Finite Element Simulation of a Steady-State Stress Distribution in a Four Stroke Compressed Natural Gas-Direct Injection Engine Cylinder Head

The main aim of this work is to predict the design performance based on the stress/strain and thermal stress behaviour of cylinder head under various operating conditions. The effects of engine operating conditions such as combustion gas temperature and maximum internal pressure, components initial temperature and engine speed on the stress and thermal stress behaviour of the cylinder head have been analyzed. The analysis was carried out using a finite element analysis (FEA) software package, MSC.NASTRAN which is use to simulate and predict the von-Mises stress and strain pattern and thermal distribution of the cylinder head structure during the combustion process in the engine and the geometry modelling was carried out using a popular computeraided engineering tool, CATIA V5. The result can be used to determine the quality of the design as well as identify areas which require further improvement. In this investigation, structural analyses of the cylinder head highlight several areas of interest. The maximum stress is found not exceeding the material strength of cylinder head, and thus the basic design criteria, namely no yielding and no structural failure under firing load case, can be satisfied. In addition, the effect of thermal stress/strain provides a good indication on structural integrity and reliability of the cylinder head, which can be improved in the early stages of design. This steadystate finite element method (FEM) stress analysis can play a very effective role in the rapid prototyping of the cylinder head

Catastrophic forgetting: still a problem for DNNs

We investigate the performance of DNNs when trained on class-incremental visual problems consisting of initial training, followed by retraining with added visual classes. Catastrophic forgetting (CF) behavior is measured using a new evaluation procedure that aims at an application-oriented view of incremental learning. In particular, it imposes that model selection must be performed on the initial dataset alone, as well as demanding that retraining control be performed only using the retraining dataset, as initial dataset is usually too large to be kept. Experiments are conducted on class-incremental problems derived from MNIST, using a variety of different DNN models, some of them recently proposed to avoid catastrophic forgetting. When comparing our new evaluation procedure to previous approaches for assessing CF, we find their findings are completely negated, and that none of the tested methods can avoid CF in all experiments. This stresses the importance of a realistic empirical measurement procedure for catastrophic forgetting, and the need for further research in incremental learning for DNNs.Comment: 10 pages, 11 figures, Artificial Neural Networks and Machine Learning - ICANN 201

Effect of confinement potential geometry on entanglement in quantum dot-based nanostructures

We calculate the spatial entanglement between two electrons trapped in a nanostructure for a broad class of confinement potentials, including single and double quantum dots, and core-shell quantum dot structures. By using a parametrized confinement potential, we are able to switch from one structure to the others with continuity and to analyze how the entanglement is influenced by the changes in the confinement geometry. We calculate the many-body wave function by `exact' diagonalization of the time independent Schr\"odinger equation. We discuss the relationship between the entanglement and specific cuts of the wave function, and show that the wave function at a single highly symmetric point could be a good indicator for the entanglement content of the system. We analyze the counterintuitive relationship between spatial entanglement and Coulomb interaction, which connects maxima (minima) of the first to minima (maxima) of the latter. We introduce a potential quantum phase transition which relates quantum states characterized by different spatial topology. Finally we show that by varying shape, range and strength of the confinement potential, it is possible to induce strong and rapid variations of the entanglement between the two electrons. This property may be used to tailor nanostructures according to the level of entanglement required by a specific application.Comment: 10 pages, 8 figures and 1 tabl

Geometry induced entanglement transitions in nanostructures

We model quantum dot nanostructures using a one-dimensional system of two interacting electrons. We show that strong and rapid variations may be induced in the spatial entanglement by varying the nanostructure geometry. We investigate the position-space information entropy as an indicator of the entanglement in this system. We also consider the expectation value of the Coulomb interaction and the ratio of this expectation to the expectation of the confining potential and their link to the entanglement. We look at the first derivative of the entanglement and the position-space information entropy to infer information about a possible quantum phase transition.Comment: 3 pages, 2 figures, to appear in Journal of Applied Physic

Cholesterol and Malondialdehyde Contents of Broiler-Chicken Meat Supplemented with Indigofera Zolingeriana Top Leaf Meal

This research aimed to increase functional value of broiler-chicken meat containing high antioxidant and low cholesterol through substitution of soybean meal (SBM) with Indigofera zollingeriana top leaf meal (ILM). The experiment used 160 day old broiler chicken (Cobb strain). The experimental chicken were provided dietary treatments when they were 15-days old (initial body weight of 460.5±1.56 g/bird) and terminated on day 35. A completely randomized design (CRD) with four treatments and four replications and ten birds in each replication was used in this experiment. Dietary treatments were: R1= diet containing 20% soybean meal (SBM) without I. zollingeriana top leaf meal (ILM); R2= diet containing 16% SBM and 5.9% ILM; R3= diet containing 12% SBM and 11.8% ILM; R4= diet containing 8% SBM and 17.74% ILM. Variables measured were performances (feed consumption, body weight gain, and feed conversion) and the quality of broiler meat (cholesterol, fat content, and malondialdehyde [MDA] concentration). The results showed that supplementation of 17.74% ILM (R4) as the substitution of 60% soybean meal protein produced the same performances of broilers as those of control diet (R1). Supplementation of 11.8% ILM as the substitution of 40% soybean meal protein (R3) decreased meat cholesterol by 34.70%, meat fat content by 52.93%, and MDA concentration by 62.52%. The conclusion of this study was that supplementation of 17.74% ILM produced the same performances as that of control diet, increased antioxidant content of the meat, indicated by a lower MDA concentration, and decreased cholesterol, as well as fat content of broiler-chicken meat

Ethnomathematics in Perspective of Sundanese Culture

This study is an exploratory research aims to find and know about a phenomenon by exploration. Therefore, the approach used in this study is ethnographic approach, an empirical and theoretical approach to get description and deep analysis about a culture based on field study. From the sustainable interviews and confirmation about field research with some community leaders in Cipatujah district, Tasikmalaya regency and in Santolo Pameungpeuk beach, Garut regency; it is found that Ethnomathematics is still widely used by Sundanese people especially in rural areas: the use of measurement units, mathematical modeling, and the use of clock symbols. The results of this study can be useful for Sundanese people and the government of West Java in education, cultural services, and tourism

Pengembangan Lembar Kegiatan Peserta Didik (Lkpd) Berorientasi Pendekatan Saintifik pada Pokok Bahasan Larutan Asam-basa Kelas XI SMA

This research is a Research and Development (R & D). The development process has been done with reference to 4-D model with steps of Defenition, Design, Development, and Disseminate. Research was conducted in FKIP UR. This research aims to obtain a student worksheet oriented scientific approach on the subject of the acid-base solution for class XI SMA. The research and development with 4-D model was conducted only until Development step, because the purpose of this research was limited to develop and produce a valid student worksheet to be implemented based on validator assessment. Feasibility of student worksheet was evaluated from feasibility of content, language, presentation, graphical and scientific approach aspects. Student worksheet validation result obtained an average value as 4,53 which showed that student worksheet which developed was valid. Means, student worksheet oriented scientific approach on the subject of the acid-base solution for class XI SMA that was developed, suitable to be used in learning process

SOME OBSERVATIONS ON FISHES AND THEIR PARASITES OF DARBANDIKHAN LAKE, KURDISTAN REGION IN NORTH IRAQ

A total of 255 freshwater fishes, belonging to 17 species, namely: Barbus barbulus, B. grypus, Capoeta trutta, Capoeta umbla, Carasobarbus luteus, Carassius auratus, Chondrostoma regium, Cyprinion macrostomum, Cyprinus carpio, Garra rufa, Hemiculter leucisculus, Hypophthalmichthys molitrix, Luciobarbus esocinus, Squalius lepidus (Family Cyprinidae), Mystus pelusius (Bagridae), Silurus triostegus (Siluridae) and Mastacembelus mastacembelus (Mastacembelidae), were collected from Darbandikhan Lake, southeast of Sulaimani city, Kurdistan region, Iraq, from March 2012 to the end of October 2012. The fishes were examined for ectoparasites and endoparasites. The study revealed the existence of 45 species of parasites including: seven species of protozoans, 29 species of monogeneans, two species of trematodes, one species each of cestode and nematode, two species of acanthocephalans and three species of crustaceans. The present study revealed that Dactylogyrus suchengtaii and D. carassobarbi were the most parasites prevalent (100% and 90.90%, respectively) in the lake, while Scyphidia arctica was scarce (1.44%). The fish C. trutta was highly infected with parasites (nine species), followed by S. lepidus (eight species) and both C. luteus and M. mastacembelus (six species each), while G. rufa and H. molitrix were less infected (one species each). The ciliated protozoan Ichthyophthirius multifiliis was recorded on seven species of fishes with prevalence ranged between 2.89% and 23.52%, followed by the crustacean Lernaea cyprinacea which was recorded on four species of fishes (5% - 27.27%)