically investigated based on the structural regulate induced by oxalic acid (OA) gradient leaching from perspectives of structure, surface attributes and ion release. In vitro and in vivo hemostasis evaluation showed that Pal with OA leaching for 1 h exhibited a superior blood procoagulant effect compared with the raw Pal as well as the others leached for prolonging time. This phenomenon might be ascribed to the synergistic effect of the intact nanorod-like morphology, the increase in the surface negative charge, the release of metal ions (Fe3+ and Mg2+), and the improved blood affinity, which promoted the intrinsic coagulation pathway, the fibrinogenesis and the adhesion of blood cells, thereby accelerating the formation of robust blood clots. This work is expected to provide experimental and theoretical basis for the construction of hemostatic biomaterials based on clay minerals.
Potential for low-emissions oil palm production in Indonesia: insights from spatiotemporal dynamics
Authors: Safitri Lisma , Galdos Marcelo V , Comber Alexis , Challinor Andrew 
Published: April 2024

Abstract
Rising global demand for palm oil has created environmental pressures related to deforestation, burning, and peat exploitation, which in turn drives increased greenhouse gas (GHG) emissions. GHG emissions in oil palm (OP) production are known to vary spatially. However, temporal changes across contrasting management and soil types, are less well studied. This paper quantifies spatiotemporal GHG emissions across contrasting regions, management types, and soil types for the period 1990–2019 to assess the potential for reducing emission. The study focusses on Indonesia, as the biggest producer of OP, and in particular on the North Sumatra and Riau provinces, where OP is intensively produced. GHG inventories in 5 year time steps were constructed to investigate the change in drivers of emissions using spatial data, resampled to a 500 m grid. Total GHG emissions were found to have increased in both regions due to expanding OP production. However, results show a reduction in emissions flux from 1.98 to 1.15 Ton Ceq. ha−1yr−1 in North Sumatra and 9.63–2.67 Ton Ceq. ha−1yr−1 in Riau over the study period. This reduced flux was linked to the decreased deforestation and burning activities, together with increased biomass increment from lower carbon stock area conversion to OP. In both provinces, smallholder plantations emitted fewer emissions than industrial ones, and production on organic soils resulted in consistently higher emissions than on mineral soils. In North Sumatra, emissions under all management and soil types were found to decrease. In Riau, however, GHG emissions on organic soils regardless of management types, remained high. Our findings emphasise that potential for low-emissions OP production is attainable by reducing emissions per unit area through an improved understanding of GHG emissions spatiotemporal variability and their drivers. These contribute to reinforcing ongoing government regulations and guiding the industry towards low-emission OP productions.
Study on fs-laser machining of optical waveguides and cavities in ULE® glass
Authors: Maia João M , Marques P V S 
Published: April 2024

Abstract
The potential of ultrafast laser machining for the design of integrated optical devices in ULE® glass, a material known for its low coefficient of thermal expansion (CTE), is addressed. This was done through laser direct writing and characterization of optical waveguides and through the fabrication of 3D cavities inside the glass by following laser irradiation with chemical etching. Type I optical waveguides were produced and their internal loss mechanisms at 1550 nm were studied. Coupling losses lower than 0.2 dB cm−1 were obtained within a wide processing window. However, propagation loss lower than 4.2–4.3 dB cm−1 could not be realized, unlike in other glasses, due to laser-induced photodarkening. Selective-induced etching was observed over a large processing window and found to be maximum when irradiating the glass with a fs-laser beam linearly polarised orthogonally to the scanning direction, akin to what is observed in fused silica laser-machined microfluidic channels. In fact, the etching selectivity and surface roughness of laser-machined ULE® glass was found to be similar to that of fused silica, allowing some of the already reported microfluidic and optofluidic devices to be replicated in this low CTE glass. An example of a 3D cavity with planar-spherically convex interfaces is given. Due to the thermal properties of ULE® glass, these cavities can be employed as interferometers for wavelength and/or temperature referencing.
128-channel optical phased array with large field of view and low main-lobe attenuation
Authors: Ma Pengfei , Yu Lei , Wang Zheng , Xin Yifan , Wang Pengfei , Zhang Yejin , Pan Jiaoqing 
Published: April 2024

Abstract
In this paper, a 128-channel non-uniform optical phased array is proposed. The antenna is based on a silicon nitride waveguide with a large cross-sectional area (3 μm × 1.2 μm) and a silicon nitride grating with a small diffraction window (grating width of 200 nm), enabling high optical power transmission and a wide 1 dB field of view. As a result, the designed sparse optical phased array achieves less than 1 dB of main lobe attenuation over a 94° field of view. Within this field of view, the main lobe will not fall below 80% of the maximum main lobe. This allows the minimum detection distance to still be about 89% of the maximum detection distance without increasing the input power. In this field of view, the maximum side-lobe suppression of the designed sparse optical phased array is 13.4 dB, and the minimum side-lobe suppression is higher than 11.9 dB. This is useful for simultaneously achieving a large field of view, low main lobe attenuation, stable side-lobe suppression, and long detection distance.
Auditing plasma transfusion in intensive care: Use of decision time interval analysis
Authors: Dzik Walter H , Ruby Kristen , Brunker Patricia A R , Collins Julia , Paik Hyun-il , Makar Robert 
Published: April 2024

Abstract

Objectives
To present a new method for displaying blood utilization data based on analysis of decision time intervals (DTIs).

Methods
Retrospective study of patients treated in a medical intensive care unit (ICU), surgical ICU, or postcardiac surgery ICU at an academic hospital between January 2018 and June 2023. Each patient’s episode of care was divided into a series of DTIs. Transfusions during each time interval were recorded.

Results
In total, 16,562 patients received 6980 units of plasma and 21,034 units of red blood cells during 111,557 time intervals of care. Patients had international normalized ratio (INR) values ranging from less than 1.0 to more than 4.0. Data on plasma transfusion at different INR values were displayed as the number of transfusion episodes, number of units given, or the proportion of DTIs with transfusion. Clinicians transfused plasma on 1.5% of occasions when the INR was 1.5 or less and on 2.2% of occasions when the INR was less than 2.0. Plasma was transfused without red blood cells in only 0.75% of DTIs. Transfusion practice was statistically different among the 3 ICUs.

Conclusions
Compared with traditional methods of displaying the results of blood audits, DTI analysis displays information regarding the decision both to transfuse and to not transfuse. Utilization reviews that display data based on decision time analysis reveal clinical practice patterns very different from those suggested by traditional displays of plasma audit data.