Design, modeling, and hardware correlation of a 3.2Gb/s/pair memory channel

With the rapid advance of silicon process technology, it is now possible to design input/output (I/O) circuits that operate at multigigabit data rates. As a result, accurate modeling and analysis of high-speed interconnect systems is essential to optimize the performance of the overall system. This paper describes the interconnect design, modeling, simulation, and characterization methodologies that are essential to achieve multigigabit data rates. It focuses on the physical layer verification and hardware correlation of functional systems and silicon to ensure robust system operation over 3.2Gb/s data rate using conventional low-cost packaging and printed circuit board (PCB) technologies. In order to capture conductor and dielectric losses, as well as other high-frequency effects of three-dimensional structures, accurate measurement-based simulation techniques that directly incorporate frequency-domain parameters from measurement or electromagnetic solver parameters into circuit simulation tools using fast Fourier transform (FFT) and bandlimiting windowing techniques are developed. Finally, simulation waveforms are correlated with prototypes at both component and system levels in both time and frequency domains.     

Supporting adaptive capacity of agropastoralists through fish production and marketing: The case of Tendaho Reservoir

The present study was conducted to share the experience of promoting fish production and marketing from the Tendaho Reservoir of the Afar region, Ethiopia. The study results indicate the reservoir is serving its purpose, namely to generate gainful employment for the pastoralist youth and to create sustainable livelihoods and sources of income for the pastoralist‐fishermen of the Afar region. Further, the reservoir fish production has improved the nutrition and food security status of children. It also created a new business entry for hotels and restaurants in the area. Fishermen in the study areas, however, face problems getting the required support for such efforts, in the form of training in fish post‐harvest practices. The present study also indicates dried catfish marketing should be targeted in the short run to address the substantial fish spoilage observed in the high‐production hot season. Dried catfish marketing is highly recommended for the Afar region since it is well adapted to the climate of the study area, noting the product is less perishable and can be sold throughout the country. Dried catfish marketing is also expected to address the problem of gender inclusiveness, an issue clearly missing in the fish production system in the study areas.     

An empirical study of software release notes

Release notes are an important source of information about a new software release. Such notes contain information regarding what is new, changed, and/or got fixed in a release. Despite the importance of release notes, they are rarely explored in the research literature. Little is known about the contained information, e.g., contents and structure, in release notes. To better understand the types of contained information in release notes, we manually analyzed 85 release notes across 15 different software systems. In our manual analysis, we identify six different types of information (e.g., caveats and addressed issues) that are contained in release notes. Addressed issues refer to new features, bugs, and improvements that were integrated in that particular release. We observe that most release notes list only a selected number of addressed issues (i.e., 6-26 % of all addressed issues in a release). We investigated nine different factors (e.g., issue priority and type) to better understand the likelihood of an issue being listed in release notes. The investigation is conducted on eight release notes of three software systems using four machine learning techniques. Results show that certain factors, e.g., issue type, have higher influence on the likelihood of an issue to be listed in release notes. We use machine learning techniques to automatically suggest the issues to be listed in release notes. Our results show that issues listed in all release notes can be automatically determined with an average precision of 84 % and an average recall of 90 %. To train and build the classification models, we also explored three scenarios: (a) having the user label some issues for a release and automatically suggest the remaining issues for that particular release, (b) using the previous release notes for the same software system, and (c) using prior releases for the current software system and the rest of the studied software systems. Our results show that the content of release notes vary between software systems and across the versions of the same software system. Nevertheless, automated techniques can provide reasonable support to the writers of such notes with little training data. Our study provides developers with empirically-supported advice about release notes instead of simply relying on adhoc advice from on-line inquiries.     

Dietary and bioactive properties of the berries and leaves from the underutilized Hippophae salicifolia D. Don grown in Northeast India

Food Science and Biotechnology - The physico-chemical, polyphenols, antioxidant and antibacterial properties of berries and mixture of male and female leaves of Hippophae salicifolia were...     

Strategies to raise the off-design efficiency of chiller machines

Most HVAC systems in large buildings are equipped with centrifugal chillers which are typically designed for maximum efficiency at 70% at 80% of their full-load. But, below about 30% full-load, their part-load efficiency starts to deteriorate rapidly (increasing kilowatts per ton). For older centrifugal chillers, this rapid drop may start at even higher part-load, rendering their operation at low part-load undesirable. In many cases chillers are over-sized, forcing operation below 50% of the full-load most of the time. Furthermore, the field performance of most chiller machines is genearlly not documented, and there is no tradition of recording chiller performance history. There is growing incentive-driven interest in chiller monitoring. But, field visits, discussions with HVAC engineers and opinions from manufacturers have proven that virtually no chiller systems are currently monitored for kilowatts per ton. Only recently has field data gathering been initiated, and part-load performance of chillers in the field started drawing serious attention. The problem, however, still remains poorly disclosed to the end-user. As a result, chiller machines actually operate at much lower efficiency than the design values. There are opportunities for profoundly improving their field performance. Part-load operation is particularly poor for sites with single centrifugal chillers. This research is an appraisal of strategies for improving the part-load performance of chiller systems. A review of simulation results and field data indicate that chiller machines operate at higher kilowatts per ton than allowed for by current technology. Energy consumption of various chiller types and configurations for a generic building indicate that there are possibilities for lowering chiller energy consumption, and these opportunities can be harvested with simple measures.     

Effects of a titanate coupling agent on the mechanical and thermo‐physical properties of talc‐reinforced polyethylene compounds

An experimental study was carried out to investigate the effects of a titanate coupling agent on the mechanical properties, moisture absorption, and thermal conductivity of talc‐filled high‐density polyethylene (HDPE). Talc (0–35 wt %) was used as reinforcement particulate filler in an HDPE matrix and samples were prepared in a micro‐compounder and an injection molding machine. Isopropyl tri(dioctyl)phosphate titanate (0.5 wt %) was used as coupling agent. Composites with and without coupling agent were evaluated for changes in mechanical and thermo‐physical properties, morphology, and void content. Addition of the titanate coupling agent most often resulted in an increase in stiffness and tensile strength. Furthermore, both the void content and the elongation at break of composites were reduced. Results also showed that the coupling agent had no effects on the thermal conductivity, thermal diffusivity, and specific heat capacity of the composites. In addition, it was observed that the coupling agent was more effective at low concentrations of filler. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40449.     

Aero-elastic behavior of a flexible blade for wind turbine application: A 2D computational study

This paper presents a computational study into the static aeroelastic response of a 2D wind turbine airfoil under varying wind conditions. An efficient and accurate code that couples the X-Foil software for computation of airfoil aerodynamics and the MATLAB PDE toolbox for computation of the airfoil deformation is developed for the aero-elastic computations. The code is validated qualitatively against computational results in literature. The impact of a flexibility of the airfoil is studied for a range of design parameters including the free stream velocity, pitch angle, airfoil thickness, and airfoil camber. Static aero-elastic effects have the potential to improve lift and the lift over drag ratio at off-design wind speed conditions. Flexibility delays stall to a large pitch angle, increasing the operating range of a flexible blade airfoil. With increased thickness the airfoil deformation decrease only linearly.     

Heat recovery from automotive engine

Heat recovery from automotive engines has been predominantly for turbo-charging or for cabin heating. Studies relative to application of the recovered heat to run absorption chillers is scarce. In this project, a 10.55 kW (three ton) absorption chiller was modified for hot gas intake and matched to a 2.8 L V6 internal combustion engine. Mathematical model and experimental test results suggest that the concept is thermodynamically feasible and could significantly enhance system performance depending on part-load of the engine. However, possible challenges during transient operations as well as issues related to scalability and reliability require further investigation.