Excellent Technology Research Articles

Artificial Noise Elimination: From the Perspective of Eavesdroppers

Artificial noise (AN), aiming to disturb the eavesdropper while avoiding the influence on the legitimate receiver, has arisen as an excellent technology for improving the physical-layer security of wireless communications. In order to challenge AN, zero-forcing elimination (ZFE) has been introduced as a possible countermeasure to mitigate the AN for the eavesdropper at the cost of more available receive antennas. In this contribution, from the perspective of eavesdroppers, we further conceive a class of efficient null-space elimination (NSE) schemes in order to reduce the number of receive antennas while enhancing the detection quality compared to original ZFE. Furthermore, the performance of secrecy rate as well as bit-error rate (BER) is quantified for both ZFE and NSE schemes through theoretical derivation, while the influence of imperfect channel state information (CSI) is also evaluated. The performance comparison of the above-mentioned schemes illustrates that NSE can provide more robust performance for eavesdroppers over ZFE, with lower hardware requirements as well as moderate complexity increase.

Fast and Excellent Drilling and Completion Technology for Deep Shale Gas Wells in Fuling Baima Block

Fast and Excellent Drilling and Completion Technology for Deep Shale Gas Wells in Fuling Baima Block

Pea transformation: History, current status and challenges

This review recapitulates the history, important milestones, the current status, and the perspectives of the pea (Pisum sativum L.) transformation as a tool for pea crop breeding. It summarises the developments of the pea transformation from the first methodological experiments to achieving the complete transformation and regeneration of genetically modified (GM) plants, transformation with the first genes of interest (GOI), to recent techniques of targeted genome editing. We show how recent biotechnological methods and genetic engineering may contribute to pea breeding in order to speed up the breeding process and for the creation of new pea cultivars. The focus is laid on genetic engineering which represents an excellent technology to enhance the pea gene pool with genes of interest which are not naturally present in the pea genome. Different methods of pea transformation are mentioned, as well as various GOI that have been used for pea transformation to date, all aimed at improving transgenic pea traits. Tolerance to herbicides or resistance to viruses, fungal pathogens, and insect pests belong, among others, to the pea traits that have already been modulated by methods of genetic engineering. The production of phytopharmaceuticals is also an important chapter in the use of genetically modified peas. We compare different methods of introducing transgenes to peas and also the usage of different selective and reporter genes. The transformation of other major legumes (soybeans, beans) is marginally mentioned. The effect of genetically modified (GM) peas on animal health (feeding tests, allergenicity) is summarised, the potential risks and benefits of pea modification are evaluated and also the prime expectations of GM peas and the real current state of this technology are compared. Unfortunately, this technology or, more precisely, the products created by this technology are under strict (albeit not scientifically-based) legislative control in the European Union.

Tip-enhanced Raman spectroscopy

As the "fingerprint" spectrum of substances, surface-enhanced Raman scattering (SERS) has extremely high sensitivity. It can detect the molecular traits on the metal surface and reflect the internal structure information of the substance. It is an excellent surface spectroscopy technology. Nevertheless, SERS substrates rely on roughened substrates and nanoparticles of appropriate size, making it hard to use SERS technology to study smooth surface materials or substrates and molecules that do not have SERS active. With the maturity of scanning probe microscopy (SPM) technology, the tip-enhanced Raman spectroscopy (TERS) combining SPM and Raman spectroscopy technology has solved the typical problems in SERS well. Based on the TERS metal tip structure, the spatial detection resolution can be significantly improved, and the research scale can be raised to the single-molecule level. With the rapid development of TERS technology, detection equipment constructed with the help of different types of SPM-TERS systems, metal tip structures, and enhanced modes are used in bioimaging, medical detection, etc. We recognize that it is necessary to provide some new TERS research results. In this review, we initially reviewed the mechanism and structure of TERS. Subsequently, we introduced different novel SPM-TERS systems. Finally, we summarized the research on the tip, gap, and other characteristics of the TERS system and related applications.

Development of a spectroscopic approach for non-destructive and rapid screening of cucumbers based on maximum limit of nitrate accumulation

In this research, a non-destructive and low-cost approach based on Vis/NIR spectroscopy was developed for rapid measurement of nitrate concentrations in cucumbers and screening of the samples based on maximum limit of nitrate accumulation. Vis/NIR spectra of intact cucumbers including both field and greenhouse samples with different concentrations of nitrate were analyzed. PLS models were developed based on the pre-processed spectra and reference measurements. Moreover, PCA-DA classification models with different methods of linear, quadratic and Mahalanobis were developed to discriminate the samples based on maximum limit of nitrate accumulation according to Iranian National Standardization Organization (INSO) and World Health Organization (WHO), as well as based on the type. The best PLS model for prediction of nitrate concentrations in the cucumbers was achieved using D2 pre-processing method (rp =0.87, SEP=60.92 mg kg−1, RPD=2.07). It was concluded that Vis/NIR spectroscopy is adequate for screening the cucumbers based on their nitrate concentrations. The results also confirmed that this technology combined with PCA-DA is appropriate (accuracy=72.22%, sensitivity=76.74%, specificity=54.55%) and fairly suitable (accuracy=64.81%, sensitivity=59.26%, specificity=70.37%) for screening of the cucumbers based on maximum limit of nitrate accumulation according to INSO and WHO, respectively. It was excellent technology for classification of the cucumbers based on their type (accuracy=94.44%, sensitivity=93.55%, specificity=95.65%). Consequently, the proposed spectroscopic approach can be used for safety assessment of cucumbers as a rapid method with easy and out-of-laboratory usability.

Method development and validation of a near-infrared spectroscopic method for in-line API quantification during fluidized bed granulation

Near-infrared spectroscopy (NIRS) is an excellent process analytical technology (PAT) tool for active pharmaceutical ingredient (API) quantification during fluidized granulation. Therefore, a portable near-infrared spectrometer combined with a new innovative method of extended iterative optimization technique (EIOT) was used to in-line monitor the API content uniformity during fluidized bed granulation. The principal component analysis (PCA) and partial least squares regression (PLSR) were also used to characterize and predict API concentration with changes from 75% to 125% of the label claim to prove the superiority of EIOT. The API content prediction accuracy of the EIOT method was verified through offline High Performance Liquid Chromatography (HPLC) measurement. Also, the spatial distribution of API in granules was visualized by Raman imaging technology. The results showed that the established NIRS method was suitable for the prediction of API content in fluidized bed granulation, which provides a new idea for the determination of API content during granulation.

Development of new computational machine learning models for longitudinal dispersion coefficient determination: case study of natural streams, United States.

Natural streams longitudinal dispersion coefficient (Kx) is an essential indicator for pollutants transport and its determination is very important. Kx is influenced by several parameters, including river hydraulic geometry, sediment properties, and other morphological characteristics, and thus its calculation is a highly complex engineering problem. In this research, three relatively explored machine learning (ML) models, including Random Forest (RF), Gradient Boosting Decision Tree (GTB), and XGboost-Grid, were proposed for the Kx determination. The modeling scheme on building the prediction matrix was adopted from the well-established literature. Several input combinations were tested for better predictability performance for the Kx. The modeling performance was tested based on the data division for the training and testing (70-30% and 80-20%). Based on the attained modeling results, XGboost-Grid reported the best prediction results over the training and testing phase compared to RF and GTB models. The development of the newly established machine learning model revealed an excellent computed-aided technology for the Kx simulation.

SOUTH KOREA’S CULTURAL DIPLOMACY DURING COVID-19 AND IMPACTS OF ONLINE LEARNING:

The purpose of this study is to assess the effects of South Korea’s excellent Information Technology infrastructure on students learning in online classes amid the COVID-19 pandemic. A survey was administered on Pakistani and African (N=156) students to investigate their perceptions regarding new paradigm shift towards online learning through correlational and cross-sectional study design. Results show a significant difference between African and Pakistani students on mean scores of teaching mode and learning environment in online classes in the year 2020; t (156) = -5.353, p < .001); indicated an insignificant difference between Pakistani and African Students on mean scores of personal characteristics and factors towards online classes; t (156) =-.716, p-value .095. According to hierarchical regression, the country of the respondents emerged as the strong predictor of attitude towards online teaching that accounted for 16 % of the variance in total attitude towards online teaching, β =.38, t = 5.39, ***p < .001. Personal attributes also emerged as a significant predictor for attitude towards online teaching, β =.30, t = 4.30, ***p < .001 which accounted for 9 % variance in the attitude towards online teaching.

Impact of Molecular Modification on the Efficiency of Recombinant Baculovirus Vector Invasion to Mammalian Cells and Its Immunogenicity in Mice.

The baculovirus display system (BDS), an excellent eukaryotic surface display technology that offers the advantages of safety, efficiency, and economy, is widely used in biomedicine. A previous study using rBacmid-Δgp64-ires-gp64 expressed in low copy numbers of the gp64 gene achieved high-efficiency expression and co-display of three fluorescent proteins (GFP, YFP, and mCherry). However, low expression of GP64 in recombinant baculoviruses also reduces the efficiency of recombinant baculovirus transduction into mammalian cells. In addition, the baculovirus promoter has no expression activity in mammalian cells and thus cannot meet the application requirements of baculoviral vectors for the BDS. Based on previous research, this study first determined the expression activity of promoters in insect Spodoptera frugiperda 9 cells and mammalian cells and successfully screened the very early promoter pie1 to mediate the co-expression of multiple genes. Second, utilizing the envelope display effect of the INVASIN and VSVG proteins, the efficiency of transduction of recombinant baculovirus particles into non-host cells was significantly improved. Finally, based on the above improvement, a recombinant baculovirus vector displaying four antigen proteins with high efficiency was constructed. Compared with traditional BDSs, the rBacmid-Δgp64 system exhibited increased display efficiency of the target protein by approximately 3-fold and induced an approximately 4-fold increase in the titer of serum antibodies to target antigens in Bal B/c mice. This study systematically explored the application of a new multi-gene co-display technology applicable to multi-vaccine research, and the results provide a foundation for the development of novel BDS technologies.

A review on electrocoagulation process for the removal of emerging contaminants: theory, fundamentals, and applications.

Electrocoagulation (EC) is an excellent and promising technology in wastewater treatment, as it combines the benefits of coagulation, flotation, and electrochemistry. During the last decade, extensive researches have focused on removal of emerging contaminants by using electrocoagualtion, due to its several advantages like compactness, cost-effectiveness, efficiency, low sludge production, and eco-friendness. Emerging contaminants (ECs) are micropollutants found in trace amounts that discharging into conventional wastewater treatment (WWT) plants entering surface waters and imposing a high threat to human and aquatic life. Various studies reveal that about 90% of emerging contaminants are disposed unscientifically into water bodies, creating problems to public health and environment. The studies on removal of emerging contaminants from wastewater are by global researchers are critically reviewed. The core findings proved that still more research required into optimization of parameters, system design, and economic feasibility to explore the potential of EC combined systems. This review has introduced an innovative collection of current knowledge on electro-coagulation for the removal of emerging contaminants.

Microstructural investigation on friction stir welded AA6063 pipe

Friction stir welding (FSW) is a solid-state joining technique that has came out as an excellent welding technology for almost all difficult to weld materials and for various weld joint configurations. However, pipe welding remains very challenging due to low contact surface area between the tool and pipes to be welded. In the present work, FSW was carried out on AA6063 aluminium pipes using high speed steel tool of tapered cylindrical tool pin geometry. During experimentation, the rotational speed of 1120 rpm was used while the pipes were rotated at a speed of 1.57 mm/s. Two passes of FSW were performed to weld the pipes and their effect were investigated on the microstructural evolution and the microhardness. The microstructural examination revealed the big sized tunnel defect in the cross-section of welded region in one pass welded sample. With repeated/second pass on the pipe the tunnel size was substantially reduced. Microstrucral characterization confirmed the presence of all characteristically different regions of FSW with refined and equiaxed grain structure in stir zone. Microhardness profile for both samples shows similar trend.

Ethical issues in computer as an instrument of technology growth

The digital computer is a key technology of the modern era and has been central and essential to key operations in modern industrial society, including manufacturing, transport and distribution, government, the military, health services, education and research. Their impact as instrument for technological growth will most likely increase over the next century. Due to the numerous applications of computer in daily activities, they are vulnerable to malfunction and misuse, creating problems such as computer crime, software theft, hacking, viruses, invasions of privacy, an over- reliance on intelligent machines and workplace stress, each of which has created one or more ethical dilemmas for the computer profession. This study therefore (i) discusses some of the fundamental aspects of ethical issues (such as privacy, computer crime, software piracy, and accessibility) in computer as an instrument of technology growth and its significance for the computer professional, (ii) evaluates the influence of computer ethics on technology growth from computer professionals’ perspective and (iii) proposes solutions to ethical issues in computer through the help of practitioners who had excellent computer, information and communication technology background.

Evaluating an Unconventional Shale Completion with Repeat Crosswell Tomography

Evaluation of hydraulic fracturing relies on indirect inference from measurements that are distorted by distance and noise of various kinds, so reservoir monitoring technology that places the measurement as close to the completion as possible is important. Crosswell tomography is just such a technology, placing source and sensor in the plane of the feature to be analysed, and is an excellent technology for making in situ estimates of subsurface properties in simple geologic settings when source-receiver separation is small and when noise levels are low. Since these conditions are not typical in-field scale surveys of unconventional shales, this study overcomes these deficits by incorporating vertically transverse isotropy in raytracing and applying a strong source effort to increase signal-to-noise. The survey used Schlumberger’s Ztrac source and multicomponent geophones to both generate and record compressional and shear wave energy, matching baseline and repeat surveys within a few days of hydraulic fracturing to detect subtle timelapse changes prior to flowback and fluid diffusion. The result is a unique characterization of fracture creation due to hydraulic fracturing, highlighting an out of zone response and subsequent impact on the bounding limestone layers.

태양광 발전량 증대를 위한 에너지 하베스팅 연구

In energy harvesting technology, the United States and Europe are leading the technology development, but since the technology is in the stage of introduction around the world, it is a national investment to secure excellent harvesting-related technology through concentration of capabilities of domestic companies and to preoccupy the global market. The power level that can be used through energy harvesting technology is limited to low power of several watts or less, but in terms of energy cost that can be provided per unit time and unit area provided by energy harvested over a long period of several years or more even compared to the batteries currently in use, it can have a significant alternative meaning. Therefore, in this paper, a voltage coupling method near the lowest voltage of inverter operation was developed and converted as a study to increase the amount of solar power generation in the low sunlight section at sunrise and sunset through voltage tightening amplification adjustment and energy storage technology. In addition, through the solar module voltage series/parallel variable connection conversion technology, the power generation time is extended even under the lowest inverter operating voltage to increase the amount of power generation.

Cryptocurrency as Investment in Commodity Futures Trading in Indonesia; Based on Maqāṣid al-Sharī’ah Approach

Lately, cryptocurrency investors and transactions in Indonesia are thriving, the number of crypto asset investors as of the end of February 2021 has reached 4.2 million people, which exceeds the number of stock investors in Indonesia. This study aims to determine specifically cryptocurrency as an investment in commodity futures trading in Indonesia using the Maqāṣid al-Sharī’ah approach. This research uses a qualitative approach. The data collection technique used is literature study by collecting data from previous studies in the form of documentation of articles, journals, or books as well as publication data from other parties. The data analysis techniques used were data reduction, data presentation, and concluding, from the collected data analyzed through SWOT analysis (strengths, weaknesses, opportunities, and threats) then continued using the Maqāṣid al-Sharī’ah approach (Maṣlaḥah and Mafsadah). The results show that cryptocurrency technology with blockchain can indeed be recognized as an excellent revolutionary technology, but the position of cryptocurrency as an investment in commodity futures trading contains an element of gambling because it contains high speculation and is gambling by taking advantage of the level of volatility. In addition, cryptocurrencies are prone to be used by illegal practices such as money laundering, so that when compared to Maṣlaḥah and Mafsadah it contains greater Mafsadah.

Restoring the Midlands of Tasmania: An introduction

SummaryAt the dawn of the Anthropocene, with the imminent threat of climate change delivering 3–4°C rise in temperature by the end of the century and biodiversity loss across the globe, restoration projects need to focus on re‐establishing connectivity in vegetation structure at a landscape scale to facilitate the movement of wildlife. To achieve this requires long‐term commitment, robust partnerships and planning and excellent planting technology underpinned by research. In this Special Issue, consisting of 15 papers, we present a multidisciplinary, multi‐institutional, science‐based approach to environmental restoration, focused on a single geographic region, the Midlands of Tasmania. This introductory paper describes the breadth of the material covered in the series and sets the scene for following papers by describing the Midlands, its geography, climate and history, its extraordinary natural values as a biodiversity hotspot, the degree of degradation that has resulted from 200 years of intensive farming and the objectives of the Midlands restoration project. The Midlands also offers opportunities as a model system for landscape scale restoration given it is a circumscribed region, heterogeneous in land forms and land uses. Furthermore, in land management, there is a high level of cooperation between land owners, government departments, environmental agencies and university researchers. We describe how the contributions from a wide range of disciplines can be focused to meet the challenges of ecological restoration in highly altered agricultural landscapes.

Do extraordinary science and technology scientists balance their publishing and patenting activities?

This study investigated whether 12 scientists who had received the National Medal of Science and the National Medal of Technology and Innovation balanced publishing and patenting activities. The results demonstrated that although the scientist were recognized for their contributions to science and technology, the majority of recipients were not prolific researchers, and some were not influential. Notably, one scientist had not been granted a single patent. This indicated that scientific and technological contributions may not necessarily correspond with influential scientific publications and patents. Moreover, only two scientists had filed for patents before publishing, and they also invested more time developing technological inventions. Most recipients were science- or technology-oriented scientists. Few scientists balanced their publishing and patenting activities, and demonstrated excellent research and technology performance.

Extended Reality in Higher Education, a Responsible Innovation Approach for Generation Y and Generation Z

This study aims to provide a comprehensive overview of the XR challenges, opportunities, and future trends that will impact higher educational institutions. The article discusses (using observation, participatory observation and as well as document analysis) the potential for augmented reality to be used in higher education, having in mind characteristics of Millennials (Generation Y) and Post-Millennials (Generation Z) and raises issues about responsible innovation, the future of work, and formal education. Additionally, survey research was completed among students in Serbia and Romania (103 respondents) within selected generations regarding their knowledge of extended reality and their attitudes towards opportunities and challenges of extended reality in Higher Education Institutions, and thus this paper also utilises quantitative analysis. A correlation matrix, composite reliability, and regression model were used to code the data and extract knowledge. A thorough review of the existing literature on one hand and primary research as well, using the chosen scientific methods, the planned purpose of the research will be obtained: to gain a better-understanding of the education needs of Generation Y and Generation Z and the potential use of XR as a response to the needs observed. The results of the quantitative analysis confirmed our starting assumptions: XR is an excellent technology facilitating the teaching processes allowing learners to more actively control their learning strategies and supporting the interactivity and connectivity that students and faculties experience. Furthermore, Generation Z students are more applicative for stating XR’s opportunities (instead of challenges) in higher education institutions.

Highest Ever Achieved Current Densities for Zinc/Polyiodide Redox Flow Batteries

With the aim of environment protection and security of energy supply in the coming decades, electricity is increasingly generated from renewable sources. Since availability of these sources such as solar and wind power and therefore electricity generation varies with time, importance of energy storage also increases tremendously. Rechargeable batteries represent an excellent technology for that purpose, as they convert electrical to chemical energy quickly and efficiently and are independent of geographical conditions. The market is currently dominated by lithium ion batteries, but they are expensive, especially on a larger scale. Redox flow batteries (RFBs) have therefore received a lot of interest in the recent years. However, the most commonly used RFB, the all-vanadium system, suffers from a low energy density with only around 30 Wh/l.A promising alternative is the recently suggested zinc/polyiodide RFB. In this system, an aqueous solution of zinc iodide is used as electrolyte. This compound contains the active species for both half-cells, while zinc ions also act as charge carriers since they can diffuse through the cation exchange membrane. These properties lead to enhanced energy density in three ways. First, zinc iodide is soluble in water up to 5 mol/l, which is about two and a half times the solubility of vanadium ions. Secondly, two electrons are transferred in each redox process and thirdly, the anolyte volume can be kept very small. This adds up to almost 10 times higher energy density for zinc/polyiodide RFBs in comparison to all-vanadium RFBs. Up to 200 Wh/l has already been reached experimentally as reported in literature.Here, a novel 100 cm² cell design for this battery type is presented. Graphite compound plates with three different flow field types (flow-through, serpentine, interdigitated) were fabricated. Their electrochemical performances were investigated with the help of current-voltage curves and charge/discharge cycle experiments. In this cell, the highest ever reported current densities for zinc/polyiodide flow batteries at more than 500 mA cm-2 could be achieved. These experimental results were accompanied by CFD simulations, which provided further insights. The results will be reported at the conference.

Water purification system based on self-powered ozone production

Ozone treatment is an excellent sterilization technology, but high voltage is essential for ozone generation. Here, for the first time, we report a multifunctional water purification system based on self-powered ozone generation. The TENG with “like charges repel” strategy (LCR-TENG), which can obtain a maximum short-circuit current of 22.15 uA, a peak power of 80 mW, and a maximum transient voltage over 30.7 kV, is designed as the power source of the system. Then, an air-breakdown-discharge is generated by this TENG to support the ozone generation, while the maximum concentration of generated ozone can be up to 30 mg/m3 and it is enough for the application of water treatment. With continuous injection of ozone into solutions, Rhodamine B with 5 ppm concentration can be degraded by 97.6% in 20 min. The ozone generated by the system are effective for bio-sterilization in water, indicating the promising application for the treatment of organic matter and microorganisms in water. A variety of external loads, such as ultraviolet lamp and step-down circuit can be simultaneously integrated in the current loop and the function of the system can be further expanded without disturbing the ozone generation. Hence, this work broadens the high voltage applications of TENG for the multifunctional purification system.