bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a shooting strategy to neutralize UAV swarms based on multi-shot cooperation
Authors: Shaohui Xue , Ji Fan , Baohua Wang , Fengge Wang , Yong Hou , Jiajia Ma , Ye Wu
Published: May 2023

Economical and efficient assault methods using drones and drone swarms severely assailed the defenders during the conflict in the Middle East. In view of the current situation, based on medium and large-caliber anti-aircraft artillery platforms, this article analyzes and calculates the advantages of using multiple anti-aircraft guns against drones, the threat of a drone colony, and the drone colony density. Additionally, this study determines the firing sequence of a drone swarm, and provides anti-aircraft gun firing position points to reduce the firing cost and increase the efficiency. This ensures the optimization of an air defense system within a short duration of time. Ammunition is an effective defense against drone swarms. The experimental results demonstrate that compared with that of the conventional methods of individually shooting the swarms, this strategy can simultaneously neutralize multiple targets, assign shooting tasks to multiple artillery guns, and can cause greater damage to a drone swarm.
Simulation Research of rigid chain failure in a modular gunpowder delivery machine
Authors: Jian Wang , LongMiao Chen , Liu Yang , JunWei Li , ZhiGang Li
Published: May 2023

Based on the theory of a low-recoil rarefaction wave (RAVEN) gun firing cased telescoped ammunition (CTA), the models of interior ballistics and dynamics were established. The dynamic characteristic curves were obtained by numerical simulation analysis, and the results were verified by firing tests. Compared with traditional closed-breech guns, the low recoil force swing chamber gun keeps the projectile’s muzzle velocity basically unchanged, while the maximum recoil is reduced by up to 74%. Based on these results, the parameters of the inertial breech buffer spring were optimized while the maximum recoil force of the breech reduced by 14.2% without affecting system performance and structural installation size, which effectively improved the overall performance of the weapon system.
Numerical Simulation on the Muzzle Shock Wave Pressure for Aircraft Gun
Authors: Tian Nan , Li Yong , Wang Kaizheng , Liu Jie , Xie Yangyang , Liu Bin
Published: May 2023

The muzzle shock wave has a great impact on the airborne structure, airborne personnel and airborne equipment. Therefore, the muzzle flow field of the aircraft gun is used as the research object, based on the three-dimensional reynolds-averaged Navier-Stokes control equation and the standard k − ε turbulence model, a finite element simulation model of the powder gas motion process in the after-effect period without considering the projectile motion is established, the adaptive grid technique is used to divide the mesh inside the barrel and the muzzle brakes, and the The finite volume method is applied to numerically calculate the flow field control equations at the muzzle to obtain the muzzle shock wave pressure with the muzzle brakes and its development law, and to build an experimental verification platform to verify the accuracy of the simulated shock wave pressure. The research results show that the established finite element simulation model of the muzzle flow field can accurately predict the muzzle shock wave pressure.
Research on Application of Three Closed-loop Autonomous Current Sharing Control Technology in Artillery Power System
Authors: Zhang Zhipeng , Liu Qitao , Wang Tianshi , Gu Shuanghao , Ma Jie
Published: May 2023

The new artillery power system adopts the power supply mode of multiple power modules in parallel, which has the advantages of strong versatility, high power, high reliability, and low cost. The main difficulty lies in the current sharing of the power supply modules. Aiming at the shortcomings of traditional current sharing method such as low current sharing accuracy, poor dynamic response, poor output voltage stability, and low anti-interference ability, this article analyzes the necessity of parallel power supply current sharing and the principle of traditional average current sharing method, based on average current sharing method, a three-closed-loop autonomous current sharing control method is proposed, and a system model of power supply modules operating in parallel is established to realize the intelligent and autonomous average current distribution of power supply modules operating in parallel in the artillery power system to meet the power required by the load in the system. Through simulation analysis and prototype test, it is verified that the three closed-loop autonomous current sharing control has the advantages of high current sharing accuracy, fast dynamic response, good stability and strong robustness.
Disturbance Observer based Backstepping Control for Electro-hydraulic Position Servo System of the Projectile Coordination Arm
Authors: Fan Rui-dong , Qian Lin-fang , Chen Guang-song , Wei Yu-kai
Published: May 2023

Due to the existence of unmodeled friction and unknown load disturbance, the position tracking control of electro-hydraulic position servo system of projectile coordination arm becomes an important problem to be solved urgently. In this paper, a dynamic surface backstepping control strategy is proposed based on the disturbance observer(DOB). To be specific, the disturbance observer is applied to estimate the unknown disturbance force, and the backstepping controller realizes the position tracking control. In order to improve the position tracking performance, The estimated value of the observer output is brought into the backstepping controller to realize the model compensation of the disturbance. Meanwhile, the dynamic surface method is utilized to handle the differential explosion problem in the backstepping method. The global stability of the closed-loop system is verified by Lyapunov stability theory. The co-simulation results show that the proposed method can effectively compensate the unknown disturbance in the electro-hydraulic position servo system, and has better tracking performance and strong robustness.
Development Status and Trend of Stealth Technology of Tactical Missiles
Authors: Xu D G , Liu J S , Luo S , Li P
Published: May 2023

In modern warfare, precision guided munitions have become one of the major equipment to attack and hit the enemy’s crucial value targets. In addition, they are the critical targets of the missile defense and anti-aircraft interceptor system of varying countries during interception and destruction, and the world has increased investment in missile defense. Therefore, the penetration and countermeasures capacities of missiles holds the key to the victory, and the stealth technology of tactical missiles provides a vital orientation for the future advancement of weapons and equipment technology. Based on the current military requirements, this paper summarizes the application of stealth technology in varying tactical missiles and analyzes the development trend of such technology in the future, which is expected to have great implications for further research and application of both stealth and anti-stealth technology.
Aerodynamic characteristics of Spin-stabilized Projectile at High Angle of Attack
Authors: Yang B Q , Zhang L , Shen Q , Liu L X , Shi C
Published: May 2023

Researching the aerodynamic characteristic of projectile at high angle of attack could serve to determine the launching condition and the design method of aerodynamic configuration. The aerodynamic coefficients of a kind of spin-stabilized projectile were calculated and analyzed by CFD. An efficient and precise method of calculating the pitching damping moment was obtained to research the aerodynamic coupling characteristic of spinning motion and pitching motion. The results showed that the aerodynamic coefficients of projectile at high angle of attack was nonlinear, the pitching damping moment was proportional to the pitching angular velocity, magnus force had hysteresis characteristic which was affected by pitching amplitude and frequency.
Modeling and Calculation of Hydraulic Equation of Recoil Brake Which is Unfilled in counterrecoil throttling Chamber
Authors: Yang JM , Yu YN , Shi CM
Published: May 2023

In order to lower muzzle vibration, the major caliber gun reduced the recoil resistance in the in_bore period. When the recoil brake was designed, throttling area was enlarged to reduce the hydraulic resistance. This made the counterrecoil throttling chamber (III chamber) was unfilled in the beginning of recoil. In the middle of recoil, III chamber was filled all of a sudden. This made the pressure in the working chamber (I chamber) and III chamber and the recoil resistance increase sharply. According to the equation, Hydraulic equation of recoil brake was set up when the III chamber was unfilled. The conditon of that III chamber was unfilled was deduced. Recoil mechanism was designed in this algorithm, and the recoil motion was computed in compare to the tested curevs. The result indicated that computation result matched well with the actual test result. This study offered reference of design of this kind of recoil mechanism.
Applications of Chromatic Confocal Technology in Precision Geometric Measurement of Workpieces
Authors: Ma YD , Xiao YC , Wang QQ , Yao K , Wang XR , Zhou YP , Liu YC , Sun Y , Duan J
Published: May 2023

Chromatic confocal technology is increasingly applied in industries that require high-precision geometric measurements such as aerospace, naval ordnance, and medical electronics owing to its advantages in testing accuracy, real-time performance, anti-interference, and no damage to tested workpieces. This paper introduces the measurement principle of chromatic confocal technology and the structure of chromatic confocal sensors, and enumerates several typical application scenarios of the technology from the aspects of thickness measurement, profile, 3D topography scanning, roughness measurement, and wafer comprehensive parameter measurement. It also looks into potential development directions of chromatic confocal technology.
The Application of Grooveless Remelt Deposit Welding to the Joining of Large-Caliber Thin-Walled Projectile to Guide Band
Authors: Yang L , Liu W J , Liang J F , Li M , Zhang P J , Wang H , Li X L
Published: May 2023

This paper introduces the research on guide band welding in China and other countries, analyzes the characteristics of guide bands produced by remelt deposit welding and the application of the welding process to the joining between thin-walled submunition-based projectiles with a large caliber and launched by a howitzer. In addition, this paper raises the performance testing requirements for the grooveless remelt deposit welding process.
Development of Graphene /PBO Nanocomposite
Authors: Meng ZR , Liu Q , Zhong WH , Dai Y
Published: May 2023

The study of graphene/poly (p-phenylene benzobisoxazole) (PBO) nanocomposites in recent years is introduced, while the research interests and application fields of graphene/PBO nanocomposites in the future are prospected in this review. In the process of polymer formation, two modification methods, in-situ polymerization modification and blending modification are mainly used to improve the dispersion uniformity of graphene in the PBO matrix. The polymer can be divided into the surface modification of PBO fiber and the modification of PBO nanofiber according to the existing state of PBO, and the effects of two modification methods on mechanics, thermal characteristics, surface morphology and aging resistance of graphene/PBO nanocomposites are compared.
Test and Analysis of the Protection Efficiency of a New Type Thermal Sleeve
Authors: Liu YY , Ding LH , Zhang H
Published: May 2023

As an additional part of the artillery barrel, the thermal sleeve is a cladding made of insulation or thermal conductive material mounted on the outer surface of the barrel, which can greatly reduce the bending deformation caused by sunlight exposure of the barrel, thus improving the shooting accuracy of the artillery. In this paper, a new type diamond thermal sleeve on the barrel thermal protection efficiency is tested and analyzed, after testing, the protection efficiency can be as high as 71.6%, much higher than the ordinary thermal sleeve’s protection performance, so research of thermal sleeve is of great significance to improve the shooting accuracy of the artillery.
Effect of Rifling Height on Convective Heat Transfer Flux and Erosion for Cannon Barrel
Authors: Guo J H , Zhang H , Zhang X D
Published: May 2023

The effect of rifling height on erosion for cannon barrel was studied in this paper. An erosion velocity kernel function which is an Arrhenius type function revealing thermal and chemical effects is proposed. The erosion function is employed in numerical simulations to obtain the erosion depth after several rounds for two kinds of gun barrels at commencement of full rifling. By comparing final erosion depths obtained by numerical simulations and firing tests, it can be concluded that heat transfer flux between propellant gas and barrel with different rifles are absolutely different. Then the effect of rifle height on convective heat transfer flux is discussed in this paper.
Determination of Total Sulfur in Graphene with Organic Elemental Analyzer
Authors: Lu Y , Zhao H , Liu HC , Guo GJ , Wu LJ , You XR
Published: May 2023

In the present work, a method for the determination of total sulfur in graphene with the organic elemental analyzer is presented. The effects of combustion temperature, combustion time, oxygen flow rate, filling reagent, and other factors on measurement results were examined. The results showed that the optimum test results can be obtained when the combustion tube temperature is 1050°C, combustion time 80s, the oxygen flow rate 25 ml/min and tungsten oxide/copper scraps used as the filling reagent. The repeatability, stability, and spike recovery of this method fall into the ranges of 3.4%~ 5.1%, 4.5% ~ 6.6%, and 92.5% ~ 108.6%, respectively. The detection limit is 0.09%, and the deviation between this method and the Eschka method as an arbitration method is -0.02%~-0.08%. Since there is no significant difference between the two methods, both can be used for the accurate determination of total sulfur in graphene.
Study on damage of reactive fragment impacting partially-filled fuel tank
Authors: Xie Jian-wen , Guo Meng-meng , Liu Cheng-zhe , Wang Hai-fu
Published: May 2023

The damage effect of PTFE/Al/W reactive fragment impacting partially-filled fuel tank is investigated by combining the ballistic gun experiment and theoretical analysis. The experimental results show that, with the impact velocity ranging from 806m/s to 1331m/s, the reactive fragments successfully perforate the front plate of fuel tank and cause the flash-ignition of fuel/air mixture, but the fuel tank does not fail obviously. Based on the experimental results, a temperature analysis model of reactive debris is developed by combining the energy release characteristic of reactive material and the convective heat transfer model. The model result shows that the high-temperature reactive debris can effectively ignite fuel/air mixture, which is in good agreement with the experimental results.
Research on Mechanical Properties of Domestic T700S Carbon Fibers
Authors: Wang M , Zheng ZC , Xiao YC , Chen Y , Meng XW , Wang Q
Published: May 2023

Two types of domestic T700S carbon fibers (CF1 and CF2) were investigated in three batches to find out their mechanical properties, including tensile properties of multifilament, tensile and bending properties of composites. The results showed that the mechanical properties of domestic T700S CF are comparable to those of Toray T700S CF with a small discrete coefficient obtained from experiments for the three batches of CF, and that the unidirectional CF2 composite laminates has the biggest tensile strength discrete coefficient, 3.84%. The difference of properties between the two types of fiber composites was analyzed using the optical contact angle measuring device. It was found that CF2 and resin have better wettability. The two types of carbon fibers were examined by the Ø150 mm standard pressure vessel. Temperature (high temperature, low temperature, and temperature impact) tests and aging tests revealed that: high temperature, low temperature, and temperature impact have little effect on the characteristic index of the pressure vessel; after 800h aging, the characteristic index of the pressure vessel decreased by 15.2%.
Demand and Current Situation of 3/8 mm Dual Band Transparent, Bulletproof and Stealth Integrated Radome Technology
Authors: Zhang K , Song HP , Zhou L , Liu ZT , Sun MJ
Published: May 2023

Starting from the threats faced by land-based ground platforms and the battlefield environment, this paper discusses the necessity of the development of 3/8 mm dual band transparent, bulletproof and stealth integrated radome technology. By analyzing the domestic and international development status of relevant technologies, the main problems existing in the research of bulletproof radome are summarized. Finally, the difficulties in the development of this technology are analyzed.
New Explosive Composite Armor Technology for Light Armored Vehicles
Authors: Wang L , Han X , Wang LL , Ruan GG , Xin PX , Li N , Huang YS , Zheng W
Published: May 2023

Taking the future add-on armor of light armored platforms as the application background and research object, in view of armored combat vehicles’ weak survivability and low protection capability against RPGs and armor-piercing projectiles in urban warfare, and based on the research on protection mechanisms of traditional reactive and ceramic composite armor, a new type of explosive composite armor consisting of a composite shell, an explosive structural unit and a lightweight composite unit has been successfully developed. It provides effective protection against RPGs and armor-piercing projectiles at the same time. Compared with foreign data, its weight loss has reached 19%, making it a lightweight composite armor with low after-effect.
The Development Status and Trend of Guided Weapon Simulation Technology
Authors: Chao Yue , Guocai Dong , Manguo Liu , Ge Yu , Yixuan He
Published: May 2023

As simulation technology plays an increasingly important role in the development of precision-guided weapons, it is urgent to study theories and methods in the intelligent, standardized and industrialized simulation technology. This paper mainly introduces the development status of guided weapon system simulation technologies in and outside of China in recent years. The domestic and foreign development of simulation technologies, methods and equipment of different guided weapon systems, including the system of image, laser, millimeter wave and integrated navigation, is compared and analyzed in detail. Finally, the insufficiency, development trend, and coping strategies of China’s guided weapon simulation technologies are proposed.
Attitude Calculation of Quadrotor UAV Based on Extended Kalman Filter and Complementary Filter
Authors: Bin Han , Zhongping Fan , Yilin Xun , Meng Wang , Yu Liu , Can Tao , Wei Wang , Hang Xu
Published: May 2023

Quadrotor UAV obtain the attitude calculation result from inertial measurement unit (IMU), but IMU has the the problems of high noise and low precision, to solve the problems, this paper first introduces the extended Kalman filter (EKF) and complementary filter, and uses them to filter the output of the accelerometer and magnetic sensor. The effects of the two methods are compared by static testing and dynamic testing. The results show that both filtering methods can improve the precision of the attitude angle solutions, but the EKF algorithm performs better.
Cooperative Task Allocation Algorithm of Loitering Munition Based on Exchange Contract
Authors: Wang Y Z , Shen L J , Luo Q , Lan Y X , Xue J G , Hou T , Hao F , Yue C
Published: May 2023

Aiming at the task allocation of loitering munitions, a cooperative task allocation algorithm based on exchange contract is designed considering the target value, threat cost and battle path cost. Compared with the traditional contract net algorithm, its complexity is simplified, the calculation speeds up, and the local optimal problem is solved.
Application Scheme Design of BeiDou Ground-based Augmentation System for Guided Rockets
Authors: Shuanhu Yang , Peng Wu , Pengxiang Yang , Deming Chen
Published: May 2023

China’s BeiDou Ground-based Augmentation System (GBAS) improves the accuracy of BeiDou satellites navigation system to the sub-meter level. GBAS is widely used in the navigation fields, such as civil vehicles, ships, drones, which produces significant economic benefits and lays the foundation for application of high dynamic missile. According to the application requirements of guided rocket, this paper designed a high dynamic real time differential (RTD) based on GBAS, and proposed the composition, principle, working flow, missile equipment devices and ground terminal, etc. Through the design analysis, it is hoped that this paper can provide reference for high dynamic application of GBAS.
Research on the Mode for New Quality Air Defense Weapons Integration into Air Defense System
Authors: Feng WQ , Shen JQ , Liu JT
Published: May 2023

To address the evolving problem of how to applicate the increasingly developed laser, microwave, electromagnetic rail gun and other new quality air defense weapons after they are integrated into the air defense system, this paper summarizes three development states of the new quality air defense weapons system, namely, a small amount of equipment, a large number of equipment and intelligent integration, based on the performance development of new quality air defense weapons. For the first time, the system proposes three combat modes of new quality air defense weapons, namely, “pointed mode”, “layered mode” and “networked mode”, the air raid threat and application of each mode are clarified. This will provide ideas and methods for the operational application of new air quality defense weapons at different stages of development.
An Overview of Countermeasures Against Low-altitude, Slow-speed Small UAVs
Authors: Chi Zhang , Chun Zhang , Ruyi Kong , Shiyong Xing , Jiao Zhang
Published: May 2023

With the rapid development of air combat weapons and integrated air defense system, air raid UAVs are developing towards miniaturization and clustering, which has higher requirements for air defense weapon system and greater air defense difficulty. In view of the threat of Low-altitude, Slow-speed Small UAVs to air defense system, this paper briefly describes the basic classification of UAV, introduces the market demand of anti Low-altitude, Slow-speed Small UAVs at the present stage, summarizes the basic strategies and five Damage methods of anti Low-altitude, Slow-speed Small UAVs, and analyzes the advantages and disadvantages of various methods, which provides a reference for understanding the current research status and carrying out the next research work.
Study on Artillery Aiming Control and the Development of Intelligent Autonomous Technology
Authors: Han CW , Li Z , Li CH , Hou JY , Dai P , Li W
Published: May 2023

In recent 70 years, the artillery aiming control technology has developed rapidly, and the control mode has experienced the development process of manual, semi-automatic and full-automatic. The development of the control mode of the new generation artillery aiming control system in the future is still in the stage of research and exploration, with relatively few research results and lack of systematicness. This paper analyzed the development related technologies of aiming control mode, puts forward an intelligent autonomous development mode and basic concept of artillery weapon equipment aiming control, discusses the characteristics and differences between artillery intelligent autonomous and conventional computer automatic control from the aspects of signal perception layer, control strategy layer and drive execution, and analyzes the development trend of artillery weapon equipment aiming control technology.
A teacher professional development course on quantum technologies: discussion of results
Authors: Sutrini C. , Malgieri M. , Zuccarini G. , Macchiavello C.
Published: May 2023

We first present the evaluation of a professional development course for in-service teachers on quantum technologies which was initially presented at the GIREP Malta 2020 webinar about halfway into its development. The primary purpose of the course was to enhance physics teachers’ knowledge and awareness of topics related to quantum computation and quantum information, and of their relevance for technological advancement. However, our choice was not to present such topics as a simple addition to high school physics in the final year, but rather to inspect the whole physics and mathematics curriculum in the search for a longitudinal perspective, roughly based on the relationship between physics and computation, which could culminate in the treatment of quantum information topics. In the present contribution, we will focus on the educational outcomes of the course in terms of teacher appreciation, interest level and judgement of usefulness coming from both a final questionnaire and individual interviews. We will also describe a follow-up course structured to frame the topic from the standpoint of curriculum design and action research projects currently underway.
How to promote and sustain active-learning pedagogical reforms in University Physics through instructor apprenticeship
Authors: Feldman Gerald
Published: May 2023

We describe a pedagogical reform at George Washington University and the means by which this innovation has been sustained over 14 years. We present the SCALE-UP collaborative group-learning approach and show data on student learning gains that confirm the effectiveness of this pedagogical methodology. By pairing experienced instructors with new instructors unfamiliar with the pedagogical approach, the new instructors can see the pedagogy in action and learn the techniques so they can conduct their own classes in later semesters. Over this period, we have involved 24 separate physics instructors (and also 8 astronomy instructors) who have taught class sections in this collaborative group-learning mode.
Specific moments in detection of superheavy nuclei: DGFRS-2 spectrometer
Authors: Ibadullayev D. , Tsyganov Y.S. , Polyakov A.N. , Voinov A.A. , Shumeiko M.V.
Published: May 2023

In this paper, we present the results of the first beam tests of the detection system at the focal plane of the Dubna Gas-Filled Recoil Separator-2 (DGFRS-2), which receives beams from the DC-280 FLNR cyclotron. The high beam intensity of 48Ca+10 heavy ions from the cyclotron enables us to obtain a number of superheavy recoils sufficient to compare both the measured and calculated spectra of superheavy recoils implanted into a silicon detector. A real-time algorithm to search for an Evaporation Residue (ER) — α correlated sequences is described in brief. It should be noted that the DGFRS-2 spectrometer operates in conjunction with the 48 × 128 strip DSSD (Double-sided Silicon Strip Detector; 48 × 226 mm2) detector and a low-pressure pentane-filled gaseous detector (1.2 Torr; 80 × 230 mm2). A block-diagram of the spectrometer and the event format are also presented. Special attention is paid to the response of a low-pressure pentane-filled ΔE multiwire proportional chamber for recoils of Fl, synthesized in the 242Pu + 48Ca → 287Fl + 3n complete fusion nuclear reaction. Some actual parameters of the detection system have also been extracted from natYb + 48Ca, 232Th + 48Ca, 243Am + 48Ca, 238U + 48Ca reactions. The effect of neighbor strip charge sharing for the ohmic side of the DSSD detector is also under consideration.
Fabrication and testing of bioinspired microstructured alumina composites with sacrificial interpenetrating polymer bonds
Authors: Sapasakulvanit Slocha , Chan Xin Ying , Le Ferrand Hortense
Published: May 2023

Bioinspired composites exhibit well-defined microstructures, where anisotropic ceramic particles are assembled and bonded by an organic matrix. However, it is difficult to fabricate these composites where both the ceramic particles and organic matrix work together to unlock toughening mechanisms, such as shear dissipation, particle rotation and interlocking, etc, that lead to stiff, strong, and tough mechanical properties. Here, we produce composites inspired by seashells, made of alumina microplatelets assembled in complex microstructures and that are physically bonded by a small amount of interpenetrated polymer network (IPN) made of polyacrylamide (PAM) and poly-N-isopropylacrylamide (PNIPAM). The fabrication employs magnetically assisted slip-casting to orient the microplatelets as desired, and in situ gelation of the IPN, followed by drying. The process was successful after carefully tuning the slip casting and gelation kinetics. Samples with horizontal, vertical, and alternating vertical and horizontal microplatelets orientations were then tested under compression. It was found that the IPN threads bonding the microplatelets acted as sacrificial bonds dissipating energy during the compression. Paired with the alternating microstructure, the IPN significantly enhanced the compressive toughness of the composites by 205% as compared to the composites with horizontal or vertical orientation only, with less than 35% reduction on the stiffness. This study demonstrates that microstructure control and design combined with a flexible and tough matrix can effectively enhance the properties of bioinspired ceramic polymer composites.
Global estimates of suitable areas for marine algae farming
Authors: Liu Yue , Cao Ling , Cheung William W L , Sumaila U Rashid
Published: May 2023

Marine algae, both macro and micro, have gained increasing attention for their numerous ecosystem service functions, such as food and raw materials provision and climate change mitigation. Currently, the practice of large-scale algae farming is limited to Asian waters, but significant interest has arisen from other continents. However, there is a lack of knowledge about the areas with suitable environmental conditions for expanding algae farming on a global scale. Previous studies have primarily focused on nutrient availability and thermal constraints when assessing the potential for algae culture. This study uses species distribution models based on an ensemble consensus approach to determine the extent of suitable areas and takes into account multiple environmental factors that may affect the feasibility of algae culture. Our results show that approximately 20.8 million km2 of the ocean (∼13.8% of the economic exclusive zones) is suitable for farming marine algae species, with most potential areas located near the coastline. Surprisingly, four out of the top five countries with the largest area suitable for seaweed farming, including Australia, Russia, Canada, and the US, account for 30% of the total suitable areas, yet they currently produce less than 1% of the global seaweed. Several species show promising characteristics for large-scale cultivation, but their viability for commercial production remains uncertain and subject to further assessment of economic feasibility and social acceptance. Further research on the ecological benefits of seaweed farming could also promote the development of an ecologically friendly and financially viable algae mariculture industry. This study provides a scientific basis for decision-makers to understand potential expansion areas and feasible pathways for seaweed farming, with the ultimate goal of ensuring the sustainable utilization of marine resources.
The shrinking Great Salt Lake contributes to record high dust-on-snow deposition in the Wasatch Mountains during the 2022 snowmelt season
Authors: Lang Otto I , Mallia Derek , McKenzie Skiles S
Published: May 2023

Seasonal snowmelt from the Wasatch Mountains of northern Utah, USA, is a primary control on water availability for the metropolitan Wasatch Front, surrounding agricultural valleys, and the Great Salt Lake (GSL). Prolonged drought, increased evaporation due to warming temperatures, and sustained agricultural and domestic water consumption have caused GSL water levels to reach record low stands in 2021 and 2022, resulting in increased exposure of dry lakebed sediment. When dust emitted from the GSL dry lakebed is deposited on the adjacent Wasatch snowpack, the snow is darkened, and snowmelt is accelerated. Regular observations of dust-on-snow (DOS) began in the Wasatch Mountains in 2009, and the 2022 season was notable for both having the most dust deposition events and the highest snowpack dust concentrations. To understand if record high DOS concentrations were linked to record low GSL levels, dust source regions for each dust event were identified through a backward trajectory model analysis combined with aerosol measurements and field observations. Backward trajectories indicated that the exposed lakebed of the GSL contributed 23% of total dust deposition and had the highest dust emissions per surface area. The other potential primary contributors were the GSL Desert (45%) and the Sevier +Tule dry lakebeds (17%), both with lower per-area emissions. The impact on snowmelt, quantified by mass and energy balance modeling in the presence and absence of snow darkening by dust, was over 2 weeks (17 d) earlier. The impact of dust on snowmelt could have been more dramatic if the spring had been drier, but frequent snowfall buried dust layers, delaying dust-accelerated snowmelt later into the melt season.
Free Energy and Equilibrium States for Families of Interval Maps
Authors: Dobbs Neil , Todd Mike
Published: May 2023

We study continuity, and lack thereof, of thermodynamical properties for one-dimensional dynamical systems. Under quite general hypotheses, the free energy is shown to be almost upper-semicontinuous: some normalised component of a limit measure will have free energy at least that of the limit of the free energies. From this, we deduce results concerning existence and continuity of equilibrium states (including statistical stability). Metric entropy, not semicontinuous as a general multimodal map varies, is shown to be upper semicontinuous under an appropriate hypothesis on critical orbits. Equilibrium states vary continuously, under mild hypotheses, as one varies the parameter and the map. We give a general method for constructing induced maps which automatically give strong exponential tail estimates. This also allows us to recover, and further generalise, recent results concerning statistical properties (decay of correlations, etc.). Counterexamples to statistical stability are given which also show sharpness of the main results.
Auslander theorem for PI Artin-Schelter regular algebras
Authors: Zhu Ruipeng
Published: May 2023

We prove a version of a theorem of Auslander for finite group actions or coactions on noetherian polynomial identity Artin-Schelter regular algebra.
Optimizing lipid management—impact of the COVID 19 pandemic upon cardiovascular risk in England
Authors: Newton Julia L , Hamed Joseph , Williams Helen , Kearney Matt , Metcalfe Alison M , Ford Gary A
Published: May 2023

Background

We sought to understand the impact of the COVID-19 pandemic on lipid-lowering therapy prescribing as a potential cause of the excess cardiovascular mortality seen post-pandemic in England. We examined temporal changes over 3 years in the prescribing of high-intensity and non-high-intensity statin therapy and ezetimibe.

Sources of data

We utilized data available via the National Health Service (NHS) Business Services Authority (NHSBSA) Information Services Data Warehouse, extracting 3 monthly data from October 2018 to December 2021 on high- and low-intensity statin and ezetimibe prescribing, (commencement, cessation or continuation) through each time period of study and those before, and after, the period of interest.

Areas of agreement

Optimizing lipid management is a key component of the NHS Long Term Plan ambition to reduce deaths from cardiovascular disease, stroke and dementia.

Areas of controversy

The COVID-19 pandemic and associated lockdown have seen a significant reduction in prescribing of lipid-lowering therapies. If cardiovascular risk is not to worsen in the forthcoming years, urgent action is needed to ensure that the impact of the pandemic upon optimization of cholesterol and the historical undertreatment of cholesterol is reversed and improved.

Areas timely for developing research

Prescription data available via NHSBSA can support our understanding of the implications of policy and behaviour and highlight the impact of guidelines in practise.

Growing points

Understanding the impact of the COVID-19 pandemic upon cholesterol management and the opportunities for newer lipid-lowering therapies delivered using a population health approach have the potential to enhance lipid-lowering and improve cardiovascular mortality and morbidity and reduce health inequalities.
Characterization of cellular senescence in radiation ulcers and therapeutic effects of mesenchymal stem cell-derived conditioned medium
Authors: Chen Wanchao , Wang Yang , Zheng Jiancheng , Chen Yan , Zhang Can , Yang Wei , Wu Lingling , Yang Zeyu , Wang Yu , Shi Chunmeng
Published: May 2023

Background

Radiation ulcers are a common and severe injury after uncontrolled exposure to ionizing radiation. The most important feature of radiation ulcers is progressive ulceration, which results in the expansion of radiation injury to the nonirradiated area and refractory wounds. Current theories cannot explain the progression of radiation ulcers. Cellular senescence refers to as irreversible growth arrest that occurs after exposure to stress, which contributes to tissue dysfunction by inducing paracrine senescence, stem cell dysfunction and chronic inflammation. However, it is not yet clear how cellular senescence facilitates the continuous progression of radiation ulcers. Here, we aim to investigate the role of cellular senescence in promoting progressive radiation ulcers and indicate a potential therapeutic strategy for radiation ulcers.

Methods

Radiation ulcer animal models were established by local exposure to 40 Gy X-ray radiation and continuously evaluated for >260 days. The roles of cellular senescence in the progression of radiation ulcers were assessed using pathological analysis, molecular detection and RNA sequencing. Then, the therapeutic effects of conditioned medium from human umbilical cord mesenchymal stem cells (uMSC-CM) were investigated in radiation ulcer models.

Results

Radiation ulcer animal models with features of clinical patients were established to investigate the primary mechanisms responsible for the progression of radiation ulcers. We have characterized cellular senescence as being closely associated with the progression of radiation ulcers and found that exogenous transplantation of senescent cells significantly aggravated them. Mechanistic studies and RNA sequencing suggested that radiation-induced senescent cell secretions were responsible for facilitating paracrine senescence and promoting the progression of radiation ulcers. Finally, we found that uMSC-CM was effective in mitigating the progression of radiation ulcers by inhibiting cellular senescence.

Conclusions

Our findings not only characterize the roles of cellular senescence in the progression of radiation ulcers but also indicate the therapeutic potential of senescent cells in their treatment.
International Economic Law in the ‘Asian Century’
Authors: Petersmann Ernst-Ulrich
Published: May 2023

The current non-compliance with United Nations (UN) and World Trade Organization (WTO) agreements protecting transnational public goods, military aggression among WTO members, violent suppression of human and democratic rights, global health pandemics, climate change, ocean pollution, overfishing, and other biodiversity losses reflect ‘governance failures’ (e.g. to limit ‘market failures’) and ‘constitutional failures’ (e.g. to protect human and democratic rights and the sustainable development goals). The geopolitical rivalries among totalitarian governments and democracies render constitutional UN and WTO reforms unlikely. They entail ‘regulatory competition’ (e.g. among neoliberalism, state capitalism, and ordo-liberal constitutionalism) and plurilateral responses aimed at limiting abuses of power (like collective countermeasures against Russia’s illegal wars and war crimes) and at protecting transnational public goods (like plurilateral ‘climate change mitigation clubs’, appeal arbitration among WTO members, regional human rights and security agreements). The power politics disrupting the UN and WTO legal systems is bound to promote regionalization of economic law, re-globalization of supply chains, and geopolitical rivalries resulting from conflicting value priorities and neglect for the human rights underlying the sustainable development goals.
Dipping Titan implants in Irrisept solution (0.05% chlorhexidine gluconate) and exposure to various aerobic, anaerobic, and fungal species
Authors: Karpman Edward , Griggs Ryan , Twomey Carolyn , Henry Gerard D
Published: May 2023

Background

The organisms causing penile implant infections are changing from predominantly indolent gram-positive infections to more aggressive gram-negative and fungal infections because of antibiotic selection pressures based on novel next-generation sequencing DNA data.

Aim

To evaluate the effectiveness of Irrisept solution (0.05% chlorhexidine gluconate) in decreasing isolate colony counts from a Titan implant by using a novel kill time washout methodology to mirror real-world usage.

Methods

Sterilized Titan discs were dipped in Irrisept or saline. An inoculum of 109 organisms of a single bacterial or fungal species was placed on the discs. Bacterial and fungal strains were tested: Bacteroides fragilis, Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. The discs were then irrigated 3 times with Irrisept or saline. Microorganisms were sonicated off the discs and placed on appropriate agar and conditions for each species. The plates were incubated for 48 to 72 hours at the temperature and under the conditions appropriate for each species. Colonies on the plates were hand counted.

Outcomes

Irrisept effectively decreased microbial colony counts in all the species tested.

Results

Irrisept was shown to effectively decrease microbial colony counts from 3 to 6 log10 in all species tested. A 3-log10 reduction is considered the target level of performance that would indicate that a compound or product has effective killing activity against an organism of interest. The saline control with bulb syringe irrigation did not demonstrate reduction of microbial colony counts in any of the species tested.

Clinical Implications

Irrisept is effective against all of the organisms causing modern-day infections with penile implant surgery and may decrease clinical infection rates to lower levels.

Strengths and Limitations

The strength of this study is that we used quantitative microbial reduction counting and the largest array of bacterial and fungal species causing modern-day penile implant infections. The limitation is that this is an in vitro study and the clinical implications of our findings are not yet known.

Conclusion

Quantitative microbial reduction counting shows that Irrisept is effective against the most commonly known modern-day organisms causing penile implant infections.
Severe pneumonia due to Legionella and SARS-CoV-2 co-infection necessitating medical evacuation from a cargo ship
Authors: Kitaya Shiori , Baba Hiroaki , Okamoto Michiko , Sakamoto Masahiro , Nakayama Asami , Takei Yumiko , Seike Issei , Takei Kentarou , Oshima Kengo , Tokuda Koichi , Shiga Takuya , Kanamori Hajime
Published: May 2023

Cargo ships are at risk of disease outbreaks like Legionella and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to their cramped and shared conditions. A case of medical evacuation due to co-infection of Legionella pneumophila with SARS-CoV-2 highlights the need for international infection control guidelines, information networks and molecular epidemiological approaches for identifying infection routes.
Infections transmitted via the faecal–oral route: a simple score for a global risk map
Authors: Stürchler Dieter
Published: May 2023

Introduction

Faecal-oral transmission refers to the process whereby disease is transmitted via the faeces of an infected individual to the mouth of a susceptible individual. This transmission can occur through failures in sanitation systems leading to exposure via various routes in particular contaminated water, food, and hands. Travellers’ diarrhoea is the most common travel-related illness. A score could enhance risk assessment and pre-travel advice.

Methods

A simple score was developed based on the frequency of defecating in the open (country prevalence > 1%), occurrence of cholera in the period between 2021 and 2017 (one or more case in a country) and reported typhoid fever cases between 2015 and 2019.

Results

Data were available for 199 out of 214 countries for the score to be applied. 19% of the 199 countries scored as high risk countries for faecal-oral transmission (score 3), 47% as medium risk (score 2), and 34% as minimal risk (score 0). The percentage of countries scoring 3 was highest in Africa (63%) and lowest in Europe and Oceania (score 0).

Conclusions

A global risk map was developed based on a simple score that could aid travel medicine providers in providing pre-travel risk assessment. For travellers to high and medium risk countries, pre-travel consultation must include detailed advice on food and water hygiene.
Mid- and far-infrared spectroscopy of nucleobases: molar extinction coefficients, integrated molar absorptivity, and temperature dependence of the main bands
Authors: Iglesias-Groth Susana , Cataldo Franco
Published: May 2023

The nucleobases, namely the purines adenine and guanine and the pyrimidines cytosine, thymine, and uracil, are the key monomers of the information polymers DNA and RNA. All the nucleobases were recently detected in the analysis of certain meteorites known as carbonaceous chondrites. The concentration of the nucleobases found in meteorites is smaller than the concentration of amino acids. However, the nucleobases were successfully synthesized abiotically by ultraviolet irradiation of interstellar ice analogues at 10 K. Consequently, it is possible that the purines and pyrimidines may be present in the interstellar medium or in other space environments and may be detectable by the new orbiting telescopes that indeed are able to cover not only the mid-infrared spectral range but also the far-infrared. This work supplies the reference spectra of the five nucleobases used by the terrestrial biochemistry in the mid-infrared and in the far-infrared with the purpose to facilitate the search and identification of these astrobiological and astrochemical relevant molecules in space. The mid-infrared spectra of all nucleobases were recorded at three different temperatures from −180 °C to nearly ambient temperature and at +250 °C. Furthermore, the molar extinction coefficients (ε) of all mid- and far-infrared bands were determined, as well as the integrated molar absorptivities (ψ). With the reported infrared spectra together with the ε and ψ values, it will be possible to identify qualitatively the nucleobases and estimate their relative abundance in space.