bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamic Simulation of Cascade Cooling System for Vacuum Freeze Drying
Authors: Buana I , Kosasih E A
Published: April 2024

Vacuum freeze drying (VFD) is a drying method carried out at pressures and temperatures below the triple point of water. Drying occurs by sublimation. The results of the VFD method are able to maintain the quality of dry ingredients (taste, colour, nutrient, etc.). To achieve a condition below the triple point of water, it is conditioned so that the pressure is under a partial pressure of 6.11657 mbar at a temperature of 0.01°C. The refrigeration system is simulated using refrigerants R-134a and R-22. The purpose of the simulation is to obtain the optimum system conditions. The variables varied were the saturated temperature of the LTC (Low-Temperature Circuit) evaporator, the saturation temperature of the HTC (High-Temperature Circuit) evaporator, the difference in the temperature of the pinch point between the LTC condenser and the HTC evaporator and the temperature of the HTC condenser. The simulation results are the saturated temperature of the LTC evaporator -30°C, the saturation temperature of the HTC evaporator -15°C, the difference in the temperature of the pinch point between the LTC condenser and the HTC evaporator 10°C and the temperature of the HTC condenser 40°C. The highest Coefficient of Performance (COP) of the cascade cooling system with these parameters is 2.55 using a combination refrigerant R22 in HTC and R134a in LTC.
Application of Soy Wax Phase Change Material as Thermal Energy Storage in Wall Building
Authors: Trisnadewi T , Putra N
Published: April 2024

High solar radiation in the tropics area buildings and inappropriate selection of building materials cause an increase in room temperature which interferes with thermal comfort. This study aims to reduce the absorption of heat received in the building with the modification of building walls by adding Phase Change Material (PCM) as Thermal Energy Storage (TES). Soy wax is an organic PCM that is abundant in Indonesia, cheap, and has a melting point of 43.92°C and a freezing point of 38.49°C, which are the range of solar heat radiation in buildings. The application of soy wax on the walls of the building is carried out using a prototype room 80x105x60 cm made of Plywood with a 1 cm thickness of soy wax in the middle of the wall. The test was carried out by comparing the prototype without and with a layer of soy wax pack on the wall. Based on the tests carried out for 24 hours, it was found that the addition of soy wax on the prototype wall can decrease the room temperature to 37°C from 41°C during the day. The use of soy wax can absorb the heat received by the building by 10% at peak load and has a small heat transfer rate of 15.56 W so the heat transferred into the room is small. Soy wax walls function as insulators on the walls and can withstand heat absorbed from outside the building so that it is not completely transferred into the room.
Thermal Properties Characteristic of Aluminium-Alumina Composite for Solar Water Heating System Application
Authors: Hasan Basri Muhammad , Jalaluddin  , Tarakka Rustan , Syahid Muhammad , Amijoyo Mochtar Andi , Anis Ilahi Ramadhani M.
Published: April 2024

Thermal Energy Storage (TES) is an energy storage mechanism or material with modern technology at low costs, such as metal, concrete, composites, and others. Aluminum (Al)–Alumina (Al2O3) Composite is a solid material with high strength and hardness characteristics that can work in low-temperature applications. This study aims to analyze the features of the thermal properties of composite materials in the form of thermal conductivity and specific heat capacity. Composite specimens were prepared using powder metallurgy techniques. The weight fraction of alumina in the composite is 35%, 50%, and 65%. There are three (3) composite models, namely C1(35Al-65Al2O3), C2 (50Al-50Al2O3), and C3(65Al-35Al2O3). Models were made using the cold compaction method with a compressive load of around 20-25 MPa, and the specimens were fired in a furnace at a temperature of 550 °C with a holding time of 30 minutes. Scanning Electron Microscopy analyzed the microstructure of the composites. Composite thermal conductivity test using a thermal conductivity apparatus, and composite heat capacity test using a Differential Scanning Calorimetry (DSC). The results showed that C1(35Al-65Al2O3) composite had higher density and specific heat capacity than C2 and C3 composites. The theoretical density and specific heat capacity values of the C1 composite are 3.39 g/cm3 1.36 J/g.°C. However, the value of the thermal conductivity of C1(35Al-65Al2O3) material is lower than the other composites with a value of 0.37 W/m.°C. The greater the percentage by weight of alumina in the aluminum-alumina composite, the more theoretical density and specific heat capacity will also increase. Still, the thermal conductivity of the composite will decrease. Composite C1 35Al-65Al2O3 can potentially be a heat energy storage material used in solar water heating systems because of its high density and heat capacity.
Surface Roughness Analysis and Optimization for ST 37 Steel in Lathe Operation using Design of Experiments Method
Authors: Siti Nurrohkayati Anis , Syach Sabaruddin , Takdir Muhammad
Published: April 2024

The machining process is one of the processes used to process steel materials. The value or level of material roughness is one of the values that is considered in the machining process, according to the desired roughness value. One example is in the turning process, spindle speed, depth of feed, and feed motion are factors that can affect the level of roughness of a material. The level of roughness that is not according to demand is one of the problems in the manufacturing industry, especially in the results of the turning process. One of the causes of the discrepancy in the roughness value is because the parameters used are not suitable. Therefore, this study aims to determine the optimal parameters in the turning process to obtain the optimal roughness value, and to determine the parameters that most influence the roughness of the turning process. In this study, ST 37 steel was used. This study used an experimental design method with Orthogonal Array L8. The experiment was carried out with 5 control factors and 3 noise factors. Each factor has 2 levels and is repeated 8 times. In this study using a conventional lathe and for roughness testing using a Surface Roughness Tester. Based on the results of data analysis, the movement factor has the highest influence on the surface roughness value. The ranking factors that affect the roughness value are as follows: spindle speed of 345 rpm, feed motion of 0.051 mm/rad, depth of cut 1 mm, dry cooling, and automatic sledding. The Design of Experiments (Taguchi) method use quality characteristics to determine the results of the analysis. In this study, the quality characteristic is smaller the better. Smaller the better characteristics is where the smaller value, then better the quality. In variations of the spindle rotation speed and feed motion, we get where if the spindle speed is high and the feed motion is low it will produce a low level of roughness, whereas if the spindle speed is low and the feed movement is high it will produce a high level of roughness.
Effect of Tool Profile on Mechanical Properties, Temperature, and RPM Using Micro Friction Stir Spot Welding (mFSSW) on Aluminum Alloy AA1100
Authors: Safitri L A , Fakhrurrozi I F , Amat M A , Baskoro A S , Rupajati P , Kiswanto G
Published: April 2024

Micro friction stir spot welding (mFSSW) is a type of solid-state spot welding of nonconsumable tools using friction and force to join material of thickness less than 1 mm. This research aimed to investigate the shape of the tools for best welding results among the proposed tool’s profile. The material specimen was aluminum alloy AA1100, with a thickness of 0.42 mm. This study aims to measure the temperature and RPM of the welding process with thermocouples and tachometers. And then investigate the mechanical properties using the tensile shear test, microhardness, and macrostructural observation to find the welding zone and hook profile. Four tools’ profiles are named tool 1, tool 2, tool 3, and tool 4. The result of this study was that tool 3 (Shoulder 450μm) had the highest temperature, around 428˚ C, and the shear tensile test was 450 N (the highest). The macrostructural observation used to define the zone on the welding result there are stir zone (SZ), thermos-mechanically affected zone (TMAZ), and heat affected zone (HAZ).
Identification of Water Hyacinth Fiber (Eichornia Crassipes) and Polyethylene Terephthalate Waste as an Alternative Material
Authors: Junus S , Uloli R F , Rauf F A , Renreng I , Syahid M , Hayat A , Uloli H
Published: April 2024

Synthetic fiber is reinforcing material made and developed by human involving chemical reactions to change the structure or strengthen certain material. Synthetic fiber has high temperature resistance and is sturdy, strong, and elastic. Although synthetic fiber has good properties, it poses a serious problem of non-organic waste. Thus, it encourages changes in composite technology to pay more attention to natural fiber that are enviromentally friendly. This research used water hyacinth fiber and plastic waste as filler and polyester resin as matrix, to determine the mechanical properties of tensile test. The research employed hand lay-up method by arranging the fiber randomly at the composition of fiber variations of 10%, 20%, and 30% of the stress, strain, and modulus elasticityof the composite. The research finding were described in each fiber variations, where the average stress value at fiber variations of 10% 48,556 Mpa, strain was 1,4% and modulus elasticity was 36,264 Mpa. In addition, the fiber variation of 20% contained an average stress value of 44,178 Mpa, strain of 1,3% and modulus elasticity of 35,037 Mpa. Lastly, the fiber variation 30% contained an average stress value of 54,556 Mpa, strain of 1,2% and modulus elasticity of 46,811 Mpa. In the meantime, the tensile strength of 30% fiber variation owned the largest value compared the other fiber variations. While the 10% fiber variation strain owned the largest value compared the other fiber variations. Additionally, the elastic modulus of 30% fiber variation owned the largest value compared to the other fiber variations.
Utilization of Bamboo Roots as Reinforcing Composite Materials for Light Vehicle Dashboards
Authors: Mulyanti J , Sukamto  , Supriyanto  , Hendra D , Megaprastio B
Published: April 2024

Bamboo roots are residual material from the utilization of bamboo trees’ waste. Bamboo roots utilize in engineering by making new materials in the form of composites. Bamboo roots are easy to get, and getting bamboo root fiber is relatively easy compared to getting bamboo stem fiber. Bamboo root fibers are used as reinforcement in composites with resin binders and catalysts as hardeners. The composite made by mixing the composition consists of 10% bamboo root fiber, 89% resin, and 1% catalyst from the weight of the specimen. This composition uses three variations of fiber direction; straight, random, and woven fiber—each variation tests tensile strength, impact, and bending strength. Those three test results show that the highest values come from the woven fiber, which are 21.04 MPa from the tensile strength, 0.0693 J/mm2 from the impact value, and 34.789 MPa from the bending strength value. The test result found that applying bamboo roots composite material suits dashboard material for light vehicles (cars and motorcycles). This test result meets the standard material for dashboard vehicles based on plastic material data ABS (Acrylonitrile butadiene styrene). This research on natural fiber composite material is novel and valuable as a waste utilization solution for engineering materials.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Joint effects of indoor air pollution and maternal psychosocial factors during pregnancy on trajectories of early childhood psychopathology
Authors: Christensen Grace M , Marcus Michele , Vanker Aneesa , Eick Stephanie M , Malcolm-Smith Susan , Suglia Shakira F , Chang Howard H , Zar Heather J , Stein Dan J , Hüls Anke
Published: April 2024

Prenatal indoor air pollution and maternal psychosocial factors have been associated with adverse psychopathology. We used environmental-exposure mixture methodology to investigate joint effects of both exposure classes on child behavior trajectories. For 360 children from the South African Drakenstein Child Health Study, we created trajectories of Child Behavior Checklist scores (at 24, 42, and 60 months) using latent-class linear mixed effects models. Indoor air pollutants and psychosocial factors were measured during pregnancy (second trimester). After adjusting for confounding, single-exposure effects (per natural log-1 unit increase) were assessed using polytomous logistic regression models, joint effects using self-organizing maps, and principal component analysis. Three trajectories were chosen for both internalizing and externalizing problems, with “high” (externalizing) or “increasing” (internalizing) being the most adverse trajectories. High externalizing trajectory was associated with increased exposure to particulate matter of ≤ 10 microns in diameter (PM10) (odds ratio [OR] = 1.25; 95% CI, 1.01-1.55) and self-organizing maps exposure profile most associated with smoking (OR = 2.67; 95% CI, 1.14-6.27). Medium internalizing trajectory was associated with increased emotional intimate partner violence (OR = 2.66; 95% CI, 1.17-5.57), increasing trajectory with increased benzene (OR = 1.24; 95% CI, 1.02-1.51) and toluene (1.21; 95% CI, 1.02-1.44) and the principal component most correlated with benzene and toluene (OR = 1.25; 95% CI, 1.02-1.54). Prenatal exposure to environmental pollutants and psychosocial factors was associated with internalizing and externalizing child behavior trajectories. Understanding joint effects of adverse exposure mixtures will facilitate targeted interventions to prevent childhood psychopathology.

This article is part of a Special Collection on Mental Health.
Alcohol to-go sales policies at on-premise drinking establishments near large public US universities during the COVID-19 pandemic
Authors: Rosen Erika M , Walker Andrew , Trangenstein Pamela J , LoParco Cassidy R , Livingston Melvin D , Barry Adam E , Rossheim Matthew E
Published: April 2024

Aims

Sweeping policy changes during the COVID-19 pandemic increased alcohol availability through permitted to-go sales, potentially posing unique risks to college students. While to-go sales may make binge drinking more convenient, little remains known about these practices. Therefore, this study aimed to assess whether drinking establishments’ to-go sales practices are associated with their other operational practices and state policy.

Method

This cross-sectional analysis included 221 randomly selected bars, nightclubs, and restaurants within two miles of a large public university. Telephone interviews assessed establishment practices, and the Alcohol Policy Information System provided state alcohol to-go laws. Regression models tested whether establishment to-go sales practices were associated with their business practices (logistic regression) and state policy (generalized estimating equations).

Results

Nearly one-half (44.8%) of drinking establishments sold alcohol to-go. Establishments with higher vodka prices had nearly 30% higher odds of selling spirits to-go (aOR = 1.29) and establishments offering happy hours specials had more than twice the odds of selling beer (aOR = 2.22), wine (aOR = 2.53), and spirits to-go (aOR = 2.60). Additionally, establishments that implemented physical distance requirements had higher odds of selling wine to-go (aOR = 3.00). State to-go laws were associated with higher odds of selling wine (aOR = 3.99) and spirits to-go (aOR = 5.43) in the full sample and beer to-go (aOR = 4.92) in urban counties.

Conclusions

Establishments that sell alcohol to-go tend to engage in other practices designed to drive sales. Evaluations of alcohol to-go sales laws on risky consumption among priority populations, including college students, are urgently needed to inform decisions about how to appropriately regulate sales.
Efficient cytometry analysis with FlowSOM in Python boosts interoperability with other single-cell tools
Authors: Couckuyt Artuur , Rombaut Benjamin , Saeys Yvan , Van Gassen Sofie
Published: April 2024

Motivation

We describe a new Python implementation of FlowSOM, a clustering method for cytometry data.

Results

This implementation is faster than the original version in R, better adapted to work with single-cell omics data including integration with current single-cell data structures and includes all the original visualizations, such as the star and pie plot.

Availability and implementation

The FlowSOM Python implementation is freely available on GitHub: https://github.com/saeyslab/FlowSOM_Python.
Integrative annotation scores of variants for impact on RNA binding protein activities
Authors: Duan Jingqi , Gasch Audrey P , Keleş Sündüz
Published: April 2024

Motivation

The ENCODE project generated a large collection of eCLIP-seq RNA binding protein (RBP) profiling data with accompanying RNA-seq transcriptomes of shRNA knockdown of RBPs. These data could have utility in understanding the functional impact of genetic variants, however their potential has not been fully exploited. We implement INCA (Integrative annotation scores of variants for impact on RBP activities) as a multi-step genetic variant scoring approach that leverages the ENCODE RBP data together with ClinVar and integrates multiple computational approaches to aggregate evidence.

Results

INCA evaluates variant impacts on RBP activities by leveraging genotypic differences in cell lines used for eCLIP-seq. We show that INCA provides critical specificity, beyond generic scoring for RBP binding disruption, for candidate variants and their linkage-disequilibrium partners. As a result, it can, on average, augment scoring of 46.2% of the candidate variants beyond generic scoring for RBP binding disruption and aid in variant prioritization for follow-up analysis.

Availability and implementation

INCA is implemented in R and is available at https://github.com/keleslab/INCA.
Association between repeat imaging and readmission in patients with acute ischaemic stroke: a 16-year nationwide population-based study
Authors: Liang Han-Hsuan , Liu Hung-Yi , Kosik Russell Oliver , Chan Wing P , Chien Li-Nien
Published: April 2024

Objectives

This study aims to evaluate such usage patterns and identify factors that may contribute to the need for repeat imaging in acute ischaemic stroke patients and determine the association between repeat imaging and readmission in Taiwan.

Methods

We searched and analysed data from the Taiwan National Health Insurance Research Database for patients admitted for acute ischaemic stroke between 2002 and 2017. Cases where repeat brain imaging during the initial hospital admission occurred and where patients were readmitted within 30 days following discharge were documented.

Results

Of a total of 195 016 patients with new onset ischaemic stroke, 51 798 (26.6%) underwent repeat imaging during their initial admission. Factors associated with repeat brain imaging included younger age, longer hospital stay, use of recombinant tissue plasminogen activator (rt-PA) therapy (odds ratio = 2.10 [95% CI, 1.98-2.22]), more recent year of diagnosis, higher National Institutes of Health Stroke Scale (NIHSS) score, and admission to a hospital offering a higher level of care. Repeat imaging was also associated with an increased risk of ischaemic stroke and all types of stroke readmission.

Conclusions

Repeat brain imaging of patients with stroke has increased in recent years, and it is associated with certain factors including age, length of stay, use of rt-PA, hospital level of care, and NIHSS score. It is also associated with increased readmission.

Advances in knowledge

Knowledge of the associations of repeat imaging may help clinicians use repeat imaging more carefully and efficaciously.
Different learning aberrations relate to delusion-like beliefs with different contents
Authors: Rossi-Goldthorpe Rosa , Silverstein Steven M , Gold James M , Schiffman Jason , Waltz James A , Williams Trevor F , Powers Albert R , Woods Scott W , Zinbarg Richard E , Mittal Vijay A , Ellman Lauren M , Strauss Gregory P , Walker Elaine F , Levin Jason A , Castiello Santiago , Kenney Joshua , Corlett Philip R
Published: April 2024

The prediction error account of delusions has had success. However, its explanation of delusions with different contents has been lacking. Persecutory delusions and paranoia are the common unfounded beliefs that others have harmful intentions towards us. Other delusions include believing that one's thoughts or actions are under external control or that events in the world have specific personal meaning.

We compare learning in two different cognitive tasks, probabilistic reversal learning and Kamin blocking, that have relationships to paranoid and non-paranoid delusion-like beliefs, respectively.

We find that clinical high-risk status alone does not result in different behavioural results in the probabilistic reversal learning task but that an individual's level of paranoia is associated with excessive switching behaviour. During the Kamin blocking task, paranoid individuals learned inappropriately about the blocked cue. However, they also had decreased learning about the control cue, suggesting more general learning impairments. Non-paranoid delusion-like belief conviction (but not paranoia) was associated with aberrant learning about the blocked cue but intact learning about the control cue, suggesting specific impairments in learning related to cue combination. We fit task-specific computational models separately to behavioural data to explore how latent parameters vary within individuals between tasks and how they can explain symptom-specific effects. We find that paranoia is associated with low learning rates in the probabilistic reversal learning task and the blocking task. Non-paranoid delusion-like belief conviction is instead related to parameters controlling the degree and direction of similarity between cue updating during simultaneous cue presentation.

These results suggest that paranoia and other delusion-like beliefs involve dissociable deficits in learning and belief updating, which, given the transdiagnostic status of paranoia, might have differential utility in predicting psychosis.
Computational screening of PCP-type pincer ligands for Mo-catalyzed nitrogen fixation
Authors: Egi Akihito , Tanaka Hiromasa , Nakamura Taiji , Arashiba Kazuya , Nishibayashi Yoshiaki , Yoshizawa Kazunari
Published: April 2024

Computational screening of N-heterocyclic carbene-based PCP-type pincer ligands (PCP = 1,3-bis(di-tert-buthylphosphinomethyl)benzimidazole-2-ylidene) has been performed for the design of molybdenum-based molecular catalysts for nitrogen fixation. Previously, we theoretically and experimentally demonstrated that the introduction of electron-donating/withdrawing substituents to the original PCP ligand is a promising way to control the catalytic activity. Here, we investigate electronic and energetic properties of nitrogenous Mo intermediates bearing 40 substituted PCP ligands [MoI(NHx)(R-PCP)] (x = 1 to 3) that are involved in the rate-determining step in our proposed catalytic mechanism. Electron-withdrawing substituents enhance the π-accepting ability of R-PCP and effectively stabilize the lowest unoccupied molecular orbital (LUMO) of the corresponding Mo–nitride (Mo≡N) complexes, which is expected to be advantageous for the transformation of the nitride N atom via proton-coupled electron transfer. The introduction of strong electron-withdrawing substituents to the PCP ligand also increases the N–H bond energy of [MoI(NHx)(R-PCP)] evaluated using the bond dissociation free energy and the bond dissociation enthalpy. As a result of the computational screening, we newly propose an alternative strategy for designing PCP ligands with high π-accepting ability: the extension of the π-conjugated system of the PCP ligand by introducing fused benzene rings.