Observation of halo implant from the drain side reaching the source side and vice versa in extremely short p-channel transistors

The merging of halo implants from the drain side and the source side creates a maximum in the magnitude of the threshold voltage and thus a minimum in the off-current in the metal-oxide-semiconductor transistors. This paper demonstrates that the halo implant from the drain side can cross-over to the source side and vice versa for the look-ahead transistor test structures (transistor test structures with gate length smaller than that of the target transistor). The phenomenon of the cross-over of halo implant is more readily observed in PMOS transistors compared to NMOS transistors because for the same mask gate length, the effective channel length of PMOS transistor tends to be smaller than that of NMOS transistor. The advantage of the cross-over of halo implants can be understood as follows. Since the hole mobility is smaller than the electron mobility in silicon, PMOS transistor tends to have smaller on-current (I_on) than NMOS transistor. The on-current can be increased by using PMOS transistor with smaller mask gate length compared to the NMOS transistor. However, this approach will make the PMOS transistor very sensitive to the statistical variation in the gate electrode length during manufacturing. By making use of the above reported phenomenon, PMOS transistor can be made shorter without running into manufacturing control problem, resulting in bigger I_on but the penalty is that the I_off will become significantly higher.     

Global warming mitigation and renewable energy policy development from the Kyoto Protocol to the Copenhagen Accord—A comment

Global warming is a grave environmental issue that has caught the attention of the globe. Due to the consequences of global warming, UNFCCC has established the Kyoto Protocol and the Copenhagen Accord as measures of combating climate change due to the emission of greenhouse gases. It has been three years since the first commitment period of the Kyoto Protocol and the Copenhagen Accord was just newly established. Therefore, there is a necessity to evaluate the performance of the Kyoto Protocol and to comment upon the Copenhagen Accord in its contributions toward climate change mitigation. Major greenhouse gas (GHG) emitters who are among the Kyoto Protocol ratifying developed nations exhibit the potential to achieve the desired Kyoto pledges through the aid of Clean Development Mechanisms (mainly from using renewable energy), as proposed in the Kyoto Protocol. However, the nullifying effects from non-ratified major emitters like the US and ratified but still developing countries have difficulties in adhering to the Kyoto Protocol. The Copenhagen Accord, on the other hand, is considered to be less ambitious and provides limited financial aid through the Copenhagen Green Climate Fund. The formulation of such a document indicates that modern societies continues to waste time in negotiations that emphasize on individual economic and political advantages, rather than taking into account true global considerations. It raises questions regarding how much time is needed before we decide to fully commit to the effective and collective efforts of climate change mitigation.     

High-definition X-ray fluorescence elemental mapping of paintings

A historical self-portrait painted by Sir Arthur Streeton (1867-1943) has been studied with fast-scanning X-ray fluorescence microscopy using synchrotron radiation. One of the technique's unique strengths is the ability to reveal metal distributions in the pigments of underlying brushstrokes, thus providing information critical to the interpretation of a painting. We have applied the nondestructive technique with the event-mode Maia X-ray detector, which has the capability to record elemental maps at megapixels per hour with the full X-ray fluorescence spectrum collected per pixel. The painting poses a difficult challenge to conventional X-ray analysis, because it was completely obscured with heavy brushstrokes of highly X-ray absorptive lead white paint (2PbCO(3)·Pb(OH)(2)) by the artist, making it an excellent candidate for the application of the synchrotron-based technique. The 25 megapixel elemental maps were successfully observed through the lead white paint across the 200 × 300 mm(2) scan area. The sweeping brushstrokes of the lead white overpaint contributed significant detrimental structure to the elemental maps. A corrective procedure was devised to enhance the visualization of the elemental maps by using the elastic X-ray scatter as a proxy for the lead white overpaint. We foresee the technique applied to the most demanding of culturally significant artworks where conventional analytical methods are inadequate.     

Grease Penetration and Browning Resistance of Pulpboard and Paperboard Coated with Whey Protein

Whey protein concentrate (WPC) was explored alone and in combination with sucrose (Suc) plasticizer as a grease‐barrier coating for bulrush pulpboard and solid bleached sulfate paperboard used in food packaging. WPC‐coated and WPC : Suc‐coated pulpboards showed better oil‐barrier properties compared with untreated, water‐treated or Suc‐coated pulpboards. Coating formulations with 10% WPC, without and with Suc, resulted in oil barriers comparable with commercial fluorinated hydrocarbon for pulpboard. When pulpboard trays containing cheesy pasta were microwave‐heated, 10% WPC : 20% Suc solution‐coated trays showed grease barrier property comparable with fluorinated hydrocarbon‐treated trays. Caramelization and Maillard browning of WPC and WPC : Suc coatings were initiated at 300°F, but microwave‐heated foods do not normally reach this high temperature. Paperboard with 10% WPC : 20% Suc solution coating had oil barrier comparable with polyethylene‐coated paperboards. WPC : Suc solution mixture at 2.5% : 5% and 3.3% : 7% were determined as the solution concentration minima for 4 and 24 h tests, respectively. HunterLab colorimeter L and b values indicated slight colour change of the paperboard coated with the higher WPC concentration solutions. Coating resulted in thicker paperboards but not in a linear manner. The 10% WPC : 20% Suc solution‐coated solid bleached sulfate paperboards on which slabs of butter sat in a refrigerator did not show any butterfat penetration, comparable with polyethylene‐coated paperboards and unlike uncoated paperboards that showed poor butterfat‐barrier properties. WPC : Suc coating was shown in this study to have potential to replace synthetic materials as a grease barrier. Copyright © 2011 John Wiley & Sons, Ltd.     

Mechanical properties of chemically-treated hemp fibre reinforced sandwich composites

In this study, hemp fabrics were used as reinforcements with polyester resin to form composite skins while short hemp fibres with polyester as a core for making composite sandwich structures. To improve the fibre matrix adhesion properties, alkalisation, silane and acetylation treatments on the fibres surface were carried out. Examinations through fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were conducted to investigate the physical and thermal properties of the fibres. Mechanical properties such as flexural and compressive strengths of the sandwich structures made by treated and untreated hemp fibres were studied. Based on the results obtained from the experiments, it was found that the fibre treated with alkalic solution and post-soaked by 8% NaOH exhibited better mechanical strength as compared with other treated and untreated fibre composite samples. Besides, DSC and TGA analysis showed that the thermal stability of all treated fibre was enhanced as compared with untreated samples.     

Localized elastic modulus distribution of nanoclay/epoxy composites by using nanoindentation

The enhancement of mechanical properties by the use of nanoclay platelets in epoxy resin has been extensively investigated through numerous experimental techniques recently. Elastic modulus was obtained mainly from the tensile test of bone-like nanoclay/epoxy specimens. The results from the tensile test have only showed the globalized mechanical properties of composites and their localized elastic modulus distribution has been neglected. Despite the orientation and the degree of exfoliation of nanoclay platelets inside nanoclay/epoxy composites, the localized elastic modulus is important for the understanding of the distribution of agglomerations of nanoclay platelets. The elastic modulus of nanoclay/epoxy composite samples made under different sonication temperatures would be examined by nanoindentation to compare their localized mechanical behaviors. Scanning electron microscopy (SEM) would also be employed to study the distribution of the nanoclay clusters throughout the composites. The results showed that the elastic modulus varied throughout the composites and the nucleation theory of clusters was modified to explain the behavior of nanoclay agglomerations under different sonication temperatures in which the viscosity of the epoxy resin was varied. The gravitational effect was significant to cause the non-uniform distributions of nanoclay clusters at low sonication temperature.     

Comments on “Dynamic Routing of Restorable Bandwidth-Guaranteed Tunnels Using Aggregated Network Resource Usage Information”

This paper identifies and corrects two flaws in the paper ldquoDynamic routing of restorable bandwidth-guaranteed tunnels using aggregate network resource usage informationrdquo, Kodialam and Lakshman, IEEE/ACM Trans. Networking, 2003.     

Ductile damage development in friction stir welded aluminum (AA2024) joints

Ductile damage development in a friction stir welded aluminum joint subjected to tension is analyzed numerically by FE-analysis, based on a total Lagrangian formulation. An elastic-viscoplastic constitutive relation that accounts for nucleation and growth of microvoids is applied. Main focus in the paper is on the interaction between changes in the material parameters in different regions of the weld, the damage development and the position of the final fracture. Especially changes in the yield stress profile transverse to the weldline are examined, since some process parameters have been shown experimentally to affect this. It is found that damage development is highly influenced by changes in the yield stress profile and a shift in final failure is shown for comparable yield stress in the thermo-mechanically affected zone (TMAZ) and the nugget zone (NG).     

A three-terminal SOI gated varactor for RF applications

This paper presents a new CMOS compatible SOI gated varactor for use in RF ICs. With its additional third terminal, the device offers an exceptional large tuning range and a good quality factor. The result of the MEDICI simulation of the structure of the varactor has been confirmed with measured data. A VCO circuit that can potentially exploit the three-terminal property is also reported