1,353 research outputs found
The Sediment Transport Prediction For Mountain Rivers
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Whistler mode waves upstream of Saturn
Whistler-mode waves are generated within and can propagate upstream of
collisionless shocks. They are known to play a role in electron
thermodynamics/acceleration and, under certain conditions, are markedly
observed as wave trains preceding the shock ramp. In this paper, we take
advantage of Cassini's presence at ~10 AU to explore the importance of
whistler-mode waves in a parameter regime typically characterized by higher
Mach number (median of ~14) shocks, as well as a significantly different IMF
structure, compared to near Earth. We identify electromagnetic precursors
preceding a small subset of bow shock crossings with properties which are
consistent with whistler-mode waves. We find these monochromatic,
low-frequency, circularly-polarized waves to have a typical frequency range of
0.2 - 0.4 Hz in the spacecraft frame. This is due to the lower ion and electron
cyclotron frequencies near Saturn, between which whistler waves can develop.
The waves are also observed as predominantly right-handed in the spacecraft
frame, the opposite sense to what is typically observed near Earth. This is
attributed to the weaker Doppler shift, owing to the large angle between the
solar wind velocity and magnetic field vectors at 10 AU. Our results on the low
occurrence of whistler waves upstream of Saturn also underpins the
predominantly supercritical bow shock of Saturn.Comment: Published in Journal of Geophysical Research: Space Physics (January
2017) 21 pages, 4 figure
Taxonomic studies on the genus Indigofera Linn. (Indigofereae, Fabaceae) in parts of Katsina and Kaduna States, North-Western Nigeria
Indigofera is a large genus in the family Fabaceae comprising about 750 species. In Nigeria, particularly the northwestern savanna region, identification and naming of Indigofera species have been very difficult, ambiguous and controversial for a long time. Thus, proper identification and naming of the species within this genus are paramount. Several field surveys were carried out in the study area and twelve species were successfully collected and identified. Multivariate analyses (CA and PCA) were used to determine whether the species are distinct or not, and to identify the most useful characters for the identification of the species in the region. Fresh specimens were collected purposely for this work and herbarium specimens were used. The result of the cluster analysis revealed 12 distinct clusters (at an Euclidean distance of 0.08) with a cophenetic correlation coefficient value (r) of 0.89. The result of the PCA revealed 12 distinct groups. The character loadings indicated that number of seeds per pod, petiole length, leaflet length, internode, fruit length and leaflet width contributed the highest variation among the species, which could be more useful in delimiting the species. These characters can, therefore, be used in the identification and distinguishing of Indigofera species in the region. We provided a key for the identification of the species
Flood vulnerability and resilience: Exploring the factors that influence flooding in Sarawak
Flooding is the most common natural disaster in Malaysia, resulting in chaos and disruptions to social and economic activities, damage to roads and railway tracks, vehicles, affecting the level of properties, loss of life, and rise in vulnerability. In addition to natural causes, floods are mainly attributed to continuous heavy rainfall, rapid development, unplanned urbanization, poor drainage system, and environmental degradation. This annual occurrence of floods has given a big impact on the lives of humans and other living beings. Due to the negative impact of floods, we need to pay serious attention and take alternative ways to reduce this disaster. This study aimed to investigate the vulnerability factors and understand the concept of vulnerability and resilience to manage floods in Sarawak. The researcher primarily focused on reviewing the printed and documented material of disasters in order to find the vulnerability factors. Based on the findings, it can be concluded that nature, human, and governance factors, contributed mostly to floods. The present study shows that vulnerability reduction along with emergency preparedness can reduce flood damages and fatalities. The innovative technologies must have to be considered to reduce vulnerability and build resilience for sustainable disaster risk reduction
The Pulsating Nature of Bed Load Transport With and Without Cluster Microform
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Linear and nonlinear arx model for intelligent pneumatic actuator systems
System modeling in describing the dynamic behavior of the system is very important and can be considered as a challenging problem in control systems engineering. This article presents the linear and nonlinear approaches using AutoRegressive with Exogenous Input (ARX) model structure for the modeling of position control of an Intelligent Pneumatic Actuator (IPA) system. The input and output data of the system were obtained from real-time experiment conducted while the linear and nonlinear mathematical models of the system were obtained using system identification (SI) technique. Best fit and Akaike’s criteria were used to validate the models. The results based on simulation reveals that nonlinear ARX (NARX) had the best performance for the modeling of position control of IPA system. The results show that nonlinear modeling is an effective way of analyzing and describing the dynamic behavior and characteristics of IPA system. This approach is also expected to be able to be applied to other systems. A future study exploring the execution of other model structures in demonstrating the position control of IPA system would be exceptionally intriguing
Functionalized Multi-Walled Carbon Nanotube-Reinforced Epoxy-Composites: Electrical And Mechanical Characterization
Carbon nanotubes (CNTs) got great attention because of their interesting physical and mechanical properties. Due to these interesting properties observed at the nanoscale have motivated scientific community to utilize CNTs as reinforcement in composite materials. In the present study, different CNTs and epoxy nano-composites with different wt% (1, 2, 3, and 4%) of f-MWCNTs were prepared and their surface morphology and orientation has been investigated in detail. Further, the surface investigation, electrical and mechanical tests were carried out on CNTs-filled and unfilled epoxy at maximum sonication time 30 minute to identify the loading effect on the properties of the materials. Experimental results depicts well dispersion of f-MWCNTs, significant improvement that the resistivity of pure epoxy decreased from 108 .m to average value 103 .m with 1, 2, 3, and 4wt% f-MWCNTs. The 4.5wt% CNTs/epoxy was attributed to poor dispersion of f-MWCNTs in the nanocomposte. The hardness of nanocomposite loading 1, 2, 3, 4wt% of CNTs, increased 20.7%, 23.02%, 25.62%, 29.09% respectively as compared to pure epoxy. We believe that our strategy for obtaining CNT–reinforced epoxy nanocomposites is a very promising technology and will open a new doors in fields of aviation, aerospace, marine and sporting goods
Analisa Situasi Kini Tentang Isi Dan Pelaksanaan Kegiatan Gizi Dalam "Primary Health Care"
Dalam USAha untuk meningkatkan keadaan gizi masyarakat berpenghasilan rendah diberbagai negara di kawasan Asia Tenggara, termasuk Indonesia, langkah pertama ialah mengadakan penelitian mengenai isi dan pelaksanaan kegiatan gizi dengan pendekatan PHC yang telah dijalankan oleh negara bersangkutan. Penelitian ini mendapat bantuan dari WHO-SEARO.Sehubungan dengan itu telah dilakukan penelitian, dengan tujuan untuk memperoleh data saat ini, tentang isi dan pelaksanaan kegiatan gizi dengan pendekatan PHC pada organisasi kesehatan (Puskesmas-UKIA, UPGK-Kes, KB-Gizi dan PKMD) di berbagai daerah, agar hasilnya dapat digunakan dalam meningkatkan pelaksanaan kegiatan gizi.Daerah terpilih ialah propinsi Jawa Barat, Jawa Tengah dan Sumatera Barat
Demystifying communication signal lost for network redundancy connectivity: evidence from coverage analysis studies on AMR systemarticle
These studies report on the communication signal lost factors that were analyzed and supported by evidences on coverage analysis activities for Automatic Meter Reading (AMR) systems. We have categorized the influential signal lost factors into four core elements that were concluded based on our field measurement studies. We have conducted measurement on Received Signal Strength Indicator (RSSI) parameter and outline the steps and techniques of such research activity. Our results show that a single network connection might not be able to support for reliable Internet network connectivity for critical communication device like AMR system. Hence, applying network redundancy technique into developing a more functional communication module could be an effective solution to combat the issue on signal lost for AMR meters.Keywords: Signal strength; AMR; Cognitive Network Selection; Network redundancy;Signal lost
Software Requirement Analysis and Design: Object-oriented approach with UML
This book is aimed primarily as lab sessions for software requirement and design. It focuses on the basic concepts of object-oriented software analysis and design using Unified Modeling Language (UML). The chapters of this lab module are arranged based on the phase by phase in software development process beginning with project planning, requirement analysis, analysis and design, testing and implementation. Upon completion of this module, the students would have understood the fundamentals of object-oriented software analysis and design using UML and know how to develop the software from scratch to the final product. The first edition of this lab module acts as a baseline for the future improvements. We welcome any response and constructive comments from students, academicians and anyone who is interested with this module
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