Origin of Life

The evolution of life has been a big enigma despite rapid advancements in the fields of biochemistry, astrobiology, and astrophysics in recent years. The answer to this puzzle has been as mind-boggling as the riddle relating to evolution of Universe itself. Despite the fact that panspermia has gained considerable support as a viable explanation for origin of life on the Earth and elsewhere in the Universe, the issue remains far from a tangible solution. This paper examines the various prevailing hypotheses regarding origin of life like abiogenesis, RNA World, Iron-sulphur World, and panspermia; and concludes that delivery of life-bearing organic molecules by the comets in the early epoch of the Earth alone possibly was not responsible for kick-starting the process of evolution of life on our planet.Comment: 32 pages, 8 figures,invited review article, minor additio

Analytical Design Algorithm of Planar Inductor Layout in CMOS Technology

A layout design algorithm for a variable-width inductor is proposed to minimize metal resistance. For a given chip area, the proposed algorithm can rapidly design metal widths of each coil in a planar inductor due to the analytical form. Two on-chip inductors with identical chip areas and inductance are fabricated to verify the proposed method in foundry 90-nm CMOS technology. Measurement results demonstrate that the improvement of metal resistance in the proposed device is approximately 19%. The results of this paper provide an effective algorithm to design a high-Q inductor for RFIC applications

TaqMan real-time PCR for detection and quantitation of squash leaf curl virus in cucurbits

A real-time PCR assay based on the TaqMan chemistry was developed for reliable detection and quantitation of the squash leaf curl virus (SLCV) in melon and squash plants. This method was highly specific to SLCV and it was about one thousand times more sensitive than the conventional PCR method. The protocol of the real-time PCR established in this study enabled detection of as little as 10(2) copies of SLCV DNA with CP gene as the target. This TaqMan real-time PCR assay for detection and quantitation of SLCV would be a useful tool for application in quarantine and certification of SLCV in cucurbits as well as in the research of disease resistance and epidemiology. (C) 2011 Elsevier B.V. All rights reserved

High-density one-dimensional well-aligned germanium quantum dots on a nanoridge array

The selective growth of high-density one-dimensional well-aligned Ge quantum dots (QDs) on the top of nanoridges patterned on Si substrate is reported. The period of ridge array is 150 nm, the width of each ridge is 80 nm, and the depth of the trench is 20 nm. The areal density of QDs is about 5.4 x 10(9) cm(-2). Simulations of the chemical potential show that a proper distribution of the surface curvature may give rise to a suitable chemical potential minimum helping positioning the QDs. These ridges can also be used to control the shape and the uniformity of QDs. (C) 2008 American Institute of Physics

Smart Control of Home Appliances Using Hand Gesture Recognition in an IoT-Enabled System

Recently, with the vigorous development of the Internet of Things (IoT) technology, all kinds of intelligent home appliances in the market are constantly innovating. The public requirements for residential safety and convenience are also increasing. Meanwhile, with the improvement of indigenous medical technology and quality of life, people’s average lifespan is gradually increasing. However, countries around the world are facing the problem of aging societies. Hand gesture recognition is gaining popularity in the fields of gesture control, robotics, or medical applications. Therefore, how to create a convenient and smart control system of home appliances for the elderly or the disabled has become the objective of this study. It aims to use Google MediaPipe to develop a hand tracking system, which detected 21 key points of a hand through the camera lens of a mobile device and used a vector formula to calculate the angle of the intersection of two lines based on four key points. After the angle of bending finger is obtained, users’ hand gesture can be recognized. Our experiments have confirmed that the recognition precision and recall values of hand gesture for numbers 0–9 reached 98.80% and 97.67%, respectively; and the recognition results were used to control home appliances through the low-cost IoT-Enabled system

Polyaspartic polyurea/graphene nanocomposites for multifunctionality: Self-healing, mechanical resilience, electrical and thermal conductivities, and resistance to corrosion and impact

Polyurea elastomers have attracted increasingly more attention due to excellent mechanical performance, and their wide industrial applications are in need of multifunctionality such as thermal conductivity. We herein prepared polyaspartic polyurea elastomers with optimal tensile strength and fracture strain by adjusting the isocyanate index and free isocyanate content. As a class of nanofiller, isocyanate-modified graphene nanoplatelets (IP-GNPs) were developed and they formed a stable, robust interface with the polyurea matrix, resulting in mechanical reinforcement and multifunctionality. The nanocomposite at 0.05 vol% of IP-GNPs revealed a tensile strength of 15.72 ± 0.67 MPa, representing an increment of 108.21% over pure polyurea, with excellent resistance to acidic and alkali corrosion. After 9 h of post-maintenance at 60 ◦C, the nanocomposite reached a healing efficiency up to 80.10% as driven by hydrogen bonds. An electrical percolation threshold was observed at 3.61 vol% of IP-GNP for the nanocomposites. The thermal conductivity reached 38.49 W/m K at 7.00 vol% due to the formation of the IP-GNP network in polyurea, where the electron thermal conductivity plays a dominant role. In comparison with those high thermal conductivity values obtained by back-filling polymers into a network established beforehand, this facile approach would be highly favored in industry for the development of elastomer nanocomposites with multifunctionality for many applications, e.g. smart sensors, protective coatings, energy harvesting, etc.Qingshi Meng, Peng Wang, Yin Yu, Jianbang Liu, Xiao Su, Hsu-Chiang Kuan, Baozhu Wang, Liqun Zhang, Yingyan Zhang, Dusan Losic, Jun M

Development and Evaluation of an Intelligent System for Calibrating Karaoke Lyrics Based on Fuzzy Petri Nets

In the home entertainment system, karaoke is a popular leisure facility in our daily life. Via the karaoke system, users can sing along with the lyrics based on the recordings of pop songs. However, a lot of karaoke systems can display lyrics semi-automatically. Traditionally, some lyrics are input manually and need to be synchronized with the tonal music stepwise, which is time-consuming. One of the famous musical phrase segmentation theories is a generative theory of tonal music, through which we have implemented a karaoke system in C# programming language. This intelligent system can automatically segment music phrases and use a high-level fuzzy Petri net model to calibrate the lyrics in pop songs. Fifty Chinese pop songs are selected to evaluate its performance. The experimental results have shown that the average calibration precision value (92.78%) and recall value (90.46%) are highly acceptable