bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on reducing PAPR of QAM‐OFDM radar‐communication integration sharing signal
Authors: Yang Yongjun , Mei Jinjie , Hu Dengpeng , Lei Yunlong , Luo Xiaoli
Published: October 2019

In order to solve the problem of high peak‐to‐average power ratio (PAPR) of the sharing signal for radar‐communication integration based on quadrature amplitude modulation‐orthogonal frequency division multiplexing modulation, according to the theoretical model of the sharing signal, the authors analyse the PAPR, subsequently employing the active constellation extension algorithm to suppress the PAPR of the sharing signal. The simulation results show that, with designing the number of iterations reasonably, the active constellation expansion algorithm will effectively reduce the PAPR of the sharing signal. Meanwhile, for radar sub‐systems, the target detection performance and the transmitter power are less affected. For communication sub‐systems, the error vector magnitude is small, and the bit error rate of the system is comparable to the original signal.
Multi‐target tracking of birds in complex low‐altitude airspace based on GM_PHD filter
Authors: Hong Tao , Zhang Wu , Chen Weishi , Chen Xiaolong , Fu Xinru
Published: October 2019

GM_PHD (Gaussian mixture of probability hypothesis density) cannot completely track multiple targets, such as the flying birds in the complex low‐altitude airspace near the airport, due to the lack of the steps of birth detection, track extraction and death detection. A new algorithm is proposed to solve this problem, which mainly contributes to the following three aspects. First, the k‐nearest neighbour algorithm is used to detect the birth of bird targets from measurements which is necessary to construct the birth intensity function. Second, the clustering algorithm is introduced into the probability hypothesis density filter framework to extract the bird targets’ tracks from the filtering results. Third, an algorithm is added to detect the death of bird targets for better tracking. The Gaussian mixture implementation of the algorithm denoted as BT_GM_PHD (Bird Tracking GM_PHD) is presented. The test results on simulation and ground‐truth data show that the proposed BT_GM_PHD algorithm can effectively track the multiple flying bird targets in the complex low‐altitude airspace near the airport, outperforming the GM_PHD filter.
Micro‐motion feature extraction of narrow‐band radar target based on ROMP
Authors: Chen Shuai , Feng Cunqian , Xu Xuguang
Published: October 2019

In this study, a new method based on regularised orthogonal matching pursuit (ROMP) decomposition is proposed to extract the feature of the ballistic target's rotating micro‐motion. Based on the establishment of the ballistic target rotation model, the general model of target's narrowband radar echo is obtained. An over‐complete dictionary of atoms is established by combining the intrinsic characteristics of the signal model, and the selection of the matched atoms is carried out according to the regularisation principle. The extraction of the target's rotating micro‐motion feature and the reconstruction of the original signal are realised. Simulation results show that the method can extract the micro‐motion feature efficiently and accurately.
Transmitter and receiver polarisation optimisation design for target
Authors: Hu Kexiao , Liu Zhiwen , Shi Shuli , Xu Yougen
Published: October 2019

In radar systems, transmitting and receiving waveforms with different polarisations benefit to acquire complete information about the target and its environment, ensuring significant enhancement of the radar's performance. Here, the authors consider the optimisation problem of jointly designed transmitter and receiver (TR) polarisation from the view of target scattering estimation. Under the condition that the target and clutter scattering covariance is known as a prior, they first use sequential linear minimum mean square error estimation to obtain the target scattering matrix and then optimise the sensing vector, which contains the polarisation information under the constraint of minimising the mean square error. The mentioned problem can be solved by eigenvector decomposition. Then, a method to get the TR polarisation parameters is provided. Finally, they use numerical simulations to show the advantage of the proposed methods.
Ship target detection and segmentation method based on multi‐fractal analysis
Authors: Zhu Liyang , Xiong Gang , Guo Dongmei , Yu Wenxian
Published: October 2019

A novel automatic ship target detection and segmentation approach based on modified multi‐fractal method in synthetic aperture radar (SAR) image is proposed in this study. Firstly, singular power spectrum (SPS) is developed to two‐dimensional SPS (2D‐SPS), and applied to feature extraction and SAR target detection. Secondly, 2D Holder exponent and 2D multi‐fractal spectrum are jointly used to ship target segmentation in SAR image. The algorithm steps and detection flow is here conceptually assessed, analytically derived, numerically verified, and also tested on actual SAR images. Results indicate that the proposed method has significant advantages in ship target detection and segmentation in SAR image.
Role of hydrodynamic size in colloidal and optical stability of plasmonic Copper nanoparticles
Authors: Sharma Purnima , Goyal Dinesh , Chudasama Bhupendra
Published: October 2019

Metallic nanoparticles (NPs) exhibit interesting plasmonic characteristics that depend on their size, shape and dielectric medium. Any change in these parameters can lead to significant alternation in plasmonic behaviour of NPs. Plasmonic nanostructures are prepared by wet chemical approaches, which produce NPs with a moderate yield. Amongst plasmonic class of NPs, gold and silver are widely explored in sensors because of their strong plasmon excitation. Copper NPs (CNPs) are gaining increasing attention in plasmonic sensors because of its economic advantages over silver and gold. However, major limitations of these nanostructures are their low yield and poor colloidal stability. In this Letter, authors report scale up of CNPs yield by 100% and studied their colloidal stability in terms of changes in hydrodynamic size and its influence on surface plasmon resonance (SPR). It has been observed that SPR of CNPs is independent of their yield. A gradual decrease in SPR is observed with ageing. This can be attributed to the aggregation‐induced microstructural changes in the dispersion. CNPs irrespective of their yield are stable up to 180 days beyond which they lose their colloidal stability and plasmonic properties. Loss of colloidal and plasmonic characteristics of CNPs can be attributed to enhanced hydrodynamic size.
Rule induction based on rough sets from information tables having continuous domains
Authors: Nakata Michinori , Sakai Hiroshi , Hara Keitarou
Published: October 2019

Information tables having continuous domains are handled by neighborhood rough sets. Two approximations in complete information tables are extended to handle incomplete information. Consequently, four approximations are obtained: certain and possible lower ones and certain and possible upper ones without computational complexity. These extended approximations create the same results as the ones from possible world semantics by using possible indiscernibility relations. Therefore, the extension is justified. In complete information tables two types of single rules that an object supports are obtained: consistent and inconsistent ones. The single rule has low applicability. To increase applicability, a series of single rules are brought into one combined rule with an interval value. In incomplete information tables four kinds of single rules are obtained. From them, four kinds of combined rules are obtained: certain and consistent, possible and consistent, certain and inconsistent, and possible inconsistent ones. A combined rule has higher applicability than the single rules from which it is assembled.
Update ESC-Leitlinie: Myokardiale Revaskularisation
Authors: Behm Patrick , Nührenberg Thomas , Bönner Florian , Neumann Franz-Josef
Published: October 2019

Was ist neu

Präprozedurale, diagnostische und die Wahl der Revaskularisationsstrategie betreffende Aspekte Interventionen zur Revaskularisation sollten nur an Kliniken mit ausreichend hohen Fallzahlen bzw. ausreichend hoher Expertise erfolgen. Die Indikation zur Revaskularisation kann bei stabiler koronarer Herzkrankheit (KHK) aus prognostischen sowie symptomatischen Gründen gestellt werden. Zur Indikationsstellung ist eine Ischämie-Testung wichtig; hier stehen verschiedene nichtinvasive Techniken zur Verfügung. Ob eine perkutane Koronarintervention (PCI) oder Bypass-Operation durchgeführt werden soll, ist möglichst evidenzbasiert auch mithilfe von Risiko-Scores zu entscheiden. Wichtig ist zudem die Nephroprotektion: Laut Klasse-I-Empfehlung soll bei allen Patienten vor Intervention das Risiko für das Auftreten eines kontrastmittelinduzierten Nierenversagens abgeschätzt werden. Zudem ist eine ausreichende Hydrierung zu gewährleisten.

Intraprozedurale, die Revaskularisation selbst betreffende Neuerungen Für die Intervention ist der radiale Zugangsweg dem femoralen vorzuziehen. Der arterielle Bypass ist dem venösen überlegen. Für die intraprozedurale Beurteilung der Flussreserve in stenosierten Koronargefäßen gibt es geänderte Empfehlungen. Bezüglich der zu verwendeten Stents sind „drug-eluting stents“ (DES) der neuen Generation erste Wahl. Als Antikoagulans während der Intervention wird unfraktioniertes Heparin empfohlen.

Postprozedurale Aspekte nach erfolgter Myokardrevaskularisation Nach erfolgter Revaskularisation soll der Patient im Hinblick auf mögliche Ischämien systematisch reevaluiert werden. Zur antithrombotischen Therapie ist Clopidogrel bevorzugt mit neuen oralen Antikoagulanzien (NOAKs) zu kombinieren (statt mit Vitamin-K-Antagonisten (VKA)). Bei bestimmten Patienten kann von einer Therapie mit potenteren P2Y12-Rezeptorantagonisten auf Clopidogrel umgestellt werden.
Sex Differences in Physiological Stress Induced by a Long-Lasting Adventure Race: A Prospective Observational Analytical Study
Authors: Silva Romeu P.M. , Vilaça Alexandre , Guerra Fredy D. , Mundim Antonio V. , de Agostini Guilherme G. , de Abreu Luiz Carlos , Zhiguo Zhang , Sorpreso Isabel C. , Valenti Vitor E. , Penha-Silva Nilson
Published: October 2019

Background In order to provide additional information on the behaviour of biochemical parameters related to stress responses to a specific long-term competition, we aimed to compare the stressful effects of a long-lasting competition on physiological variables in men and women.

Methods This is a prospective observational analytical study. Twenty-five professional athletes, 15 men and 10 women, travelled 460 km for 4 days in an international edition of the Ecomotion/Pro AR World.

Results After the competition, we detected an increase in α-amylase and cortisol levels and a decrease in salivary immunoglobulin A (lgA) levels. The relative percentage changes in α-amylase, IgA and cortisol levels were significantly higher in women than in men, whereas women had lower relative percentage changes in glucose and lactate levels compared with men. There was a decrease in lymphocyte, eosinophil and monocyte counts, with relative percentage decreases in lymphocytes and monocytes being significantly higher in female athletes than in males. There were increases in the serum activities of total creatine kinase (CK), the creatine kinase myocardial isoform (CKMB), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) at the end of the test, with significantly higher elevations of total CK, CKMB and LDH in men and ALT in women.

Conclusion Long-lasting competition induced stress, muscle damage, anaemia and changes in the immune system. Women had more intense responses of cortisol and leukocytes.
Linear response in neuronal networks: From neurons dynamics to collective response
Authors: Cessac Bruno
Published: October 2019

We review two examples where the linear response of a neuronal network submitted to an external stimulus can be derived explicitly, including network parameters dependence. This is done in a statistical physicslike approach where one associates, to the spontaneous dynamics of the model, a natural notion of Gibbs distribution inherited from ergodic theory or stochastic processes. These two examples are the Amari-Wilson-Cowan model [S. Amari, Syst. Man Cybernet. SMC-2, 643–657 (1972); H. R. Wilson and J. D. Cowan, Biophys. J. 12, 1–24 (1972)] and a conductance based Integrate and Fire model [M. Rudolph and A. Destexhe, Neural Comput. 18, 2146–2210 (2006); M. Rudolph and A. Destexhe, Neurocomputing 70(10–12), 1966–1969 (2007)].
Fabrication of tunnel barriers and single electron transistors in suspended multi-wall carbon nanotubes
Authors: Ghazali Norizzawati M. , Tomizawa Hiroshi , Hagiwara Noriyuki , Suzuki Katsuya , Hashim Abdul M. , Yamaguchi Tomohiro , Akita Seiji , Ishibashi Koji
Published: October 2019

Fabrication processes have been developed to form the tunnel barriers in the suspended multi-wall carbon nanotubes (MWCNTs). Individual MWCNTs are positioned under the optical microscope to bridge them between the two metal electrodes. The tunnel barrier is formed by irradiating them with focused Ga ion beam (FIB), and its characteristics are evaluated with the resistance increase by the irradiation and the barrier height. It is found that those values depend not only on the dose of the Ga ions, but also on a diameter of the MWCNT. The single electron transistors (SETs) are fabricated by forming the double barriers in the suspended MWCNT. We find some devices show regular and stable SET behaviours.
Extension of the historic range of Pristis pristis on the east coast of Australia
Authors: Hudgins Jessica L. , Bell Michael C. , Wueringer Barbara E.
Published: October 2019

Populations of all species of sawfish have been depleted worldwide, and sawfish are now absent from much of their historic range. Much of the historic sawfish capture and encounter data does not provide information useful for species identification, and so cannot be used to reconstruct the historic ranges of the different species. For a long time, these data were also not easily accessible, as they were not digitised. Thus historic populations and distribution ranges of the different species could have been underestimated. Here, we examine historical newspaper articles (n=237) from the Australian National Library’s online database ‘Trove’, that were found by searching for the generic term ‘sawfish’. Articles were examined for information that could be relevant to sawfish biology and distribution, as outlined in the IUCN’s Sawfish Conservation Strategy, such as date of capture, circumstance of capture, location, animals’ weight and length, and potential species identifiers. One of the articles is presented in detail as it outlines a capture of Pristis pristis outside of the currently described range of this species, by over 800km. This evidence highlights the need for a global examination of historical print resources, which use generic terminology to report sawfish encounters. Examination of global news resources may help provide greater understanding of the full historic range of sawfishes, and allow a more accurate estimation of areas in which they no longer occur.
Addressing the challenge of carbon-free energy
Authors: Eisenberg Richard , Gray Harry B. , Crabtree George W.
Published: October 2019

This century will witness a major transformation in how energy is acquired, stored, and utilized globally. The impetus for this change comes from the deep impacts that both developed and developing societies have had on our planet’s environment during the past century, and the projections going forward of what will happen if we do not act transformatively within the next 2 decades. This paper describes the basis for a meeting held in October 2018 on the need for decarbonization in our energy landscape, and specifically the status and challenges of the science that provides the foundation for such technology. Within the realm of decarbonization in energy generation lies the science of solar energy conversion using new or improved photovoltaic materials and artificial photosynthesis for water splitting and other energy-storing reactions. The intimately related issue of renewable energy storage is being addressed with new strategies, materials, and approaches under current investigation and development. The need to improve the interactions between scientists working on these connected but separately considered challenges and on the transition of scientific achievement to practical application was also addressed, with specific efforts enumerated.
Probing the electric field across thylakoid membranes in cyanobacteria
Authors: Viola Stefania , Bailleul Benjamin , Yu Jianfeng , Nixon Peter , Sellés Julien , Joliot Pierre , Wollman Francis-André
Published: October 2019

Significance

Cyanobacteria were the first organisms to develop oxygenic photosynthesis using water as a source of electrons. Today they remain widespread primary photosynthetic producers and hold a high biotechnological potential. In cyanobacteria, respiration and photosynthesis are interconnected in a complex network of electron fluxes. The study of cyanobacterial physiology is hampered by the lack of techniques, allowing a direct measurement of the transmembrane electric field that develops across their photosynthetic/respiratory membranes. Here, we characterized a probe of the transmembrane electric field, based on the ElectroChromic Shifts of carotenoids, thus opening unprecedented avenues to bioenergetics studies of these major photosynthetic organisms.
Recent progress in epitaxial growth of III–V quantum-dot lasers on silicon substrate
Authors: Pan Shujie , Cao Victoria , Liao Mengya , Lu Ying , Liu Zizhuo , Tang Mingchu , Chen Siming , Seeds Alwyn , Liu Huiyun
Published: October 2019

In the past few decades, numerous high-performance silicon (Si) photonic devices have been demonstrated. Si, as a photonic platform, has received renewed interest in recent years. Efficient Si-based III–V quantum-dot (QDs) lasers have long been a goal for semiconductor scientists because of the incomparable optical properties of III–V compounds. Although the material dissimilarity between III–V material and Si hindered the development of monolithic integrations for over 30 years, considerable breakthroughs happened in the 2000s. In this paper, we review recent progress in the epitaxial growth of various III–V QD lasers on both offcut Si substrate and on-axis Si (001) substrate. In addition, the fundamental challenges in monolithic growth will be explained together with the superior characteristics of QDs.
Hydride vapor phase epitaxy for gallium nitride substrate
Authors: Hu Jun , Wei Hongyuan , Yang Shaoyan , Li Chengming , Li Huijie , Liu Xianglin , Wang Lianshan , Wang Zhanguo
Published: October 2019

Due to the remarkable growth rate compared to another growth methods for gallium nitride (GaN) growth, hydride vapor phase epitaxy (HVPE) is now the only method for mass product GaN substrates. In this review, commercial HVPE systems and the GaN crystals grown by them are demonstrated. This article also illustrates some innovative attempts to develop homebuilt HVPE systems. Finally, the prospects for the further development of HVPE for GaN crystal growth in the future are also discussed.
Size effect on optical performance of blue light-emitting diodes
Authors: Ge Chang , Li Jing , Wang Guohong , Su Kang , Lu Xingdong
Published: October 2019

In this paper, size effects on optical performance of blue light-emitting diodes (LEDs) are investigated. The essential physical mechanism is studied by fabricating LEDs with various sizes of the active area and testing optical characteristics. It is found that micro-LEDs have better light extracting efficiency and thermal dissipation compared with broad-area LEDs, which is likely due to the small ratio of perimeter and active area. Furthermore, micro-LEDs are more beneficial for displays due to the stable wavelength under the low pulse width modulation (PWM) current density.
Preparation and characterization of AlN seeds for homogeneous growth
Authors: Zhang Li , Qi Haitao , Cheng Hongjuan , Jin Lei , Shi Yuezeng
Published: October 2019

Large size AlN bulk crystal has been grown on SiC heterogeneous seed by physical vapor transport (PVT). The properties of AlN wafer were characterized by high resolution X-ray diffraction (HRXRD), Raman spectroscopy, etched method and atomic force microscope (AFM). Growth mechanism of AlN crystal grown on heterogeneous SiC seeds was proposed. Crystallization quality of AlN samples were improved with the growth process, which is associated with the growth mechanism. AlN single wafer has excellent crystallization quality, which is indicated by HRXRD showing the (0002), (

) XRD FWHM of 76.3, 52.5 arcsec, respectively. The surface of the AlN wafer is measured by AFM with a roughness of 0.15 nm, which is a promising seed for AlN homogeneous growth.
Different carbon fibrous morphologies triggered by varying the average diameter of precursor electrospun fibers
Authors: Svinterikos E , Zuburtikudis I , Marzouqi M Al
Published: October 2019

Investigation of the factors affecting the carbonization process is very important for the manufacture of desired, on-demand carbon fibrous morphologies. In this work, the effect of the average fiber diameter on the carbonization of precursor polymer fibers into carbon fibers was examined. Three electrospun fibrous mats consisting of a lignin/recycled PET blend with mass ratio of 1/1 and having different average fiber diameter (80, 387 and 781 nm) were prepared. After they were carbonized at 600 °C, it was found that the thicker fibers (387 and 781 nm) yield well-formed carbon fibrous morphologies, with average diameter of the same range as the precursor ones. In contrast, the thinnest nanofibers with an average diameter of 80 nm fuse with each other and lose their fibrous morphology, due to the maximization of heat and mass transfer during the process. These results highlight the decisive role of the nanoscale dimension in processes controlled by heat and mass transfer phenomena, as in the case of carbon fiber manufacture.
Synthesis and Characterization of Pectin-Chitosan as Candidate Materials for Slow Release System
Authors: Hastuti Budi , Hadi Saptono
Published: October 2019

The polyelectrolyte complex (PEC) is a complex formed between opposite charge particles which have recently attracted attention for their potential for drug delivery applications. In this study, PEC from pectin (anionic species) and chitosan (cationic species) was studied. Pectin and chitosan solutions in 2% v/v acetic acid were mixed in the ratio pectin : chitosan of 1:1. The difference in characteristics of PEC pectin-chitosan (Pec-Chi) with its original polymer is indicated by functional group analysis using FTIR. Morphology characterization of films were investigated by XRD. The results showed that Pec-Chi adsorbent had better stability and resistance to the acidic environment. Characterization using FTIR showed that the adsorbent has functional groups of amines, carboxyl and hydrogen. Furthermore, XRD data show that the adsorbent was a not crystalline.
Development of a PEMFC dynamic model and the application to the analysis of fuel cell vehicle performance
Authors: Liu Wei , Peng Zhijun , Kim Bill , Gao Bo , Pei Yiqiang
Published: October 2019

In order to investigate basic output performances of PEMFC (Proton Exchange Membrane Fuel Cell) stack, a dynamic model of PEMFC stack has been developed by combining electrochemical sub-model and thermodynamic sub-model. With necessary validation, it demonstrates that modelling results and experimental data are in very good agreement in terms the U-I curve and power output. By applying the dynamic model to analyse performance outputs of PEMFC stack and applying the model for FC-Hybrid vehicle powertrain configuration, it demonstrates that improved PEMFC quality with increased maximum current density could increase the peak power output and also increase the working efficiency, although the increase of peak power is not linear relation with the increase of maximum current density. Higher working temperature of PEMFC would benefit the increases of both peak power output and efficiency. Compared to working temperature, ambient temperature’s increase could also make positive influence on power output and efficiency, though the influence is weak. Coupling the dynamic model with a powertrain model of FC-Electric hybrid vehicle, the analysis suggests that both PEMFC stack and battery stack should have similar size for general driving condition. Too big either PEMFC stack or battery stack would increase the total weight then contaminate the fuel/energy economy.
Kinetic study of the photocatalytic oxidation of ethylene over TiO2 thin films
Authors: Stroe Rodica-Elisabeta , Rosendahl Lasse A.
Published: October 2019

The photocatalytic oxidation process has been recognized as an environmental friendly, sustainable and low-cost technology for air treatment. A photocatalytic batch reactor has been employed to assess the kinetics of the oxidation of ethylene (C2H4) over immobilized titanium dioxide (TiO2) and the effect of initial pollutant concentration on the kinetics. The rate model based on the simplified mono-molecular Langmuir-Hinshelwood (LH) kinetic model was found to represent the degradation satisfactorily, however with numerical constrains. These were overcome by employing two different approaches. On one hand the Langmuir-Hinshelwood model was solved by means of the Lambert W-function and on the other hand it was reduced to a pseudo-first order rate law, both resulting in a good fit to the experimental data, thus proving that the photodegradation of C2H4 over TiO2 can be modelled by a first order rate law under low concentration conditions. Moreover, both models give a linear dependence between the reaction rate and the initial C2H4 concentration, making an estimation of reaction rate as a function of concentration possible, for a larger interval of C2H4 concentrations.
Fabrication, experimental investigation of jute fiber reinforced epoxy composites and hybrid composites
Authors: Aranno Tazbiul Mahmud , Mia Sobahan , Ullah Khan Md. Shafayet , Hasan M. A. Mehedi , Shams Supto Nyhan , Shaid Sujon Abu , Bin Rashid Adib , Ferdous Md. Shafiul
Published: October 2019

A special type of jute fiber woven mat was introduced by a hand loom. Epoxy jute fiber composites were fabricated using the woven fiber mat. A series of jute-hybrid epoxy composites based on the arrangement of the direction of jute fibers, and additional material were introduced to ensure the elevated mechanical properties of the composites. Improved mechanical properties were found in some cases of hybrid epoxy composites. It is discussed that the mechanical behavior is related to the fiber orientation, types of additional materials used in hybrid materials. The purpose of this study is to propose a simple technical method to prepare woven jute fiber mat by hand loom, and to produce epoxy jute fiber, hybrid composite materials to exhibit the elevated mechanical properties.
Study of photovoltaic solar materials development trend by deductive logic method using big data
Authors: Su Yi-Huei , Wu Jung-Hua
Published: October 2019

In recent years, the development of solar materials in the field of science and technology has experienced many major breakthroughs. This study collects relevant data to evaluate the development of solar energy technology based on deductive reasoning approach in the popular types, and then utilize big data to investigate the trend of smart materials development in solar energy research. This study aims to understand the impact of materials science on the development of photovoltaic solar energy and understand the trends in the research field from the number of published journals in past years.

The period of study in this paper is from 1970 to 2018. The research scope is limited to an analysis of solar journals from Web of Science®, which indicates that various solar materials have very obvious difference in growth trends.

From 1970 to 2010, although the United States was the country with the largest number of published solar journals, the percentage gradually decreased. Then from 2011 to 2018, China became the first among the top countries in solar energy materials publications.Among them, the field of “Dye-sensitized solar” grew the most, the highest research publications in the field of solar energy research is “Materials science”.
Deformation and energy distribution of metal tubes under internal explosive loading
Authors: Feng L N , Li D , Tian J D , Zhang Z F , Hu Z X
Published: October 2019

Deformation and energy distribution of two kinds of metal tubes under internal explosive loading have been studied by means of experiments and simulations in this paper. The velocity and displacement-time history of characteristic points on the flat metal tubes were measured by Photonic Doppler Velocimetry (PDV). Ls-dyna fluid-solid coupling algorithm was used to simulate the experiment. Simulation results agree well with the experimental results. On this basis, the expansive properties of the round tube in the same condition were obtained, the round tube directly expands to the maximum diameter, does not like the expansion and contraction fluctuant process of the flat tube. The simulation result shows that the flat tube will output more energy in the form of kinetic energy, while the round tube tends to store energy in the form of plastic strain energy.
Component layout optimization design based on genetic algorithm
Authors: Shen B , Pan Z W , Lin H , Li W Z
Published: October 2019

When working, electronic equipment is often subjected to a mechanical environment dominated by vibration. The printed circuit board (PCB) in the equipment is prone to deformation and transmits vibration to the components on the board. As the weakest link, the component corner position has a large acceleration, which is one of the important reasons for the failure of components and the entire electronic equipment. Based on the finite element modeling of PCB, the interaction between the finite element analysis software NASTRAN and the programming software MATLAB is realized, and the application of genetic algorithm in component layout optimization becomes possible. The optimization results show that the method adopted in this paper can effectively reduce the acceleration value at the component corner and optimize the mechanical environment when the electronic equipment works.
Formation of weld defects in cold metal transfer arc welded 7075-T6 plates and its effect on joint performance
Authors: İpekoğlu G , Çam G
Published: October 2019

This study aims at investigating the formation of weld defects (i.e., pores) and determining the effect of pores on mechanical performance of the AA7075-T6 plate joints produced using cold metal transfer (CMT) gas metal arc welding (GMAW) technique. For this purpose, AA7075-T6 Al-alloy plates with a thickness of 2 mm were joined using CMT welding technique. The microstructural and mechanical properties of the welded plates were investigated by detailed optical microscopy investigations, micro-hardness measurements and tensile tests. A correlation between the joint performance and the formation of porosity in the fusion zone (FZ) was also attempted to show the effect of the presence of large pores on the mechanical behavior of the joint.
Mechanical properties of reactive powder concrete: A review
Authors: Shi R J , Xiang Z , Liu S G , Wang D H , Ju Y Z
Published: October 2019

To promote engineering application of reactive powder concrete (RPC), based on the domestic and foreign research achievements, the preparation, mix proportion, mechanical properties of RPC were discussed. The results showed that different admixtures have different influence on mechanical properties of reactive powder concrete. High temperature curing can excitant material’s activity and improve the compressive strength of RPC. The axial tensile strength of RPC was usually in the range of 4∼12 MPa, and the splitting tensile strength and flexural strength of RPC were close and higher than that of axial tensile strength. The tensile properties of RPC can be greatly improved by increasing the fiber volume fraction.
Effects of process parameters on the microstructure and mechanical properties of medium-carbon steels for improving high-strain rate properties
Authors: Song Y B , Ham J H , Kim H K
Published: October 2019

The effects of accelerated continuous cooling and isothermal heat treatment process on the microstructure and mechanical properties of medium carbon bainitic steels was investigated to find an alternative process of the conventional austempering treatment process. Two kinds of medium carbon steel billets melted by Vacuum Induction Melting (VIM) were hot rolled to the thickness of 6∼12mm plates and accelerated-cooled to predetermined temperatures and then isothermal heat treatment was conducted immediately. For quantitative analysis of microstructures, the fraction of constituent phases such as retained austenite, martensite, and bainite was measured by XRD and dilatometry. A series of hardness, tensile, and impact tests was conducted to evaluate the mechanical properties of the plates. As the finish cooling temperature increased, the fraction of retained austenite increased and the fraction of martensite and bainite decreased due to the differences in carbon diffusion and transformation kinetics during isothermal heat treatment process. Microstructural observation results showed that the lath/block thickness and fraction of bainite and martensite were mainly dependent on austempering temperature and time. The thickness of bainite and the fraction of martensite were found to be the major factors influencing mechanical properties of the present medium-carbon nanostructured bainitic steels.
Mechanical characterization of mortars used in the restoration of historical buildings: an operative atlas for maintenance and conservation
Authors: Grazzini A , Zerbinatti M , Fasana S
Published: October 2019

The complexity of the architectural and structural restoration of historical buildings requires a careful choice in the use of repair mortars compatible with the original materials of the existing building. It is important to set up an atlas of reference, compared to many mixtures of mortars and conglomerates, useful to support the operational choices in the project of restoration, recovery, and maintenance of historical buildings. The aim is also to encourage the use of local materials with a “short supply chain”, compatible with buildings and applied by traditional techniques. The research makes use of experimental bending, compression and elastic modulus tests on different mixtures of mortars. This paper describes some of the first results obtained so far, because the research is still underway for many different mixtures to test and catalogue. The comparison between the data and the reference values that will be identified, will lead to set up a reference atlas of mechanical behaviour of repair mortars in order to direct the design and operational choices in function of requirements and performance (of the wall systems) of each specific cases in the field of the restoration of historical buildings.
Crack tip shape effect on stress-strain fields in plastically compressible materials
Authors: Alam M I , Khan D , Mittal Y , Kumar S
Published: October 2019

In the present study, the effects of crack tip shape on near tip deformation and fields are numerically investigated for a mode I crack under plane strain and small scale yielding conditions. The material is characterized by finite strain elastic-viscoplastic constitutive relation with bi-linear hardening and hardening-softening-hardening hardness functions. Both plastically incompressible and compressible solids have been considered for analyses. It has been observed that the combination of crack tip profile and plastic compressibility has significant effect on the near tip deformation and plastic fields.
Current trends in bioactive peptides from muscle foods and their potential application
Authors: Yongsawatdigul J , Hamzeh A
Published: October 2019

Muscle protein is a valuable source of energy and essential amino acids, which are needed for growth and maintenance of physiological functions. It also provides peptides known as bioactive peptides exerting some health benefits, including antihypertension, antioxidant activity, immunomodulatory activity, and improving brain function, among others. Bioactive peptides can be generated from digestion or enzymatic reaction. Cooking condition is found to critically affect digestibility of chicken breast and release of bioactive peptides. Extreme thermal treatment at 121°C/15 min reduces simulated gastrointestinal digestion (GI) of chicken breast. In addition, release of peptides inhibiting angiotensin converting enzyme (ACE) that regulates blood pressure via renin–angiotensin system decreases. This implies that extreme thermal process of muscle food lower nutritional values and available ACE inhibitor peptides. Enzymatic hydrolysis is also an effective means to produce bioactive peptides, providing appropriate protease(s) is applied under the optimal condition. Hydrolysates or bioactive peptides would likely be modified through GI digestion. Thus, changes of bioactivities upon GI digestion should be taken into consideration for optimization of protein hydrolysate production. Structural changes of bioactive peptides further take place during transepithelial transport. This would definitely affect bioactivities of peptides reaching the target organ in either positive or negative manner. To further develop functional food or nutraceutical products, efficacy of bioactive peptides should be tested in vivo to assure their health benefits.
Microbiological profile of fresh goat milk: Impact of goat farmer practices in “Taruna Mukti” goat farmer group, Sragen, Central Java
Authors: Nuhriawangsa A D M , Kartikasari L R , Hadi R F , Wati A K , Hertanto B S
Published: October 2019

Goat milk is susceptible to be contaminated by many microorganisms including microbial pathogens responsible for causing diseases. Various contaminations come from every stage of goat milk produce including feeding, milking, and milk treatments. The aim of this study was to assess the practice of dairy goat farmer and evaluate the microbiological profile of raw goat milk in dairy goat farmer group. The study showed that row milk had high total plate count (7, 8x106 CFU/ml). Thus, Coliform and E. coli were detected in the samples of fresh goat milk. Overall, it can be seen that fresh goat milk was relatively poor hygienic quality and was not conformed to the Indonesian Nasional Standard.
The utilizing of zeolite and manures for increasing potassium availability, uptake, and yield on soybean in Alfisols
Authors: Haniati I L , Minardi S , Nastiti A H L , Harieni S , Syamsiyah J , Hartati S
Published: October 2019

Enhancement soybean production is needed to fulfill its high demand in Indonesia by utilizing the widespread potential land, such as Alfisols. Zeolite and manure addition used to overcome the nutrient availability in Alfisols and decrease the use of inorganic fertilizer. This study was conducted in field condition in a factorial randomized complete block design with three replicates in an Alfisols aimed to assess the effect of applying three rates of zeolites (Z0: 0 t.ha−1, Z1: 2.5 t.ha−1 and Z2: 5 t.ha−1) and three types of 5 t.ha−1 manures (P0: 0 No Manure, P1: quail manure (5 t.ha−1), P2: cattle manure (5 t.ha−1)) on K availability, its uptake, number of pods and seed weight/plot on soybean [Glycine max. (L) Merrill]. Zeolites showed a significant result of potassium availability at the rate 5 t.ha−1. The similar result is given by cattle manure for potassium uptake in soybean. An interaction between zeolites at the rate 5 t.ha−1 and cattle manure showed the significant result on a number of pods.plant−1, 100-seeds weight and seed yield.
Efficacy of betaine as carcass modifier in female broiler chickens to produce leaner carcass for human consumption
Authors: Ratriyanto A , Prastowo S , Widyas N
Published: October 2019

Betaine is a methyl group donor which involved in protein and energy metabolism, offering an opportunity to the poultry producers to satisfy consumer needs by producing leaner carcass. This study was conducted to investigate the efficacy of betaine as carcass modifier in female broiler chickens fed diet containing sufficient methyl group donor. Two hundred female day-old chicks (DOC) were allotted to four assay diets with 5 replicates of 10 birds. The starter and finisher diets contained 0.50 and 0.38% methionine as methyl group donor, respectively. The basal diets were fed without supplementation or supplemented with 0.10, 0.20 and 0.30% betaine. The assay diets were fed from the age 8–42 days. Two birds per replicate were slaughtered at the age of 42 days to measure the carcass characteristics. The fat content was derived from breast meat samples. Supplementation of betaine did not influence the slaughter weight, carcass and breast yield, indicating similar growth and carcass production. Furthermore, administration of betaine produced 29.8–42.5% lower abdominal fat pad deposition and 9.2 – 35.9% lower meat fat content than those without betaine administration (P<0.05). It can be concluded that betaine can modify carcass characteristic in female broiler chickens by lowering fat deposition.
Predicting yolk and albumen weight using egg weight of quails (Coturnix coturnix japonica) fed diet supplemented with betaine
Authors: Ratriyanto A , Amirullah Y H , Prastowo S , Widyas N
Published: October 2019

Betaine as a methyl donor is proven to increase the synthesis of egg components which presence in poultry diet is suspected to modify the composition of the eggs. Eggs are multipurpose animal product. It is utilized in various ways; either as a whole or separated between its yolk and albumen. For the later purpose, the knowledge about egg composition is essential. This study aimed to build models to predict the yolk and albumen weight using egg weight of quails (Coturnix coturnix japonica) fed diet supplemented with betaine. In total, 239 data obtained from 3 assay diets were subjected to analysis of variance, correlation, regression and cross validation. The assay diets consisted of a basal diet containing 16.5% protein fed without or with supplementation of 0.06 and 0.12% betaine. The supplementation of 0.12% betaine increased egg, yolk and albumen weight (p<0.01). The correlation of egg weight∼yolk weight and egg weight∼albumen weight ranged between 0.65–0.69 and 0.69–0.79, respectively. The regression models showed high predictability between 92.7–94.5% for yolk weight prediction and 96.0 – 97.2% for egg weight prediction based on egg weight. Thus, egg weight is a good predictor to predict the yolk and albumen weight of quail eggs.
Egg production patterns of quails given diets with different nutrient density
Authors: Widyas N , Nugroho T , Hidayat B F , Masykur A , Prastowo S , Ratriyanto A
Published: October 2019

Energy and protein ratio in the diet plays an important role in laying quails production. High nutrient density could expose the quails into heat stress due to inefficient metabolic process and nutrient absorption. On the other hand, lower density possesses the risk of nutrient insufficiency. Both cases are potential in affecting the egg production. This study aimed to investigate the egg production patterns of quails fed different nutrient density with constant ratio of metabolizable energy (ME) and crude protein (CP). Egg production data was obtained from two hundred laying quails (Coturnix coturnix japonica) which were randomly assigned into two distinct experimental diets. Dietary treatments were given for eight weeks and replicated five times each with 20 quails. Two diets were formulated to contain High ME-CP (2,800 kcal/kg ME and 18.7% CP) and Low ME-CP (2, 600 kcal/kg ME and 17.3% CP). The data were analysed using t-test and egg production patterns were plotted. Quails fed with different nutrient density yielded similar egg production values and patterns. We fit non-linear mathematical model into the datasets; similar trends and fitness were also observed (R2 = 0.96). It is concluded that quail fed with different nutrient density exhibited minor difference in egg production pattern.
The consistency of quail’s egg production supplemented with vitamin C in the diets
Authors: Ratriyanto A , Nugroho T , Masykur A , Hidayat B F , Prastowo S , Sunarto  , Widyas N
Published: October 2019

In tropical area, animals are prone to stress due to high environmental temperature hence affecting the production. Vitamin C has been offered as an agent to help animal to cope with heat stress. This paper aimed to estimate the consistency of quail’s egg production supplemented with vitamin C through repeatability estimates. A total of 136 quails (Coturnix coturnix japonica) were randomly allotted into 2 dietary treatments with 4 replicates each containing 17 quails. The dietary treatments were basal diet (T0) and basal diet + 250 mg/kg vitamin C (T1). Dietary treatments were given for 8 weeks in laying phase. In total we obtained 56 days of egg production data. Data were analysed using t-test to infer the differences between the treatments and analysis of variance (ANOVA) to obtain the repeatability value. The results showed that the supplementation of vitamin C increased egg production up to 14.3% (P<0.01). Repeatability value of T0 was higher (0.33) than T1 (-0.13). Quails given T0 has a high egg production consistency but produce lower egg production than T1. It is concluded that supplementation of vitamin C increased egg production but were not yet able to produce the optimal consistency.
Postharvest application of an edible coating based on chitosan and gum Arabic for controlling respiration rate and vitamin C content of chilli (Capsicum frustecens L.)
Authors: Muthmainnah N , Suratman  , Solichatun
Published: October 2019

Chili (Capsicum frutescens L.) is the most important vegetable cum spice grown in tropical and sub tropical regions of the world. The post-harvest handling of chilli must be done well so that the quality is maintained. One way of handling post-harvest is to use edible coating such as chitosan and gum Arabic. The research was aimed to find out the effects of chitosan and gum Arabic coating to control of respiration rate and vitamin C content of post-harvest chilli. The research was conducted using a Completely Randomized Design (CRD) factorial consisting of two factors. The first factor consisted of various concentration of chitosan (0%, 1%, 1.5%, 2%) and the second factor consisted of various concentration of gum Arabic (0%, 5%, 10%, 15%) with three replications for each treatment. The coated fruits were then stored at room temperature (28°C) for 15 days. The observed data included respiration rate and vitamin C content. Data were analyzed using Analysis of Varians (ANOVA) and followed by Duncan’s Multiple Range Test (DMRT) at a 5% confidence level. The results showed that the application of chitosan and gum Arabic coating significantly affected the respiration rate and maintained vitamin C content.