bluuebunny/crossref_metadata_2025 huggingface dataset:
Chitosan coating by mechanical milling of MnFe2O4 and Mn0.5Co0.5Fe2O4: Effect of milling
Authors: Mdlalose W. B. , Dlamini S. , Moyo T. , Mokhosi S. R. , Singh M.
Published: October 2019

Manganese ferrite (MnFe2O4) and manganese-cobalt ferrite (Mn0.5Co0.5Fe2O4) fine powders were produced by glycol-thermal technique. Fine powders were then milled with chitosan for different times ranging from 5 hours to 60 hours. XRD patterns of the as-prepared and milled oxides confirm cubic phase structure with an average crystallite size of 11 nm. The observed values of lattice parameter decrease with milling due to the inversion of cations induced by milling. TEM results reveal nanoparticles with spherical shape and average particle sizes correlating to XRD data. No aggregation of particles was observed after milling suggesting effective chitosan coating. Magnetization studies performed at room temperature in fields up to 14 kOe revealed the superparamagnetic nature of both naked and coated nanoparticles with spontaneous and saturation magnetizations decreasing with milling. Larger coercive fields observed in Mn-Co oxides were attributed to higher magnetic anisotropy associated with Co ions. A reduction of coercive field due to milling duration was observed. 57Fe Mössbauer spectra of Mn0.5Co0.5Fe2O4 samples show ordered magnetic states, while paramagnetic nature is revealed in MnFe2O4 samples. Hence, current results suggest that chitosan coating can be successfully achieved through mechanical milling resulting in nanoparticles with potential for biomedical applications. The differences in the magnetic properties of the samples are discussed based on Stoner-Wohlfarth theory.
Photoinduced birefringence in azopolymer doped with Au nanoparticles
Authors: Nazarova D , Nedelchev L , Stoykova E , Blagoeva B , Mateev G , Karashanova D , Georgieva B , Kostadinova D
Published: October 2019

A study of the photoinduced birefringence in nanocomposite thin films of the azopolymer PAZO (poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl, sodium salt]) doped with gold (Au) nanoparticles (NPs) is presented. The NPs are with a spherical shape and mean size 10 nm. Transmission electron microscopy (TEM) and Dynamic Light Scattering (DLS) analyses of the particles have also been made. Samples were prepared with five different concentrations of the NPs in the azopolymer films varying from 0 (non-doped azopolymer film) to 4 a.u. (1 a.u. = 0.015 wt %). Birefringence was induced by a He-Cd laser with a wavelength 442 nm and measured with probe Diode Pumped Solid State (DPSS) laser at 635 nm. An increase of the photoinduced birefringence in doped azopolymer nanocomposite films compared to samples of undoped azopolymers was observed. The maximal enhancement was achieved for films with 2 a.u. of Au NPs.
Enhancement of magneto-optical properties in magnetic photonic crystal slab waveguide based on yttrium iron garnet
Authors: Saker K , Bouchemat T , Lahoubi M , Bouchemat M
Published: October 2019

In this work, a polarization-independent waveguide based on magnetic photonic crystal (MPC) with a triangular lattice of air holes in Yttrium Iron Garnet (YIG) slab grown on alumina (Al2O3) substrate is proposed, where both TE-like and TM-like periodic band gaps overlap. YIG is well known for its attracting magneto-optical (MO) properties and used to produce a coupling between the TE and TM modes. Thus, a nonreciprocal effect can be obtained by applying an external magnetic field parallel to the direction of propagation. At 1550 nm, the complete photonic band gap is simulated and optimized using the three dimensional plane-wave expansion method. The aim of this study is to enhance Faraday rotation (FR) while maintaining a low modal birefringence. A numerical analysis in function of magnetic gyration (g) has been reported, using the BeamProp software. The results reveal a proportional relation between FR, Δ
n
and g, such for g = 0.5, a large FR of 26.11×104 °/cm with Δ
n
= 7×10−6. The results show a real improvement of this MPC structure based on YIG with larger FR, lower modal birefringence and minimal losses. The notable enhancement in the MO behaviour could improve the performance of optical isolators, and makes it suitable for nonreciprocal devices.
Preparedness intercomparison of passive H*(10) area photon dosemeters in 2017/2018 (IC2017prep)
Authors: Dombrowski H.
Published: October 2019

This intercomparison serves to investigate the long-term behaviour of passive H*(10) dosemeters which may be used in the aftermath of a radiological or nuclear event. In routine operation, such dosemeters are generally used to monitor installations like nuclear power plants and accelerators. Such dosemeters are used in the radiation field of the natural ambient radiation, including terrestrial and secondary cosmic radiation. From October 2017 to April 2018, photon dosemeters of 38 dosimetry systems were exposed to ionising radiation at three dosimetric reference sites which are operated by the Physikalisch-Technische Bundesanstalt (PTB). In addition to measurements which were carried out under natural conditions, a number of dosemeters was also irradiated artificially under two angles in PTB's photon fields. 34 measuring bodies and institutions which are mainly involved in ambient radiation monitoring in Europe took part in this intercomparison in which the response of the dosemeters to terrestrial and also to secondary cosmic radiation was determined. As a result of this intercomparison, some sources of uncertainty and some errors were found. The intercomparison revealed the typical precision that has to be expected when long-term dose measurements are carried out in the natural environment. The successful participation in this intercomparison was documented by certificates that were issued to the participants. The short designation of this intercomparison is “IC2017prep”.
Synthesis and Characterization of Ordered Mesoporous Carbon CMK-3 with a High Loading Capacity of Ibuprofen and its Release Performance at Simulated Body Fluid
Authors: Ulfa Maria , Prasetyoko Didik
Published: October 2019

In this paper, ordered mesoporous carbon CMK-3 have been synthesized via hard templating methode using mesoporous silica as template followed by thermal carbonization. The resulting ordered mesoporous carbon sample have been loaded by ibuprofen as anti inflammantory drug model up to 75% (w/w). Characterization of textural and structural resulting ordered mesoporous carbon was examined by transmission electron microscopy, small angle X-ray scattering, Fourier transform infrared spectroscopy and nitrogen adsorption-desorption. The high loading ibuprofen effect in release performance have been reviewed and it appears that ibuprofen loading on ordered mesoporous carbon surface can be release up to 50% in simulated body fluid at pH 7.4 for 200 min. Result shows that high ibuprofen loading not only change the textural and structural material but also have great impact for release performance. Key Word: ordered mesoporous carbon, CMK-3, ibuprofen, high loading, release.
In-situ synthesis of CdS@TiO2 Nanoparticles-nanobelt Heterojunctions with high photocatalytic property
Authors: Wang YM , Du G J , Qi M L
Published: October 2019

In this study, CdS nanoparticles were in-situ deposited on the surface of TiO2 nanorods through the liquid phase synthesis method, and the CdS@TiO2 Nanoparticles-nanobelt heterojunctions were obtained. The nanobelts are 50-200nm in width and several tens of micrometers in length, while the size of CdS nanoparticles is about 10 nm. The photocatalytic properties of the products were also studied and the results showed that the photocatalytic activity of CdS@ TiO2 heterostructure is improved greatly compared with that of the common nanobelts. This is attributed to the different band energy structure of the two semiconductors, facilitating efficient charge separation and migration.
Experimental description of aging of palm oil kernel shell powder/epoxy composite
Authors: Valášek Petr , Habrová Karolína , Müller Miroslav
Published: October 2019

Aging of polymeric materials is one of the application limits of these materials. Describing the degradation will help determine the life cycle of the product, describing the degradation process is so important in determining possible application spheres. The paper focuses on the degradation of the matrix composite in the form of epoxy resin and palm oil kernel shells (PKS). Handling bio-waste arising from oil palm processing is a great challenge, material use of these commodities is an interesting alternative to other options. The filler was of irregular particle size up to 100 μm the filler concentration in the matrix was 2.5, 5.0 and 10.0 wt.%. Renewable resources are increasingly promising options for sustainable material engineering. The presence of organic microparticles can optimize some mechanical characteristics and reduce the cost of the resulting material. Microscopy was used to assess interphase interference and microscopic analysis of the surface and particle shape. The contribution showed that the presence of organic particles in the matrix did not significantly affect the decrease of mechanical properties due to degradation in laboratory conditions. Specifically, these were experiments in the climatic chamber where humidity and temperatures varied between + 70 ° C and -40 ° C for 840 hours. The decrease in shear strength on steel adherence reached 3.99 MPa in the unfilled resin and 5.77 MPa (10% PKS) in the palm kernel shell resin.
Potential adsorption mechanisms of different bio-wastes to remove diazinon from aqueous solution
Authors: Sean Sitha , Binh Quach An , Tungtakanpoung Dondej , Kajityichyanukul Puangrat
Published: October 2019

This paper investigated the isotherms, kinetics, and mechanisms of three types of bio-waste derived from agro-waste, synthesized as potential adsorbents in diazinon extraction from aqueous solution. The adsorption capacity that differentiates each of the bio-wastes were discussed. Bio-wastes were synthesized for 4 h at a temperature of 600 °C. Bio-wastes were modified by hydrofluoric acid (HF) to enhance the specific area and porosity. The SEM, BET, FT-IR, and pHpzc were used to analyse the characteristics of the bio-wastes. Experimental results showed the different BET specific surface areas ranged from 67.42 to 402.43 m2.g−1 of each bio-waste. Meanwhile, SEM showed that bio-wastes possessed an intricate pore network comprising micropores and narrow mesopores. The pore volume disseminations in the size of the micropores (<2 nm) and narrow mesopores (2-20 nm) of bio-wastes in the range of 16.88-21.24% and 56.57-69.22%, respectively. Solution pH at 4 carried out the highest removal efficiency of diazinon. Langmuir isotherm model showed the best fit to the experimental adsorption data. The maximum adsorption capacities of bio-wastes ranged from 8.60-15.83 mg.g−1. The pore filling and chemical adsorption participated in the adsorption mechanisms of diazinon and other bio-wastes.
Heritage Building Era Detection using CNN
Authors: Samaun Hasan Md. , Ali Mohammad , Rahman Mizanur , Arju Hosne Ara , Alam Mirza Mohtashim , Salah Uddin Md. , Allayear Shaikh Muhammad
Published: October 2019

The Indian subcontinent is a southern area of Asia continent which includes India, Bangladesh, Pakistan, Nepal, Bhutan, Maldives, and Sri Lanka. In the different periods, different rulers had ruled in these territories such as the Sultanate period (1206–1526) and Mughal period (1526–1540, 1555–1857). In addition, various ancient and heritage structure patterns show the different historical and religious characteristics of the old civilizations. This research presents a computational method for identifying the construction period or era of old heritage building by using feature detection. We have done this experiment for the application aspect, where the tour guide is not available this application will help the tourists for knowing the construction period or era by detecting the features of old spectacular architecture. In this study, we have focused on the constructional characteristics of old architectural sites by using Canny Edge Detector method. After using the Canny Edge Detector method, we have categorized different types of features among the buildings such as Dome, Minaret or Tower, Ratna, and Front. The different eras old structure contains different characteristics of the Dome, Minaret or Tower, Ratna, and Front. Finally, we have developed a neural network based model which can identify the building’s construction era of the Sultanate period and Mughal period.
Study of nano bioactive glass for use as bone biomaterial comparison with micro bioactive glass behaviour
Authors: Rocton N , Oudadesse H , Mosbahi S , Bunetel L , Pellen-Mussi P , Lefeuvre B
Published: October 2019

This research is based on the study of bioactivity kinetic in function of the glass particles size. Bioactive glasses have been elaborated in the ternary system SiO2-CaO-P2O5. Nano bioactive glass and micro bioactive glass have been synthesized by using two different processes. They are destined for use as bone biomaterials. The comparison was focused on the kinetic of the development of a calcium phosphate layer on their surfaces after immersion in a Simulated Body Fluid (SBF). The first bioactive glass BG is a melting-made glass with a particles size of about 60 μm. The second bioactive glass NBG is a sol-gel made glass through an emulsion system of synthesized particles of about 110 nm. The growing of the calcium phosphate layer at the surface of the glasses has been followed using several physicochemical techniques. Obtained results show the development of a calcium phosphate layer similar to carbonated hydroxyapatite. It crystallises in a hexagonal system with an P63/m space group. While melting-made glass needs 14 days to develop carbonated hydroxyapatite like crystal, sol-gel needs only 3 days to develop similar crystals. This difference offers wide opportunities and complementarities for the use of nano or micro bioactive glasses in the biomedical field.
Influence of additional elements (Si, Ti and B) on the microstructure, mechanical properties and castability of aluminum alloys (A201)
Authors: Majid S A E , Bamberger M , Katsman A
Published: October 2019

Improving the castability, mechanical properties and modifying the microstructure of the A201 alloy (Al - 4.97wt. % Cu – 0.56 wt. % Ag) were done by adding Si, Ti and B elements. The four alloys of A201 with additions of: (1) Si, (2) Ti and B, (3) Si, Ti and B, (4) non, were investigated in the as-cast, solution treated at 550°C for 20 hr and aged at 170°C up to 32 days conditions. Combination of different microscopes (HRSEM/EDS, TEM) and microhardness tests were used to investigate how the alloy properties influenced by the precipitation. Additions of Si resulted in the grain coarsening and an increase in the amount of near-grain boundary secondary phases. Additions of Ti and B resulted in the grain refinement, prevented hot tears, but caused a large amount of Al3Ti phase which makes the melt more viscose, and less fluid and castable. The mechanisms of the influence were recognized as facilitating the GP zones nucleation: Si atoms provide more probable homogeneous nucleation of the <001>α GP zones transforming to θ″ phase during aging; TiB2 particles serve as the sites for heterogeneous nucleation of <111>α GP zones which then transform to Ω phase. The precipitation sequence during aging was the following: SSSS → GP zones → θ″+ Ω → θ′ + Ω → θ′ → θ. The maximum microhardness was achieved with two kinds of semi-coherent precipitates in the structure: θ′ (Al2Cu-tetragonal) and Ω (Al2Cu-orthorhombic). Therefore, joint additions and corresponding thermal treatment can provide optimal microstructure and mechanical properties of the A201 based alloys.
Investigation into the differences of pull-out resistance between normal and osteoporotic cancellous bone
Authors: Liu C , Guo J B , Yan Y H
Published: October 2019

Pedicle screw loosening or pullout has occurred from time to time in patients with poor bone quality. However, there have been no rigorous mechanical analysis of the pullout process, and the resistance region to pullout force remains under-investigated. The objective of the current study was to investigate the stress state of cancellous resistance to pullout in normal and osteoporotic conditions using plane finite element method. The pull-out model was simplified to a simpler two dimensional axisymmetric model by symmetry. A prescribed axial displacement of 2 mm was imposed on the screw head and a fixed boundary condition was set on edge nodes of the bone to simulate the pullout process. The results of numerical simulation showed that the high-stress area of normal bone was clearly larger than that of osteoporotic bone, and the normal bone provided the higher pullout force of 86.09 N, which was about 3 times than that for osteoporotic bone. From the study it was found that osteoporosis would diminish the active region of resistance to pullout around the screw and decrease the pullout strength about threefold. The results of the current study can be used for screw augmentation techniques.
Techniques to accelerate thermo-mechanical simulations in large-scale FE models with nonlinear plasticity and cyclic input
Authors: Benasciutti D , Bona F De , Moro L , Srnec Novak J
Published: October 2019

A procedure is proposed to reduce the computation time of thermo-mechanical simulations with large nonlinear finite element (FE) models that involve cyclic plasticity. The procedure is helpful when it is practically unfeasible to simulate the huge amount of cycles needed to bring the material model to its fully stabilised state (an unfavourable situation that often occurs when small plastic strains are present), as required before assessing the structural durability. A “reference” test case, with combined kinematic and isotropic nonlinear model calibrated on actual material properties, is compared to accelerated models as well as pure kinematic models. Guidelines on how to set up the accelerated model are finally discussed.
Investigation of mechanical and microstructural properties of friction stir welded dual phase (DP) steel
Authors: Küçükömeroğlu T , Aktarer S M , Çam G
Published: October 2019

The application of dual phase (DP) steels has been increasing significantly in the automotive industry because of their high strength as well as good ductility, thus, cold formability. These steels are generally joined using conventional welding methods such as resistance spot welding and laser welding in the production of automotive parts. In recent years, several studies have been conducted to investigate the possibility of joining the advanced high-strength steels such as DP steels using the solid-state friction stir welding (FSW) method due to its advantages over conventional fusion joining methods such as metallurgical benefits, energy efficiency, and environmental friendliness. The aim of this study is to investigate the microstructure, hardness and tensile properties of friction stir welded DP 600 steel plates. Thus, 1.5 mm thick DP 600 steel plates were friction stir butt-welded by a tungsten carbide stirring tool consisting of a concave shoulder having a diameter of 14 mm and a conical pin (angle=30°) with a diameter and length of 5 mm and 1.25 mm, respectively. In the weld trials conducted, the tool was tilted 2° and the down-force of the tool was kept constant at 6 kN. The tool rotation and traverse speeds used in FSW trials were 1600 rpm and 170 mm.min-1, respectively. The microstructure of friction stir welded zone comprised of main martensite, bainite, and refined ferrite. The average hardness of the stir zone has increased to about 400 HV. The tensile specimens failed in the base plate away from the weld zone and tensile strength as high as that of the base plate was obtained from the welded specimens, i.e., about 640 MPa. However, the elongation of the welded plates was significantly reduced, i.e. about 55% of that of the base.
Microstructure and wear behaviour of high alloyed hot-work tool steels 1.2343 and 1.2367 under thermo-mechanical loading
Authors: Malik I Y , Lorenz U , Chugreev A , Behrens B-A
Published: October 2019

Tools and their maintenance costs in hot forging processes account for a considerable proportion of the total components’ costs. Forging tools undergo extreme heating and subsequent cooling during the forging process and between the forging cycles, respectively. This cyclic heating and cooling of the tool surfaces leads to local changes in the tool microstructure which result in hardening or softening of the material in different regions of the tool and consequently influence the tool strength. Temperature in the tool areas experiencing high thermo-mechanical loadings can exceed the austenitic temperature. Hence, a strong cooling, for example by spraying or lubrication, can lead to formation of a martensitic layer in the boundary zone of the tool. Due to its higher hardness, martensitic layer has greater resistance to wear as compared to the basic or tempered materials. In the scope of this paper, the austenitisation behaviours of two high alloyed hot-work tool steels, 1.2343 and 1.2367, have been characterized by means of dilatometer tests to obtain time-temperature-austenitisation (TTA) diagrams for specimen under thermo-mechanical loads. Moreover, continuous-cooling-transformation (CCT) diagrams were recorded. Metallographic investigations were carried out to gather a detailed understanding of the microstructure behaviour and its resulting hardness. With the results of this works, it is aimed to gather a detailed and accurate insight into the arising hardening and softening effects. This would eventually lead to an optimisation of the numerical modelling for tool wear prediction.
Crack propagation in mixed-mode specimens described via multi-parameter fracture mechanics
Authors: Malikova L , Miarka P , Simonova H
Published: October 2019

The main objective of the paper is to employ a multi-parameter fracture mechanics concept to describe crack propagation through a specimen loaded in mixed-mode. This concept in particular was used because it has been shown that application of the generalized fracture mechanics concept can play a key role for materials with specific fracture behaviour, i.e. when fracture processes occur not only in the very vicinity of the crack tip, but also at larger distances from it. Two mixed-mode (I+II) geometries for the investigation of crack behaviour are presented here. The Williams series expansion is used for crack-tip stress field approximation. Then, considering the higher-order terms of the Williams expansion with regard to maximum tangential stress criterion can provide better estimates of the crack deflection angle. The coefficients of the Williams expansion were determined by means of the over-deterministic method for the purposes of this work. This analysis was performed for each cracked configuration, which is very time-consuming and makes the analysis very extensive. The crack propagation angle obtained by means of the generalized fracture criterion is discussed in detail. It was found that single-parameter fracture mechanics is sufficient when applied close to the crack tip and when mode I of loading prevails, while multi-parameter fracture mechanics can be recommended at larger distances from the crack tip and for configurations where mode II becomes dominant.
Research and application of micro-bead ultra-high performance concrete
Authors: Feng N Q , Yang W
Published: October 2019

Micro-bead is an ultra-fine fly ash of spherical vitreous with an average particle size of no more than 1.2 μm. In this paper, the physicochemical properties of micro-bead, the preparation method of micro-bead ultra-high performance concrete (MUHPC) were described. Furthermore, the characteristics and slump-loss retarding of fresh MUHPC, the strength and durability of MUHPC and the change of mechanical properties and fracture characteristics of MUHPC after incorporating fiber were studied. Results indicated that UHPC with the cement-micro-bead-silica powder as the main binder and incorporated with the appropriate water reducer had a strength reaching up to 150 MPa and a plasticity reaching up to 3 h and no bleeding segregation phenomenon. The C120 UHPC has a low Cl- diffusion coefficient and is resistant to freeze-thaw damage and has a high durability. And for the C120 UHPC incorporating polypropylene fiber, as the fiber content increased, the fracture energy, the brittle characteristic length and the toughness of the concrete all increased. C120 concrete has been applied in the Jingji Building in Shenzhen and the East Tower project in Guangzhou and the pumping height is 500 m or more.
Water entry behaviours of hemisphere-head projectiles with high velocity
Authors: Wu S Y , Shao Z Y , Feng S S , Zhou T , Zhang B
Published: October 2019

The water-entry behaviours of projectiles with hemisphere-head were studied experimentally and theoretically, focusing on projectile dynamics and drag coefficient. Based on equivalent cone theory proposed by Baldwin, the equation of drag coefficient was developed to describe the resistance of hemispherical head projectiles from the time when the projectile contacts the water to the time the hemispherical head is submerged. A set of experimental apparatus was set up to record the water-entry process by high-speed photography, the variation of resistance during water-entry was obtained experimentally. Compared the acceleration calculated by conventional method, new method and experimental results, the new method is more consistent with the experimental value.
Effect of groove structure on penetration performance of annular grooved projectiles impacting metal targets
Authors: Huang Q , Feng S S , Lan X K , Chen C N , Zhou T
Published: October 2019

With the continual development of advanced ammunition, a study on the effect of groove geometry on penetration performance is conducted. Based on ogive nose, an annular grooved projectile (AGP) was proposed and can generally be divided into two types (groove A and B) when considered the transition ways between groove and projectile nose. Difference in groove structures result in various penetration performance. According to dynamic cavity expansion theory and FEM simulation, the nose shape coefficient N*, depth of penetration (DOP) and acceleration curves were analysed comparatively. The results also indicated that the firm embedded behaviour of groove B nose projectile is mainly due to the filling-material in the groove rather than the friction on contact surface, unlike traditional nose shape. Furthermore, a good agreement in calculation and simulation proved the analysis method was reasonable and feasible, and would have application potential in new concept warheads.
An analytical method for J-resistance curve based on a new fracture criteria and finite element aided testing method
Authors: Yao D , Cai L X , Luo J C , Sun L , Li P Z
Published: October 2019

J-resistance curve of ductile material is important to describe the ability of a crack structure or material to resist fracture. Experimental and theoretical methods are developed to obtain J-resistance curve of metallic material. However, there are rare reports to predict J-resistance curve directly by tensile test on ductile materials. In this paper, an analytical method is proposed to predict the J-resistance curve for metallic material. Based on a new method, true stress-strain curve up to failure of ductile material is obtained. Thus, fracture threshold in different constrains are calculated using different kinds of specimens. A simple logarithmic-relationship between σ1f and σ*f (Yao-Cai criteria) is proposed. The new fracture criterion and full-range constitutive relationship are then used to describe the fracture behaviour near the crack tip. Stress triaxiality and critical fracture first-principle stress around crack tip are obtained. Therefore, fracture procedure is divided into two parts: crack tip blunting and steady crack growth. The relationship of J-integral and crack growth amount R is established respectively according to the blunting line equation and HRR stress field. The predicted results for test specimens (CT, SENT, CIET) with different initial crack length of the A508-3 steel coincide well with the test results. The results show that stress triaxiality at crack tip is a typical characteristic feature following the constraint effect and the Yao-Cai criteria is recommended for the fracture threshold of ductile material.
Experimental study on inductive method for online material loss detection with high debris concentration
Authors: Li T Y , Wang S P , Zio E , Shi J , Hong W
Published: October 2019

Online Oil debris detection is a complex and systemic issue that multiple requirements should be met for a practical application. When severe wear or tear happens, more accurate detection is needed for higher debris concentration. Aiming at promoting detection accuracy under the practical high debris concentration conditions, in this work, an experimental study is carried out to test the performance of an inductive oil debris detection method using a multi-channel sensor based on dual excitation sources with serial layout. Ferrous powders with different sizes and amounts are used for the experiment. Data processing methods including band-pass filter and anti-aliasing techniques are used for optimizing the estimation. The tested results indicate that the counting accuracy of coarse iron powder with 2.5 g/L concentration hydraulic oil at a flow rate of 40 L/min is higher than 85.8% and by data processing, the accuracy is promoted by 21.4% averagely.
Effects of using metal granules on strength and stiffness
Authors: Kockal N U , Kocaer T Z
Published: October 2019

Using metal granules, which are waste products of the metal industry, as a replacement material in mortars, is economically productive and environmentally beneficial because it contributes to reduction of the amount of the metal waste. It was attempted to develop and produce metal granule reinforced cementitious composite instead of using conventional fibers. Metal wastes bonded to the matrix with the help of adhesion effect is aimed to improve the mechanical and deformation properties of the mortar. As the amount of metal waste increased in the mortar, the compressive strength of the mortars except those with 10% granules enhanced. The rise in the maximum stress values of the samples and the growth in the modulus of elasticity were similar. 30% metal waste mortar demonstrated the highest value of compressive strength and modulus of elasticity in this study.
Influence of hot isostatic pressing on mechanical response of as-built SLM titanium alloy
Authors: Roudnicka M , Mertova K , Vojtech D
Published: October 2019

Hot Isostatic Pressing (HIP) can be used to increase the fatigue limit of additively manufactured metals. However, with no further surface treatment, its contribution might be restricted by a rough surface. We thus tested Ti6Al4V alloy prepared by selective laser melting in the as-built surface condition to evaluate the utility of HIP. The influence of HIP on microstructure, static mechanical properties and fatigue was evaluated in comparison with untreated and conventionally heat treated state.
Dynamic response of gradient cellular materials under high velocity impact
Authors: Lan X K , Huang Q , Zhou T , Feng S S
Published: October 2019

The dynamic behavior of gradient cellular materials subject to high velocity impact is investigated theoretically and numerically. A parameter refined rigid-perfectly-plastic-locking model is developed and employed in the one-dimensional shock-wave theory to predict the response of gradient cellular materials under high velocity impact. The finite element analysis is carried out based on the periodic Voronoi structure and shows good agreement with the analytical prediction. The dynamic response and energy absorption are examined for different gradient cellular rods with the same mass and length but different density gradient. It is found that, at the first part of the high velocity impact crushing process, the cellular rods with negative density gradient show higher energy absorption ability and lower pressure at the distal end compared to the positive and uniform ones. This advantage can be taken when the partial crushing happens and vanishes when the cellular rods are fully crushed.
Isolation oligosaccharides from gembili (Dioscorea esculenta Lour. Burkill) as prebiotics
Authors: Khasanah Y , Nurhayati R , Miftakhussholihah  , Btari S , Ratnaningrum E
Published: October 2019

Oligosaccharides is a potential prebiotic and used as an alternative diet therapy for diabetes mellitus. Gembili (Dioscorea esculenta (Lour.) Burkill) is known as functional food that contains oligosaccharides. This study was done to isolate oligosaccharides from gembili and evaluate its prebiotics potential. Oligosaccharides was extracted and analysed by High Performance Liquid Chromatography (HPLC). Potential of prebiotics was analysed using faecal samples from healthy volunteers in anaerobic condition at certain time interval (0, 24, and 48 hours) and bacterial growth (Bifidobacteria and Lactobacillus as probiotic bacteria, Bacteroides and Clostridium as patogen bacteria), prebiotic index were analysed. Short Chain Fatty Acid (SCFA) production (acetic acid, propionic acid, and butyric acid) analyzed using HPLC. The results showed that oligosaccharides from gembili contains lactulose (0, 231 %); inulin (2, 541 %) and rafinose (1, 485 %). Prebiotic index increased from 0, 86 ± 0, 20 (24 hours incubation) to 1, 12 ± 0, 05 (48 hours). This oligosaccharides increased probiotics and decreased patogen bacteria. It could be concluded that oligosaccharides from gembili were potential as prebiotics.
Characteristics stability of cheese whey-tomato juice fermented beverages with pectin and CMC addition
Authors: Saidah N , Nurhartadi E , Nursiwi A , Sari A M , Utami R
Published: October 2019

The aim of this study was to investigate the chemical and microbiological stability of 12 days of storage (±4°C) of fermented beverages from cheese whey and tomato juice with addition of pectin:carboxy methyl cellulose combination (0%:0%; 0.15%:0.25%; 0.25%:0.15%; 0.2%:0.2%; 0.1%:0.3%) and to determine the best formula to find out it’s hypocholesterolemic effects. Fermented cheese whey beverages was prepared from cheese whey:tomato juice (95%:5%), sucrose (10% w/v), and 5 variation of pectin:CMC combination. This research used a Completely Random Design (CRD) with one factor, combination of pectin and CMC. The result was analyzed by applying one-way analysis of variance (ANOVA) followed by Duncan test with 5% significant level. The result showed that during 12 days of storage, the addition of pectin:CMC combination in fermented beverages from cheese whey reduced the rate of pH, antioxidant activity, total lactic acid bacteria, and the rate of lactic acid rise. The best formula of fermented beverage from cheese whey and tomato juice is fermented beverage with 0.1%:0.3% (w/v) of pectin:CMC addition which has 34.636% of hypocholesterolemic effect.
Effects of drying time on essential oil production of kaffir lime (Citrus hystrix DC) leaves at ambient temperature
Authors: Wulandari Y W , Anwar C , Supriyadi S
Published: October 2019

Drying was one of the primary processes in essential oil production. Time factor in drying affects both the content and chemical compositions of essential oils. This study aims to evaluate the influence of the drying time of kaffir lime leaves on the yield at room temperature and the major volatile compounds in the essential oils by observing day-to-day treatments. As a key odorants in essential oils, the quantity of citronellal was determined by Gas Chromatography (GC) using the standard compound. Based on the daily observation results, a long-time drying gave a significant effect on the yield and the major volatile compounds. The highest yield 1.26±0.07 % (w/w) was obtained on the fourth day, while the highest content of citronellal compounds, 87.58±0.33% was achieved on the fifth day of drying,. A prolonged drying time resulted in a negative effect on not only the quantity, but also the quality of essential oils. Accordingly, this study suggests that the drying technique at room temperature best lasts for four until five days to obtain the most favorable quality and quantity of essential oils.
Process optimization for producing pumpkin (Cucurbita moschata D) and arrowroot (Marantha arundinaceae L) starch-based instant porridge
Authors: Slamet A , Praseptiangga D , Hartanto R , Samanhudi
Published: October 2019

Pumpkin is a potential source of vitamin A and β-carotene as an antioxidant, thus it is promising to be developed as functional food ingredients. However, pumpkin-based manufactured food is still limited. Hence an experiment is initiated to produce pumpkin and arrowroot starch-based instant porridge which is easy to prepare and people ranging from children to adults fond of it. Pumpkin was whisked and mixed with arrowroot starch in the ratio of 1:1, 2:1, 3:1, 4:1, and 5:1 until it became an instant porridge. The porridge was then put into a drum dryer (1 bar) and it was rotated at the speed of one or one and a half round per minute. Color and viscosity of the produced instant porridge were determined. The results indicated that physical characteristics of instant porridge were affected by ratio of pumpkin with arrowroot starch and the rotation speed of the drum dryer. Instant porridge made from pumpkin-arrowroot starch in the ratio of 5:1 and produced at the speed of one and a half round per minute had a color value of L: 74.43, a: 9.33, b: 32.50, and viscocity 47.4 cP.
Egg quality in F1 cross between brown and black lines of Japanese quail
Authors: Dewanti R , Fadilla P , Cahyadi M
Published: October 2019

The objective of this study was to determine both external and internal egg quality in F1 cross between Brown and Black lines of Japanese quail. A total of 186 eggs given basal diets have been collected at the age of ten weeks and those eggs were then tested to evaluate their external and internal qualities. They were produced by four group of F1 cross between two lines of Brown male and Black female of Japanese quail and vice versa. Cross between Brown male and Black female lines produced Brown layer lines (B1 and B2 lines, respectively) while cross between Black male and Brown female lines was called L1 and L2 lines, respectively. The data was analyzed by using one-way analysis of variance (ANOVA) with an alpha level of 5%. Furthermore, the pairwise differences among populations were tested using Duncan’s multiple range test (DMRT). The results showed that egg weight, shell weight and egg interior traits including yolk index, albumin index, Haugh unit (HU), and yolk color score were significantly difference among F1 populations (P<0.05). Egg and shell weights were highest in B1 line, on the other hand, albumin index, yolk index, HU, yolk color score were found highest in B2 line. In addition, no differences among lines have been observed for shell thickness, egg index, and air cavity of egg. These results suggested that Brown quail line was better both exterior and interior qualities of egg.
Production of antioxidant C-phycocyanin using extraction process of Spirulina platensis in large scale industry
Authors: Wachda  , Hadiyanto H , Harjanto G D , Huzain M L , Aji R W
Published: October 2019

Spirulina platensis is one of the popular species that containing C-Phycocyanin. C-Phycocyanin has been used in many applications such as antioxidant, anti-inflammatory, and natural blue colorant. The increase of phycocyanin production from S. platensis is influenced by extraction method and solvent ratio. The phycocyanin pigment can be massive extracted using mechanical cell rupture like freezing thawing method and distillated water as solvent. This research aimed to produce high concentration of antioxidant phycocyanin from S. platensis using simple and efficient method for large scale industry and develop a method for primary extraction from dry biomass of S. platensis. There were 3 treatments and each treatment was conducted in 3 replications. Standardization of process treatments such as biomass : solvent ratio (1:6, 1:50 and 1:100) and processing time were carried out at thawing time (1 hour), freezing time (2 hours) and stirring time in water bath (0, 5 hour). The phycocyanin concentration and yield were determined by using spectrophotometer. The result showed that at biomass : solvent ratio of 1:50, resulted C-PC concentration of 0.179 mg/ml and its yield of 17.944 mg/g.
The use of solid phase spectrophotometry for control toxic metal ion content in milkfish cultivation
Authors: Saputro S , Mahardiani L , Ninda DCD
Published: October 2019

Solid-Phase Spectrophotometry (SPS) has been widely used in the study of trace element speciation in water. This spectrophotometer has advantages that have a high sensitivity, a small device (portable), and easy to use in the analysis process. This study aims to: (1) increase the use of SPS values in controlling toxic ions in water used for milkfish cultivation, and (2) determine SPS sensitivity for the determination of Cd(II) in pond water samples analyzed. The method used is laboratory experiment. The result showed that the SPS method can be used in the analysis of the content of Cd(II) in the pond water with such a high enough sensitivity results obtained LoD of 0.51 µg/L, RSD < 5% and recovery of 95-105%.
Effects of Kaempferia galanga L. essential oil incorporation on sensory and physical properties of dark chocolate bar
Authors: Handiati Y D , Praseptiangga D , Manuhara G J , Khasanah L U
Published: October 2019

Chocolate is the world’s most popular confectionery product of processed cocoa. The antioxidant content of cocoa flavanols in dark chocolate is higher than other types of chocolate. Widely cultivated in Indonesia, kencur (Kaempferia galanga L.) rhizome has many health benefits, including antitussive, expectorant, antioxidant, and hypocholesterolemic. The aims of this research were to evaluate the effects of variation concentration of kencur (Kaempferia galanga L.) rhizomes essential oil incorporation on sensory and physical properties of dark chocolate bar. Three formulas of dark chocolate bar with an addition of Kaempferia galanga L. rhizomes essential oil (0.1%, 0.2%, and 0.3%) were studied. The results showed that the addition of variation of the essential oil concentration (0.1%, 0.2%, and 0.3%) had no significant effect on the overall sensory properties. However, dark chocolate bar with the addition of 0.3% Kaempferia galanga L. essential oil (F3) showed the highest panelist acceptance on aroma attributes. It had very small color difference and the lowest hardness based on the result of physical characterization, suggesting that dark chocolate bar with the addition of 0.3% Kaempferia galanga L. essential oil (F3) is expected to be developed as one of chocolate-based functional food products.
Fruit identification and effect of starch isolation methods on color attributes of Cilacap bread fruit’s starch
Authors: Rahayu N S , Praseptiangga D , Hariyanto B , Samanhudi
Published: October 2019

Utilization of Cilacap breadfruit as a food source is very important for supporting local food diversification. The objectives of this study were to identify the Cilacap breadfruit based on morphology identification method and to evaluate the effects of starch isolation methods on color properties of its starch. The results showed that the morphological identification of Cilacap breadfruit was round - slightly oval, and the brownish green white spots-colored was shown on the ripe stage of fruit at the tree. The average weight of Cilacap breadfruit was 1.506 kg, and the yield of starch was 11.08%. The fruit identification was determined by LIPI Bogor Indonesia, of which confirmed that Cilacap breadfruit used in this study was a species of Artocarpus altilis (Parkinson ex. F.A. Zorn) Fosberg (Moraceae family). Starch isolation by using sediment separation extraction method after three-time decantation was shown as a better method than the non-separation isolation method. Color attributes of starch by using sediment separation extraction method gave a value of L* = 94.113, a* = 5.253 and b* = -1.506 for the white bottom sediment, while the brown color of the upper sediment gave L* = 87.587, a* = 5.063 and b* = 1.956.
Antioxidant capacity of pigeon pea (Cajanus cajan L.) sprouts elicited using NaCl with various elicitation time
Authors: Kristiani L S , Rajendra F M , Ariviani S
Published: October 2019

Previous research showed that pigeon pea has potential as an anti-diabetic functional drink related to its antioxidant capacity. Antioxidant capacity in legumes can be increased by elicitation. Improvement of antioxidant capacity in legumes elicited by NaCl was significantly higher than that of other abiotic elicitation. The objective of this study was to determine the antioxidant capacity of pigeon pea (Cajanus cajanL.) sprouts which were elicited using NaCl (50mM) with various elicitation times (8 hours, 12 hours, 16 hours) and germinated for 48 hours. The results showed that elicitation time did not have a significant effect on the total flavonoids content, but significantly increased antioxidant activity (DPPH radical scavenging, and reducing power) of pigeon pea sprouts along with increasing elicitation time. This study proved that elicitation using NaCl 50mM for 16 hours increases the total flavonoid content (69, 36%), DPPH radical scavenging activity (134, 18%), and reducing power (24, 54%) of pigeon pea sprouts. Elicitation using 50mM NaCl with 16 hours elicitation time and 48 hours germination time can be considered as a technique to enhance antioxidant capacity in legumes sprouts.
The effect of reduced acetic acid concentration on nano-chitosan formulation as fish preservative
Authors: Winayu I J , Ekantari N , Puspita I D , Ustadi  , Budhijanto W , Nugraheni P S
Published: October 2019

Nano-chitosan has antibacterial activity and can be used as fish preservative. Acetic acid concentration of 1% is commonly used to produce nano-chitosan but it affected consumer acceptance because of its acidity. This study aimed to reduce the concentration of acetic acid and observed its effects on particle size, pH, and bacterial growth inhibition activity. Besides, it was also observed the effect of nano-chitosan with acetic acid concentration reduction on total bacteria and sensory value when applied on tilapia fillets. The results showed that the higher concentration of acetic acid resulted smaller particle size of chitosan and higher bacterial growth inhibition. The similar trend was also shown by acetic acid solution in same concentration. However, the bacterial inhibition zone of nano-chitosan solution was higher than acetic acid solution for each variation of acetic acid concentrations. This was evidenced by the observation of the clear zone formation of Gram positive and negative bacteria culture grown on nutrient agar. The optimum acetic acid concentration in nano-chitosan production was 0.43% because it was able to inhibit the growth of bacteria on the tilapia fillet and resulted in good consumer acceptance even when tilapia fillet was soaked up to 25 minutes in the nano-chitosan solution.