Design of a Symmetrical Quad-rotor Biplane Tail-Sitter Aircraft without Control Surfaces and Experimental Verification

This paper presents the design of a symmetrical quad-rotor biplane tail-sitter VTOL UAV (Vertical Take-off and Landing Unmanned Aerial Vehicle) which is composed of four rotors and two symmetrically mounted fixed wings. This aircraft achieves high accuracy in the attitude control and smooth flight mode transition with four rotors rather than the conventional VTOL UAVs using control surfaces. The proposal of angled rotor mounting is adopted to address the issue of insufficient yaw control authority. The layout of symmetrically mounted fixed wings makes the aircraft have capability of rapid bidirectional flight mode transition to improve maneuverability. To validate the performance of the aircraft, simulation and flight experiments are both implemented. These results show that the aircraft has a rapid yaw response under condition of the stable attitude control. In comparative experiment, it is shown that the aircraft is more flexible than other similar configuration of aircrafts. This symmetrical quad-rotor biplane tail-sitter VTOL UAV will have a wide range of potential applications in the military and civilian areas due to its superior performance..

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The State versus the People

10.1093/oso/9780198840428.001.0001 ◽

2020 ◽

Author(s):

Matthew Rendle

Keyword(s):

French Revolution ◽

Effective Means ◽

State Control ◽

Scarce Resources ◽

Soviet State ◽

The People ◽

Wide Range ◽

Complex Picture ◽

The Military

This book provides the first detailed account of the role of revolutionary justice in the early Soviet state. Law has often been dismissed by historians as either unimportant after the October Revolution amid the violence and chaos of civil war or even, in the absence of written codes and independent judges, little more than another means of violence. This is particularly true of the most revolutionary aspect of the new justice system, revolutionary tribunals—courts inspired by the French Revolution and established to target counter-revolutionary enemies. This book paints a more complex picture. The Bolsheviks invested a great deal of effort and scarce resources into building an extensive system of tribunals that spread across the country, including into the military and the transport network. At their peak, hundreds of tribunals heard hundreds of thousands of cases every year. Not all ended in harsh sentences: some were dismissed through lack of evidence; others given a wide range of sentences; others still suspended sentences; and instances of early release and amnesty were common. This book, therefore, argues that law played a distinct and multifaceted role for the Bolsheviks. Tribunals stood at the intersection between law and violence, offering various advantages to the Bolsheviks, not least strengthening state control, providing a more effective means of educating the population on counter-revolution, and enabling a more flexible approach to the state’s enemies. All of this adds to our understanding of the early Soviet state and, ultimately, of how the Bolsheviks held on to power.

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Low Power Cusped Field Thruster Developed for the Space-Borne Gravitational Wave Detection Mission in China

Applied Sciences ◽

10.3390/app11146549 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6549

Author(s):

Hui Liu ◽

Ming Zeng ◽

Xiang Niu ◽

Hongyan Huang ◽

Daren Yu

Keyword(s):

Low Power ◽

Gravitational Wave ◽

Attitude Control ◽

High Efficiency ◽

Experimental Investigations ◽

Attitude Control System ◽

Gravitational Wave Detection ◽

Wave Detection ◽

Wide Range ◽

Institute Of Technology

The microthruster is the crucial device of the drag-free attitude control system, essential for the space-borne gravitational wave detection mission. The cusped field thruster (also called the High Efficiency Multistage Plasma Thruster) becomes one of the candidate thrusters for the mission due to its low complexity and potential long life over a wide range of thrust. However, the prescribed minimum of thrust and thrust noise are considerable obstacles to downscaling works on cusped field thrusters. This article reviews the development of the low power cusped field thruster at the Harbin Institute of Technology since 2012, including the design of prototypes, experimental investigations and simulation studies. Progress has been made on the downscaling of cusped field thrusters, and a new concept of microwave discharge cusped field thruster has been introduced.

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A Slot-Die Technique for the Preparation of Continuous, High-Area, Chitosan-Based Thin Films

Polymers ◽

10.3390/polym13101566 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1566

Author(s):

Oliver J. Pemble ◽

Maria Bardosova ◽

Ian M. Povey ◽

Martyn E. Pemble

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

High Volume ◽

Mechanical Anisotropy ◽

Diverse Range ◽

Direction Parallel ◽

High Area ◽

Wide Range ◽

Slot Die ◽

Potential Applications

Chitosan-based films have a diverse range of potential applications but are currently limited in terms of commercial use due to a lack of methods specifically designed to produce thin films in high volumes. To address this limitation directly, hydrogels prepared from chitosan, chitosan-tetraethoxy silane, also known as tetraethyl orthosilicate (TEOS) and chitosan-glutaraldehyde have been used to prepare continuous thin films using a slot-die technique which is described in detail. By way of preliminary analysis of the resulting films for comparison purposes with films made by other methods, the mechanical strength of the films produced was assessed. It was found that as expected, the hybrid films made with TEOS and glutaraldehyde both show a higher yield strength than the films made with chitosan alone. In all cases, the mechanical properties of the films were found to compare very favorably with similar measurements reported in the literature. In order to assess the possible influence of the direction in which the hydrogel passes through the slot-die on the mechanical properties of the films, testing was performed on plain chitosan samples cut in a direction parallel to the direction of travel and perpendicular to this direction. It was found that there was no evidence of any mechanical anisotropy induced by the slot die process. The examples presented here serve to illustrate how the slot-die approach may be used to create high-volume, high-area chitosan-based films cheaply and rapidly. It is suggested that an approach of the type described here may facilitate the use of chitosan-based films for a wide range of important applications.

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Health Benefits of Uses and Applications of Moringa oleifera in Bakery Products

Plants ◽

10.3390/plants10020318 ◽

2021 ◽

Vol 10 (2) ◽

pp. 318

Author(s):

Paula García Milla ◽

Rocío Peñalver ◽

Gema Nieto

Keyword(s):

Moringa Oleifera ◽

Essential Amino Acids ◽

Bakery Products ◽

Unani Medicine ◽

Functional Value ◽

Organoleptic Characteristics ◽

Wide Range ◽

Potential Applications ◽

Medicinal Properties ◽

Excellent Source

Moringa oleifera belongs to the Moringaceae family and is the best known of the native Moringa oleifera genus. For centuries, it has been used as a system of Ayurvedic and Unani medicine and has a wide range of nutritional and bioactive compounds, including proteins, essential amino acids, carbohydrates, lipids, fibre, vitamins, minerals, phenolic compounds, phytosterols and others. These characteristics allow it to have pharmacological properties, including anti-diabetic, anti-inflammatory, anticarcinogenic, antioxidant, cardioprotective, antimicrobial and hepatoprotective properties. The entire Moringa oleifera plant is edible, including its flowers, however, it is not entirely safe, because of compounds that have been found mainly in the root and bark, so the leaf was identified as the safest. Moringa oleifera is recognised as an excellent source of phytochemicals, with potential applications in functional and medicinal food preparations due to its nutritional and medicinal properties; many authors have experimented with incorporating it mainly in biscuits, cakes, brownies, meats, juices and sandwiches. The results are fascinating, as the products increase their nutritional value; however, the concentrations cannot be high, as this affects the organoleptic characteristics of the supplemented products. The aim of this study is to review the application of Moringa oleifera in bakery products, which will allow the creation of new products that improve their nutritional and functional value.

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Sporulation in solventogenic and acetogenic clostridia

Applied Microbiology and Biotechnology ◽

10.1007/s00253-021-11289-9 ◽

2021 ◽

Author(s):

Mamou Diallo ◽

Servé W. M. Kengen ◽

Ana M. López-Contreras

Keyword(s):

Current Knowledge ◽

Carbon Sources ◽

Cost Effective ◽

Biotechnological Production ◽

Key Points ◽

Wide Range ◽

Potential Applications ◽

A Cell ◽

Sporulation Initiation ◽

Solventogenic Clostridia

AbstractThe Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.

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Click Chemistry Enabling Covalent and Non-Covalent Modifications of Graphene with (Poly)saccharides

Polymers ◽

10.3390/polym13010142 ◽

2020 ◽

Vol 13 (1) ◽

pp. 142

Author(s):

Hu Li ◽

Raffaello Papadakis

Keyword(s):

Click Chemistry ◽

Life Science ◽

Environmental Applications ◽

Energy Materials ◽

Sensors And Actuators ◽

Polar Solvents ◽

Wide Range ◽

Potential Applications ◽

Covalent Modifications

Graphene is a material with outstanding properties and numerous potential applications in a wide range of research and technology areas, spanning from electronics, energy materials, sensors, and actuators to life-science and many more. However, the insolubility and poor dispersibility of graphene are two major problems hampering its use in certain applications. Tethering mono-, di-, or even poly-saccharides on graphene through click-chemistry is gaining more and more attention as a key modification approach leading to new graphene-based materials (GBM) with improved hydrophilicity and substantial dispersibility in polar solvents, e.g., water. The attachment of (poly)saccharides on graphene further renders the final GBMs biocompatible and could open new routes to novel biomedical and environmental applications. In this review, recent modifications of graphene and other carbon rich materials (CRMs) through click chemistry are reviewed.

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Structural design and gait research of a new bionic quadruped robot

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405421995663 ◽

2021 ◽

pp. 095440542199566

Author(s):

Jiu-Peng Chen ◽

Hong-Jun San ◽

Xing Wu ◽

Bin-Zhou Xiong

Keyword(s):

Stability Margin ◽

Static Stability ◽

Quadruped Robot ◽

Superior Performance ◽

Linkage Mechanism ◽

Wide Range ◽

Planning Algorithm ◽

Planning Experiment ◽

Strength And Stiffness ◽

Foot Trajectory

Quadruped bionic robot has a strong adaptability to the environment, compared with wheeled and tracked robots, it has superior motion performance, and has a wide range of application prospects in rescue and disaster relief, ground mine clearance, mountain transportation, so it has become a research hotspot all over the world. Leg structure is an important embodiment of the superior performance of quadruped robot, and it is also the key and difficult point of design. This article proposes a novel quadruped robot with waist structure, which can complete a variety of gait forms. Based on the theory of linkage mechanism, a novel leg structure is designed with anti-parallelogram mechanism, which improves the strength and stiffness of the robot. Using D-H description method, the kinematics analysis of this quadruped robot single leg is carried out. On this basis, in order to ensure the foot contact with the ground and achieve zero impact, polynomial programming is used to plan the foot trajectory of swing phase and support phase. Based on the static stability margin, the optimal static gait of the quadruped robot is planned. A co-simulation study has been carried out to investigate further the validity and effectiveness of the quadruped robot on gait. The simulation results clearly show the robot can walk steadily and its input and output meet the expected requirements. The solid prototype platform is built, and the trajectory planning experiment of single leg is carried out, and the foot trajectory of single leg is obtained by using laser tracker. The gait planning algorithm is applied to the whole robot, and the results show that the robot can walk according to the scheduled gait, which proves the effectiveness of the proposed algorithm.

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Deeply Learned Pose Invariant Image Analysis with Applications in 3D Face Recognition

Mathematical Problems in Engineering ◽

10.1155/2019/3547416 ◽

2019 ◽

Vol 2019 ◽

pp. 1-21 ◽

Cited By ~ 15

Author(s):

Naeem Ratyal ◽

Imtiaz Ahmad Taj ◽

Muhammad Sajid ◽

Anzar Mahmood ◽

Sohail Razzaq ◽

...

Keyword(s):

Face Recognition ◽

Superior Performance ◽

Support Vector ◽

Complex Nature ◽

Alignment Algorithm ◽

3D Face Recognition ◽

3D Face ◽

Norm Minimization ◽

Wide Range ◽

The Face

Face recognition aims to establish the identity of a person based on facial characteristics and is a challenging problem due to complex nature of the facial manifold. A wide range of face recognition applications are based on classification techniques and a class label is assigned to the test image that belongs to the unknown class. In this paper, a pose invariant deeply learned multiview 3D face recognition approach is proposed and aims to address two problems: face alignment and face recognition through identification and verification setups. The proposed alignment algorithm is capable of handling frontal as well as profile face images. It employs a nose tip heuristic based pose learning approach to estimate acquisition pose of the face followed by coarse to fine nose tip alignment using L2 norm minimization. The whole face is then aligned through transformation using knowledge learned from nose tip alignment. Inspired by the intrinsic facial symmetry of the Left Half Face (LHF) and Right Half Face (RHF), Deeply learned (d) Multi-View Average Half Face (d-MVAHF) features are employed for face identification using deep convolutional neural network (dCNN). For face verification d-MVAHF-Support Vector Machine (d-MVAHF-SVM) approach is employed. The performance of the proposed methodology is demonstrated through extensive experiments performed on four databases: GavabDB, Bosphorus, UMB-DB, and FRGC v2.0. The results show that the proposed approach yields superior performance as compared to existing state-of-the-art methods.

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State of the Science in Dried Blood Spots

Clinical Chemistry ◽

10.1373/clinchem.2017.275966 ◽

2018 ◽

Vol 64 (4) ◽

pp. 656-679 ◽

Cited By ~ 51

Author(s):

Jeffrey D Freeman ◽

Lori M Rosman ◽

Jeremy D Ratcliff ◽

Paul T Strickland ◽

David R Graham ◽

...

Keyword(s):

Systematic Approach ◽

Full Range ◽

Dried Blood Spots ◽

Blood Spots ◽

Highly Sensitive ◽

Wide Range ◽

Potential Applications ◽

Review Of Reviews ◽

Near Term ◽

State Of The Science

Abstract BACKGROUND Advancements in the quality and availability of highly sensitive analytical instrumentation and methodologies have led to increased interest in the use of microsamples. Among microsamples, dried blood spots (DBS) are the most well-known. Although there have been a variety of review papers published on DBS, there has been no attempt at describing the full range of analytes measurable in DBS, or any systematic approach published for characterizing the strengths and weaknesses associated with adoption of DBS analyses. CONTENT A scoping review of reviews methodology was used for characterizing the state of the science in DBS. We identified 2018 analytes measured in DBS and found every common analytic method applied to traditional liquid samples had been applied to DBS samples. Analytes covered a broad range of biomarkers that included genes, transcripts, proteins, and metabolites. Strengths of DBS enable its application in most clinical and laboratory settings, and the removal of phlebotomy and the need for refrigeration have expanded biosampling to hard-to-reach and vulnerable populations. Weaknesses may limit adoption in the near term because DBS is a nontraditional sample often requiring conversion of measurements to plasma or serum values. Opportunities presented by novel methodologies may obviate many of the current limitations, but threats around the ethical use of residual samples must be considered by potential adopters. SUMMARY DBS provide a wide range of potential applications that extend beyond the reach of traditional samples. Current limitations are serious but not intractable. Technological advancements will likely continue to minimize constraints around DBS adoption.

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Biodiversity of Secondary Metabolites Compounds Isolated from Phylum Actinobacteria and Its Therapeutic Applications

Molecules ◽

10.3390/molecules26154504 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4504

Author(s):

Muhanna Al-shaibani ◽

Radin Maya Saphira Radin Mohamed ◽

Nik Sidik ◽

Hesham Enshasy ◽

Adel Al-Gheethi ◽

...

Keyword(s):

Secondary Metabolites ◽

Bioactive Compounds ◽

Extreme Environments ◽

Software Tool ◽

Gene Clusters ◽

Well Being ◽

Bioactive Substances ◽

Diverse Range ◽

Wide Range ◽

Potential Applications

The current review aims to summarise the biodiversity and biosynthesis of novel secondary metabolites compounds, of the phylum Actinobacteria and the diverse range of secondary metabolites produced that vary depending on its ecological environments they inhabit. Actinobacteria creates a wide range of bioactive substances that can be of great value to public health and the pharmaceutical industry. The literature analysis process for this review was conducted using the VOSviewer software tool to visualise the bibliometric networks of the most relevant databases from the Scopus database in the period between 2010 and 22 March 2021. Screening and exploring the available literature relating to the extreme environments and ecosystems that Actinobacteria inhabit aims to identify new strains of this major microorganism class, producing unique novel bioactive compounds. The knowledge gained from these studies is intended to encourage scientists in the natural product discovery field to identify and characterise novel strains containing various bioactive gene clusters with potential clinical applications. It is evident that Actinobacteria adapted to survive in extreme environments represent an important source of a wide range of bioactive compounds. Actinobacteria have a large number of secondary metabolite biosynthetic gene clusters. They can synthesise thousands of subordinate metabolites with different biological actions such as anti-bacterial, anti-parasitic, anti-fungal, anti-virus, anti-cancer and growth-promoting compounds. These are highly significant economically due to their potential applications in the food, nutrition and health industries and thus support our communities’ well-being.

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