bluuebunny/crossref_metadata_2025 huggingface dataset:
The improvement of molluscs population: as a parameter of success of local scale mangrove conservation on the south coast of Lombok
Authors: Al Idrus Agil , Nunung Hidayati Baiq , Ajizah Erna , Bintang Ilahi Wahyu , Syukur Abdul
Published: December 2021

Mangroves are known by local people as mangrove plants that contribute to the sustainability of the diversity of marine biota species, such as molluscs. At the study site, mangrove conservation activities have been carried out by the community and are thought to influence the development of molluscs populations significantly. The study aims to assess the results of local-scale mangrove conservation with the development of molluscs populations. The research method uses observation methods with transect methods for ecological data. Ecological data analysis uses the index of evenness, richness, and diversity. The analysis found 27 species of molluscs consisting of 21 species of gastropods and 6 species of bivalves. The highest evenness and diversity was found at 2.4 in Gerupuk, while the highest wealth index was 16.8 in Poton Bakau. Furthermore, the molluscs species found consists of two classes, namely bivalves and gastropods. The main factor in determining species richness, is more determined by the condition of the substrate. In this case, the presence of mangroves is very important in creating the substrate conditions needed by the diversity of mollusc species. Therefore, mangrove conservation is very important for the protection and preservation and diversity of molluscs species. Information on the ecological potential of mangroves on fauna diversity, especially molluscs, can be a major source of ecosystem-based marine resource management, such as at the study site.
Long-term Storage of Bacterial Isolates by Using Tryptic Soy Broth with 15% Glycerol in The Deep Freezer (-70 to -80 °C)
Authors: Sunarno  , Nursofiah S , Hartoyo Y , Amalia N , Febrianti T , Febriyana D , Saraswati R D , Puspandari N , Sariadji K , Khariri  , Rukminiati Y , Muna F , Susanti I , Multihartina P
Published: December 2021

For different bacterial preservation techniques, there is no single method applicable for all bacteria. This study aimed to assess the viability of seven species/species groups of clinical bacteria isolates on the long-term storage (more than 5 years) by using Tryptic Soy Broth with 15% glycerol in the deep freezer (-70 to -80°C). A total 10,654 clinical bacteria isolates used as samples in this study. The isolates consisted of seven species/species groups (i.e. Escherichia coli, Campylobacter spp, Shigella spp, Vibrio spp, Salmonella spp, Aeromonas hydrophila, and Neisseria gonorhoeae). The isolates were collected from some previous studies and preserved in the Tryptic Soy Broth (TSB) with 15% glycerol and stored in the deep freezer (-70 to -80°C) for more than five years. The samples were revived on the suitable medium to evaluate the viability of bacteria. Identification conducted by microscopic examination, biochemical test, and latex agglutination. The study showed that the viability of Salmonella spp, Shigella spp, Aeromonas hydrophila and E. coli was 100%, while Campylobacter spp, Vibrio spp, and N.
gonorhoeae were 66.7%, 66.4%, and 52.5% respectively. We concluded that viability of Salmonella spp, Shigella spp, A. hydrophila, and E. coli was optimum thus better than Campylobacter spp, Vibrio spp, and N. gonorhoeae for more than 5 years storage by using TSB with 15% glycerol in the deep freezer (-70 to -80 °C).
Microplastics evaluation in edible tissues of flying fish (Parexocoetus mento) from the Bintaro fish market, Lombok, Indonesia
Authors: Abidin A S , Ilhami B T K , Martyasari N W R , Kirana I A P , Widyastuti S , Candri D A , Jupri A , Hernawan A , Sunarpi H , Prasedya E S
Published: December 2021

Microplastics (MPs) are plastic fragments that are degraded into small particles with a diameter of <5 mm. Pollution in the ocean by MPs has become a global threat which damages aquatic and marine ecosystems. There are several types of MPs detected in the digestive tract and in edible fish tissue. However, such report remains limited in Indonesia. Despite the high rate of plastic pollution in Indonesian coastal areas. This study aims to determine the presence, abundance and characteristics of MPs including type, shape, and color in the edible tissue of commercially important pelagic fish species from the Bintaro fish market, Lombok, West Nusa Tenggara. Flying Fish(Parexocoetus mento)was evaluated for MPs content in their edible tissue. Isolation of MPs in fish meat was conducted by firstly adding 10% KOH solution followed by incubation for 24 h. Furthermore, the solution was incubated in the oven for 48 h at a temperature of 90oC. The WPO (Wet Peroxide Oxidation) reaction was carried out by adding 30 mL of 0.05 M Fe(II) oxide and 30 mL of 20% Hydrogen peroxide (H2O2) continued by heating on a hotplate at 75oC at 350 rpm for 45 minutes to remove organic matter from fish. The remaining filtrateswere treated by further heating, followed by filtration with stainless steel sieves (45//m). Current results show five types of MPs detected in fish sample were Fragment, Filament/fiber, Film, Foam and Pellet. The most abundant type of MPs was fragment type (368.67 particle/fish). Current results show a significant amount of MPs were found in edible tissue of flying fish in Bintaro market. However further characterization of MPs would be needed to confirm the MPs types. Nevertheless, current study show the potential contamination of MPs inP. mentofish commercially sold in fish market at Lombok, Indonesia. Hence, awareness should be raised in local communities to reduce plastic pollution in marine and coastal areas.
Preparation and evaluation of gelatin and pectin-based Moringa oleifera chewable-gummy tablets
Authors: Rani K C , Jayani N I E , Feneke F , Melanda S
Published: December 2021

Chewable gummy tablets consist of sugar and a gelling agent. Adding Moringa oleifera leaf powder to this dosage form provides health benefits since it contains high antioxidants and nutrients. This study developed chewable gummy tablets containing moringa leaf powder using two types of gelling agents, each prepared with three different concentrations. Gelatin was made in 5.0%, 7.5%, and 10.0% concentrations, while pectin was 1.0%, 1.5%, and 2.0%. This study aimed to analyze the effect of the type of gelling agent and concentration on the physical characteristics of the chewable gummy tablets produced, including visual appearances, weight variation, tablet dimension, swelling ratio, dispersion time, syneresis, and texture profile (hardness, chewiness, and gumminess). The chewable gummy tablets were prepared by heating and congealing, and then their physical characteristics were analyzed using a completely randomized design (α=0.05). The results showed that the type and concentration of the gelling agent and the interaction between the two factors significantly affected the dispersion time, syneresis, hardness, gumminess, and chewiness (p<0.05). Among the prepared formulations, chewable gummy tablets developed using 10% gelatin and 1.5% pectin are considered optimal because these fulfill all the physical characteristics requirement, show no syneresis, and provide the best texture.
In vitro analysis of human immune response (IgG) against salivary gland extract of dengue vector from dengue hemorrhagic fever (DHF) endemic area in Jember, Indonesia
Authors: Oktarianti R , Damara D R , Qudsiyah S U R , Wathon S , Senjarini K
Published: December 2021

The mosquito speciesAe. aegyptiandAe. albopictusare two potential vectors of dengue fever. The salivary glands of these species contain substances that play a role in the transmission of pathogens. These include vasodilators and immunomodulatory compounds. Immunomodulatory components can modulate the host immune system by producing specific antibodies (IgG). This study aims to investigate the human immune response (IgG) against the salivary gland extract ofAe. aegyptiandAe. albopictus. Samples were collected from individuals who were Dengue patients, as well as healthy individuals and neonates from the Jember endemic area. Results show that the levels of IgG response vary across the individual. Generally, Dengue patients and healthy people in the DHF-endemic area had higher levels of IgG. The highest immune response was found in DHF patients, followed by healthy persons, and finally the neonate samples, respectively.
Anthelmintic activity assay of Starchytarpeta jamaicensis L. Vhal tea against Fasciola sp
Authors: Fahlevi M R , Pratama I S , Sriasih M
Published: December 2021

Stachytarpeta jamaicensis L. Vhal(SJ) tea has been empirically used as an anthelmintic, but scientific evidence on its use as an anthelmintic against Fasciola sp. is still limited. The aim of this study was to determine the effective concentration of SJ tea as an anti-Fasciola.S. jamaicensisleaves were cut, dried and then packed in the form of tea bags. The presence of secondary metabolites in the tea was also analyzed phytochemically. The anthelmintic activity assay of SJ tea was carried out using anin vitroexperimental design with a post-test with control group design. Thein vitrotest consisted of negative control (0.9% NaCl), positive control (10% Albendazole) and SJ tea with a concentration of 10%, 5%, and 2.5%. The worm’s movement was observed and the time required for the death of Fasciola was recorded and analyzed. Phytochemical analysis shows that SJ tea contained alkaloid compounds, flavonoids, saponins, tannins and triterpenoids. Time required for death of Fasciola in the positive control, the negative control, the tea concentration of 10%, 5%, and 2.5% were 18.75, 168.75, 23.75, 42.5, and 66.25 min, respectively.S. jamaicensistea with a concentration of 10% showed comparable effectiveness (p>0.05) to standard reference 10% Albendazole as an anti-Fasciola and resulted in the fastest death of Fasciola fluke compared to other concentrations of the tea. The results of this study indicate that SJ tea can be used as an alternative in overcoming Fasciola infestation. Further works are required to determine its safety when usedin vivo.
Enteric pathogen among children under five years old with diarrheal diseases in Indonesia
Authors: Puspandari N , Amalia N , Hartoyo Y , Nursofiah S , Sunarno S , Sariadji K , Soekarso T , Febrianti T , Khariri K , Muna F , Rizky A , Saraswati R D , Febriyana D , Rukminiati Y , Susanti I , Anandari D , Agtini M D
Published: December 2021

Diarrheal diseases are the second cause of the high morbidity and mortality in children under five years old. According to the Basic Health Survey 2018 conducted by the Ministry of Health, the prevalence of diarrheal diseases among children under five years old that were diagnosed by healthcare workers was 11.0%. The aim of this study was to describe the enteric pathogen isolated from children with diarrhea. The study was conducted in five cities in Indonesia: Jakarta, Serang, Denpasar, Makassar, and Mataram. The Inclusion criteria were children aged one month to five years old, with diarrhea that was diagnosed by a healthcare worker. The rectal swabs were sent to the Centre for Research and Development for Biomedical and Basic Health Technology, National Institute of Health Research and Development, Ministry of Health in Jakarta. Virus and Enterotoxigenic Escherichia coli (ETEC) identification by using multiplex PCR from Seegene, meanwhile bacteria identified by conventional method. As many as 2626 children under five years old participated in this study. The highest viral pathogen that causes diarrhea is viral 1.807 (68,81%) and 486 (18,56%). The virus etiology was Rotavirus 982 (54,34%) cases, followed by Adenovirus 916 (50.69) cases, Norovirus II 444 (24,57%) cases, meanwhile the bacteria pathogen were Enterotoxigenic Escherichia coli detected in 262 (9,98%) followed by Campylobacter jejuni and Shigella spp. This study described Rotavirus is the prevalence etiology of diarrhea among children under five years old followed by Adenovirus and Norovirus, some other cases reported the cause of diarrhea were bacteria ETEC E. coli followed Campylobacter jejuni, Shigella spp, etc.
Advantages of yeast-based recombinant protein technology as vaccine products against infectious diseases
Authors: Lestari C S W , Novientri G
Published: December 2021

The yeast expression system is widely used to produce functional recombinant proteins in the biopharmaceutical industry, such as vaccine products. The expression system choices using yeast as the host has many advantages. Various vaccines have been produced commercially using yeast expression systems. This review aims to explore the advantages of the yeast expression system in Saccharomyces cerevisiae, Pichia pastoris, and Hansenula polymorpha, which emphasize vaccine products to prevent human infectious diseases. Selection of the appropriate expression system is carried out by identification at the genetic and fermentation levels, taking into account host features, vectors and expression strategies. We also demonstrate the development of a yeast expression system that can produce recombinant proteins, virus-like particles and yeast surface displays as a novel vaccine strategy against infectious diseases. The recombinant protein produced as a vaccine in the yeast system is cost-effective, immunogenic, and safe. In addition, this system has not introduced new microbe variants in nature that will be safe for the environment. Thus, it has the potential to become a commercial product used in vaccination programs to prevent human infectious diseases.
Phytochemical profiles and ethnomedicine preliminary studies on seagrass species in the Southern Coast of Lombok Island Indonesia
Authors: Zulkifli L , Muksin Y D , Hartanto P , Desimarlina Y , Idrus A A , Syukur A
Published: December 2021

Seagrass is a coastal plant that is not only important in maintaining the stability of coastal ecosystems, but also provides many benefits in daily life. Seagrass has long been used as traditional medicine by coastal residents in South Lombok. The purpose of this study was to screen the main types of secondary metabolites contained in seagrass in the southern coast of Lombok Island and to obtain information about the species of seagrass used as traditional medicine for certain types of diseases in local residents. Seagrass samples were taken from the south coast and the extraction process was carried out by maceration method using 96% ethanol as solvent. The crude extract obtained was then subjected to qualitative and quantitative phytochemical tests. The phytochemical qualitative test showed that Syringodium isoetifolium, Enhalus acoroides, Halophila decipiens, Cymodocea rotundata, Thalassia hemprichii, and Cymodocea cerulata contain compounds such as flavonoids, tannins, and phenols. Quantitative phytochemical analysis showed that E. acoroides had the highest total flavonoid content (3.7 mg QE/g) compared to that of other species, while the highest total phenolic content was indicated by T. hemprichii (33 mg GAE/100 g). The results of interviews related to the ethnomedicinal aspects of seagrass indicate that four species commonly used by local residents in healing diseases are E. acoroides, S. isoetifolium, T. hemprichii, and C. cerulata. They are widely used both as an external medicine (itching-skin diseases and external wounds) and internal medicine, such as heart, cancer, and kidney disease. Based on the phytochemical profile and ethnomedicine studies, the four seagrass species can be an alternative source in obtaining bioactive compounds for the development of specific drugs in the future.
The correlation between total protein content and antioxidant activity of collagen isolated from a marine sponge Stylissa flabelliformis collected from North Lombok Indonesia coast
Authors: Sunarwidhi A L , Rosyantari A , Prasedya E S , Ardiana N , Ilhami B T K , Abidin A S , Ambana Y , Kirana I A P , Wirasisya D G , Anugrah W , Fersiyana R D , Dewi N M A R
Published: December 2021

Abstract.Collagen is a fibrous protein that has recently gained high attention from the pharmaceutical industry due to its benefits on the skin. Collagen can be isolated from various resources including marine sponges. Marine sponges are found in a large amount in Indonesia and has not been widely explored for its pharmacology benefits. Here we isolate collagen from a marine sponge Stylissa flabelliformis found in North Lombok Indonesia coast. The isolation of collagen was performed followed by total protein content analysis using modified Bradford protein assay and antioxidant activity measurement using 2,2-diphenyl-1-picrylhydrazyl(DPPH) assay. The total yield of the collagen isolate obtained was 3.5% and it had a total of 0.755mg/ml protein. DPPH assay has shown that the collagen isolate had antioxidant activity with an IC50 of 61.5±2.132 ppm. Based on Spearman correlation assay, the antioxidant activity was found to be correlated with the protein content of the isolate (r value=0.8). These results show the potency of using the collagen isolated from marine sponge Stylissa flabelliformis for further antioxidant benefits.
Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and Antioxidants Activity of Marine Sponge Stylissa flabelliformis Ethanol Extract
Authors: Rosyantari A , Prasedya ES , Ilhami BTK , Martyasari NWR , Padmi H , Abidin AS , Ambana Y , Kirana IAP , Sunarwidhi AL
Published: December 2021

Marine sponge Stylissa flabelliformis is a marine sponge species that is widely found in Indonesia. Marine sponges have been proven to have pharmacological activities including wound healing, cytotoxicity and antimicrobial activity. All these activities are related to its antioxidant potential. Antioxidants are important for human health due to its ability to protect cell damage caused by free radicals. The aim of this research was to study the antioxidant activity of marine sponge (Stylissa flabelliformis) and to observe the phytochemical compound of the marine sponge such as the phenolic and flavonoid content. Extraction was performed using cold maceration with 96% ethanol solvent and continued by rotary evaporator to get the concentrated extract. Antioxidants activity was analysed using DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which examines the inhibitory concentration (IC50) of the ethanol extract. Total phenolic content (TPC) was examined using Gallic acid as the standard, while total flavonoid content (TFC) was examined using quercetin as the standard. The result showed a concentration-dependent antiradical activity by reduction of DPPH with an IC50 value 2000 µg/mL. Total phenolic content was 152,67 mg GAE/g, while the total flavonoid content was 155,79 mg QE/g.
Investigating the implementation of Indonesian regulation in drinking water supply system
Authors: Suminar L , Werdiningtyas R , Kusumastuti
Published: December 2021

Drinking water is an aspect of development that has an essential function in supporting community welfare because it relates to health, social and economic conditions. Therefore, the urban water system needs good planning, design, and operational infrastructure. This paper aims to identify actors and their roles in the drinking water supply system in Indonesia. Analysis was carried out on laws and regulations related to drinking water through content analysis. The results showed that government capacity in building and administering drinking water supply system was still lacking. In addition, the government shared the responsibilities to enterprises, both owned by the government and by private institutions. Finally, it is necessary to equip and expand laws and regulations to provide drinking water distribution. The critical implication to stop the massive exploitation of groundwater for consumption includes the improvement of drinking water reliability by synergizing and integrating all attempts by various actors in providing drinking water.
Energy greenhouse gas emission inventory in Batu City
Authors: Sari K E
Published: December 2021

The development of the tourism sector in Batu City is in line with the development of non-agricultural activities in Batu City that dominates 66.7% of Batu City’s land use pattern. This pattern is related to the energy demand in Batu City and contributes to the increasing GHG emissions from the energy sector. The energy sector contributes 24-25% of GHG emissions and it will increase along with further development of activities. The GHG emission inventory is an important step related to GHG emission reduction, and, due to the uncertainty of GHG emission distribution, the inventory was based on the sources of emission. The main purpose of this research is to make an inventory of the amount of GHG emission from the energy sector in Batu City from 3 main emission sources in Batu, namely transportation, commercial, and household. The analytical method used is the Tier 1 approach using a database of energy consumption and the number of activities as an emission source. The results show that the total amount of GHG emissions from the energy sector in Batu City is 2,562,159,822,007.89 kg/year with an average increase of 0.75% per year and is dominated by emission sources from the household sector. The average increase in GHG emissions from the transportation sector is 58.83% with a significant increase in 2015. In the commercial sector, the average annual increase in GHG emissions is 3.83%, and the household sector—as the largest energy consumer—has an average increase in GHG emissions each year of 0.75%.
Building facade components in a historical corridor. Case study: Karet Street, Surabaya
Authors: Andrian D , Soemardiono B , Noerwasito T
Published: December 2021

Today’s cities are developing at a breakneck pace, resulting in physical modifications to buildings. This growth can also be witnessed in the presence of new structures designed to house city-related operations. This research was conducted in the corridor area of Surabaya’s Karet Street, a historical district. Numerous historical structures may be seen along Karet Street, including surviving colonial and Chinese-style structures. Historically, this Karet Street corridor region served as a commerce hub due to its proximity to the Kali Mas (Mas River) trade route. However, as the era progressed, the buildings in the corridor of Karet Street became abandoned, many were neglected, and other structures were added, resulting in inconsistency between buildings. Thus, this research aimed to characterize the building facade components along the Karet Street corridor. The research technique used was descriptive qualitative research. Sixty-two structures along the Karet Street corridor comprise the sampled area. The factors consisted of the building’s door/entrance, windows, walls, roof, and the stylef the building—a qualitative descriptive analysis based on the state of the building’s facade in the field. Direct observation, existing literature, and documentation were employed to obtain data. The study’s findings revealed inconsistencies in the building’s exterior components, particularly in the structure’s modern style. In an area that contains colonial and Chinese-style buildings, this contradiction might undermine the area’s historical assets. Additionally, modifications and damage to facade components might obliterate the authenticity of existing historical value.
The characteristics of riverbank slum settlement in Indonesia. Case study: Depok, Palembang, Surabaya, and Surakarta
Authors: Pramantha R Q , Agustian E , Suminar L , Refnitasari L
Published: December 2021

Slum settlement is one of the problems faced by various big cities in developing countries, including Indonesia. Cities in Indonesia that are developing and functioning as a centre of activity have invited the surrounding population to migrate to cities in the hope of finding a better job and life. This is not in line with the limited housing and settlement facilities in urban areas, thus encouraging low-income people to live in slum settlements, including riverbank areas. Settlement in riverbank areas that grows uncontrollably has formed a slum area and degraded the riverbank’s main function. This research aims to find the characteristics of riverbank slum settlements in Indonesia with observational case study in Depok City, Palembang City, Surabaya City, and Surakarta City. The research method used is descriptive qualitative by describing the characteristics of the slum settlement at the location of the study. Data collection was carried out by direct observation, literature study, and interviews. The result shows that the characteristics of riverbank slum settlement in the observed locations are formed by several aspects: (1) physical aspects including land availability, infrastructure, and house building, (2) socio-economic aspects including people’s livelihoods, the local community awareness, ethnic, and kinship factor.
A Study on the potential of branding aspect in Balikpapan Kota District, Balikpapan City, Indonesia
Authors: Pratama R Y , Ulimaz M
Published: December 2021

Balikpapan is experiencing urbanization quite rapidly and has a role in residential development to accommodate the needs of its citizen. One of the strategic issues of settlements in Balikpapan is the settlements that have decreased in quality in settlement area. Based on the City Service Center System Plan of the Balikpapan Spatial Plan, Balikpapan Kota District functions as a Government Service Center, Trade and Service Center, Health Service Center, and Education Center in a City-wide Scale. Balikpapan Kota District Settlement Area is included in the area with a mild level of slum. Naturally, this will result in a shift in public perception of the area and, thus, undermines the image of the area or, arguably, the area does not have the essence of city branding value. Thus, it is necessary to study the potential in the aspect of branding in the Balikpapan Kota District Settlement Area. In achieving these objectives, an analysis related to the city’s branding aspects was carried out. The branding aspect approach in this study used the City Branding Hexagon approach. The analysis was conducted by means of quantitative descriptive method (scoring method). The results of this study provided a score from the branding aspect of the settlement area. The results of the branding aspects analysis in the Balikpapan Kota District have been identified from the neighbourhood, sub-district, and district scale. Balikpapan Kota District Settlement Area has the most substantial potential in the dimensions of Potential (2.90) and Prerequisite (2.76). There are two branding potentials but they are quite weak compared to the other aspects, which are the Presence (1.75) and Pulse (1.67) dimensions. Moreover, there are dimensions of Place (2.03) and People (2.50), which have potential that can be developed.
Tsunami early warning chain assessment utilizing social network analysis
Authors: Fardani I , Emirul F B
Published: December 2021

The application of rapid and accurate disaster early warning information has served as the key to successful mitigation for natural disaster. For example, in a tsunami disaster condition, precise information from authorized stakeholders must be immediately and accurately conveyed to the people potentially affected by the disaster. However, in practice in the field, the disseminated information has been however uncertain, failing to reach the lowest level of society. For this reason, a study is required to identify the information network that existed in the community when the tsunami disaster occurred. One method in determining this information includes Social Network Analysis (SNA), referring to a study method of structural relationships among the interacting network members, involving: individuals, organizations, or institutions. In this study, a survey was conducted to 90 respondents at the disaster location. From the results, it was found that 14 actors were involved in disseminating information on the tsunami disaster in the lowest community. The result of the Social Network Analysis indicated that the value of the degree of centrality, actor of mosque information obtained the highest value of 0.231, implementing that most of the community at the lowest level received tsunami information from announcements disseminated through information from mosques. Meanwhile, the lowest value of network closeness centrality was hamlet (RT/RW), having a value of 0.876, indicating that information from the mosque was beneficial as disaster early warning information. Upon calculating the degree of centrality and closeness at the lowest level of society, information from mosques and hamlet (RT/RW) serves as the most influential actor in disseminating tsunami information in Pandeglang Regency, Banten, Indonesia.
Post-processing of additively manufactured metal parts by ultrashort laser pulses for high-quality net shape geometries and advanced functionality
Authors: Holder Daniel , Buser Matthias , Leis Artur , Weber Rudolf , Graf Thomas
Published: December 2021

Additive manufacturing by means of laser-based powder bed fusion (LPBF) offers high flexibility with respect to the generation of individualized and light-weight metal parts. However, the produced parts are typically attached to support structures and deviate a few tens of micrometers from the targeted final component in geometrical net shape and surface roughness due to the melt-based fusion process. Therefore, different post-processing techniques were examined in the past to resolve the mentioned quality drawbacks. In our work, we investigated the potential of post-processing of LPBF-generated Ti6Al4V parts with ultrashort pulse laser ablation. As a result, the support structures were effectively removed, the surface roughness was reduced by 81% and complex geometries with high shape accuracy were fabricated. Furthermore, the LBPF-generated parts were laser surface structured to investigate the potential of post-processing with ultrashort laser pulses for advanced functionality, such as water-repellent surfaces. The generation of surface structures on the LPBF-generated Ti6Al4V part changed the wetting behaviour from hydrophilic to hydrophobic with an increased contact angle from 73° up to 130°.
Hardening in laser forming under the temperature gradient mechanism
Authors: Nikolaev Nikolov Georgi , Noel Thomsen Anders , Kristiansen Morten
Published: December 2021

Laser forming is a contactless thermal forming process that can be applied for both single and double-curved geometries. When it comes to prototyping and small batch production, laser forming has the potential to compete with conventional sheet-metal forming processes; however, an investigation of the relationship between process parameters, hardness distribution and the bend rate is lacking. This study examines the influence of using different sets of processing parameters on the bend rate and the hardness distribution. ANSI 304 stainless steel samples of 1 and 3 mm thickness are laser formed up to 90° with a bend radius equal to their thickness. A theoretical discussion of the material’s hardening kinetics is used to generalize the results. Micro-Vickers hardness test is used to measure the hardness distribution along the 3 mm samples to support the theoretical discussion. The results show that the bend rate increases when using different sets of process parameters; furthermore, the bend arc length has shown to have a significant influence over the bend rate. An increase of hardness is observed on the bottom side of the laser formed samples, indicating potential strain hardening.
Root formation and mechanical properties in laser keyhole welding of 15 mm thick HSLA steel
Authors: Bunaziv Ivan , Dørum Cato , Erik Nielsen Steen , Suikkanen Pasi , Ren Xiaobo , Nyhus Bård , Eriksson Magnus , Magne Akselsen Odd
Published: December 2021

Deep penetration laser welding is promising in joining thick (> 10 mm) steel sections. Focused laser beam by drilling vapour cavity, the keyhole, generates deep and narrow welds. Full penetration single-pass joining has a persistent problem with root quality where humping is one of the most frequent imperfection. This strongly hampers the use of high-power laser for thick plate welding. A 16 kW disk laser was used for single-pass welding of 15 mm thick plates in a butt joint configuration. Root humping occurred within a wide range of welding parameters. This provides narrow processing window. By adding an arc source to the laser beam process, the tendency of root humping increases. To achieve humping-free welds and consistent root quality over length, a delicate balance of process parameters is required. High heat input (> 0.50 kJ/mm) was positive to achieve a combination of low hardness (< 325 HV) and good Charpy toughness at -50 °C (> 50 J).
On multi-sensor monitoring of fiber laser fusion cutting
Authors: Levichev Nikita , Duflou Joost R.
Published: December 2021

Laser cutting is a well-established industrial process for sheet metal applications. However, cutting thick plates is still accompanied by problems because of the characteristic limited process parameter window. Since cutting by means of fiber lasers has become dominant, tailored solutions are required in such systems for industrial applications. The development of a robust real-time monitoring system, which adapts the process parameters according to a specific quality requirement, implies a significant step forward towards automated laser cutting and increases the process robustness and performance. In this work, a coaxial multi-sensor monitoring system is tested for fiber laser cutting of stainless steel thick plates. A high-speed camera and a photodiode sensor have been selected for this investigation. Experiments at different cutting speeds, representing primary cut quality cases, have been conducted and various features of the obtained process zone signals have been examined. Finally, the feasibility of industrial application of the developed setup for high-power fiber laser cutting is discussed, followed by several implementation recommendations.
Comparation of Two Different Methods for Fighting Moisture in Historic Masonry
Authors: Makýš Oto , Gašparík Jozef , Šťastný Patrik
Published: December 2021

Nearby all historic building built in Central Europe before the half of the 20th century have to face problems with unwanted moistening of their constructions. A significant part of them stands under legal protection as architectural monuments. There are several technologies which can be used to deal with this problem. Some of them are more invasive into historical masonry, some of them are less invasive. Some of them are much more effective in insulating effort, some of them are less. According to the Venice charter from 1964 methods which are less invasive should be preferred. Some of them are the ventilation methods. But are they really effective? On the other side of the spectrum are undercutting methods, which are drastically invasive. So, they are standing in a clear opposition the recommendations of the Venice charter. Why should they be used? Are they really so effective? And what should be done with their conflict with the Venice charter? The article tries to find answers on these questions on a base of introduced anti-moistening technologies from both sides of the mentioned spectrum. From a couple of renovation interventions undertaken in Slovakia, in the climate of Central Europe, two typical examples were taken out to support a – hopefully – right result. We used natural ventilation in a church in Western Slovakia and we achieved a success. Then we used the undercutting technology in some other church - again in Western Slovakia. We were also successful. So what is the matter? The matter is that one of this method was not successful in an adequate extend. The other one was.
Considerations Regarding the Climate Change Induced Hazards on Airports in Romania – A Case Study of Timişoara International Airport
Authors: Mărăzan Vlad , Cozma Antoanela , Hälbac-Cotoară-Zamfir Rareş
Published: December 2021

Climate change is regarded as a global scale process in which an increase of magnitude and intensity of severe weather events is observed, thus affecting both air travel as well as airport infrastructure. Although the COVID-19 crisis has a significant negative impact on air travel and thus on the further development of airport infrastructure, the demand for air travel will continue to rise as the crisis nears the end. The aim of this paper is to analyse and highlight the climate change associated hazards for the airport infrastructure as well as for the safety of passengers and goods in the Western part of Romania, mainly Traian Vuia International Airport from Timişoara. Throughout this analysis, aviation related severe weather events, such as thunderstorms, hail events, fog, icing, squalls, low level wind shear, snow falls and heavy precipitation, which affect airport infrastructure and thus air travel, are highlighted. By analysing meteorological parameters from the time scale 1980-2010 together with climate change scenarios, and thus developing weather hazard maps, a better perspective of area-related hazards and therefore customized mitigation measures and adaptation strategies are to be developed. The implementation of modern forecasting equipment such as dual polarization Terminal Doppler Weather Radar (TDWR) is thus necessary in order to prevent loss of human lives, to reduce financial losses and to protect the airport infrastructure and the aeronautical navigation and communication facilities. Long term changes in meteorological parameters include an increase in air temperature, an increase in speed for both horizontal and vertical windshear during severe weather events, an increasing number of air mass thunderstorms and an increase of situations with limited visibility especially during the late autumn and early spring time.
Strain Monitoring of an Aluminium Joint with an Optical System
Authors: Both Ioan , Feier Anamaria , Brînduşoiu Mihai , Achim Mirela
Published: December 2021

The stresses distribution can be easily determined in the cross-section of the elements but in a joint, the distribution of stresses is more complicated. Its complexity is also increased if stiffeners are added to the joint and if the connecting bolts are not positioned in a regular configuration. An aluminium cantilever with a two bolts connection is experimentally tested to determine the real capacity. Stiffeners reduce the stress intensity in the connection, but they are prone to instability problems if they are subjected to compression. In order to determine the real stress development in the stiffeners, the Digital Image Correlation (DIC) technique was used. This technique determines the strains in the loaded parts which then can be equivalated to the stress distribution. The paper presents the stress development in the compressed stiffeners of an aluminium joint considering also improvement solution for increasing the bending capacity by reducing the instability parameters.
Verifying the Shear Load Capacity of Masonry Walls by the V
Rd–N
Ed Interaction Diagram
Authors: Jasiński Radosław
Published: December 2021

Verification of shear load capacity is required for all shear walls that take horizontal wind loads, loads imposed by ground action or other non-mechanical (rheological or thermal) loads. Shear walls are exposed not only to shear forces, but also vertical actions caused by dead load or imposed loads as shear walls also usually function as bearing walls. This load combination is quite important as shear load capacity V
Rd depends on mean design stresses σd which, in turn, depend on design forces N
Ed. Interactions between shear V
Rd and vertical load N
Ed in shear walls are the consequence of observed combinations of actions in these types of walls. Additionally, the vertical load N
Ed acts on the wall at certain eccentricity eEd, which can result in a change in the length of the compressed part of the cross-section l
c. This paper describes the procedure for verifying shear load capacity by means of the interaction diagram drawn as specified in Eurocode 6 (prEN 1996-1-1:2017). Necessary equations for determining load-carrying capacity of cross-section against vertical load N
Ed were worked out. The effect of wall shape and eccentricity of vertical load on the shape of the interaction diagram was analysed.
Transformation of Danube Recreational Sites
Authors: Bašová Silvia , Sopirová Alžbeta , Hajduková Romana
Published: December 2021

The purpose of the research was to verify models of sustainable urbanization of the Danube riverside landscape in the suburban surroundings of Bratislava. The research focused on landscape-ecological forms of suburban urbanization in the contact of the river Danube, in the context of meanders of the Danube branches with the formation of recreational localities. The implementation of ecological principles was based on the concept of regional structures with a vision of the renewal of the ancient branches of the Danube for the creation of the climatic envelope of Bratislava from the southwestern side. The completion of the Petržalka, Slnečnice, Južné Mesto, and rural structures near Jarovce, Rusovce, and Čuňovo, conditioned by ecological urbanization, will acquire more landscape elements and a system of blue and green infrastructure. The hierarchical transition of the city to the suburban localities is solved by creating zones of recreation and sports on the Danube. Variant case studies of the "Danubia Park" near the village of Čuňovo are located on the southwestern bank of the Hrušov Reservoir of the Danube, with access to the Wild Water sports zone and the Danubiana Gallery complex. The research followed up on the verification of the recreational function in the landscape and focused on the level of low occupancy, the integration of sports and recreational functions, accessibility by all modes of transport, the penetration of recreation into the open landscape. For the identity of the original landscape, freely modeled connections to the riparian zone, work with water flow in the area, port, pedestrian and cycling connections to the EuroVelo route, outdoor museums of the Danube meadows, lakes and wetland communities, workouts, and multifunctional playgrounds, forms of wellness, sauna world and natural swimming. Ecological recreation concepts in the landscape of the Danube floodplains on the banks of the Danube used the modeling of banks, watercourse lines, meandering of recreational areas, green axes, play areas, elements, and zones. They used lighthouses and lookout towers for accent and orientation. The hierarchy of the release of small urban structures and loose forms of sensitive urbanization with functional flexibility and attractiveness proved the justification and location in the landscape of the Danube meadows, in the contact zones of the protected landscape and the watercourse. In this way, the importance of the suburban landscape structure is beneficial for the city not only in terms of functional attractiveness but also in terms of landscape protection and the climatic influence of the city's hinterland on its compact structures.
A Comparative Analysis on the Methods of Strengthening Isolated Reinforced Concrete Columns
Authors: Vritesh Mungur Ved , Asish Seeboo
Published: December 2021

In the construction industry, there are several methods which have been used to improve the capacity and effectiveness of structural concrete structures. Engineers can extend the life of the structures by implementing strengthening techniques. One of the techniques to strengthen columns and beams is the use of jacketing. The strength of the structural members is enhanced through the surface structural bonding of materials such as Carbon-Fibre Reinforced Polymer (CFRP), Glass-Fibre Reinforced Polymer (GFRP), ferrocement, steel angles, steel plates, wire mesh and so on. In this study, 18 reinforced concrete short columns of cross-sectional size 60 mm × 60 mm and 500 mm height were cast using concrete grade 30 MPa. The columns were subjected to compressive axial loads till failure. Moreover, the damaged columns were strengthened using three structural strengthening techniques namely, Reinforced Concrete Jacketing (RCJ), Reinforced Concrete Wire Mesh Jacketing (RCWJ) and, Steel Jacketing (SJ). The columns strengthened using RCJ and RCWJ had a cross section of 120 mm × 120 mm while SJ had a cross section of 66 mm × 66 mm. Six different configurations were used for each technique. The experimental investigations showed a minimum increase of 48.0%, 48.7% and 35.2% in the axial compressive strength when strengthened using RCJ, RCWJ and SJ respectively. Among the three strengthening techniques, SJ was determined to be the effective technique on considering structural design, time production and costs.
Inverted Umbrella-type Hyperbolic Paraboloid Reinforced Concrete Shell Structures (Inverted Umbrella HP RC Shells)
Authors: Slivnik Lara
Published: December 2021

The inverted umbrella HP RC shells became a predominant type of single column structure during the 1950s and 1960s. The paper provides a historical overview of architecturally most attractive inverted umbrella HP structures made out of reinforced concrete. It starts in the second quarter of the 20th century with the world’s oldest umbrella structures, designed by three pioneers: F. Aimond, A. Williams and K. Hruban. The most notable master in designing was F. Candela, as he constructed a number of this structures in Mexico between 1953-68. During the 1960s this form became widely used all over the Western world but suddenly disappear after 1975. The results of the paper are presented in three figures where the inverted umbrella HP RC shells are analysed according to several criteria (number of built elements, roof dimensions with shapes, use of the structures in relationship to year of completion). The similarities and differences between elements of the analysed buildings are compared and discussed. In the conclusion, the advantages and disadvantages are briefly exposed.
River Re-naturalization - a Nature-based Solution for Climate Change in Urban Areas
Authors: Mazur Katarzyna
Published: December 2021

The subject of the article is river management and their reconstruction in connection with the need to adapt urban areas to climate change. The article presents a fragment of a wider research. The aim of the study is to identify and indicate the main directions of activities undertaken in the field of river reconstruction, based on the analysis of documents and literature on the subject. The case study of the Wandle River - one of the tributaries of the Thames, running through heavily urbanized areas in London, is an example of the restoration of the river. In this case, the use of natural solutions improved: flood and drought risk management, stormwater retention, inhabitants' access to the river and biodiversity of natural habitats associated with the river.