bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas production kinetic and organic matter digestibility in vitro of diet supplemented by biochar and liquid smoke
Authors: Qomariyah N , Retnani Y , Jayanegara A , Wina E , Permana I G
Published: March 2021

This research aimed to evaluate the use of biochar and liquid smoke as feed additives on gas production and organic matter digestibility of a complete feed in the in vitro rumen fermentation system. Biochar and liquid smoke came from the pyrolysis process of cacao pod husks. Treatments consisted of: control (substrate), biochar BC1 (0.1 mg / ml), BC2 (0.2 mg / ml), BC3 (0.3 mg / ml), BC4 (0.4 mg / ml), liquid smoke LS1 (0.25 ul / ml), LS2 (0.5 ul / ml), LS3 (0.75 ul / ml) and LS4 (1.0 ul / ml). The samples were incubated in vitro with buffered-rumen fluid in four replicates, represented by two incubation units per replicate, and conducted for 48 h at 39oC. Parameters measured in the in vitro evaluation were total gas production and digestibility of organic matter. Data were tested using analysis of variance (ANOVA) and if there was a significant difference at P<0.05 then continued with Duncan’s multiple range test. The results showed that supplementation of biochar and liquid smoke did not affect gas production. However, the addition of biochar and liquid smoke decreased the digestibility of dry matter and organic matter as compared to a control substrate (P <0.05). Furthermore, the addition of biochar and smoke caused a decrease in total protozoa (p<0.05). It was concluded that biochar supplementation and liquid smoke as feed additive reduce protozoa without affecting total gas production and gas production rate.
A brief review on advanced renewable materials for supporting artificial insemination technology
Authors: Kusumawati E D
Published: March 2021

This paper is a review paper. National meat self-sufficiency program (MSSP), which has been launched since 2000, has been well improved in term of concept, policy instrument, and program management, but the supporting technologies are still as one of some constraints. The study was aimed to metaanalyze comprehensively the frontier technologies supporting the national MSSP, especially advanced materials for artificial insemination technology in order to enhance animal population. The meta-analysis study adopted Wilson and Kelly metanalisis methods consisting of nine steps. Results of the study showed that (1) there were some frontier advanced technologies on animal husbandry in terms of breeding, fattening up and farm management, as well as animal feeds and feedstock’s; (2) those technologies consisted of advancing materials dan methods/process; and (3) particularly, in supporting breeding technology, advancing artificial insemination technologies take important role for significantly enhancing the animal population as well as effectiveness of animal breeding, thus advancing the materials as well as processes involved are highly needed. The study concluded that advanced renewable materials for supporting artificial insemination technology should be taken into account for advancement of animal husbandry technology.
Study on the microstructure and mechanical properties during cold rolling and annealing process of Cu-30Zn-1Al-1Mn Alloys
Authors: Basori I , Krishartadi G D , Sirojuddin S , Sari Y , Syamsuir S
Published: March 2021

This research was conducted to determine the effect of cold rolling and annealing process on the microstructure and mechanical properties of the Cu-30Zn-1Al-1Mn brass alloy produced by gravity casting. Samples were cold rolled with deformation levels of 20%, 40% and 70% and followed by annealing process with temperature variations of 300°C, 400°C, 500°C, and 600°C for 30 minutes. Sample characterization includes chemical composition analysis, microstructure observation and hardness testing. The results illustrate that the Cu-30Zn-1Al-1Mn brass alloy shows the appearance of α and β phases. The cold rolling process with a deformation levels of 20% and 40% promote the formation of a slip and twinning mechanism. On the other hand, samples with a 70% deformation level are dominated by shear bands. The annealing process induces the phenomena of recovery, recrystallization and process of grain growth. The higher the deformation level, the faster the recrystallization process. Furthermore, the smaller the grain size, the higher the sample hardness.
Study on the aluminum addition to the microstructure and mechanical properties of Cu-10Zn alloys produced by gravity casting
Authors: Basori I , Ali I N K , Sirojuddin S , Dwiyati S T , Sari Y
Published: March 2021

In this research, the samples of Cu-10Zn-xAl alloys were manufactured by gravity die casting process using Cu, Zn and Al ingots as the feeding materials. The aluminum addition was varied to 1, 2.5, and 6 wt. %, respectively. The as-cast samples with dimension of 100x100x6 mm3 were homogenized at temperature of 800 °C for 2 hours. Samples characterization includes chemical composition analysis, microstructure observation, tensile and hardness testing. The results showed that the addition of Al to the Cu-10Zn alloys significantly affected the microstructure and mechanical properties. The addition of 5.93 wt. % Al promotes the presence of β phase at the as-cast sample. Furthermore, the addition of Al to the Cu-10Zn alloy tends to increase the tensile strength, elongation and hardness.
The meaning of sign, contradiction between modern and tradition in visualization (Case study: Pocari Sweat TV Commercial)
Authors: Putri F E N I , Murwonugroho W
Published: March 2021

Pocari Sweat is a Japanese beverage product. One of the TVC run by Pocari Sweat is in Japanese 2D animation style (anime) titled “High School Star. This paper aims to study the character visual style, place settings, and creative strategy plan with the intention of understanding the key visual of acculturation style between Japan and Indonesia, in this case Japanese anime style with Indonesian local culture. The methodology of this research uses Semiotic. In his theory, Saussure divides sign as signifier and signified. On the discussion and analysis section, we discovered that the Ad told a story of two high school students named Ayu and Reza while chasing their dreams. The “High School Star” is unique as it mixes two different cultures, displaying Indonesian characters and settings told in a form of Japanese animation. Yoshitosi Shinomiya used environmental art approach to draw the settings. He interviewed Indonesian high school students and showed the colourful life of Indonesian youth. The 2D animation made by traditional means. This Japanese themed ad shows the same meaning of sign on either enjoying the natural beauty of Bali or the exhaustion of modern city. What younger generation need is to have the spirit of life as if enjoying refreshing drink, Pocari Sweat.
Application Ecogel Incorporation additive for maintain freshness of Strawberry fruit during storage
Authors: Suriati L , Suardani N M A
Published: March 2021

Strawberries are popular fruits with high economic value and nutritional content, which are easily damaged. Therefore, the edible coating is one of the steps used to extend the shelf-life of strawberry and maintain its quality. This process uses aloe gel, which contains glucomannan, capable of cross-linking with other ingredients, to bridge the mass transfer of destructive components. The purpose of this study is to examine the influence of additives against the stability of ecogel as an edible coating method for Strawberry fruit in order to maintain its freshness during storage. The method used a factorial complete randomized design to determine the treatment of additives such as acid, potassium sorbate, and calcium chloride into Aloe gel. Secondly, it determines the storage time of Strawberry fruit for 0, 3, 6, 9, 12, and 15 days. The result showed that the Ecogel treatment with the addition of ascorbic acid additives retains the freshness of strawberry fruit till the 9th in cold temperatures of 7 ± 1°C. It also reduces the weight, vitamin C, pH, and total soluble solid of the fruit, while retaining the moisture content.
Estimation of carbon stock in true mangrove stands in the Cipalawah Block of Sancang Sea Nature Reserve Garut West Java
Authors: Amalia L , Juniarti Y , Ardiana C , Saputra I D
Published: March 2021

This research aims to determine the estimation of biomass, carbon stock, density, and CO2 absorption of true Mangrove stands. This is important to know how much the area of the mangrove forest is able to absorb CO2 from the air, so that it can support the area’s sustainable management activities in relation to reducing the concentration of CO2 in the atmosphere. The research method used is a quantitative descriptive method with purposive sampling data collection techniques. Based on the research results obtained 6 types of mangroves namely Sonneratia alba, Rhizophora gymnorhiza, Aegiceras corniculatum, Avicenia marina, Bruguiera gymnorhiza, and Xylocarpus granatum. Based on the calculation using allometric equations, biomass results were 277.945 tons/Ha, estimation of carbon stock was 127.855 tons/Ha, true mangrove stand density was 737 individuals/Ha, and total CO2 absorption of true Mangrove stands was 468.802 tons/Ha.
Molecular Dynamics study on size dependencies of melting dynamics in Gold thin film
Authors: Fahdiran R , Sugihartono I , Handoko E , Budi E , Susila A B , Prayitno T B , Sunaryo S
Published: March 2021

We explore the size dependencies of melting dynamics of Gold in the form of thin film. The sizes are 4.896 nm, 7.344 nm and 9.792 nm which is comparable between nanoparticle diameter and thin film thickness. The systems are treated by increasing temperature from 300 K to 1400 K. Molecular Dynamics (MD) scheme is employed to follow the trajectories of the systems up to 20 ps. Structure factor analysis indicated that the melting is suppressed by the increasing size.
Analysis of Pelecypoda Ecology Index in Rancabuaya Beach Garut District
Authors: Hernawan H , Hasanah N U , Taofik D B I , Susila A A R
Published: March 2021

This study aims to determine the Pelecypoda species and Pelecypoda Ecological Index values include diversity, abundance, evenness, dominance and density in Rancabuaya Beach Garut District. The method used is descriptive method with purposive sampling technique, Line transect and Quadrat transect. Sampling was carried out by dividing the study area into three observation stations totaling 90 samples. Observations were obtained, Pelecypoda species as many as 12 species including: Barbatia foliata, Antigona puerpera, Antigona materna, Anadara turonica, Cardita aviculina, Anodontia vesícula, Gafrarium pectinatum, Antigona puerpera, Antigona materna, Anadara turonica, Cardita aviculina, Anodontia vesicula, Gafrarium pectinatum, Anigontia edentpera, Antigona materna, Anadara turonica, Cardita aviculina, Anodontia vesicula, Gafrarium pectinatum, Anigontia edentperula, Anigontia edentula Septifer bilocularis, Tellina scobinata, Tridacna maxima, and Anadara antiquata. The results of the analysis of diversity index 0.0069-0.1596 are in the low category, an abundance index of 0.3-35.3% are in the average category enough, evenness index 0-0.0753 evenness is in a depressed condition, 0-0,12456 which is in the low category and the density index ranges from 0.1 to 13.2 is in the low category. This indicates the threat to the survival of Pelecypoda and the low quality of waters on the coast of Rancabuaya.
The effect of voltage bias on the yield and electrical properties of Exfoliated Graphene synthesized via electrochemical method
Authors: Abdillah O B , Floweri O , Iskandar F
Published: March 2021

Graphene has been gaining immense attention from scientists over the world for its exceptional properties, which makes it promising for several applications such as energy storage, electronic devices, and biomedicine. Graphene synthesis via the electrochemical exfoliation route offers a cheap, simple, eco-friendly, and scalable process for industrial purposes. In this work, the effect of voltage bias during electrochemical exfoliation on the electrical properties and yield of the obtained exfoliated graphene (EG) was studied. Graphite sheet as raw material was pre-treated by immersing it into H2SO4/H2O2 mixture before the electrochemical process. By applying the optimum voltage of 10 V, the electrochemical method was able to produce EG with yield as high as 40.95% in a relatively shorter time. Moreover, EG also demonstrated the highest electrical conductivity of 25.45 S/cm.
Nature of Science learning design for elementary school students
Authors: Yuniasih N , Widodo A
Published: March 2021

This study aims to describe the increased understanding of NOS students after the application of the Nature of Science learning design. This study uses a pre-experimental research with a one-group pretest-posttest design research design. The number of samples in this study were 29 students. The research instrument used in this study was in the form of students NOS understanding questionnaire. The results showed that the level of understanding of NOS students got a percentage of 77,5% means that with this percentage students understanding of NOS is included in both criteria. The results of the study also showed a significance value of 0,000 <0.05 then H0 was rejected and H1 was accepted so that it could be concluded that there were significant differences between students NOS understanding before and after learning by using the NOS learning design. In accordance with these results it can be concluded, the teaching of NOS in Elementary Schools can be done effectively through the use of appropriate learning designs, so as to improve students NOS understanding.
Performance of fan chips on drilling aluminium process
Authors: Sifa A , Suwandi D , Endramawan T , Rachman A A
Published: March 2021

The metal fabrication process, especially in the metal drilling process, one of the parameters that affect the quality of metal drilling results is cooling media, because it affects the life of the tool used. This paper aims to determine the performance of using fan chips as an alternative to cooling media in the metal drilling process area. The method used with flow simulation and drilling process experiments on workpiece made from aluminum alloy 5086 in experimental testing uses a variation of the spindle rotation of a metal drilling machine with the aid of taking test data with an anemometer and infrared thermometer in the drilling process of the aluminum alloy 5086 workpiece. After experimenting with chips through spindle rotation variations, cooling of the process area occurs when the engine spindle rotation rotates above 1000 rpm and the temperature decreases at the end of the tool area by 5°C compared to without using fan chips. A decrease in the temperature of the work area of the drilling workpiece aluminum alloy 5086 compared without using fan chips has an impact on increasing the tool life limit by 12% or increasing tool life by 5 minutes.
Flame spread simulation of fire occurrence at motorcycle parking building
Authors: Setyadi P , Yoga N G , Kusumohadi C S , Triyono T , Nanda Y F
Published: March 2021

This research is motivated by the condition of the parking building in A Campus, State University of Jakarta that development that very compact and crowded with wide openings. This study aims to estimate the flame spread of motorcycle parking. This study used computer fire modeling by simulating flame starting point and direction of the wind, numbers of fuel source and forms. This research will discuss about the development of the fire where the fire development will be represented by HRR (Heat Release Rate), burning rate, and visualization of each simulation. This step is very advantageous because it can figure out how the spread of fire during a fire and how fire simulated. With the fire of this modeling can be a practical engineering approach to provide additional review of aspects of fire safety on campus parking building at Jakarta State Univeristy. From these results it can be concluded that the rapid spread of the fire affected by the starting point of fire, wind speed and direction. HRR where the greater value the greater the value of burning rate obtained and the greater the level of occurrence of fire.
Optimum parameters of Organic Rankine Cycle (ORC) power plant using coconut shell as fuel
Authors: Harmiansyah H , Hartulistiyoso E , Widodo S , Nugroho L P E
Published: March 2021

The scarcity of energy sources is an important issue now. The increasing number of populations causes higher energy needs. The use of renewable energy as an alternative is a good solution. Organic Rankine Cycle (ORC) is a Rankine cycle that can work at low temperatures and pressures. The working fluid of ORC is an organic one such as R-134a refrigerant; because its boiling point is lower than that of water and has low environmental impact. In this study, work simulations were performed by using Cycle Tempo software to analyze the performance of the ORC system using coconut shells and to obtain optimum parameter variations based on thermal efficiency values. The simulated data consists of 12 variations of fuel rate parameters and mass flow rate. Based on the simulation results, 2.5 kg 2 GPM variation is obtained as the optimum parameter variation with a thermal efficiency value of 6.17%.
Analysis of number propeller blades on traditional boats 3 GT capacity with engine rotation speed variation
Authors: Endramawan T , Sifa A , Dionisius F , Rachman R D
Published: March 2021

Limited range of fishing areas is one form of loss experienced by fishermen in Indonesia, especially fishermen who still use traditional boats 3 GT capacity. The driving component of one of the problems, one of which is a propeller. Propeller commonly used by fishermen still uses 3 blades propeller with less than maximum thrust distribution and fluid velocity. The purpose of this study is to optimize the number of propeller blades in traditional boats 3 GT capacity with variations in the number of propeller blades 2,3 and 4 and rotational speed of 700 RPM, 1200 RPM, 1700 RPM, and 2200 RPM. The method used to determine the amount of thrust and fluid velocity through CFD simulations. Flow simulation results show the maximum thrust obtained at 1700 RPM rotational and the maximum fluid velocity obtained at 2200 RPM with a pressure of 15.3Mpa and a fluid speed of 3340.16 m/s on a propeller of 2 blades. Whereas the minimum thrust force is obtained at 700 RPM rotational with pressure 0.21Mpa in propeller with 3 blades and the minimum fluid speed is obtained at 700 RPM rotational with a fluid speed 369.33 m/s on propeller with 4 blades.
Analysis of ST-37 metal cutting with machine-cut tools using Oxy-LPG
Authors: Tauvana A I , Widodo W , Subekti M I , Syafrizal S , Nulhakim L
Published: March 2021

This gas cutting machine is a ST-37 metal cutting tool in a semi-automatic way using LPG and Oxygen gas materials. LPG gas is used with a composition of propane 99,5% and Isobutan 5%. In the process of cutting metal must pay attention to several parameters, namely: metal thickness, oxygen gas pressure and LPG gas and cutting speed. Before cutting down the metal, the preparation stage is done by conditioning the test equipment and work equipment used to collect test data. The method used in this research is to select the type of metal and cutting equipment then do the recording and taking test data. Further analysis and examination are carried out as follows: visual inspection of the results of cutting and flame shape, a better composition results from testing in accordance with applicable rules such as pressure, plate thickness and time of cutting. 99,5% and 0,5% LPG gas composition at gas working pressure: 0.2 kg / cm2; oxygen pressure: 2.5 kg / cm2, cutting distance of 2mm. The results of this test are overall in good condition and no defects occur.
Optimization of relative density to geometric parameter ratio for honeycomb structure using Finite Element Analysis
Authors: Octarina A J , Saptaji K , Kurniawan T
Published: March 2021

Honeycomb structures are becoming preferred choice for increasing the efficiency of automotive, aerospace, construction and other related industries as it provides low-density ratio to specific strength. Out-of-plane orientation honeycomb core structure has significant advantage in load-bearings and energy absorption. However, previous studies were mostly focusing on the specific strength of the structure. In this paper, optimization of relative density to geometric parameter ratio for honeycomb structure is conducted with the focus on compressive properties. It is expected that high compressive properties with low relative density can be achieved. Relative density and geometric parameter are obtained from RVE (Representative Volume Element) which affected by variable-thickness. Finite Element Analysis (FEA) using ANSYS software were conducted to simulate compression test with 300kN compressive load to the honeycomb structure with various ratios. FEM results illustrate that relatively higher geometric parameter tends to have higher compressive properties. Initial analysis shows that structure with the lowest ratio of relative density to geometric parameter of around 22.70% has higher equivalent elastic strain and equivalent stress around 0.50896 and 1.7152 GPa compared to other parameters.
Armadillo modelled foldable motorcycle helmet: A preliminary design concept for rider in Indonesia
Authors: Maulidati N , Cahyo A D N , Irodatillah K , Triawan F
Published: March 2021

Safety is an important thing while riding a bicycle or motorcycle. Using a helmet is one of the solutions to increase safety of the rider, but sometimes people are too lazy to bring the helmet because of its big size. In the present work, a foldable helmet adopting the Armadillo concept was proposed to make people feel more comfortable in carrying the helmet. The design also follows the safety standard required by the SNI (Indonesia National Standard). A locking system for the folding mechanism is discussed, and a honeycomb foam for impact absorber is considered in the design. As a result, the proposed foldable helmet can have a reduction volume of 23.75% compared with the non-foldable one. This work is expected to contribute to the innovative engineering design field.
Performance analysis of R290 as a substitute for R404A on 12,000 Btuh cold storage capacity
Authors: Widodo W , Syafrizal S , Tuvana A I , Subekti M I , Nulhakim L
Published: March 2021

Cold Storage is a machine that has a very low temperature:-30°C which is used for the freezing process. Cold storage used for this research has a capacity of 18,000 Btuh with R404A. This refrigerant does not contain ODP but still contains a very high GWP: 3940 compared to R290. R290 (propane) is GWP:4 and ODP:0. But this refrigerant has flammable properties between LFL-UFL: 2-10%. The cold room dimensions: 3 x 1.5 x 2.5:11.25m3. The testing methodology by comparing the performance of R404A with R290 cold storage conditions was tested without using a cooling load with a room temperature setting of -29°C, room temperature of 35°C and RH: 70%. Time Testing is carried out for 90 minutes. From the test results obtained data: evaporator temperature: -29°C with a time of 68 minutes for R290 and 95 minutes for R404A, LP: R404A / R290: 12/6 Psig, discharge pressure: 215 / 175 Psig and the amount of refrigerant entered in the system: 3500/1800 grams and electric current: 4.1/2.9 Amperes. From the data analysis, it can be concluded that R290 has better performance, energy-saving, and environment friendly compared to R404A.
Effects of the superficial gas velocity on the distribution of solid particles in the circulating fluidized bed using CFD simulations
Authors: Daryus A , Siswantara A I , Budiarso B , Pujowidodo H , Gunadi G G R
Published: March 2021

The purpose of the study is to investigate the effects of various air flow rate or superficial gas velocity in term of excess air to obtain the optimum distribution of solid phase in the Circulating Fluidized Bed (CFB). The Computational Fluid Dynamics (CFD) method used for simulations uses the Multi-fluid Eulerian approaches incorporating the Kinetic Theory of Granular to calculate the motion of particles and the standard k-ॉ turbulence model to simulate the fluid flows. The simulations were carried out using five different air mass flow rates, based on the air consumption in the combustion of coal used in real CFB boiler operation. Since this simulation is the preliminary study of the particle dynamics in CFB, the combustion process had not simulated yet. In this work, the complex flow has been resolved by applying the CFDSOF commercial CFD software. The pressure on bed, the distribution of pressure, the particle velocity and volume fraction in the CFB were investigated to obtain the optimum results of the fluidization. The values of the pressure found from experiments at the bottom of bed was around 4,500 Pa, and the results from simulations were not different significantly with this values. At the excess air of 90%, the velocity of particles at the surface of bed is highest that can lead to the erosion on the firewall in long term operations, meanwhile at the lower excess air values, their velocity were relatively small. The optimum of excess air that found to be safe for boiler to operate was around 60% - 75% for average particle size 1 mm.
Investigations on properties and tribological behavior of AlMg4.5Mn0.7(AA5083)-MoO3 composites prepared by stir casting method
Authors: Anandaraj T , Sethusundaram P P , Meignanamoorthy M , Ravichandran M
Published: March 2021

Molybdenum Trioxide (MoO3) has received extensive consideration as a prospective reinforcement for metal matrix composites (MMCs) to improve the properties. The goal of this work is to fabricate and examine the properties of AA5083-MoO3 composites. AA5083-MoO3 composites by several weight percentages were produced via liquid metallurgy technique. The compositions of the composites are AA5083, AA5083-4wt.%MoO3, AA5083-8wt.%MoO3 and AA5083-12wt.%MoO3. The microstructure inspection was made on the synthesized AA5083-MoO3 composites using Scanning Electron Microscope (SEM). The effect of MoO3 weight percentage on the properties such as density, porosity, mechanical and wear behavior were investigated. The SEM images expose the even dispersion of MoO3 particles with AA5083 matrix. The combination of MoO3 particles enhanced the properties of the composites. The wear behavior was examined via pin on disc apparatus at various process parameters wt.%, load, sliding velocity (V) and sliding distance. Trials were conducted as per L16 orthogonal array (OA). Optimum process parameters to acquire least wear rate and co-efficient of friction (COF) was done by Grey Relational Analysis (GRA). The ANOVA results exposes that wt.% is the major important parameter inducing wear and COF.
Exploration of PTFE sub-micron particles for enhancing the performance of commercial oils
Authors: Solanki Raghavendra , Saini Vinay , Bijwe Jayashree
Published: March 2021

This paper reports on the tribo-performance enhancement of commercial gear oil and engine oil by inclusion of PTFE particles of submicron (230 nm) size (SMPs). It also reports on the investigations on various concentrations of SMPs to find the optimum doses. Results revealed that optimum dosage of 6 and 3 wt.% SMPs led to a significant improvement in EP property by 175% and 58% respectively in Engine oil and Gear oil. The EP performance of PTFE added engine oil surpassed that of PTFE added-gear oil confirming that it can be used as multipurpose oil. Importantly anti-wear and anti-friction properties also showed improvement confirming no antagonistic influence of PTFE particles on selected commercial oils. Synergistic action between SMPs and other additives led to formation of stable tribo-film as a result of chemical interaction of mating surfaces. The mechanisms involved were analyzed by investigating worn surfaces using SEM-EDX, x ray photoelectron spectroscopy (XPS) techniques. The stability of suspension in case of engine oils was up to 2 months and for gear oil it did not show any deterioration in the observed period of 4 months.
Effect of FSP on mechanical properties, wear and corrosion behavior of A356 Al alloy
Authors: Hasona Khadija M , Afify Rasha M , Mansour El-Sayed H , Gaafer Ahmed M , Mahmoud Tamer S , Mosleh Ahmed O
Published: March 2021

Grain refining and microstructure homogenization are fundamental challenges for enhancing the performance of the materials. One of the effective ways to solve these challenges is the Friction stir processing (FSP) technique. This paper investigates the FSP parameters’ impact on the microstructure, hardness, wear, and corrosion behavior of A356 Al–Si cast alloy. The FSP parameters are rotational speed (355–900 rpm), trasverse speed (10–40 mm min−1), and two different tool geometries. The results revealed that the intense plastic deformation and dynamic recrystallization fragmented the needle-shaped eutectic silicon particles. The particle size change was more pronounced as the rotational speed was increased than the transverse speed and the pin profile tool geometry. The fragmented and homogeneously distributed Si particles in the investigated alloy increased their hardness, wear, and corrosion resistance compared with those of the unprocessed base metal. The hardness increased by two times, and the wear rate reduced by ten times, while the corrosion rate decreased by 200 times than the BM at lower tool rotational speeds and higher transverse speed. The Possible reasons were discussed for these enhancements.
Molecular dynamics simulation of monocrystalline copper nano-scratch process under the excitation of ultrasonic vibration
Authors: Jian-Hao Chen , Qiu-Yang Zheng , Zhen-Yu Zhou , Cong Ding , Zhong-Yu Piao
Published: March 2021

In order to explore the mechanism of unidirectional ultrasonic vibration-assisted machining from a microscopic point of view, the molecular dynamic (MD) simulation method is used to simulate the scratch process of monocrystalline copper under ultrasonic excitation. By comparing the simulation results of traditional scratching and ultrasonic vibration-assisted scratching, the influences of ultrasonic vibration on the surface morphology, the tangential force, and the evolution of the crystal’s internal defects are discussed. The results show that the ultrasonic vibration can improve the surface quality of the workpiece, reduce the tangential force, and reduce the energy consumption. Simultaneously, ultrasonic vibration promotes the interaction between dislocations, accelerates the annihilation of dislocations, effectively reduces work hardening caused by dislocation accumulation, and forms a large number of vacancies and interstitial atoms.
Study on the effect of singlewalled carbon nanotubes on junction properties of Safranin –T dye-based organic device
Authors: Sen Sudipta , Kumar Das Pallab , Manik N B
Published: March 2021

In this work, junction properties of metal-organic dye contact have been studied and alteration of these properties in presence of single walled carbon nanotubes has been observed. Junction properties of metal-organic interface significantly influence the device performance. Present work studies barrier potential and trap energy under the influence of single walled carbon nanotubes. Barrier inhomogeneity and the effect of image charge on lowering of barrier potential have also been studied. Formation of the organic device has been done by sandwiching Safranin - T dye in between two electrodes which are Indium Tin Oxide coated glass substrate and Aluminium respectively. Charge flow at the metal–organic layer interface has been analyzed by Richardson –Schottky thermionic emission theory. Both barrier potential and trap energy have been estimated from the steady-state current-voltage characteristics of the device. The incorporation of single walled carbon nanotubes lowers both of these parameters results in improvement of current flow at the metal-organic contact.
Piezoelectric property investigation on PVDF/ZrO2/ZnO nanocomposite for energy harvesting application
Authors: Naik Rahul , S Mohit , Chavan Santosh
Published: March 2021

Recent days, considerable research efforts have been emphasized on the development of lightweight, portable, shock resistance, and flexible wearable devices that are powered by harvesting energy from abundant mechanical forces or vibrational energy. In this paper, we report piezoelectric nanogenerator (PNG) based on poly (vinylidene fluoride) (PVDF)/Zirconium oxide (ZrO2)/Zinc oxide (ZnO) nanocomposite. The addition of nanofillers significantly affects the structural property of PVDF, and their addition helps in the improvement of the piezoelectric property. The PNGs are fabricated and tested under various stress conditions (at different loads, tapping and walking). The hybrid PVDF/5% ZrO2/5% ZnO nanogenerator showed a maximum peak to peak voltage (Vpp) of 3.2 V, which is nearly eight times more than pristine PVDF nanogenerator. A prototype of shoe pad nanogenerator is demonstrated as an application.
Spectral broadening and ultrafast dynamics of a nitrogen-vacancy center ensemble in diamond
Authors: Liu Albert , Cundiff Steven T , Almeida Diogo B , Ulbricht Ronald
Published: March 2021

Many applications of nitrogen-vacancy (NV) centers in diamond crucially rely on a spectrally narrow and stable optical zero-phonon line transition. Though many impressive proof-of-principle experiments have been demonstrated, much work remains in engineering NV centers with spectral properties that are sufficiently robust for practical implementation. To elucidate the mechanisms underlying their interactions with the environment, we apply multi-dimensional coherent spectroscopy to an NV center ensemble in bulk diamond at cryogenic temperatures. Our spectra reveal thermal dephasing due to quasi-localized vibrational modes as well as ultrafast spectral diffusion on the picosecond timescale. The intrinsic, ensemble-averaged homogeneous linewidth is found to be in the tens of GHz range by extrapolating to zero temperature. We also observe a temperature-dependent Stark splitting of the excited state manifold, relevant to NV sensing protocols.
A Brief Motivational Intervention Differentially Reduces Sugar-sweetened Beverage (SSB) Consumption
Authors: Mason Ashley E , Schmidt Laura , Ishkanian Laura , Jacobs Laurie M , Leung Cindy , Jensen Leeane , Cohn Michael A , Schleicher Samantha , Hartman Alison R , Wojcicki Janet M , Lustig Robert H , Epel Elissa S
Published: March 2021

Background

Environmental and behavioral interventions hold promise to reduce sugar-sweetened beverage (SSBs) consumption.

Purpose

To test, among frequent SSB consumers, whether motivations to consume SSBs moderated the effects of (a) a workplace SSB sales ban (environmental intervention) alone, and (b) a “brief motivational intervention” (BI) in addition to the sales ban, on changes in SSB consumption.

Methods

We assessed whether (1) baseline motivations to consume SSBs (craving, psychological stress, or taste enjoyment) impacted changes in daily SSB consumption at 6-month follow-up among frequent (>12oz of SSBs/day) SSB consumers (N = 214); (2) participants randomized to the BI (n = 109) versus to the sales ban only (n = 105) reported greater reductions in SSB consumption at follow-up; and (3) motivations to consume SSBs moderated any changes in SSB consumption.

Results

In response to the sales ban alone, individuals with stronger SSB cravings (+1 SD) at baseline showed significantly smaller reductions in daily SSB consumption at 6-month follow-up relative to individuals with weaker (−1 SD) SSB cravings (2.5 oz vs. 22.5 oz), p < .01. Receiving the BI significantly increased reductions for those with stronger SSB cravings: Among individuals with stronger cravings, those who received the BI evidenced significantly greater reductions in daily SSB consumption [M(SE) = −19.2 (2.74) oz] than those who did not [M(SE) = −2.5 (2.3) oz, p < .001], a difference of 16.72 oz.

Conclusions

Frequent SSB consumers with stronger SSB cravings report minimal reductions in daily SSB consumption with a sales ban only, but report greater reductions if they also receive a motivational intervention. Future multilevel interventions for institutions should consider both environmental and individualized multi-level interventions.

Clinical Trial information

NCT02585336.
What Determines Step-Rate at Work? An Investigation of Factors at the Shift, Worker, Ward, and Nursing Home Levels in Eldercare
Authors: Stevens Matthew L , Karstad Kristina , Mathiassen Svend Erik , Januario Leticia Bergamin , Holtermann Andreas , Hallman David M
Published: March 2021

Objectives

Current knowledge on the determinants of step-rate at different organizational levels is limited. Thus, our aim was to identify, in eldercare, at what workplace level differences in step-rate occur and to identify determinants of workers’ step-rate at these levels.

Methods

Participants were 420 eldercare workers from 17 nursing homes (126 wards) in Denmark. Accelerometry was used to assess step-rate (steps per hour) of workers over multiple shifts. We assessed various determinants at different levels of the workplace, i.e. at the (i) shift, (ii) worker, (iii) ward, and (iv) nursing home levels. Variance components analysis identified the percentage contribution to total variance in step-rate from each respective level. Multi-level linear regression modelling was used to investigate the association between candidate determinants at each level and step-rate.

Results

Differences in eldercare workers’ step-rate occurred primarily between shifts (within workers; 44.9%) and between workers (within wards; 49.1%). A higher step-rate was associated with: (i) weekend and evening shifts (versus weekday/day); (ii) job as a care helper (versus care aide) and an increased proportion of time spent on direct care tasks; (iii) working in a somatic ward (versus dementia), an increased resident–staff ratio and permission to take unscheduled breaks; and (iv) lack of elevators.

Conclusions

We found that nearly all variability in step-rate in eldercare work occurs between shifts (within workers) and between workers (within wards). The main determinants of step-rate were related to the type of shift, type of work tasks, staffing ratio, break policy, and availability of elevators.
Grow or go? Energetic constraints on shark pup dispersal from pupping areas
Authors: McMillan M N , Semmens J M , Huveneers C , Sims D W , Stehfest K M , Gillanders B M
Published: March 2021

Many sharks and other marine taxa use natal areas to maximize survival of young, meaning such areas are often attributed conservation value. The use of natal areas is often linked to predator avoidance or food resources. However, energetic constraints that may influence dispersal of young and their use of natal areas are poorly understood. We combined swim-tunnel respirometry, calorimetry, lipid class analysis and a bioenergetics model to investigate how energy demands influence dispersal of young in a globally distributed shark. The school shark (a.k.a. soupfin, tope), Galeorhinus galeus, is Critically Endangered due to overfishing and is one of many sharks that use protected natal areas in Australia. Energy storage in neonate pups was limited by small livers, low overall lipid content and low levels of energy storage lipids (e.g. triacylglycerols) relative to adults, with energy stores sufficient to sustain routine demands for 1.3–4 days (mean ± SD: 2.4 ± 0.8 days). High levels of growth-associated structural lipids (e.g. phospholipids) and high energetic cost of growth suggested large investment in growth during residency in natal areas. Rapid growth (~40% in length) between birth in summer and dispersal in late autumn–winter likely increased survival by reducing predation and improving foraging ability. Delaying dispersal may allow prioritization of growth and may also provide energy savings through improved swimming efficiency and cooler ambient temperatures (daily ration was predicted to fall by around a third in winter). Neonate school sharks are therefore ill-equipped for large-scale dispersal and neonates recorded in the northwest of their Australian distribution are likely born locally, not at known south-eastern pupping areas. This suggests the existence of previously unrecorded school shark pupping areas. Integrated bioenergetic approaches as applied here may help to understand dispersal from natal areas in other taxa, such as teleost fishes, elasmobranchs and invertebrates.
Low desiccation and thermal tolerance constrains a terrestrial amphibian to a rare and disappearing microclimate niche
Authors: Hoffmann Emily P , Cavanough Karen L , Mitchell Nicola J
Published: March 2021

Drier and hotter conditions caused by climate change threaten species that exist close to their physiological limits, as well as those with limited ability to move. Habitat specialists may also be particularly vulnerable if they have specific abiotic requirements. Here we assess whether thermal and hydric constraints can explain the highly restricted and declining distributions of the critically endangered terrestrial-breeding frog, Geocrinia alba. We also evaluate the species’ vulnerability to climate change based on the similarity of current microclimatic conditions to their physiological limits. We found that G. alba had low thresholds of thermal and desiccation tolerance relative to other anuran species. The estimated thermal optimum (Topt) and critical thermal maxima (CTmax) were 23.3°C and 29.6°C, respectively, and adult frogs had an absorption threshold (AT, the lowest water potential at which water can be absorbed from a substrate) of −50 kPa, the lowest recorded for an amphibian. Comparing environmental conditions and water loss in the field using agar models showed that riparian habitats where frogs occur provide a unique microclimate in the landscape, offering significantly lower desiccation risk during extreme summer conditions compared to immediately adjacent riparian and terrestrial habitats. Monitoring of microclimate conditions within occupied frog habitats over 2 years showed that in extreme dry and hot years the AT was exceeded at six of eight sites, and Topt was exceeded at two of eight sites. Given their specific physiological limits, the apparent rarity of suitable microclimates and a regional drying–warming trend, we suggest that G. alba occupies a potentially disappearing niche and may be indicative of other habitat specialists that rely on ephemeral drainages. More broadly, this study highlights that desiccation thresholds may tightly constrain amphibian distributions and need to be considered along with thermal tolerance thresholds when predicting the impacts of climate change.
Prognostic implications of cardiac damage classification based on computed tomography in severe aortic stenosis
Authors: Hirasawa Kensuke , vanRosendael Philippe J , Fortuni Federico , Singh Gurpreet K , Kuneman Jurrien H , Vollema E Mara , Ajmone Marsan Nina , Knuuti Juhani , Bax Jeroen J , Delgado Victoria
Published: March 2021

Aims

An echocardiographic staging system of severe aortic stenosis (AS) based on additional extra-valvular cardiac damage has been associated with prognosis after transcatheter aortic valve implantation (TAVI). Multidetector row computed tomography (MDCT) is key in the evaluation of AS patients undergoing TAVI and can potentially detect extra-valvular cardiac damage. This study aimed at evaluating the prognostic implications of an MDCT staging system of severe AS in patients undergoing TAVI.

Methods and results

A total of 405 patients (80 ± 7 years, 52% men) who underwent full-beat MDCT prior to TAVI were included. The extent of cardiac damage was assessed by MDCT and classified in five categories; Stage 0 (no cardiac damage), Stage 1 (left ventricular damage), Stage 2 (left atrium and mitral valve damage), Stage 3 (right atrial damage), and Stage 4 (right ventricular damage). Twenty-seven (7%) patients were stratified as Stage 0, 96 (24%) as Stage 1, 152 (38%) as Stage 2, 78 (19%) as Stage 3, and 52 (13%) as Stage 4. During a median follow-up of 3.7 (IQR 1.7–5.5) years, 150 (37%) died. On multivariable Cox regression analysis, cardiac damage Stage 3 (HR vs. Stage 0: 4.496, P = 0.039) and Stage 4 (HR vs. Stage 0: 5.565, P = 0.020) were independently associated with all-cause mortality.

Conclusion

The MDCT-based staging system of cardiac damage in severe AS effectively identifies the patients who are at higher risk of death after TAVI.
Colchicine and the heart
Authors: Imazio Massimo , Nidorf Mark
Published: March 2021

Colchicine is a unique, sophisticated anti-inflammatory agent that has been used for decades for the prevention of acute inflammatory flares in gout and familial Mediterranean fever. In recent years, clinical trials have demonstrated its potential in a range of cardiovascular (CV) conditions. Colchicine is avidly taken up by leucocytes, and its ability to bind to tubulin and interfere with microtubular function affects the expression of cytokines and interleukins, and the ability of neutrophils to marginate, ingress, aggregate, express superoxide, release neutrophil extracellular traps, and interact with platelets. In patients with acute and recurrent pericarditis, clinical trials in >1600 patients have consistently shown that colchicine halves the risk of recurrence [relative risk (RR) 0.50, 95% confidence interval (CI) 0.42–0.60]. In patients with acute and chronic coronary syndromes, multicentre randomized controlled trials in >11 000 patients followed for up to 5 years demonstrated that colchicine may reduce the risk of CV death, myocardial infarction, ischaemic stroke and ischaemia-driven revascularization by >30% (RR 0.63, 95% CI 0.49–0.81). The use of colchicine at doses of 0.5–1.0 mg daily in CV trials has proved safe. Early gastrointestinal intolerance limits its use in ∼10% of patients; however, ∼90% of patients tolerate it well over the long term. Despite isolated case reports, clinically relevant drug interactions with moderate to strong CYP3A4 inhibitors/competitors or P-glycoprotein inhibitors/competitors are rare if this dosage of colchicine is used in the absence of advanced renal or liver disease. The aim of this review is to summarize the contemporary data supporting the efficacy and safety of colchicine in patients with CV disease.
Linear and Nonlinear Associations Between Physical Activity, Body Composition, and Multimorbidity Over 10 Years Among Community-Dwelling Older Adults
Authors: Balogun Saliu A , Aitken Dawn , Wu Feitong , Scott David , Jones Graeme , Winzenberg Tania
Published: March 2021

Background

This study aims to describe the relationships between physical activity (PA), body composition, and multimorbidity over 10 years.

Method

Participants (N = 373; 49% women; average age 61.3 ± 6.7 years) were followed for 10 years. Multimorbidity was defined by self-report as the presence of 2 or more of 12 listed chronic conditions. PA (steps per day) at baseline was assessed by pedometer, handgrip strength (HGS) by dynamometer, and appendicular lean mass (ALM) and total body fat mass by dual-energy x-ray absorptiometry. Relative HGS and ALM were calculated by dividing each body mass index (BMI). Regression cubic splines were used to assess evidence for a nonlinear relationship.

Results

After 10 years, 45% participants had multimorbidity. There was a nonlinear relationship between PA and multimorbidity—PA was associated with lower multimorbidity risk among individuals who engaged in <10 000 steps/d (relative risk [RR] = 0.91, 95% CI: 0.85, 0.97, per 1 000 steps/d), but not among those who participated in ≥10 000 steps/d (RR = 1.04, 95% CI: 0.93, 1.09, per 1 000 steps/d). Higher BMI (RR = 1.05, 95% CI: 1.02, 1.08, per kg/m2) and fat mass (RR = 1.03, 95% CI: 1.01, 1.04, per kg), and lower relative HGS (RR = 0.85, 95% CI: 0.77, 0.94, per 0.1 psi/kg/m2) and ALM (RR = 0.93, 95% CI: 0.88, 0.98, per 0.1 kg/kg/m2) were linearly associated with a higher risk of multimorbidity. Absolute HGS and ALM were not significantly associated with multimorbidity.

Discussion

These findings highlight the potential clinical importance of maintaining adequate levels of PA and of reducing adiposity and maintaining muscle function for minimizing the risk of multimorbidity in older adults.