bluuebunny/crossref_metadata_2025 huggingface dataset:
Biodiversity of Bivalves in South Bintan Waters, Riau Archipelago, Indonesia
Authors: Jaida I F , Widowati I , Hartati R , Nurdin N
Published: December 2021

Bivalves is the second most diverse group of molluscs after gastropods, they are also one of the most important members in marine ecosystems. Their taxonomic classifications are based on their morphology which tend to represent adaptation responses to ecology. The samples of bivalves examined in this study were taken in the South Bintan waters by Marine Geological Research and Development Center, Bandung. Identification of the bivalves shell samples was with the aid of a microscope and NIS-Elements software and identified using an identification book. There were 34 species of bivalves found in South Bintan Waters belong to 14 families. The highest abundance was in Station 1 the location close to the overflow of the river and a harbor (1162.5 ind.m-2) and the lowest was in Station 10 the location Station 10 the location close to a small island which is usually used as a tourist spot (62.5 ind.m-2). Their diversity and eveness index were included in the medium category with H’ value of 0.58-4.12 and e value of 0.11-0.89 respectively. There was species dominance in Station 3 (Liralucina lyngei of Lucinidae) and 10 (Cardites bicolor of Carditidae) but not in other stations. Both species was the most frequent species. Bivalves in South Bintan waters showed many different morphologies which represented their adaptation. The bivalve shells found were of different morphology. There are several forms of bivalve shell morphology that have shape round like species Chama japonica, triangular like species Gemma gemma, fragile like species Dendostrea rosacea. The shell decorations found in the bintan Bivalves samples are Spinose, Commarginally, Commarginally and radially ribbed. The hinge teeth are heteroodont, isodont, and schizodont.
Behavioral and Biophysical Studies of Dugong (Dugong dugon) Habitat in Waters Mali Beach, Kabola District, Indonesia.
Authors: Plaimo P E , Wabang I L , Hendrizal A
Published: December 2021

Dugongs are generally shy animals, so observing their existence is very limited to hundreds of meters. In contrast to the behavior of Dugong who lives in the coastal waters of Mali, Kabola Regency, Indonesia. Its uniqueness can interact with humans at a very close distance and can even be on the back. It is, therefore, necessary to explore other behavioral patterns and habits and biophysical habitats of Dugongs as information to maintain their survival. This research aims to find out the behavior and biophysics of dugong habitat in the coastal waters of Mali, Kabola Subdistrict, Indonesia. The study uses direct observation methods in the form of observing the characteristics and biophysical conditions of dugong habitats including (1) determining dugong activity areas using GPS coordinates; (2) observe habitat characteristics and biophysical conditions by observing biotic and abiotic conditions, and (3) measuring physicochemical parameters, namely temperature, salinity, and pH. Next, to observe the daily behavior of dugongs when interacting with their habitat environment in the form of time: breathing, going around the boat, swimming at the bottom, swimming on the surface, swimming in the water column, resting at the bottom, eating and exposing the back. In the observations, dugongs swimming around the ship immediately responded and then approached and rubbed his body to the leg then through the pectoral fins that tried to hug to get a leg on the model being tested. Then turn under the boat and remove the penis. In general, the biophysical conditions of sandy and dense habitats are overgrown with seagrass.
Prevalence of Cymothoidae (Isopoda) Infestation in Bigeye Scad (Selar crumenophtalmus) from Batangas, Philippines
Authors: Muji T F S , Sorreta J R , Ragaza J A
Published: December 2021

Cymothoid isopod research is relatively scarce in the Philippines, despite the local economic significance of bigeye scad as an inexpensive source of protein and other nutrients. Isopod parasitism has also been shown to have detrimental effects on their fish hosts. The current study aimed to define the host-parasite relationship between cymothoid isopod and bigeye scad by determining cymothoid isopod prevalence, intensity, and host-parasite length correlations in bigeye scad (Selar crumenophthalmus) hosts sourced from Batangas, Philippines. Fish samples were sampled from the Tagaytay City Market in Cavite, which sources fish directly from Batangas. Fish samples were immediately measured and inspected for isopods in the branchial and buccal cavities. Isopods found were extracted, measured, and preserved in ethanol for identification. The isopods were identified as cymothoid isopods and consisted mostly of Norileca indica specimens and one Glossobius impressus. Prevalence and mean intensity of cymothoid isopod infections in bigeye scad were 30% and 1.6, respectively. A possible correlation between isopod size and host size was speculated for non-ovigerous female isopods, but data for male and ovigerous female isopod specimens were inconclusive. The host-parasite size relationships between bigeye scad and isopods are less likely based on body size of either the host or the parasite and are more likely based on other factors such as host cavity size.
Preliminary Characterization of Seaweed Agar Sheet Products: Case Study of Local Small and Medium Enterprise in Java Island
Authors: Jasmadi  , Novianty H , Sefrienda A R , Permadi S , Suryaningtyas I T , Kumayanjati B , Setyono D E D , Poeloengasih C D
Published: December 2021

Micro, Small, and Medium Enterprises (MSMEs) in Indonesia have grown quite rapidly and play an important role in modern economies. Many innovative products have been developed; however, the monitoring of product quality is rare. The aim of this study was to perform a comparative evaluation of the characteristics of agar sheet products from local MSMEs in Java Island, Indonesia. Moisture content, acid-insoluble ash content, total mould count, heavy metals (Pb, Zn, and As, Cu, Sn, Hg) and gel strength of three different agar sheet products were evaluated. Moreover, evaluation of its commercial packaging was carried out according to the regulation of the National Agency of Drug and Food Control (NADFC). The results reveal that the moisture content of agar sheets ranged from 17.48 % to 21.64 %, the acid-insoluble ash contents were lower than the maximum limit by Indonesian National Standard (INS), whereas according to the sensory inspection, the presence of mould was not found. Heavy metals were found at low levels, below the maximum allowable limit by INS. However, all agar sheets have poor gel strength (approximately 32.24 g/cm2 – 77.49 g/cm2). The result of packaging evaluation showed that neither packaging design, nor packaging label of all agar sheet products were excellent. The packaging label was prepared inappropriately according to NADFC. In conclusion, these agar characteristics and packaging quality were lack the minimum standard required. Therefore, product enhancements, such as processing and packaging innovations can be introduced to meet the minimum standard and improve the quality.
Development and Characterization of Alginate Based Biocomposite Films Reinforced by Gracilaria Powder
Authors: Fransiska D , Basriman I , Falafi A R , Priambudi P , Nurhayati  , Agusman
Published: December 2021

The edible film is a thin sheet that functions as a coating or packaging material on foods that may be eaten simultaneously as packaged products. The ingredient that is often used is alginate made from seaweed. The advantage of using seaweed as a bioplastic material is that it can be produced in a large quantity, low price, and is non-toxic; it can also produce bioplastic that resembles conventional plastic. The experimental method with two components of Completely Randomized Factorial Design was employed in this study (CRFD), the concentration of Gracilaria seaweed powder with four levels (0%, 0.5%, 1%, 1.5%, and 1%) and concentration of alginate with three levels (1%, 1.25%, dan 1.5%). The result showed that the concentration of seaweed powder and concentration of alginate that used in the making of the edible film had a significant effect on the quality of the edible film on all parameters, which is thickness, moisture content, tensile strength, elongation, water vapor transmission rate, water-solubility, color, opacity and surface morphology. There is an interaction between the concentration of seaweed powder and concentration of alginate at the significant effect on the quality of the edible film, which is a concentration of seaweed powder at the level of 1.5% and concentration of alginate at the level of 1.5%. The film has a the thickness of 0.25mm, moisture content of 6.94%, tensile strength of 54.29 Mpa, elongation of 3.26%, the water solubility of 64.41%, water vapor transmission rate of 3242 g/cm2/24 h, and opacity of 81.7%.
Application of Toddler Biscuits which Meets Omega 3 and Omega 6 Standards
Authors: Ilza M , Karnila R
Published: December 2021

Biscuits are additional food for toddlers. Biscuits on the market are biscuits that contain trans fatty acids which are less safe for toddlers to consume. Because it is necessary to create biscuits that are safe for toddlers to consume by adding fish oil in their manufacture, then biscuits can be given to children who are malnourished. Applications for biscuits are 50 grams/day for children whose body weight is less than WHO standards, 40 grams/day for children whose body weight is less than WHO standards, and 30 grams/day for children whose body weight is according to WHO standards. Every week (for 8 weeks) a toddler’s body weight is measured, as well as observing motor, cognitive, language and social emotional development. Based on the initial weight of the child without the addition of biscuits, it is known 33.3% have a normal weight gain and 66.3% have a late weight gain. After biscuit administration, it was found that weight gain was in a better direction, with 87.4% having a normal weight according to their age and the remaining 13.6% still having late weight development, children whose initial weight was very less than WHO standards. Weight gain is greatly influenced by the number of biscuits given to toddlers. So anatomically, growth will occur in a child’s body structure that increases proportionately with age. A lack of initial body weight will hinder the rate of weight gain of the child, can directly inhibit the growth of the child, as a result the proportion of the body structure of the child is not following their age which in the end it will have implications for other developments. Growth that occurs will affect the development of gross motor and fine motor skills, cognitive, language, and social-emotional toddlers.
Characteristics of Sargassum plagyophillum Extract as An Active Compound on Non-Alcoholic Hand Sanitizer
Authors: Sidauruk S W , Sari N I , Diharmi A , Arif I , Sukmiwati M
Published: December 2021

Excessive use of non-alcoholic hand sanitizers irritate to the skin, moreover a burning effect, that alternative natural active compound is required, namely Sargassum plagyophillum extract. S. plagyophillum extract contains secondary metabolites that can act as antibacterial and can moisturize the skin. This research aimed to determine the microbiological and physical characteristics of S. plagyophillum of the non-alcoholic hand sanitizer. The sample used in this research was 2% S. plagyophillum extract obtained by maceration using methanol. The production of non-alcoholic hand sanitizers was conducted using other ingredients such as carbopol, triethanolamine, methyl paraben, propilen glycol, and distilled water. The test parameters were testing for gram-positive and gram-negative antibacterial activity, pH, and viscosity. The results showed that non-alcoholic hand sanitizer containing 2% S. plagyophillum extract had characteristics in the form of a gel with gram positive antibacterial activity (Listeria monocytogenes) with an inhibition zone of 2.50 mm, while gram negative antibacterial activity (Pseudomonas aeruginosa) with an inhibition zone of 4.33 mm. Subsequently, the pH value produced from the hand sanitizer containing S. plagyophillum was in accordance with recommended skin pH of 7.33. Meanwhile, based on the value of the viscosity, the hand sanitizer containing S. plagyophillum had a viscosity value according to the viscosity standard, namely 2600 cPs.
Enriching terpinen-4-ol from tea tree (Melaleuca alternifolia) oil using vacuum fractional distillation: Effect of column and packings on the separation
Authors: Le M T , Nguyen N M , Le X T
Published: December 2021

Two types of columns, three types of packings, and four levels of column height were considered to investigate how column and packings affected the separation in the vacuum fractional distillation process of raw tea tree (Melaleuca alternifolia) oil (TTO). This study discussed those effects on purity, yield, and overall discovery to select the most excellent operating conditions for enriching terpinen-4-ol. After the experiments, the essential oil was successfully separated into two fractions, in which the second one composed mostly the main TTO constituent, terpinen-4-ol. The best result was achieved by conducting the distillation on a 300-mm Hempel column filled with small Fenske helices (10 mm × 2 mm i.d.) at the system pressure of 60 mmHg. GC/MS analysis showed an almost 2.5-fold increase in the content of terpinen-4-ol, from 39.23% to 95.77% after fractionation. Meanwhile, there was 75% of terpinen-4-ol successfully recovered from its parental oil. Hence, the vacuum fraction distillation could be an effective method to enrich the terpinen-4-ol content in TTO.
Mathematical model simulation of the reaction process between 2,4,6-trinitrotoluen and hydroxyl radio in water environment
Authors: Nguyen Minh Tien , Le Anh Kien , Huynh Anh Kiet , Le Duc Trung
Published: December 2021

In this study, the author formulated the equation that describes the reaction rate (mathematical modelling) of 2,4,6-trinitrotoluen and hydroxyl radical (OH*) of v = 4.3×108×[CTNT]1.1×[COH*]3.2 and mathematical simulation for the reaction process of 2,4,6-trinitrotoluen and OH* radical. The simulation results showed a decrease in concentration [CTNT] and a reaction rate proportional to each other; during the first 0-30 minutes of the reaction, the reaction speed is very fast. From the experimental results, the authors also determined that the 2,4,6-trinitrotoluen treatment performance in wastewater of the nonthermal plasma model reached >99% when increasing the treatment time to 120 minutes.
A dynamic simulation of a styrene production process
Authors: Phuoc Pham Loi Hoang Huy , Le Duc Anh , Tran Vinh Quoc , Nguyen Tuan-Anh , Nguyen Trung Kim
Published: December 2021

Dynamic simulation plays a crucial role in process engineering, especially in designing control systems. As the interest in dynamic simulation for effective control and operation rises, the goal of the paper is to study and improve the dynamic performance of a styrene production process using simulation software to tackle various process design problems. The simulation process is carried out in four stages. In the first stage, flowsheet topology and process parameters are selected to meet the requirement of the main product. Control systems are designed for each piece of equipment in the process in the second stage. Both of the stages mentioned earlier are conducted in a steady-state environment. After finishing the second stage, steady-state simulation is complete. The third stage involves tuning control parameters of control loops in a dynamic environment. In the final stage, the performance of the system is tested by introducing disturbances in the form of pulse inputs. The results of the dynamic simulation illustrate that the control system is significantly influenced by the ethylbenzene feed flowrate disturbance. The production rate is heavily affected by the disturbance, while the production quality is assured. The average settling time of the process is 270 minutes.
Removal of aqueous organic pollutant by photo-Fenton process using low-cost Fe3O4/zeolite A
Authors: Quynh Ho Gia , Kiet Nguyen Anh , Thanh Huynh Van , Tue Ta Man , Truc Phuong Nguyen Thi , Long Nguyen Quang
Published: December 2021

Degradation of methylene blue (MB) in textile water treatment was investigated by using the photo - Fenton method (mixture of Fe2+ and H2O2 with the UV irradiation) in the presence of nano-sized and low-cost catalyst Fe3O4/Zeolite A. This catalyst was synthesized by impregnation method; furthermore, its photo – catalytic performances and durability in heterogeneous Fenton system were evaluated. Both the structure and the physical chemistry properties of the photocatalyst was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). The study investigated the influences of different parameters of the MB decolorization efficiency such as initial concentration of peroxide attending the Fenton reaction, amounts of catalyst, pH of the dye solution and comparison of utilization of H2O2 in two cases with and without UV lamps. Under the optimum conditions which is the initial concentration of MB is 50 ppm and pH of dye solution is 3, high efficiencies of degradation were achieved – performance of 92.49%. These results suggest that the low-cost nanostructure catalyst Fe3O4/Zeolite A may be the considerable option because of the durability and the stability in the photo – Fenton reaction for organic wastewater treatment in textile industry.
Determination of Methylisothiazolinone and Methylchloroisothiazolinone in personal care products by HPLC-DAD
Authors: Pham Ngoc Thuy Vy , Hung Tran Viet , Thang Phan Nguyen Truong , Dang-Bao Trung , Anh Tran Thi Kieu
Published: December 2021

Preservatives are often utilized to prevent growth of bacteria and extend shell-life of personal care products (PCPs). This causes an increase in the number of cases of allergic contact dermatitis to preservatives. This study focused on the determination of two isothiazolinones (MI and MCI) in PCPs by HPLC-DAD. Different pretreatment methods were examined for different sample matrices. Recoveries were over 80% with %RSD < 6% in three studied sample matrices (wet tissue, shampoo and cream) at three different spiked levels. The method was applied to determine MI and MCI in 84 PCPs (shampoo, shower gel, cream, etc.) purchased in Ho Chi Minh City, Vietnam from March to July in 2021. MI and MCI were detected in some PCPs.
Synthesis and application of SBA-15-supported CuO as an efficient catalyst for the oxidative C(sp2)-O coupling reaction
Authors: Le Ha V. , Ho Khanh V. , Le Tu T. , Nguyen Vy T.B. , Le Huy X. , Nguyen Khoa D.
Published: December 2021

SBA-15-supported CuO was synthesized via wet impregnation of SBA-15 with copper (II) acetylacetonate followed by calcination in the static air. The BET surface area of the Cu-containing SBA-15 was approximately 600 m2/g, which significantly decreased in comparison with that of as-synthesized SBA-15 silica (1081 m2/g). The successful loading of copper with a 3.20 wt.% content was determined by ICP-OES analysis, consistent with theoretical composition. However, no Cu-based phases were detected on the PXRD results and TEM images for CuO/SBA-15 showed regular hexagonal meso channels remained, indicating that CuO species was well distributed in the SBA-15 framework via the applied synthetic procedure. Catalytic activity of SBA-15-supported CuO was investigated for the selective C(sp2)-O coupling reaction between salicylaldehyde and N, N-dimethylformamide (DMF) in the presence of di-tert butyl peroxide (DTBP) as an oxidant. Influence of the reaction conditions on the formation of desired product was studied including reaction time, temperature, reactant ratio, amount of catalyst and oxidant. The experimental results proved that the high activity of the prepared catalyst as the C(sp2)-O coupling product could be obtained in an excellent yield of 90% with only 3 mol% of SBA-15-supported CuO in the presence of 4 equivalents of DTBP at 120 °C in 2 hours.
Cloning and expression of the bacteriophage-derived endolysin against Aeromonas hydrophila
Authors: Loc Nguyen Tan , Huyen Bui Thanh , Hoang Hoang Anh , Nga Le Phi
Published: December 2021

Hemorrhagic septicemia disease in striped catfish is caused by Aeromonas hydrophila bacterium. Antibiotics are commonly used to treat this disease, however, due to antibiotic resistance in A. hydrophila, it is necessary to have an alternative antibacterial agent to antibiotics. Endolysins are bacteriophage-encoded peptidoglycan hydrolases that are synthesized at the end of the lytic phage replication cycle, they lyse the host bacterial cell wall and release new bacteriophage virions. In this study, an endolysin (cell wall hydrolase) derived from A. hydrophila phage PVN02 was artificially synthesized, cloned into pET28a(+) and successfully expressed in E. coli BL21 (DE3). The recombinant endolysin, cell wall hydrolase strongly exhibited antimicrobial activity against A. hydrophila with a reduction of 3-log CFU/ml of A. hydrophila after 30 minutes of mixing and further 30 minutes of incubation, the bacterial cells were lysed completely. It should be emphasized that the lytic activity by the recombinant endolysin to A. hydrophila bacteria did not require a pretreatment with an outer-membrane permeabilizer. The results of our study showed a potential of use this recombinant endolysin as a novel antibacterial agent to replace antibiotics in the treatment of hemorrhagic septicemia diseases in striped catfish.
Effects of different treatments of silver nanoparticles (AgNPs) on the growth & physiological characteristics of lotus (Nelumbo nucifera)
Authors: Vu Nguyen Quang Hoang , Hong Hoang Thi Kim , Quang Hoang Tan
Published: December 2021

Lotus (Nelumbo nucifera Gaertn.) is an aquatic perennial plant with various values, such as ornamental flowers, vegetables, food, and herbal medicine. It is cultivated and consumed throughout the different regions in Vietnam as a symbol associated with local culture. This study was conducted to evaluate the effects of four other treatments of silver nanoparticles (AgNPs) on the growth of lotus in crop 2021. In the present study, we examined the effects of 4 treatments: control - no AgNPs (CT), treating the soil with AgNPs 4mg/L 5 days before planting (T1), treating plants with AgNPs 4mg/L before planting (T2), and a combination of soil treatment, plant treatment, and periodic foliar application at 4mg/L (T3). The results show that AgNPs application by different methods significantly increased plant height, leaf diameter, fresh leaf weight, dry leaf weight, and some biochemical aspects compared with the control. Furthermore, exposure to AgNPs elevated the activities of peroxidase (POD), superoxide dismutase (SOD). Among the different of AgNPs applications, plants treated with T3 showed the highest efficiency. In addition, the chlorophyll content and diameter of floating and upright leaves were positively correlated with dry leaf mass. Thus, the current use of AgNPs in agricultural sciences offers the prospect of researching their impact on various plants in the future.
Roles of plant growth regulators on flowering of rose (Rosa hybrida L.’Red Rose’)
Authors: Hong Linh Tran Minh , Trinh Tu Cam , Bui Viet Trang , Tran Huong Thanh
Published: December 2021

Rose is the most popular ornamental flower all over the world, which is used as garden plants and cut flowers. In the case of Rosa hybrida L. ’Red Rose’, flowering provides the major developmental transition from the vegetative to the reproductive stage, and reproduction is one of the most important phases in an organism’s life cycle. In this study, the morphological and physiological changes during the flower development of rose, which is planted in the garden, and roles of plant growth regulators on the flowering of in vitro vegetative shoots of rose were analyzed. The development of a flower includes three stages: the shoot apical meristem, floral meristem, floral bud. Levels of cytokinin, auxins, and gibberellins increased in the transition of meristem from the shoot apical meristem to the floral meristem stage. Plant growth regulators have important effects on the shoot apical meristem cell division and flowering. The combination of 0.5 mg.L−1 GA3, 0.1 mg.L−1 NAA, 2.5 or 3.0 mg.L−1 BA to Murashige and Skoog (MS) medium induces the floral transition of the in vitro vegetative shoots with the highest percentage (41%) as well as growth and development in comparison to the other treatments after 10 weeks. Then, the in vitro floral meristem continuously developed into a flower bud after 12 weeks.
Aircraft hydraulic axial piston pump fundamental pulsation and simulation
Authors: Husnić Želimir , Dedić Remzo , Ustamujić Faris , Jelačić Zlata
Published: December 2021

The axial piston pump for aircraft hydraulics systems and other high pressure hydraulic system applications is presented. This paper discusses the pump’s pressure pulsation and the fundamental frequency. Pressure pulsation associated with single piston failure is explained in relation to its fundamental frequency. A predictive approach in maintenance and pump sub system health monitoring is proposed, using numerical modelling and applicable software.
Kinematics of steam film wetting while quenching cylindrical samples in thermal oils
Authors: Behrem Šefik , Hrnjica Bahrudin
Published: December 2021

The paper presents the determination of the velocity of the vapor front along the outer wall of a cylindrical specimen in the process of two-dimensional axisymmetric quenching of the samples in thermal oils. One thermal oil is Isorapid 277 HM heated to 40°C and the other thermal oil is Marquench 722 heated to 90°C. The experimental setup of the work consists of heating to a temperature of 850°C, then quenching three dimensionally different cylindrical probes. The dimensions of the probe were: ϕ25x100 ϕ50x150 and ϕ75x225 mm. All quenchings were done in strictly controlled conditions of the flow rate of the quenchant around the cylinder as well as maintaining the temperature of the quenchant within the maximum 40±2.5°C or 90d3°C, during the quenching of the samples. The velocity of movement of the steam front on the outer surface of the cylinder was determined from the time-measured values of temperatures at the marked points of each sample. The analysis of the steam front movement velocity along the cylinder wall starts from the moment the lower base of the probe touches the quenchant. During the process of immersing the test probe in the quenchant, in addition to measuring the temperatures in time, the time of lowering the probe to contact with the quenchant sample was also measured. The approximate average velocity of the vapor front was determined based on the indications of the lower and middle thermocouples located 1.5 mm below the outer surface of the cylinder wall. Based on the distance of one half the height of each probe and time, the velocity of the steam film movement or the kinematics of the steam film wetting was obtained. The obtained results were compared with the results of quenching in water and aqueous solutions of the same probes under the same strictly controlled conditions.
Assessment of integrity and remaining working life of welded steel structures
Authors: Bajramović Ermin , Islamović Fadil
Published: December 2021

Analyzing the period of exploitation of welded steel structures it can be concluded that they are predominantly exposed to the action of variable load. The welded joint as the largest stress concentrator due to the heterogeneity of structural, mechanical and operational properties is a key problem that is further complicated by the possible and realistically probable presence of crack-type faults. The assessment of integrity largely depends on a comprehensive analysis of the welded joint as the most critical place of welded steel structures. Integrity assessment is a necessary obligation for extending the working life, as well as revitalization, as a way to keep the structures in operation, despite the long period of exploitation. This paper presented an analysis of the process of fatigue crack initiation and growth, i.e. an assessment of the of the welded steel structures’ integrity and remaining service life under the influence of variable load.
Investigation of the influence of electrode manufacturers ‘recipes on the production and chemical composition of welding fume particles
Authors: Begić Razija
Published: December 2021

The quality of the welded joint, production and chemical composition of welding fume particles in the MMAW process, in addition to the welding parameters, mostly depend on the quality of the coated electrode. As part of the preliminary experimental research of the optimal technological composition of the electrode coating, from the aspect of minimizing welding fume, an experimental research of one class of electrodes, E 42 4 B 32 H5, EN 499/94, standard production program of three manufacturers of welding consumables. The test was performed to examine the influence of the manufacturer’s recipe on the production and chemical composition of welding fume particles.
Pressure stress modeling on expanded polystyrene materials using genetic programming
Authors: Bajramović Ermin , Hrnjica Bahrudin , Hasanagić Redžo , Bajramović Emir
Published: December 2021

In the production of expanded polystyrene, the standards are very high in terms of thermal, fire, dimensional, and mechanical characteristics, because each of the characteristics is a condition for achieving quality that allows competitiveness in the market. To ensure high-quality products, it is necessary to achieve optimal performance and product quality through carefully adjusted input parameters of production. Since the production of expanded polystyrene is specific in several ways, an experimental study was conducted in which the basic parameters affecting product quality were detected and through which a series of experiments were performed to prove product quality. Experimental research for this work was conducted on three types of expanded polystyrene samples whose purpose is to insulate floors exposed to pressure. The samples were made of the same material of different densities and aging times for which the pressure stress at a deformation of 10% was tested. After the experimental phase, the modeling of the output parameters was performed. Modeling involved the development of a model that describes a given problem and the obtained modeled values were analyzed and compared with the experimental one. The modeling method used genetic programming using the GPdotNET software package. The goal of modeling with the GpdotNET tool is to obtain a realistic model that would give the value of the compression stress at a deformation of 10% as an output variable in materials made of expanded polystyrene.
Measurement of welding fume production in welding with high-alloy electrodes
Authors: Begić Razija
Published: December 2021

Due to their good structural properties, stainless Cr-Ni steels have a very wide application in various branches of technology. During the welding of stainless Cr-Ni steels with high-alloy coated electrodes, welding fumes of complex chemical composition are generated, which is very harmful for welders and the environment. For the purposes of this experiment, two variants of one rutile Cr-Ni commercial electrode, designated E 23 12 2 LR 12, were designed and fabricated. Higher production of welding fume particles also means greater danger to humans and the environment. In order to show the influence of the base material on the production of welding fume particles, an experiment for measuring the production of welding fume particles was performed in which two different steels were used as the base material, general structural steel S235JRG2 and stainless steel X6CrNiTi18.10.
Analysis of the influence of condensation temperature and compressor efficiency on heat pump system efficiency
Authors: Koruga Nemanja , Dobrnjac Mirko , Golubović Dušan , Dobrnjac Nemanja
Published: December 2021

In heat pump cycles, heat is supplied to the working fluid from a certain group of low-temperature bodies and transferred to a group of high-temperature bodies, i.e. the heat source is at a lower temperature and the heat sink at a higher temperature. Using the method of circular processes, in synergy with the possibility of mutual conversion of thermal and mechanical interactions, the process of heat transfer from a lower temperature level to a higher temperature level is enabled. Mechanical work, which, as compensation, should be given by the environment to the system (working substance), is a difference between heat removed and heat supplied. The efficiency of the heat pump mostly depends on the temperature interval at which the process takes place, however, the efficiency of the heat pump is also affected by the thermodynamic parameters of its parts: compressor, condenser, throttle valve, and evaporator. In this paper, the influence of condensing temperature and compressor efficiency on the efficiency of the system as a whole is examined. The calculation was performed for two working substances, R123 and R134a, using the EES software package (Engineering Equation Solver) which is used for numerical modeling of thermodynamic systems, process optimization, and making process diagrams.
Concept design and design optimization of the transfemoral prosthetic leg prototype
Authors: Dedić Remzo , Ustamujić Faris , Jelačić Zlata , Husnić Želimir , Kvesić Vlado
Published: December 2021

The biggest challenge with today’s lower leg prosthetic devices is to climb the stairs in a biologically inspired way. When climbing the stairs, due to the large moments in the knee joint, great forces in the knee occur. Because of the magnitude of these forces, which can be up to six times the weight of a person, it is necessary to use a hydraulic drive with an external power source in the knee and ankle joint. However, most commercially available above-knee prosthetic legs only have actuation in the form of damping in the knee joint. Hence, an amputee is forced to use a healthy leg to advance to each step first while amputated leg follows.
Measurement analysis of braking forces and braking coefficient at different loads of a passenger vehicle
Authors: Halilagić Ramo , Hodžić Nedim
Published: December 2021

This paper presented an analysis of the braking force efficiency, i.e. its intensity in the case. It presented an analysis of the efficiency of braking forces, i.e. their intensity in the case when the load of a passenger vehicle was gradually changing. The change in the load of the vehicle was done by varying the number of passengers in it from one to five which is a feature of a higher number of M1 category vehicle. By increasing in the number of passengers the weight of the vehicle varied by approximately 75kg per passenger. The experimental test was performed in the technical inspection station, i.e. on standard rollers for the brake system testing. The test results shown that the relative difference of braking forces occurred on the front axle during intensive braking and that the braking coefficient was the lowest of about 69.94% in the case when only the driver was in the vehicle. It increased with increasing load, i.e. the number of passengers in the vehicle up to 85.91% and then dropped by increasing the rear passenger behind the driver and front passenger to 80.43% which can affect the stability of the vehicle when braking in the event of a dangerous traffic situation.
The force required for the creation of wood cuttings
Authors: Talić Hasan
Published: December 2021

Wood as a material has its own peculiar role during processing due to its characteristics which depend on a number of factors. Therefore, wood-based plate materials tend to encounter the same issues. The creation of the continuous cuttings is conditioned by the strength as it is being cut orthogonally. The cutting force is shown as the sum of the forces for plastic deformation, the force for overcoming the work of the friction force on the front and rear surface of the tool and the force for creating a new surface. Each of the forces is connected to appropriate mechanical features of wood. Examining the mechanical properties of wood, which can be used to calculate the required power to create a new surface, demonstrates the dependence of cutting power on the type of wood, cutting speed, and wood moisture.
Mechanical properties changes in fir wood (abies sp.), linden wood (tilia sp.), and beech wood (fagus sp.) subjected to various thermal modification process conditions
Authors: Hasanagić Redžo , Ganguly Sauradipta , Bajramović Ermin , Hasanagić Adem
Published: December 2021

Wood is one of the most important construction materials in Europe and its use in building applications has increased in the recent decades. To enable even more extensive and reliable use of wood, this article aimed to determine the effect of thermal modification on mechanical properties of fir wood (lat. Abies sp.), linden wood (lat. Tilia sp.), and beech wood (lat. Fagus sp.). The thermal modification was conducted in a laboratory oven at five different temperatures of 170, 180, 195, 210, 220 °C and processed with a different maximum duration of the process of 78, 120, 180, 240, 276 minutes. Mechanical properties of treated wood have shown statistically insignificant fluctuations at lower temperatures compared to control samples. On the other hand, raising the temperature to 210 °C significantly affected the strength of all the species. The results revealed that thermal modification at high temperatures and longer exposure causes a decrease in the maximum force of the three wood species.
Improving Comb Aliasing Rejection Using Sharpening of Modified Comb
Authors: Jovanovic Dolecek Gordana
Published: December 2021

This paper presents an efficient method to improve the comb aliasing rejection in a comb decimation filter without increasing its passband droop. This problem is important since aliasing and comb passband droop may deteriorate the decimated signal. We propose here to apply sharpening of the modified comb in the second stage of a two-stage comb structure. The modified comb is obtained by decreasing the middle coefficient of the impulse response of the cascade of two combs by 1/2. The sharpening polynomial with the first order tangencies is used here. As a result, the comb folding bands, where the aliasing occur, become wider and with an increased attenuation in comparison with the original comb filter. However, this improvement in the folding bands did not result in an increased passband droop. The compensator from literature is used to further decrease passband droop. The method is illustrated with examples and compared with the original comb and the methods proposed in literature for increasing aliasing rejection.
Fire prediction with logistic regression on territory of Bosnia and Herzegovina
Authors: Musabašić Mursel , Mušić Denis , Babović Elmir
Published: December 2021

The Canadian Fire Weather Index system [1] has been used worldwide by many countries as classic approach in fire prediction. It represents system that account for the effects of fuel moisture and weather conditions on fire behaviour. It numerical outputs are based on calculation of four meteorological elements: air temperature, relative humidity, wind speed and precipitation in last 24h. In this paper meteorological data in combination with Canadian Fire Weather Index system (CFWI) components is used as input to predict fire occurrence using logistic regression model. As logistic regression is a supervised machine learning method it’s based on user input in the form of dataset. Dataset is collected using NASA GES DISC Giovanni web-based application in the form of daily area-averaged time series in period of 31.7.2010 to 31.7.2020, it’s analysed and pre-processed before it is used as input for logit model. CFWI components values are not imported but calculated in run-time based on pre-processed meteorological data. As a result of this research windows application was developed to assist fire managers and all those involved in studying the fire behaviour.
Interpolation on the special orthogonal group with high-dimensional Kuramoto model
Authors: Crnkić Aladin , Kapić Zinaid
Published: December 2021

The construction of smooth interpolation trajectories in different non-Euclidean spaces finds application in robotics, computer graphics, and many other engineering fields. This paper proposes a method for generating interpolation trajectories on the special orthogonal group SO(3), called the rotation group. Our method is based on a high-dimensional generalization of the Kuramoto model which is a well-known mathematical description of self-organization in large populations of coupled oscillators. We present the method through several simulations and visualize each simulation as trajectories on unit spheres S2. In addition, we applied our method to the specific problem of object rotation interpolation.
Condition diagnostics of the Stadium “Rođeni” in Mostar
Authors: Džino Jasmina , Trešnjo Faris , Šahinagić-Isović Merima , Kulukčija Salko
Published: December 2021

The paper presents a diagnosis of the condition of the stadium FK Velež “Rođeni” in Mostar, which was built in period 2006-2008 and represents an important facility for the citizens of Mostar. The steps in diagnosing the condition of an existing structure are explained, including a collection of existing documentation, an inspection of the structure, test and calculations, and assessment and decision on further action. Drawings of the stadium were given, visual inspection of the stadium was performed and calculations of the current and future layout of the structure. The calculations were performed in software Tower 8 and with respect to European norms EN0, EN1, EN2, EN3 and EN8. A visual inspection revealed a large number of damages to the stadium, which were classified into specific groups. The mechanisms of destruction and classification were performed using EN 1504.
Developing and validating a Chinese multimorbidity-weighted index for middle-aged and older community-dwelling individuals
Authors: Hu Wei-Hua , Liu Yu-Yang , Yang Cong-Hui , Zhou Tong , Yang Chun , Lai Ying-Si , Liao Jing , Hao Yuan-Tao
Published: December 2021

Objective

To develop and validate an index to quantify the multimorbidity burden in Chinese middle-aged and older community-dwelling individuals.

Methods

We included 20,035 individuals aged 45 and older from the China Health and Retirement Longitudinal Study (CHARLS) and 19,297 individuals aged 65 and older from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Health outcomes of physical functioning (PF), basic and instrumental activities of daily living (ADL and IADL) and mortality were obtained. Based on self-reported disease status, we calculated five commonly used western multimorbidity indexes for CHARLS baseline participants. The one that predicted the health outcomes the best was selected and then modified through a linear mixed model using the repeated individual data in CHARLS. The performance of the modified index was internally and externally evaluated with CHARLS and CLHLS data.

Results

The multimorbidity-weighted index (MWI) performed the best among the five indexes. In the modified Chinese multimorbidity-weighted index (CMWI), the weights of the diseases varied greatly (range 0.2–5.1). The top three diseases with the highest impact were stroke, memory-related diseases and cancer, corresponding to weights of 5.1, 4.3 and 3.4, respectively. Compared with the MWI, the CMWI showed better model fits for PF and IADL with larger R2 and smaller Akaike information criterion, and comparable prediction performances for ADL, IADL and mortality (e.g. the same predictive accuracy of 0.80 for ADL disability).

Conclusion

The CMWI is an adequate index to quantify the multimorbidity burden for Chinese middle-aged and older community-dwelling individuals. It can be directly computed via disease status examined in regular community health check-ups to facilitate health management.
Co-production of Care Leavers’ Transition Planning as Young Adults: An Analysis of Young People in California Foster Care
Authors: Park Sunggeun (Ethan) , Powers Jenna , Okpych Nathanael J , Courtney Mark E
Published: December 2021

The co-production of transition planning (i.e. care leavers having opportunities to influence decisions about their lives) is recognised as an important process internationally. However, little is known about factors influencing care leavers’ involvement in transition planning. This study uses a sample of care leavers in California (n = 423) and multiple data sources, including youth–worker matched data, to investigate predictors of transitional independent living plan (TILP) involvement. The outcome measures the mechanisms care leavers experienced during their TILP process, including worker-driven production (i.e. not aware of or not involved), youth-driven co-production (i.e. involved in and led) and youth–worker co-production (i.e. involved in but did not lead). Multinomial logistic regression was used to examine relationships between predictors measured at age 17 and TILP involvement mechanisms at age 19. Most youth led (44 per cent) or were involved in (43 per cent) TILP planning, but 14 per cent were not aware or uninvolved. Care leavers’ opportunities to influence their TILP were shaped by their individual (e.g. personality and support networks), relational (e.g. caseworker’s perception of youth’s preparedness) and contextual (e.g. regional service availability) factors. Notably, youth served by specialised caseworkers were more likely to experience youth–worker co-production than youth-driven co-production. Implications for practice and research are discussed.
The miR-345-3p/PPP2CA signaling axis promotes proliferation and invasion of breast cancer cells
Authors: Zeng Qian , Jin Fangfang , Qian Husun , Chen Hongling , Wang Yange , Zhang Dian , Wei Yu , Chen Tingmei , Guo Bianqin , Chai Chengsen
Published: December 2021

Breast cancer is the most common malignancy among women worldwide. Functional studies have demonstrated that miRNA dysregulation in many cases of cancer, in which miRNAs act as either oncogenes or tumor suppressor. Here we report that miR-345-3p is generally upregulated in breast cancer tissues and breast cancer cell lines. Overexpression and inhibition of miR-345-3p revealed its capacity in regulating proliferation and invasion of breast cancer cells. Further research identified protein phosphatase 2 catalytic subunit alpha (PPP2CA), a suppressor of AKT phosphorylation, as a candidate target of miR-345-3p. In vitro, miR-345-3p mimics promoted AKT phosphorylation by targeting its negative regulator, PPP2CA. Blocking miR-345-3p relieved its inhibition of PPP2CA, which attenuated PI3K-AKT signaling pathway. In vivo, inhibiting miR-345-3p by miR-345-3p-inhibition lentivirus suppressed tumor growth and invasiveness in mice. Together, the miR-345-3p/PPP2CA signaling axis exhibits tumor-promoting functions by regulating proliferation and invasion of breast cancer cells. These data provide a clue to novel therapeutic approaches for breast cancer.