Rapid Momentum Research Articles

I have a kit and I create worlds: synthetic ecology from synthetic genomes

The genome is the blueprint for life. A genome sequence can be transcribed and translated by molecular machines to assemble an organism capable of replication, sensation, and response. Organisms respond to each other, forming intricate interaction webs that manifest as ecosystems, defining the world we live in and rely on. It all starts with a genome. And if we can build a genome, we can create worlds. This article is protected by copyright. All rights reserved.

Sybil Attack Detection in Vehicular Ad-hoc Networks using Direct Trust Calculation

Vehicular Ad-hoc Networks (VANETs) are gaining rapid momentum with the increasing number of vehicles on the road. VANETs are ad-hoc networks where vehicles exchange information about the traffic, road conditions to each other or to the road-side infrastructures. VANETs are characterized by high mobility and dynamic topology changes due to the high-speed vehicles in the network. These characteristics pose security challenges as vehicles can be conceded. It is critical to address security for the sake of protecting private data of vehicle and to avoid flooding of false data which defeats the purpose of VANETs. Sybil attack is one of the attacks where a vehicle fakes multiple vehicle identity to compromise the whole network. In this work, a direct trust manager is introduced which derives the trust value of each of its neighbor nodes at a regular interval of time. If the trust value is deviated, it confirms sybil attack. The proposed system is compared with the existing system to prove improved sybil attack detection ratio, thus providing better security. NS2 environment is used to prove the simulation results. The experimental results show that the attack detection ratio of SAD-V-DTC is 5 times better than that of the existing system. The packet delivery ratio shows an improvement of 27.27% while the false positive shows a good increase of 65.80% than the existing system.

Ultrasonic assisted synthesis of styrylpyridinium dyes: Optical properties and DFT calculations.

The ultrasonic technique has received considerable attention in several fields; in particular, it gained rapid momentum in organic synthesis due to the larger reaction rates, milder reaction conditions, and better yields. We report herein a facile synthesis of a series of styrylpyridinium based dyes under ultrasonic irradiation. Within short reaction time (15min) under ultrasonic irradiation, compared to normal laboratory conditions, (4-16h), we can achieve good to excellent yields. The reaction time is shortened because ultrasound can accelerate the generation of the nucleophile of the pyridinium salt and subsequently a nucleophilic addition of an aldehyde followed by dehydration affords the styrylpyridinium dye, (Knoevenagel condensation). The photophysical properties of all compounds are comprehensively investigated in different solvents. All the compounds exhibit negative solvatochromism both in absorption and fluorescence emission spectra. Such behavior is due to the higher dipole moment of these molecules at the ground state. DFT calculations were performed to understand the electronic structure of the molecules. Our results show the high efficacy of sonochemistry over other methods for preparation of styrylpyridinium dyes.

Torque and Angular-Momentum Transfer in Merging Rotating Bose-Einstein Condensates.

When rotating classical fluid drops merge together, angular momentum can be advected from one to another due to the viscous shear flow at the drop interface. It remains elusive what the corresponding mechanism is in inviscid quantum fluids such as Bose-Einstein condensates (BECs). Here we report our theoretical study of an initially static BEC merging with a rotating BEC in three-dimensional space along the rotational axis. We show that a solitonlike sheet, resembling a corkscrew, spontaneously emerges at the interface. Rapid angular-momentum transfer at a constant rate universally proportional to the initial angular-momentum density is observed. Strikingly, this transfer does not necessarily involve fluid advection or drifting of the quantized vortices. We reveal that the corkscrew structure can exert a torque that directly creates angular momentum in the static BEC and annihilates angular momentum in the rotating BEC. Uncovering this intriguing angular-momentum transport mechanism may benefit our understanding of various coherent matter-wave systems, spanning from atomtronics on chips to dark matter BECs at cosmic scales.

Nanogenerators with Superwetting Surfaces for Harvesting Water/Liquid Energy

AbstractWater covers about 70% of the earth's surface and contains tremendous energy that remains untapped. Despite success in harvesting hydrodynamic energy based on heavy‐weight and bulky electromagnetic generators, a great deal of water energies stored in the low‐frequency flow of water such as in the form of raindrops, river/ocean waves, and the tide, remain largely untapped. In spite of diversity in development strategies and working mechanisms, engineering efficient water energy harvesting devices, especially nanogenerators, requires the elegant control of interfacial properties of substrates for rapid liquid mass and momentum transfer and effective electron generation/transfer. In particular, inspired by various special wetting phenomena in nature, the design of superwetting surfaces offers a new dimension to fundamentally mediate the way the liquid, as well as the charge, interact with the substrate. Herein, the latest progress in the development of nanogenerators with three distinctive interface types—solid/liquid, solid/solid, and liquid/liquid interfaces—are summarized and their representative applications, challenges, and future perspectives are highlighted.

Core–Envelope Coupling in Intermediate-mass Core-helium Burning Stars

Abstract Stars between two and three solar masses rotate rapidly on the main sequence, and the detection of slow core and surface rotation in the core-helium burning phase for these stars places strong constraints on their angular momentum transport and loss. From a detailed asteroseismic study of the mixed-dipole mode pattern in a carefully selected, representative sample of stars, we find that slow core rotation rates in the range reported by prior studies are a general phenomenon and not a selection effect. We show that the core rotation rates of these stars decline strongly with decreasing surface gravity during the core He-burning phase. We argue that this is a model-independent indication of significant rapid angular momentum transport between the cores and envelopes of these stars. We see a significant range in core rotation rates at all surface gravities, with little evidence for a convergence toward a uniform value. We demonstrate using evolutionary models that measured surface rotation periods are a biased tracer of the true surface rotation distribution, and we argue for using stellar models for interpreting the contrast between core and surface rotation rates. The core rotation rates we measure do not have a strong mass or metallicity dependence. We argue that the emerging data strongly favor a model where angular momentum transport is much more efficient during the core He-burning phase than in the shell-burning phases that precede and follow it.

An Impact of Investment of E Commerce in India

The Ecommerce has been the vibrant industry as of today. Through the innovation of internet e commerce has gained a rapid momentum in 10 years period of time. The Ecommerce market in India has transformed the path of the business to a second phase from offline business to online business. The ecommerce industry in India is expected to grow US$ 200 billion by 2026 which is a massive growth due to rapid usage of internet and smartphones. The digital India campaign is expected to flourish rapidly through the ecommerce industry. The investment of ecommerce has been captured through the big giants Flipkart and Amazon The market size of the flipkart after acquired by the giant Walmart

Critical success factors for public–private partnerships in affordable housing in the United Arab Emirates

PurposeThis study aims to identify the critical success factors (CSFs) in the implementation of the public–private partnerships (PPPs) in the United Arab Emirates’ (UAE) affordable housing sector.Design/methodology/approachA questionnaire survey was conducted to assess 17 CSFs for PPP projects derived from previous international and local studies. The collected data were analyzed using the relative importance index technique to establish the most significant factors based on feedback from 48 respondents from the public and private sectors.FindingsThe most identified CSFs were good governance, government guarantees, commitment and responsibility of the public and private sectors, favorable and efficient legal frameworks, political support and stability, and demand for and the debt-paying ability of the project.Research limitations/implicationsThere has been rapid momentum in the UAE and other Gulf Cooperation Council (GCC) countries towards engaging the private sector in the provision of infrastructure and housing after increased pressure on government budgets and falling oil prices. Thus, this study encourages strong consideration of the highest-ranked CSFs in the absence of any prior experiences or studies. On a broader scale, these CSFs are an effective policy tool for the GCC countries, which share similar contexts.Originality/valueThis paper represents the first empirical study in the GCC region and the UAE on the CSFs for PPPs in affordable housing, which is experiencing growing demand in the region to overcome the large deficit in housing supply.

Microalgae biodiesel production: a solution to increasing energy demands in Turkey

The transportation sector in Turkey, as in other parts of the world, has gained rapid momentum because of population growth and increased industrialization. The energy demand met using combustion of fossil fuels, such as gasoline and diesel, is the main issue to be assessed; however, because Turkey has a limited petroleum reservoir, > 70% of its fossil fuel is imported from foreign suppliers. In other words, Turkey’s economy is largely dependent on these countries for their fossil fuel commodities. Thus, not only would the production of microalgae-based biodiesel for Turkey’s transportation sector prevent global environmental disasters by limiting the use of unsustainable fossil fuels, thereby mitigating emissions (which have escalated over the past century), but it could also be the answer to Turkey’s increasing energy demand. The aim of this review is to use a snapshot of the energy demand not only in Turkey but throughout the entire world to assess the development of biodiesel sources, biodiesel policies, and biodiesel strategies in Turkey, and to provide a review of the technology involved in microalgae-based biodiesel production. With this study, energy solutions are provided to alleviate dependence on foreign-based energy resources by using new technologies to produce sustainable biodiesel fuel.

SWOT Analysis and Countermeasure of Jilin Province Aviation Logistics Industry Development Strategy Based on Low Carbon and Environmental Protection

Jilin Province is an important petrochemical, electronic research and development and agricultural product breeding base in China. After more than 30 years of reform and opening up, its economic construction has made great progress and has shown rapid development momentum. E-commerce and economic growth have driven the development of the logistics industry and promoted the growth and development of the aviation logistics industry. In the low-carbon and environmentally-friendly environment, the aviation logistics industry has been constrained by the macro-system, the impact of other logistics channels, the shortage of logistics talents, and the restrictions on carbon emissions, making the development of aviation logistics industry in Jilin Province difficult. Based on this background, the paper uses SWOT analysis method to systematically analyse the advantages and disadvantages of Jilin Airlines logistics industry and development opportunities and threats, and proposes solutions to how to develop aviation logistics under the current low-carbon environmental protection policy.

Social Influence on Green Consumerism: Country and Gender Comparisons between China and the United States

China's rapid economic growth and population momentum have precipitated an environmental crisis on an unprecedented scale. Consequently, green consumerism is a hot topic leaving marketing managers looking for ways to influence green buying behaviors. One way to examine this problem is to compare the effect of social influence on green behaviors against countries that have experienced a similar spike in pollution owing to rapid development (e.g., the United States). Unfortunately, a gap exists in the literature with respect to how social influence impacts green purchasing behaviors. This researchexamines the issue across country and gender between China and the United States. The findings show that Chinese consumers are indeed more susceptible to social influence with respect to purchasing behaviors. The Chinese view social influence as a multidimensional construct with both cognitive and behavioral components. Chinese females were significantly different from other respondents with respect to cognitive and behavioral social influence.

Effect of Nozzle Port Angle on Transient Flow and Surface Slag Behavior During Continuous Steel-Slab Casting

Undesirable flow variations can cause severe instabilities at the interface between liquid mold flux and molten steel across the mold top-region during continuous steel casting, resulting in surface defects in the final products. A three-dimensional Large Eddy Simulation (LES) model using the volume of fluid method for the slag and molten steel phases is validated with plant measurements, and applied to gain new insights into the effects of nozzle port angle on transient flow, top slag/steel interface movement, and slag behavior during continuous slab casting under nominally steady conditions. Upward-angled ports produce a single-roll flow pattern with lower surface velocity, due to rapid momentum dissipation of the spreading jet. However, strong jet wobbling from the port leads to greater interface variations. Severe level drops allow easy entrapment of liquid flux by the solidifying steel shell at the meniscus. Sudden level rises may also be detrimental, leading to overflow of the solidified meniscus region. Downward-angled ports produce a classic double-roll pattern with less jet turbulence and a more stable interface everywhere except near the narrow faces. Finally, the flow patterns, surface velocity, and level predicted from the validated LES model are compared with steady-state standard k-e model predictions.

Fengyun-4 Attitude Control System Design and Its In-Flight Performance

Fengyun-4, launched on 11 December 2016, is a second-generation geostationary meteorological satellite that employs a three-axis-stabilized attitude control strategy with a zero-momentum state. This Paper introduces the attitude control system of the spacecraft platform and its in-flight performance. The development status of current meteorological satellites in the same generation are reviewed. The Fengyun-4 attitude control system and technical details are presented, including highly accurate attitude determination, attitude-pointing control with high accuracy and stability requirements under the disturbance of rapid steering payloads, momentum management and adjustment, and accommodation to operate after turning 180 deg about the yaw axis, as well as fault diagnosis, isolation, and recovery. In-flight results are presented to demonstrate that the attitude control system of the spacecraft platform could fulfill the Fengyun-4 mission requirements.

A Report on Growth And Spectroscopic Studies on The L-Tartaric Acid Doped Potassium Dihydrogen Phosphate Non-Linear Optical Single Crystals

In recent years study of non-linear optical (NLO) materials is gaining rapid momentum due to their needs in several device applications. Potassium Dihydrogen Phosphate (KDP) is a well-known NLO material, whose non-linearity is enhanced by doping with amino acids. In this present study, single crystal ofL- Tartaric acid doped potassium Dihydrogen phosphate (LTKDP) have been grown by slow evaporation method at room temperature. Good quality transparent crystals were obtained with 27-30 days. The crystallinity and cell parameters were characterized by X-ray diffraction analysis (XRD), the shifts in frequency assignments of various functional groups of KDP due to the addition of L-Tartaric acid was analysed by Fourier transform infrared (FTIR) and Fourier transform Raman spectroscopic studies. The dielectric constant and the dielectric loss of the single crystals were studied as a function of frequency. Kurtz- Perry power technique was employed to determine the Second Harmonic Generation (SHG) efficiency of LTKDP single crystal.

3D simulations of accretion onto a star: Fast funnel-wall accretion

AbstractWe show the results of global 3D magnetohydrodynamics simulations of an accretion disk with a rotating, weakly magnetized central star (Takasao et al. 2018). The disk is threaded by a weak large-scale poloidal magnetic field. The central star has no strong stellar magnetosphere initially and is only weakly magnetized. We investigate the structure of the accretion flows from a turbulent accretion disk onto the star. Our simulations reveal that fast accretion onto the star at high latitudes is established even without a stellar magnetosphere. We find that the failed disk wind becomes the fast, high-latitude accretion as a result of angular momentum exchange mediated by magnetic fields. The rapid angular momentum exchange occurs well above the disk, where the Lorentz force that decelerates the rotational motion of gas can be comparable to the centrifugal force. Unlike the classical magnetospheric accretion model, fast accretion streams are not guided by magnetic fields of the stellar magnetosphere. Nevertheless, the accretion velocity reaches the free-fall velocity at the stellar surface owing to the efficient angular momentum loss at a distant place from the star. Our model can be applied to Herbig Ae/Be stars whose magnetic fields are generally not strong enough to form magnetospheres, and also provides a possible explanation why Herbig Ae/Be stars show indications of fast accretion.

Envelope oriented singularity robust steering law of control moment gyros for spacecraft attitude maneuver

The problem of steering pyramid control moment gyro (CMG) cluster for fast spacecraft attitude maneuver along eigenaxis is investigated. A novel steering law is proposed to continuously attempt to reduce the difference between the current gimbal angle and the desired one corresponding to the angular momentum envelop of the CMG cluster. The proposed steering law can be decomposed into two parts: the first one is a singularity robust term to keep maneuverability and produce control torque, and the other is a null motion term to rearrange the gimbal angles toward momentum envelope. By involving this steering law, it is expected to possess both rapid angular momentum exchange and singularity avoidance ability. In addition, by introducing a new limit vector on attitude error, classical cascade-saturation control algorithm is revised to guarantee spacecraft eigenaxis rotation. Both open-loop steering law test and closed-loop attitude maneuver simulations are performed to evaluate the efficacy of the proposed methods.

Analysis of Numerical Algorithms for Computing Rapid Momentum Transfers between the Gas and Dust in Simulations of Circumstellar Disks

Approaches used in modern numerical simulations of the dynamics of dust and gas in circumstellar disks are tested. The gas and dust are treated like interpenetrating continuous media that can exchange momentum. A stiff coupling between the gas and dust phases is typical for such disks, with the dust stopping time much less than the characteristic dynamical time scale. This imposes high demands on the methods used to simulate the dust dynamics. A grid, piecewise-parabolic method is used as the basic algorithm for solving the gas-dynamical equations. Numerical solutions obtained using various methods to compute the momentum exchanges are presented for the case of monodisperse dust. Numerical solutions are obtained for shock tube problem and the propagation of sound waves in a gas-dust medium. The studied methods are compared in terms of their ability to model media with (a) an arbitrary (short or long) dust stopping time, and (b) an arbitrary dust concentration in the gas (varying the dust to gas mass ratio from 0.01 to 1). A method for computing the momentum exchange with infinite-order accuracy in time is identified, which makes it possible to satisfy the conditions (a) and (b) with minimal computational costs. A first-order method that shows similar results in the test computations is also presented. It is shown that the proposed first-order method for monodisperse dust can be extended to a regime when the dust is polydisperse; i.e., a regime represented by several fractions with different stopping times. Formulas for computing the gas and dust velocities for polydisperse dust with each fraction exchanging momentum with the gas are presented.

RETRACTED ARTICLE: Research on consumers online shopping decision-making and recommendation of commodity based on social media network

With the rapid development of Internet and information technology, e-commerce market has shown a rapid development momentum. Online trading environment of the virtual, making the network trust perception of consumer online shopping decision-making very influential. The social media network application platform is undoubtedly the enterprise used to promote the relationship between consumers and enhance the trust of one of the most convenient channels. Therefore, it is of great significance to explore the factors that influence consumers’ online shopping decisions in the social media network. On the basis of predecessors’ research, this paper explores the influence of consumers’ cognitive ability, relationship intensity and interaction on the decision-making of consumers’ online shopping in the social media network from the perspective of network trust. And through the Sina real micro-blog data on the hypothesis of the regression analysis.

Effects of light intensity and wavelength on the production of lactobionic acid from whey by Pseudomonas taetrolens in batch cultures

AbstractBACKGROUNDLactobionic acid production from dairy waste using Psedomonas taetrolens has gained rapid momentum as it is an economically feasible and environmentally friendly approach. Although photoreceptors have been identified in P. taetrolens, the effect of light on the production of lactobionic acid has not been investigated. This research successfully demonstrates the influence of light on lactobionic acid production by P. taetrolens from cheese whey.RESULTSExperimental results indicated that while red light promoted both cell growth and lactobionic acid production, blue light could only promote cell growth. Xmax and Pmax increased from 12.78 to 15.83 g L−1 and 17.4 to 24.5 g L−1, respectively, under red LED light at 500 lux. On the other hand, Xmax increased from 12.78 to 15.18 g L−1, but Pmax decreased from 17.4 to 15.4 g L−1 under blue LED light at 100 lux. A novel two‐stage LED photo‐bioreactor process was successful in reducing fermentation time by 24 h compared with that of the photo‐bioreactor under red LED light at 500 lux.CONCLUSIONIt is proposed that light of varying wavelengths and intensities can be used as modulator to enhance lactobionic production by P. taetrolens using cheese way. © 2017 Society of Chemical Industry

China’s NTB Market: A Liquidity Dilemma

This paper introduces China’s New Third Board Market (the NTB market) and tests the market-making system in the role of improving market liquidity. The NTB Market is the main part of China’s OTC market, established in 2006. In comparing with China’s Main Board Market and the Second Board Market, it attracts a lot of start-up companies that need financing with less strict listing requirements. Meanwhile, it is full of opportunities and challenges that appeal to numerous securities traders and investors with the rapid development momentum. Since its establishment, the NTB Market has been stuck in the lack of liquidity. The authority of the NTB Market introduced market maker system, so as to solve the problem of liquidity. Using the difference-in-difference method (DID method), the market maker system has been proved to make little contribution to improving the stock liquidity. Although the problem of liquidity is difficult to solve in short term, the NTB Market is full of opportunities for all kinds of participants definitely.