bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of macroalgae total carbohydrate content found in Lendang Luar coast, Lombok, Indonesia for potential sources of bioethanol
Authors: Ilhami B T K , Abidin A S , Martyasari N W R , Kurniawan N S H , Padmi H , Sunarwidhi A L , Widyastuti S , Sunarpi H , Prasedya E S 
Published: December 2021

Abstract
Bioethanol is a renewable alternative energy through the process of fermenting sugar from carbohydrate sources by adding microorganisms such as yeast or bacteria. Macroalgae or known as seaweed is one of the producers in the marine environment which has a high carbohydrate content so that it can be used as raw material for bioethanol. Macroalgae contains specific carbohydrates including laminarin, mannitol, alginate, agar and polysaccharides. The high carbohydrate content indicates the ethanol content produced. The aim of the study was to initial screen total carbohydrates in red algae (G. latifolium and G rugosa) and brown algae (M rosea, S. crassifolium, S. cristaefolium, S. polycystum, P.australis and T. muray ana). Carbohydrate total analysis was performed by colorimetric assay using the BioVision kit. The overall carbohydrate content found in macroalgae samples in this study was 28.23 fig (DW)1. The highest carbohydrate content was obtained by G. latifolium (37.50 fig (DW)1), followed by G rugosa (34.27 fig (DW)1) and S. cristaefolium (33.33 fig (DW)1). Current results show that macroalgae exhibits sufficient amounts of carbohydrate which could potentially be further developed as source for biotehanol.
Cytotoxicity of Begonia medicinalis aqueous extract in three cancer cell line
Authors: Prihardina B , Fatmawati S 
Published: December 2021

Abstract

Begonia medicinalis or known as benalu batu in Indonesia is a herbal plant that is locally used for traditional medicines. The secondary metabolites such as flavonoids, alkaloids, steroids, and terpenoids have been reported to be found in these plant extracts. The content of flavonoids can lead to anti-cancer abilities while heat-sensitive flavonoid compounds can be extracted by the Ultrasound-assisted Extraction (UAE) method. In this study, the anticancer potential of B. medicinalis extracts from the leaves (leaves extract/LE) and stem (stem extract/SE) in three cell lines (Hela, MDA-MB, HT-29) have been performed. Extraction of the leaves and stems was carried out using water as a solvent and the ultrasound-assisted extraction (UAE) method followed by measuring the total flavonoid content (TFC) of each extract. The anticancer potential was obtained from cytotoxic measurements by the MTT method on 3 types of cancer cells incubated with the extract for 24 hours. The value of total flavonoid content (TFC) in the LE was higher than that of SE extracts. Both extracts have the potential as a remedy for the treatment of cancer. Keywords: Begonia medicinalis, Ultrasound-assisted Extraction (UAE), anticancer
Medicinal plants used by traditional healers for hemorrhoid treatment in Borneo island: Ethnopharmacological study RISTOJA
Authors: Astana P R W , Nisa U , Triyono A , Ardiyanto D , Fitriani U , Zulkarnain Z , Adwaita K P , Novianto F 
Published: December 2021

Abstract
Borneo is known as the third largest island in the world, which has enormous biodiversity. For generations, the locals used to utilize surrounding plants to treat diseases and maintain their health. Hemorrhoid is one of the diseases which is often treated using medicinal plants. An ethnopharmacological study (RISTOJA) was conducted to find potential plants to be developed in Borneo island by interviewing selected local traditional healers. Identification of medicinal plants was performed, followed by descriptive and literature studies. The most important medicinal plants were defined using the calculation of frequency of citation (FC), use value (UV), and choice value (CV). In order to establish scientific evidence, a literature review was conducted focused on the benefit and toxicity using electronic search engines Pubmed, DOAJ, Scopus, and Google Scholar. The evidence was collected from empirical use to in-vitro, animal, or clinical studies. There were 49 species under 31 families used in herbal formula for hemorrhoids. Based on FC, UV, CV, and literature review, Curcuma longa L., Graptophyllum pictum (L.) Griff., Melastoma malabathricum L., and Cocos nucifera were confirmed to have enough scientific evidence regarding its safety and efficacy. Accordingly, those plants have the potential to be further developed.
The potential and conservation of medicine plants in Central Kalimantan
Authors: Galingging R Y , Purwandari S , Tunisa H 
Published: December 2021

Abstract
Central Kalimantan consist of various type of lands e.g. peats soil, acid sulphate and uplands. Potential of the medicinal plant in Central Kalimantan forest is scattered in various forest areas and it is in high diversity various life form and uses. Method of study: exploration and collection conducted in five districts, i.e. Kotawaringin Timur, Kotawaringin Barat, Barito Selatan, Barito Utara and Murung Raya, starting from March 2016 until December 2018.The aims of this study was as follows : (1). The exploration process, (2). The ex-situ and in-situ conservation, (3). The characterization process, (4). The documentation process.The results of these activities involve ex situ collection of 5 accessions of medicinal plants that can be used as a source of biofarmaca. Medicinal plant conservation could be through in-situ and or ex-situ. The in-situ conservation held by managing the forest area as the natural habitat of the medicinal plants, while the ex-situ conservation held outside of the native habitats. Appropriate utilization and research activities are important in conservation of the medicinal plants Central Kalimantan..
A study of walkability in Surabaya urban park utilizing the space syntax
Authors: Wahyono F , Soemardiono B , Noerwarsito T 
Published: December 2021

Abstract
The urban parks are open spaces that accommodate people to do various activities. One of the most popular activities is walking. Human experience essentially leads pedestrians to have specific spatial dimensions and configurations in a park. Space syntax exists as a tool to explore the characteristics of the spatial configuration and the influence of the visitors on their activities through their perceptions. Space syntax has been widely applied in urban and human movement studies, despite rarely applied within the scope of urban parks. This study aims to address the debate and offers a new technique in applying the space syntax method. This research employed quantitative methods in interpreting the concept of Walkability and evaluated the design of urban parks by spatial exploration. The result determined the scope of research within the park, the configurational relationships between spaces as well as the visual connection and continuity of the human line of sight. This principle was developed and illustrated based on the three urban parks in Surabaya.
Collaborative planning for Surabaya Smart City 2020 Program during the pandemic
Authors: Pribadi F G , Santoso E B , Sumartinah H R 
Published: December 2021

Abstract
There have been many criticisms against the concept of smart city development, which only emphasizes technology. Implementing a smart city requires the involvement of a complex social sphere. Therefore, it cannot be separated from its smart citizens. Meanwhile, technology is the only tool in a smart city. Smart city development then shifts the planning paradigm to become more participative, creative, innovative, and collaborative. Smart citizens freely open up network space, establish communication, and collaborate with stakeholders to find the best solution for the problems in their settlements, including in the urban kampong. The researchers found the collaborative planning process of urban kampong development in the Surabaya Smart City (SSC) program. This kampong improvement program was initiated by the Surabaya City Government in 2019 and continues in 2020 despite the pandemic. After going through the selection and judging stages, Sambi Arum Kampong received the best kampong title in the program. This study aimed to determine how the collaborative planning process took place in the Sambi Arum Kampong during the pandemic. The researchers collected the data through in-depth interviews and literature reviews, which was then analyzed qualitatively using the deductive content-analysis method. This study explains that we can achieve collaborative smart city planning during a pandemic through flexible local institutional design and communication technology.
Laser Metal Wire drop-by-drop Deposition: a material and dilution investigation
Authors: Da Silva Adrien , Amiri Kasvayee Keivan , Frostevarg Jan , Zachrisson Jan , Kaplan Alexander F.H. 
Published: December 2021

Abstract
Additive Manufacturing has become a field of high interest in the industry, mostly due to its strong freedom of design and its flexibility. Numerous Additive Manufacturing techniques exist and present different advantages and disadvantages. The technique investigated in this research is a drop-by-drop deposition alternative to Laser Metal Wire Deposition. This technique is expected to induce a better control over the power input in the material, resulting in a better power efficiency and tailorable material properties. The aim of this research is to investigate selected material properties of the structures produced with the drop-by-drop deposition technique. Multi-drops structures were deposited from 316L, Inconel 625 (NW6625) and AlSi5 (AW4043) wires. Two drop deposition methods were investigated: (i) a contactless recoil pressure driven detachment for 316L and Inconel 625, (ii) a contact-based surface tension driven detachment for AlSi5. A material characterization including optical microscopy, EDS and hardness measurements was performed in transverse and longitudinal cross-sections. The microstructure of the deposited material, the dilution with the substrate and the heat affected zone were analysed. The contactless detachment showed a higher dilution than the contact-based technique due to the laser irradiating the substrate between two drop detachments, which melts the substrate that then mixes with the deposited drops.
A novel method for approximating local changes in the surface absorption for laser marking using 3D laser scanning
Authors: Mikkelstrup Anders F. , Thomsen Anders N. , Kristiansen Morten 
Published: December 2021

Abstract
Laser marking is a non-contact technique, which achieves colouring by using a laser beam to increase surface oxidation. Controlling the amount of heat induced into the part is essential in ensuring the desired degree of oxidisation. However, the induced heat is not only dependent on the process parameters, but also on the surface absorption, which in turn is dependent on the material, laser wavelength, and surface quality, i.e., current degree of oxidation and contaminants as well as surface roughness. This paper proposes a method for correlating backscatter from a 3D laser scanner with the surface absorption of sheet metal parts. The purpose is to determine local changes in the surface absorption caused by surface oxidation and contamination. The method utilises a 3D laser scanner, which projects a laser line at the surface and measures the resulting backscatter at an angle. The proposed solution applies a bi-directional reflectance model to reduce the influence of varying scanning angles. The method’s sensitivity to variations in surface treatments is investigated and validated against backscatter spectroscopy measurements. The results show that the proposed method can identify changes in the absorption. However, these were, in some cases, more than 70% higher compared to spectroscopy measurements.
Laser-TIG welding of galvanized steel – numerical and experimental assessment of the effect of arc in various setups
Authors: Šebestová Hana , Horník Petr , Novotný Jan , Mrňa Libor 
Published: December 2021

Abstract
The technology of laser-TIG welding utilizes the arc as a secondary heat source during laser welding. In TIG-leading configuration, the low-current arc precedes the beam to preheat the material. The numerical simulations representing various setups combining laser and arc were performed to study the changes of thermal cycles on the interface of thin metal sheets of overlap joint. The relations between the position of the arc towards the beam, additional heat input, and temperature gradients are discussed. The technology of laser-TIG welding of zinc-coated deep-drawing steel was experimentally applied in the same joint configuration. A good agreement between the calculated and experimental welds was achieved. The arc current less than 40 A did not cause the vaporization, neither oxidation of zinc coating on the interface surface of metal sheets. Nevertheless, the quality of laser-TIG welds was better compared to laser welds. The 40A arc current increased the heat input by about 50% and led to an almost 60% decrease in cooling rate compared to autonomous laser welding. Prolonged heating and cooling time are the key factors of improving the weld quality.
Influence of mill scale on oxygen laser cutting processes
Authors: Sandra Dewi Handika , Volpp Joerg , Frostevarg Jan , Siltanen Jukka 
Published: December 2021

Abstract
Mill scale formed on the surface of hot rolled steels consists of magnetite (Fe3O4), hematite (Fe2O3) and wustite (FeO) layers, which can protect the steels from corrosion and other atmospheric effects. Existence of mill scale on the specimens’ surface has shown to be able to decrease the cut edge quality. Since the mechanism behind influence of mill scale on the laser cutting process is unknown, this work performs direct observation of oxygen laser cutting processes on specimens with and without removed mill scale layers. Oxygen laser cutting processes were carried out using Ytterbium fibre laser 1070 nm along the edge of 20-mm-thick-steel specimens which were attached to a borosilicate glass. Focal point of the laser beam was positioned to be 0.7 mm below the specimens’ surface. A high speed imaging system was arranged to face the glass, recording the cut front and kerf dynamics during cutting processes. It was found that cut front inclination angle increase when the mill scale was removed from the specimens’ surface. This implies that mill scale on the specimens’ surface seem to contribute in increasing the exothermal energy during laser cutting processes.
Influence of the laser cutting front geometry on the striation formation analysed with high-speed synchrotron X-ray imaging
Authors: Lind Jannik , Hagenlocher Christian , Blazquez-Sanchez David , Hummel Marc , Olowinsky A. , Weber Rudolf , Graf Thomas 
Published: December 2021

Abstract
The generation of low surface roughness of the cut edge during laser beam cutting is a challenge. The striation pattern, which determines the surface roughness, can be distinguished into regular and interrupted striations, the latter resulting in an increased surface roughness. In order to analyse their formation, the space- and time-resolved cutting front geometry and melt film thickness were captured during laser beam fusion cutting of aluminium sheets with a framerate of 1000 Hz by means of high-speed synchrotron X-ray imaging. The comparison of the contours of the cutting fronts for a cut result with regular und interrupted striations shows that the contour fluctuates significantly more in case of interrupted striations. This leads to a strong fluctuation of the local angle of incidence. In addition, the average angle of incidence decreases, which results in an increase of the average absorbed irradiance. Both phenomena, local increase of absorbed irradiance and its dynamic fluctuation, result in a local increase of the melt film thickness at the cutting front which is responsible for the formation of the interrupted striations.
Determination of the geometry of laser-cutting fronts with high spatial and temporal resolution
Authors: Sawannia Michael , Berger Peter , Weber Rudolf , Graf Thomas 
Published: December 2021

Abstract
The melt flow velocity and the local surface angles of the cutting front during laser fusion cutting of 10 mm AISI 304 were determined for a laser power of 8 kW and a feed rate of 2 m/min. The cut front was recorded with a polarization goniometer, which uses the polarization of the process emission to determine the local surface angles, allowing to calculate the orientation of the normal vector of the surface. The records in this work were carried out with a frame rate of 75 kHz and a spatial resolution of about 30 µm. This allowed to identify big and small structures moving down the cutting front and to determine their velocities. The approximate velocity of the small structures was 9.1 m/s and for the big structures approx. 2.5 m/s. The information of a usual high-speed video was compared with the additionally obtained geometry information.
Influence of an external applied AC magnetic field on the melt pool dynamics at high-power laser beam welding
Authors: Üstündağ Ömer , Bakir Nasim , Gumenyuk Andrey , Rethmeier Michael 
Published: December 2021

Abstract
The study deals with the determination of the influence of an externally applied oscillating magnetic field on the melt pool dynamics in high power laser beam and hybrid laser arc welding processes. An AC magnet was positioned under the workpiece which is generating an upward directed electromagnetic force to counteract the formation of the droplets. To visualise the melt flow characteristics, several experiments were carried out using a special technique with mild steel from S355J2 with a plate thickness of up to 20 mm and a quartz glass in butt configuration. The profile of the keyhole and the melt flow were recorded with a highspeed camera from the glass side. Additionally, the influence of the magnetic field orientation to the welding direction on the filler material dilution on laser hybrid welding was studied with variating oscillation frequency. The element distribution over the whole seam thickness was measured with X-ray fluorescence (XRF). The oscillation frequency demonstrated a great influence on the melt pool dynamics and the mixing of the elements of the filler wire. The highspeed recordings showed, under the influence of the magnetic field, that the melt is affected under strong vortex at the weld root, which also avoids the formation of droplets.
Melt pool forming a buttonhole in tailored blank welding with multiple laser spots
Authors: Kaplan Alexander F. H. , Robertson Stephanie M. , Volpp Joerg , Frostevarg Jan 
Published: December 2021

Abstract
Laser beam welding of tailored blank butt joints of different sheet thickness generates asymmetric melt pool conditions. By employing two, three or four tailored laser beams, additional options for shaping the melt pool conditions can be offered. As observed by high speed imaging, in most multi-spot cases a large stable buttonhole was generated, by the trailing laser beams asymmetrically towards the thinner sheet. Correspondingly, the ablation pressure from the multiple boiling fronts has generated a fast melt jet, particularly along the thicker sheet. In many cases the boiling front kept open to the keyhole rear. The buttonhole differs from the Catenoid-like shape reported earlier. The walls are steeper and the horizontal shape can be asymmetric. The melt pool can switch between different stable modes. Inclined arrangement of three beams enabled even two separate, parallel boiling fronts and melt jets, combining behind the opening. Despite the large buttonhole, sound welds were achieved. Solely for four equal laser beams, arranged as a square, a melt pool without buttonhole was generated. Provided the driving forces from the ablation pressure along with the melt flow are sufficiently explored and understood, new opportunities to optimize the welding process are available.
Topographical evaluation of laser generated surfaces using statistical analysis of surface-normal vector distributions
Authors: Olsson Rickard , Powell John , Frostevarg Jan , Kaplan Alexander F.H. 
Published: December 2021

Abstract
Surfaces generated by Additive Manufacturing or laser texturing can involve the solidification of droplets of liquid, which can give rise to overhanging features on the solidified surface. Overhanging features add a layer of complexity to the surface topography and are undetectable by standard surface roughness measurement techniques such as profilometry. Such features are important because they can have a considerable effect on surface properties such as wettability. New techniques and algorithms are therefore required to analyse and quantify convoluted surfaces with overhanging (re-entrant) features. Earlier work by the authors introduced the concept of using X-ray micro-computed tomography (Micro-CT) to identify the directions of vectors normal to the surface at any point and thus indicate the presence or absence of overhanging features. This paper divides overhanging features into two types; simple and compound, and introduces new, size independent, analysis techniques which measure what proportion of each type is on the surface. Another extension of the analysis is the comparison of surface profiles taken in different directions in order to identify any surface roughness anisotropies.
Thermal imaging of high power ultrashort pulse laser ablation of alumina towards temperature optimized micro machining strategies
Authors: Rung Stefan , Häcker Niklas , Hellmann Ralf 
Published: December 2021

Abstract
The application of pulsed laser systems with pulse durations in the pico- and femtosecond regime for material processing is commonly associated with a cold ablation. Due to the minimized interaction-time between the ultrashort laser pulses and the material, this statement is almost valid as long as no heat accumulation effect appears. With the increasing demand of high productivity processes, the average power of ultrashort pulsed laser systems increases above 100 W, which leads, however, to increased thermal effects during laser processing. This is especially important for laser processing of technical ceramics like alumina. Large temperatures gradients, which locally occur during laser processing using high average power could lead to thermal modifications and cracks in the material. In this study, we present a process-optimization method for high power laser ablation of alumina based on thermal imaging. The use of a 2D IR camera enables the estimation of the temperature distribution during the laser processing. We investigate the influence of laser power up to 80 W, pulse duration between 900 fs and 10 ps and processing duration on the resulting material temperature. Beside the material temperature we evaluate the material removal rate and the resulting surface quality.