bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

AbstractTools 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract

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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.