bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of spherical filled particles on the energy storage density of composite materials
Authors: Yao Yang. , Xiang Tai. , Zheng Qinhong. , Yao Bin. , Zhong Runeng.
Published: September 2023

As one of the popular directions of new energy storage technology, dielectric energy storage technology has a wide application demand and market prospect in the modern new energy field. The research and manufacturing of composite materials is a core technology for the development of energy storage. In particle-filled composites, different filler particles can change a range of electromagnetic parameters of the composite, which can have an impact on the energy storage density of the composite. This paper presents an analytical study on the effect of spherical filled particles in composites on energy storage density. It turns out that when the volume ratio of filled particles is certain, as the permittivity of the filled particles increases, the energy storage density of the composite increases. When increased to a certain range, a limit value is reached. Therefore, under the condition of a certain volume ratio, it is not always possible to optimize the electrical energy storage density by changing the dielectric constant of spherically filled particles only.
Drive simulation analysis of piezoelectric valveless micropump based on ZnO nanorod array
Authors: Song Jiaming , Fu Yujia , Hou Baodong , Liu Hongmei , Dou Yanwei
Published: September 2023

In this paper, ZnO nanorods are combined with the driving mechanism of a piezoelectric micropump to design a valveless piezoelectric micropump. The ZnO nanorods were prepared by the magnetron sputtering method to grow the ZnO seed crystal layer on the silicon surface and then by hydrothermal method. The growth of ZnO nanorods under different solution concentrations, solution temperatures, and growth times was investigated, and analytical methods for analyzing the surface morphology and elemental content of ZnO nanorods. Then, the simulation of the valveless micropump using ZnO nanorods prepared under optimal conditions as piezoelectric oscillators were carried out using COMSOL finite element analysis software, and the maximum output flow rate of about 14.40 μL/s was achieved at 100 V50 Hz.
LiCl on Rheological Characteristics of PAM-LiCl Conductive Hydrogel
Authors: Hong Yang , Lin Zening , Jiang Tao , Yang Yun , Gao Yuan , Luo Zirong , Shang Jianzhong
Published: September 2023

Rheology is a science that studies the flow and deformation of materials and the relationships between various factors that cause them to flow and deform. Finding the relationship between stress and strain, or the rate of both, during fluid deformation is the core issue of rheology research. In this study, a composite hydrogel with good conductivity based on polyacrylamide (PAM) and lithium chloride (LiCl) was introduced. This PAM-LiCl conductive hydrogel is also highly stretchable and can be used for flexible actuation technology of robots. Based on the oscillating rheological testing method, the dynamic response of this material under different thermal-mechanical loads was measured, and intrinsic parameters such as shear modulus and yield stress were obtained. Based on the test results, the material ratio and mechanical properties suitable for the preparation of PAM-LiCl conductive hydrogel were obtained, which laid the foundation for the preparation of conductive hydrogel-related materials.
Static properties analysis of fiber optic wire wrapping
Authors: Tang Peiqi , Yang Dongwu
Published: September 2023

To improve the quality of fiber optic wire wrapping, the influence of each parameter of fiber optic wire wrapping on the stress distribution of wire wrapping is studied, and the mechanical properties of fiber optic wire wrapping are simulated based on the principle of fine mechanics of composite materials. Solid elements are used for modeling through finite element analysis, and the problem of using ANSYS to solve the wire package is initially solved by establishing a 1° model for analysis and calculation. The results show that the core cylinder slightly, core cylinder radius, and fiber diameter have no effect on the stress distribution state of the fiber in the wire pack, but if the core cylinder stiffness increases, the minimum stress value of the wire pack will also increase, and the minimum stress area of the fiber unit tends to be far from the core cylinder surface.
Research on the Motion Reliability of Nursing Bed Mechanism Based on Response Surface Method
Authors: Pei Tianshuo , Li Qilin , Yu Chengtao , Liu Kailei
Published: September 2023

To study the analysis and optimization of the motion reliability of multifunctional nursing bed mechanism, the ADAMS software platform was chosen to simulate the parametric modeling of the nursing bed with consideration of dimensional and clearance errors. Taking the back-raising mechanism as an example, we verify the accuracy of the model by comparing the experimental data. Based on the effect of clearance error, a response surface model with motor end hinge clearance, push rod end hinge clearance, back support pivot clearance, and bed plate hinge clearance, as the influencing factors and angular velocity reliability and angular acceleration reliability as the response values, were established, and the significance of the influencing factors of the response values was obtained by using ANOVA. Based on the reliability of angular velocity as the optimization target and each influencing factor, simulation experiments were conducted to verify that the error of the model optimization result of the response surface method was 1.64%. It shows that the model prediction is more accurate and the response surface method is feasible for the mechanism motion reliability optimization analysis.
Failure analysis of copper substrate crack in high-voltage power supply
Authors: Liu Shengsheng , Li Biao
Published: September 2023

Aiming at the crack phenomenon of a copper substrate circuit in a high-voltage power supply, the slice analysis was carried out and showed that the crack part was the dielectric layer of the copper substrate. The finite element analysis is used to study the reason for dielectric layer cracking and discuss the improvement measures from the thickness of thermal conductive gel and the layout of components. The simulations results show that the reason for dielectric layer cracking is that the surface-mounted device (SMD) is too close to the mounting hole when the copper substrate bottom is coated with thermal conductive gel, reducing the thickness of thermal conductive gel or keeping the SMD away from the mounting holes can avoid the dielectric layer cracking, but it is easier to change the location of SMD.
Study on the Calculation of Hole/Pin Floating Deviation for “Two Pins on One Side”
Authors: Tang Liyuan , Xu Xusong
Published: September 2023

“Two pins on one side” is a common clamping method in industrial production, but due to the presence of hole/pin clearance, mounting features on the part are often misaligned due to hole/pin float. To ensure the subsequent assembly of the part, the amount of deviation of the hole/pin float must be calculated to quantify the effective mounting space of the mounting feature. In this study, based on the hole/pin float model, the maximum deviations of 0.0368 mm, 0.0545 mm, 0.0520 mm, and 0.0786 mm were calculated for hole/pin float based on automotive sheet metal parts. The study of the amount of deviation of hole/pin floating is carried out to give a solution to the problem of fixture design in engineering practice.
Equivalent stiffness modeling of wedge-shaped cabin sections based on similarity theorem
Authors: Zhang Jizheng , Tao Guoquan , Liu Boyu , Chen Jialin , Xiang Bin , Wang Mingzhen , Hu Qi , Zhang Chuzhe
Published: September 2023

The cabin section of an amphibious aircraft undergoes intense hydrodynamic and aerodynamic loads during water take-off and landing. These loads are crucial for its structural design and strength analysis. Therefore, a water impact test of the cabin section is essential for structural optimization. However, a full-scale model of the cabin section is costly and time-consuming due to its large size. This study proposes a design method that combines a partial similarity model and an equivalent similarity model based on the similarity theory. It constructs a half-scale model that has equivalent stiffness to the full-scale model. This reduces the test cost and improves the test efficiency. First, the cabin section is simplified as a wedge, and the components of the half-scale model are designed individually based on the dimensional analysis method of similarity theory. The equivalence is validated by finite element simulation and theoretical results. Then, the finite element simulation of the cabin section model is conducted, and the mechanical responses of the half-scale and full-scale models under static load are compared and contrasted. The results show that the half-scale model’s mechanical test can predict the full-scale model’s mechanical characteristics.
A Reconfigurable Multi-band Resonator and Its Application to Band-pass Filter
Authors: Cheng Jun , Li Yifang
Published: September 2023

A reconfigurable tri/quad-band resonator and the application to tri/quad-band band-pass filter have been demonstrated. By changing the switching state of the PIN diodes, the filter can work in tri-band mode or quad-band mode. Correspondingly, the resonant frequencies of the band-pass filter are 1.21 GHz, 2.0 GHz, 3.23 GHz, 1.27 GHz, 2.0 GHz, 2.61 GHz, and 3.41 GHz, respectively. Especially, the filter has a combined structure of lumped capacitors and some transmission lines and achieves a small mechanical size of 0.14 λg
× 0.09 λg
, where λg
denotes the wavelength on the substrate of the filter at the first central frequency. The measurement results of the fabricated filter agree with the electromagnetic simulation data.
Analysis of Influencing Factors on Fatigue Life of a Certain Radar Structure
Authors: Jiang Yang
Published: September 2023

The factors affecting the fatigue life of radar structural parts and the measures to improve the fatigue life are analyzed systematically. On this basis, the stress concentration at the right angle of the root and low surface roughness was determined by means of finite element simulation, simulated loading test, and material performance test, which is the main factor of fatigue cracking. Risk analysis was carried out to simulate extreme cracking. The fatigue life of the support materials was increased by increasing the fillet, lifting the surface roughness to avoid stress concentration, and replacing high-strength materials. The improvement measures were verified through tests.
Development of Cutting Temperature Model Based on Experiment and Analysis of its Influencing Factors in Cutting ADI
Authors: Zhao Lidong , Li Baodong
Published: September 2023

Austempered ductile iron (ADI) is a difficult material with severe tool wear during machining, due to the high cutting temperatures in the cutting zone. In this paper, the mathematical model of the cutting temperature is developed based on the turning experiment, and the impact of cutting speed, feeding speed, and cutting depth on the cutting temperature of turning ADI is studied. When the cutting speed and the feed speed increase, a large amount of heat cannot be dissipated, and the cutting zone temperature increases. When the cutting depth increases, the increase of the heat dissipation area makes the cutting temperature change not obvious. This research has important engineering significance for studying the cutting mechanism of ADI and improving cutting efficiency.
Study on Microstructure of Pack-Borided GH4169 Alloy
Authors: Tang Jianguo , Wang Quansheng
Published: September 2023

The structure of the solid pack-boriding layer of nickel-based alloy is studied in this paper. The nickel-based alloy GH4169 was subjected to pack-boriding treatment at 850 °C and 950 °C, and the structure of the alloy boriding layer was studied. After the boriding treatment, a relatively continuous and uniform boriding layer was formed on the surface, which was mainly composed of nickel borides and chromium borides. The sample formed a layered structure of a boriding layer, diffusion zone, and substrate. After boriding treatment, Cr migrated to the surface to form CrB, Cr5B3, and Cr2B chromium borides, while Ni migrated to the lower part of the boriding layer to form Ni2B and Ni3B nickel borides.
Effect of Scratching and Bending Degree on the Residual Stress of the 7055 Aluminum Alloy Plate
Authors: Li Yang , Li Yanan , Li Xiwu , Zhang Yongan , Li Zhihui , Yan Hongwei
Published: September 2023

This study investigated the effects of scratches and bending on the surface stress of aluminum alloy plates with varying thicknesses. The purpose of this study was to provide guidance for surface stress testing of plates with different thicknesses. The “birth and death” element method was used to simulate the generation of surface scratches, while the stress field under the pre-stretched state was obtained through the displacement of one end of the board by 2.5%. The X-ray residual stress analyzer (μ-x360 s) was used to experimentally characterize the stress level on the surface of the plate. The research results showed that the residual stress level near the scratches decreases significantly, while the surface stress level of the plate decreases significantly after bending. The changes in stress values with increasing bending degree for plates of different thicknesses showed that the thicker the plate, the greater the tensile effect on the surface of the plate, resulting in smaller compressive stress. The longitudinal non-uniformity of the plates with different thicknesses was also analyzed, and it was found that the testing error of stress testing results was within ±5 MPa. In conclusion, this study provides useful guidance for the accurate measurement of surface stress on aluminum alloy plates of varying thicknesses, considering the effects of scratches, and bending.
Dual Motor Model Prediction Control with Senseless Control and Parameter Identification Function
Authors: Zhao Wenhao , Zhuo Jinliang , Wang Xikai , Tian Meiying , Lin Yihan , Zhu Yingyi , Kuai Songyan
Published: September 2023

A new control strategy is proposed to address the issues of poor stability and inability to achieve torque synchronization in dual-drive systems. Firstly, the structure of the permanent magnet assisted synchronous reluctance motor is described, and the principles of model prediction dual-torque control, Beetle Antennae Search algorithm, and Kalman filter algorithm are analyzed. The permanent magnet assisted synchronous reluctance motor is used as the main motor, and a senseless control module and parameter identification module for the motor is established on this basis, creating a model prediction dual-torque control model for the dual motor with the above functions. Finally, through simulation, the rationality and accuracy of the model are verified. The results show that the model can balance the torque of the two motors and achieve accurate senseless control and parameter identification.
Continuous pulse advances in the negative ion source NIO1
Authors: Barbisan M. , Agnello R. , Cavenago M. , Delogu R.S. , Pimazzoni A. , Balconi L. , Barbato P. , Baseggio L. , Castagni A. , Pouradier Duteil B. , Franchin L. , Laterza B. , Molon F. , Maniero M. , Migliorato L. , Milazzo R. , Passalacqua G. , Poggi C. , Ravarotto D. , Rizzieri R. , Romanato L. , Rossetto F. , Trevisan L. , Ugoletti M. , Zaniol B. , Zucchetti S.
Published: September 2023

Consorzio RFX and INFN-LNL have designed, built and operated the compact radiofrequency negative ion source NIO1 (Negative Ion Optimization phase 1) with the aim of studying the production and acceleration of H- ions. In particular, NIO1 was designed to keep plasma generation and beam extraction continuously active for several hours. Since 2020 the production of negative ions at the plasma grid (the first grid of the acceleration system) has been enhanced by a Cs layer, deposited though active Cs evaporation in the source volume. For the negative ion sources applied to fusion neutral beam injectors, it is essential to keep the beam current and the fraction of co-extracted electrons stable for at least 1 h, against the consequences of Cs sputtering and redistribution operated by the plasma. The paper presents the latest results of the NIO1 source, in terms of caesiation process and beam performances during continuous (6 ÷ 7 h) plasma pulses. Due to the small dimensions of the NIO1 source (20 cm×∅10 cm), the Cs density in the volume is high (1015 ÷ 1016 m-3) and dominated by plasma-wall interaction. The maximum beam current density and minimum fraction of co-extracted electrons were respectively about 30 A/m2 and 2. Similarly to what done in other negative ion sources, the plasma grid temperature in NIO1 was raised for the first time, up to 80 °C, although this led to a minimal improvement of the beam current and to an increase of the co-extracted electron current.
Measuring tau g-2 using ATLAS Pb+Pb collisions
Authors: Stanek-Maslouska W.
Published: September 2023

Relativistic heavy-ion beams at the LHC are accompanied by a large flux of equivalent photons, leading to photon-induced processes. Measurements of photon-induced production of tau lepton pairs can be used to constrain the tau lepton's anomalous magnetic dipole moment (g-2). A recent ATLAS measurement using muonic decays of tau leptons in association with electrons and tracks is presented. This provides one of the most stringent limits on g-2 of the tau lepton to date.
A long path-length optical property measurement device for highly transparent detector media
Authors: Hecla J. , Bernstein A. , Dazeley S. , Akindele O.A.
Published: September 2023

Measurements of the optical properties of highly transparent liquids are necessary for large-scale detectors that seek to detect optical signatures in kiloton-scale or larger volumes. Detailed understanding of the attenuation and scattering properties of fill media is critical to the ability to accurately simulate detector performance, and yet is often unavailable until in-situ measurements can be performed. Moreover, in-situ measurements may rely on effective attenuation lengths or other approximations to characterize performance, rather than absolute measurements of attenuation and scattering. To better understand the optical properties of potential fill media and purification schemes, a system has been developed which provides simultaneous attenuation and differential scattering cross-section measurements for highly transparent liquids. This horizontal, adjustable path-length “long-arm” system provides excellent isolation from the atmosphere, a high degree of vibration insensitivity, and a simple and reliable method of calibration. Further, scattering measurements can be carried out simultaneously at ports along the beamline equipped with optics allowing the selection of scatter angle and polarization. This enables both reliable quantitative scatter measurements and phase-function separation. This system has been extensively tested using deionized (DI) water as a benchmark, and has demonstrated repeatable measurements of attenuation lengths exceeding 100 m and scattering lengths approaching 1 km.
A high-precision interpolation method for pulsed radio signals from cosmic-ray air showers
Authors: Corstanje A. , Buitink S. , Desmet M. , Falcke H. , Hare B.M. , Hörandel J.R. , Huege T. , Jhansi V.B. , Karastathis N. , Krampah G.K. , Mitra P. , Mulrey K. , Nelles A. , Nivedita K. , Pandya H. , Scholten O. , Terveer K. , Thoudam S. , Trinh G. , ter Veen S.
Published: September 2023

Analysis of radio signals from cosmic-ray induced air showers has been shown to be a reliable method to extract shower parameters such as primary energy and depth of shower maximum.
The required detailed air shower simulations take 1 to 3 days of CPU time per shower for a few hundred antennas.
With nearly 60,000 antennas envisioned to be used for air shower studies at the Square Kilometre Array (SKA), simulating all of these would come at unreasonable costs.
We present an interpolation algorithm to reconstruct the full pulse time series at any position in the radio footprint, from a set of antennas simulated on a polar grid.
Relying on Fourier series representations and cubic splines, it significantly improves on existing linear methods.
We show that simulating about 200 antennas is sufficient for high-precision analysis in the SKA era, including e.g. interferometry which relies on accurate pulse shapes and timings.
We therefore propose the interpolation algorithm and its implementation as a useful extension of radio simulation codes, to limit computational effort while retaining accuracy.
The Front-End electronics for the liquid Argon instrumentation of the LEGEND-200 experiment
Authors: Abritta Costa I. , Budano A. , Burlac N. , Paissan F. , Salamanna G. , Tagnani D.
Published: September 2023

In this paper we provide a detailed technical description of the Front-End (FE) electronics for the liquid Argon instrumentation of the LEGEND-200 experiment, searching for the very rare, hypothetical neutrinoless double β decay process at the Italian Laboratori Nazionali del Gran Sasso. The design stems from the need to read out the silicon photo-multiplier response to the scintillation light in the liquid Argon with excellent single-photon resolution. The FE electronics is required to be placed far from the detectors to meet the experiment's radio-purity constraints. This constraint represents a challenge for a high signal-to-noise ratio. We address how this could be achieved in a stable way. The system was installed in July 2021 and has been commissioned with the rest of LEGEND-200, proving we could attain a very low overall level of
electrical noise of 250 μV peak-to-peak.
Low-carbon electrification as a multi-system transition: a socio-technical analysis of Norwegian maritime transport, construction, and chemical sectors
Authors: Nykamp Hilde , Andersen Allan Dahl , Geels Frank Willem
Published: September 2023

Electrification of end-use sectors is widely seen as a central decarbonisation strategy. However, the process of electrification is rarely discussed beyond electric end-use technologies such as electric vehicles or heat pumps. While electrification of end-use sectors is about new types of consumption, it also requires new technological interfaces with the electricity system. The paper provides a first conceptualisation of electrification as a multi-system interaction process, involving changes in both end-use sectors and in the electricity system. Electrification is thought to involve two core processes: (1) transitions in systems where electric niches challenge fossil energy regimes, and (2) reconfiguring patterns of multi-system interactions across production, distribution, and use of electricity. Through a case study design, we compare three sectoral cases that differ substantially in degrees and speed of electrification: ferries, construction sites and ammonia production. We explain these differences by analysing how the actors, technologies and institutions in each system shaped both the diffusion of electric end-use technologies and the interactions with the electricity distribution system. We find that the speed and ease of electrification depend on varying mixes of technological, actor, and institutional change processes. The severity and pervasiveness of grid connection challenges are arguably the most important finding. Grid connection challenges were significant in all three cases and continue to hamper electrification in two cases. Based on those findings, we conclude that grid capacity is increasingly problematic. Electricity system actors are overwhelmed with new demand, resulting in long lead times. And, they are further constrained by institutions that were designed to optimise for the efficient operation of existing assets rather than to innovate and transform electricity grids.
Design of n-i-p and p-i-n Sb2Se3 solar cells: role of band alignment
Authors: Salem Marwa S , Okil Mohamed , Shaker Ahmed , Albaker Abdullah , Alturki Mansoor
Published: September 2023

Investigations into novel device architectures and interfaces that enhance charge transport and collection are necessary to increase the power conversion efficiency (PCE) of antimony selenide (Sb2Se3) solar cells, which have shown great promise as a low-cost and high-efficiency alternative to conventional silicon-based solar cells. The current work uses device simulations to design p-i-n and n-i-p Sb2Se3-based solar cell structures. The n-i-p configuration is investigated by comparing distinct electron transport layer (ETL) materials to get the best performance. While certain ETL materials may yield higher efficiencies, the J–V curve may exhibit S-shaped behavior if there is a misalignment of the bands at the ETL/absorber interface. To address this issue, a proposed double ETL structure is introduced to achieve proper band alignment and conduction band offset for electron transport. A PCE of 20.15% was achieved utilizing (ZnO/ZnSe) as a double ETL and Spiro-OMeTAD as a hole transport layer (HTL). Further, the p-i-n configuration is designed by proposing a double HTL structure to facilitate hole transport and achieve a proper valence band offset. A double HTL consisting of (CuI/CuSCN) is used in conjunction with ETL-free configuration to achieve a PCE of 21.72%. The simulation study is conducted using the SCAPS-1D device simulator and is validated versus a previously fabricated cell based on the configuration FTO/CdS/Sb2Se3/Spiro-OMeTAD/Au.
Effect of Zn(TFSI)2 on the performance-aging time of perovskite solar cells
Authors: Kim Hyung-Joon , Jeon Young-In , Lee Wan In , Kim Hui-Seon
Published: September 2023

Hole transport layers (HTLs) are one of the essential layers of perovskite solar cells (PSCs). Generally, 2,2ʹ,7,7ʹ-Tetrakis [N,N-di(4-methoxyphenyl)amino]-9,9ʹ-spirobifluorene (spiro-MeOTAD) doped by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is used as the HTL in PSCs. PSCs employing spiro-MeOTAD require an additional aging process to reach an optimized point of photovoltaic performance due to doping and energy alignment. However, LiTFSI is responsible for low thermal stability and has a hygroscopic nature; therefore, Zinc(II) bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) has been reported as an outstanding candidate to replace LiTFSI. Nevertheless, utilization of Zn(TFSI)2 as a dopant for PSCs has rarely been reported, which is likely due to the difficulty in achieving high device performances comparable to that with LiTFSI. Herein, we investigate the effect of Zn(TFSI)2 on the doping kinetics of spiro-MeOTAD and correlate it with the time-dependent photovoltaic performance of PSCs employing Zn(TFSI)2. Devices with Zn(TFSI)2 require a considerably longer aging time (∼270 h) to reach the optimized performance, while LiTFSI takes only ∼20 h due to the different doping kinetics of spiro-MeOTAD depending on the dopant. Remarkably, engineering at the interface of the perovskite/HTL can effectively shorten the device aging time by manipulating the recombination rate, leading to a comparable aging time to LiTFSI.
Science
Authors: Adamson Peter
Published: September 2023

The first section of this chapter surveys Ibn Sīnā’s cosmology, which is clearly based on Aristotle’s but introduces new ideas especially a theory of celestial intellects that are emanated from God and ultimately bestow forms upon things in our lower, material world. Fundamental principles in his physics are also discussed, as we see how he modified and defended Aristotle’s conception of time and of place, and refuted the possibility of void or atomism. A final section looks at his output in medicine, acknowledging his experience as a practitioner but focusing on his medical theories, which are based especially on Galen.
Big telescopes
Authors: Cottrell Geoff
Published: September 2023

This chapter describes how modern optical and infrared telescopes collect and detect millions of times more light than Galileo's telescope to reveal some of the most violent, distant, and ancient objects in the cosmos. Bigger telescopes are better since they can see fainter objects and in greater detail. The chapter elaborates on the concept of diffraction, which governs the amount of detail a telescope can resolve, and how this is manifested in different telescope designs. For three centuries, telescopes collected and shepherded photons into to the eyes of astronomers, but now much fainter light and more distant light is recorded using modern detectors. The power of modern telescopes is illustrated by descriptions of of key discoveries, such as how distances of the distances of stars and galaxies are measured which has led to the discoveries of the vast size and expansion of the Universe. The development of methods to eliminate the rippling effect of the Earth’s atmosphere had led to big telescopes observing stars orbiting the supermassive black hole in centre of the Milky Way. On the biggest scales of the Universe, galaxy surveys have revealed the remarkable structure of the cosmic web.
Telescopes in space
Authors: Cottrell Geoff
Published: September 2023

This chapter describes how space telescopes have opened up new and unexpected views of the cosmos, by observing in the gamma-ray, X-ray, ultraviolet, and far infrared regions of the electromagnetic spectrum. Such radiation is unobservable from Earth. Space observations reveal the high-energy Universe including gamma-ray bursts and X-rays from the accretion discs around black holes. However, space telescopes also offer advantages at visible wavelengths, for example the Hubble Space Telescope. Other telescopes are providing exquisitely informative maps of stars in the Milky Way, and discovering new worlds orbiting distant stars, the extra-solar or exoplanets. The successor to the HST is the James Webb infrared telescope which is showing us some of the first stars and galaxies to form in the infant Universe.
Multi-messenger astronomy
Authors: Cottrell Geoff
Published: September 2023

This chapter highlights the new and different types of astronomical messengers, neutrinos and gravitational waves. These messengers can be detected in regions of the Universe that are electromagnetically hidden from view, and so are highly informative. Neutrinos are produced in massive numbers in the core of the Sun and stars, and also in the most violent events in the Universe, such as in supernovae and the accretion discs around black holes and AGN. Because they interact so weakly with normal matter, neutrinos are difficult to detect, and astronomers look for the rare interactions with matter in large volume detectors, such as the one-km block of ice which forms part of the Antarctic ice-shelf in the IceCube neutrino telescope. The first important neutrino detections, from supernova SN1987A also heralded the first multi-messenger observations. These observations, the higher energy neutrino detections from AGN are described. Gravitational waves are oscillations of the fabric of spacetime, and, unlike electromagnetic waves, are not absorbed making them informative astronomical messengers. Gravitational wave sources involve movements of large amounts of mass and energy, such as conditions of the Big Bang, merging black holes and neutron stars, as well as in supernovae. The first gravitational waves ever detected were from a pair of merging black holes, a billion light years away, by the Laser Interferometer Gravitational wave Observatories. In 2017 multimessenger gravitational and electromagnetic waves were detected from a kilonova, the violent merger of two neutron stars in a distant galaxy.
A bigger picture
Authors: Cottrell Geoff
Published: September 2023

This chapter attempts to bring together all the strands of knowledge about the Universe which have been gleaned from modern observational astronomy, and describes how they have come to shape our understanding of the Universe as a whole, the construction of a standard cosmological model. This, called the lambda-CDM model, is underpinned by the two key observations: the expansion of the Universe and the Cosmic Microwave Background radiation and is is underpinned by Einstein's General Theory of Relativity and the known laws of physics. The observations point to a singular initial event, the hot Big Bang, some 13.8 billion years ago, a state of extreme density and temperature. It is described how the model uses computer simulations to describe the growth of cosmic structures seen in the local Universe, such as galaxies and stars. However, to explain the observations, the model requires additional ingredients, from outside the known laws of physics. These are dark matter, dark energy, and cosmic inflation. The evidence for these is discussed.
Bohemians: A Very Short Introduction
Authors: Weir David
Published: September 2023

The Romantic myth of Bohemia originates in the early nineteenth century as a way of describing the new economic and cultural conditions artists and writers faced as the system of aristocratic patronage collapsed in the wake of republican revolution. This book analyses the bohemian myth likening the artist’s vagabond career to the “gypsy” life by discussing its various fictional manifestations; its historical presence in different bohemian communities; its political implications as a counter to the ascendancy of a bourgeois, commercial class; and its role in the development of both modern art and popular culture. It concludes by discussing the legacy of the bohemian myth today, arguing that the political and cultural conditions that originated that myth no longer obtain, rendering the idea of “contemporary Bohemia” problematic.
Introduction
Authors: Weir David
Published: September 2023

The introduction presents Bohemia as a myth used to explain the cultural transformation of the meaning of art and the nature of artists as the era of modernity unfolded. The bohemian emerged as an antagonist of the emerging bourgeois class and a sceptic of republican forms of government, loyal less to the nation than to metropolitan neighbourhoods of major cities, such as the Latin Quarter of Paris, the Swabbing sector of Munich, and other similarly low-rent districts in other metropolises. The chapter also observes that one does not have to be a bohemian to pursue the artistic lifestyle.
Fictional Bohemias
Authors: Weir David
Published: September 2023

This chapter examines the various fictional manifestations of the bohemian myth, beginning with George Sand’s The Last Aldini (1838), Honoré Balzac’s The Prince of Bohemia (1840), and Henry Murger’s Scenes of Bohemian Life (1851), based on a series of newspaper sketches that also served as material for a successful play produced in 1849. The Murger material inspired Giacomo Puccini’s opera La Bohème (1896), which in turn inspired Jonathan Larson’s musical Rent (1996) and the 2005 film version of that play. The chapter also shows how entangled fiction and history become as the bohemian myth undergoes its many permutations over the years from its first appearance in the nineteenth century.
Historical Bohemias
Authors: Weir David
Published: September 2023

The chapter traces the history of bohemian communities, which antedate fictional representations of Bohemia by more than a decade. Starting with bohemian enclaves in different Paris neighbourhoods (the Latin Quarter and Montmartre), the chapter shows how those communities were affected by the program of urban modernization executed by Baron Hausmann, starting in the mid nineteenth century. It also describes the migration of Bohemia to downtown New York City in the late 1850s and to the Schwabing section of Munich at the fin de siècle. The Schwabing Bohemia is noteworthy for the full participation of women in the community and for the proto-fascist politics the community embodied.
The death of Bohemia
Authors: Weir David
Published: September 2023

This chapter follows up on the conflation of bourgeois and bohemian values in Montparnasse by examining the “Bobo” (bourgeois bohemian) phenomenon in the United States as part of a broader cultural development that argues for the death of Bohemia. The chapter presents the Beat Generation as only one example of the contamination of bohemian culture with middle-class values. It uses Aki Kaurismäki 1992 film La vie de Bohème, a visually inventive retelling of Murger’s Scenes of Bohemian Life, to suggest that while Bohemia may not be dead, it is at least moribund, since the original conditions that gave birth to the myth no longer obtain.
Roman nature
Authors: Taub Liba
Published: September 2023

‘Roman Nature’ discusses authors writing in Latin who produced texts on scientific subjects that attracted a wide readership. Several authors, including Seneca and Vitruvius, continued an earlier practice of writing what may be regarded as histories of science. ‘Roman Nature’ also considers Latin translations of Greek works, which indicate that there was a Latin-language market for natural philosophical and astronomical texts. Some bilingual Roman authors translated Greek works into Latin, such as Cicero. He is an example of an author who sought to make Greek philosophy accessible to Latin readers through various of his writings, including dialogues that featured discussions of natural philosophical topics.
Going by the book—or not
Authors: Taub Liba
Published: September 2023

This chapter describes late antiquity, a historical period that is notable for the significant number of commentaries focusing specifically on philosophical, scientific, and mathematical texts, including those by Plato, Aristotle, Euclid, and Ptolemy. Ancient commentators, such as Galen, Simplicius, and John Philoponus, used the genre as a platform for communicating their own new ideas, fresh perspectives, innovative methods, and radical interpretations. Commentary was an important genre of scientific communication, particularly in later antiquity. Commentators explained and clarified earlier works, whether they fitted their own ideas and interpretations or not. They played a large role in shaping the way the works of their predecessors were read and regarded.
How populations spread
Authors: Lockwood Julie L. , Welbourne Dustin J.
Published: September 2023

This chapter explores how non-native populations spread. Population spread is a function of the established species’ population growth and their dispersal characteristics. Population growth is the key driver of population spread because space and resources are finite; hence, as populations increase they require more space and resources to survive. The chapter explains how population dispersal also influences the spread of an established species. The dynamics of population growth and dispersal can result in bi-phasic spread, which is a commonly observed geographical spread pattern of invasive species. The chapter then highlights how established species often fail to spread, for various reasons, and introduces the concept of invasion lags.
States of an ecosystem
Authors: Lockwood Julie L. , Welbourne Dustin J.
Published: September 2023

This chapter introduces and explains the concept of ecosystem states and describes the extent of influence invasive species have over the states of an ecosystem. It explains that ecosystem states are determined by the abiotic and biotic characteristics of the ecosystem. Invasive species shift the balance of the ecosystem's dynamics by amplifying some feedback processes while dampening others. Moreover, ecosystems can simultaneously exist in locally stable but globally unstable states. The chapter also covers the concept of bistable ecosystems, and how invasive species complicate ecosystem dynamics in potentially irreversible ways.
Condensed Matter Physics: A Very Short Introduction
Authors: McKenzie Ross H.
Published: September 2023

Condensed Matter Physics: A Very Short Introduction discusses how states of matter and their distinct physical properties emerge from the atoms that a material is composed of. There are many more states of matter than just solid, liquid, and gas. Examples include liquid crystal, ferromagnet, glass, superfluid, and superconductor. New states are continually, and unexpectedly, being discovered. A superconductor can be like Schrödinger’s cat and in the macroscopic world exhibit the weirdness associated with the microscopic world of atoms, photons, and electrons, that is described by quantum theory. A system composed of many interacting parts can have properties that the parts do not have. Water is wet, but a single water molecule is not. Your brain is conscious, but a single neuron is not. Such emergent phenomena are central to condensed matter physics and occur in many fields, from biology to computer science to sociology, leading to rich intellectual connections. When do quantitative differences become qualitative differences? Can simple models describe rich and complex behaviour? What is the relationship between the particular and the universal? How is the abstract related to the concrete? Condensed Matter Physics is concerned with such big questions. The materials in silicon chips, liquid crystal displays, and magnetic computer memories, may have transformed society. But understanding them has transformed how we think about complex systems. Key concepts explored include phase diagrams, phase transitions, symmetry, types of order, spontaneous symmetry breaking, spatial dimensionality, scaling, universality, macroscopic quantum states, topology, metrology, and emergence.
Adventures in Flatland
Authors: McKenzie Ross H.
Published: September 2023

‘Adventures in Flatland’ describes how condensed matter physics differs in a two-dimensional world from in our three-dimensional one. This Flatland can be accessed in a laboratory because it is possible to fabricate materials, such as graphene, that are two-dimensional or close to it. Theory can also be used to investigate this different world and led to predictions of new states of matter and a new type of phase transitions. This Berezinskii–Kosterlitz–Thouless phase transition has properties determined by topological defects such as vortices in a superfluid. A simple theoretical model for magnetic phase transitions is the Ising model. The two-dimensional version of the model illustrates concepts such as spontaneous symmetry breaking, long-range order, critical points, and emergence. A class of (almost) two-dimensional materials of great interest are crystals consisting of layers of copper and oxygen atoms. These materials superconduct at higher temperatures than any other, have a rich phase diagram, exhibit unusual metallic states, and present challenges for theoretical physicists.
To the limit: analysis in the 18th and 19th centuries
Authors: Earl Richard
Published: September 2023

The applications of calculus—via differential equations—and the inventiveness of mathematicians—especially Leonhard Euler—continued to advance, but, as ‘To the limit: analysis in the 18th and 19th centuries’ shows, it would take until the 19th century for calculus to find a firm footing. By that time mathematical analysis had become a separate subject within mathematics, with various powerful techniques of its own. The chapter also introduces the exponential and trigonometric functions, Euler’s startling connection between them, and Riemann’s work which finally put integration on a secure footing.
Dimensions aplenty
Authors: Earl Richard
Published: September 2023

The integrals of Chapter 2 represented areas but, as ‘Dimensions aplenty’ makes apparent, calculus has much to add when studied in two, three, and more dimensions. The Fundamental Theorem of Calculus can then be seen as an instance of higher-dimensional equivalents—Stokes’ Theorem and the divergence theorem—first studied by physicists for their applications to fluid flows and electromagnetism. This chapter also poses questions from the ‘calculus of variations’: what is the shortest curve between two points on a sphere? What is the largest area you can bound with a loop of rope? Why do soap films form the surfaces that they do?
Biodiversity Conservation: A Very Short Introduction
Authors: Macdonald David W.
Published: September 2023

Biodiversity Conservation: A Very Short Introduction introduces the concept of biodiversity and the basic biological processes that it involves—evolutionary, ecological, and behavioural. Biodiversity, the diversity of life, is not only fascinating and beautiful, it is the engine of all the world’s natural cycles and the source of many of the resources on which humanity depends. Biodiversity conservation is, therefore, everyone’s concern. This VSI looks at the various threats to biodiversity and their impacts. It also explores some of the solutions to the problems, considering the future of biodiversity conservation.
What is the purpose of biodiversity conservation?
Authors: Macdonald David W.
Published: September 2023

This chapter evaluates the purpose of biodiversity conservation. Two principles are candidates for guiding biodiversity conservationists: first, safeguarding the inter-generational equity of biodiversity, which can be expressed in terms of protecting natural capital; second, respecting the intrinsic value of non-human beings. The chapter then looks at the concept of respectful engagement, which suggests that the purpose of conservation is to foster coexistence. It differentiates between new conservation, orthodox conservation, and compassionate conservation. The chapter also considers the concept of transdisciplinary conservation before exploring the Convention on Biological Diversity, the Convention on the Conservation of Migratory Species, and the Convention on International Trade in Endangered Species.
Who pays, and how?
Authors: Macdonald David W.
Published: September 2023

This chapter studies the costs of biodiversity conservation. For economic growth to be sustainable, humanity’s engagement with Nature must be sustainable, thereby enhancing our collective wealth and well-being and those of our descendants. The chapter looks at the value of natural capital and the significance of the Economic Full Life-cycle Analysis and protected areas to conservation. A specific economic instrument, payments for environmental services (PES), is increasingly relevant to biodiversity conservation. The chapter then considers three approaches to realigning global and local economic values: compensation and insurance schemes, revenue-sharing initiatives, and conservation payments. Other strategies include the establishment of funding models and small changes in ecosystem services.
What next?
Authors: Macdonald David W.
Published: September 2023

This chapter reflects on the future of biodiversity conservation. Restoration, in ecology, is the science-based assisted recovery of an ecosystem that has been degraded, damaged, or destroyed. Reintroduction involves putting a species of animal or plant back into a habitat from which it has been eliminated or, in the case of reinforcement, boosting its numbers where they are precariously low. Three other forms of conservation translocation are assisted colonization, ecological replacements, and rewilding. The chapter then considers the conservation of extinct-in-the-wild species; the challenge of rewilding Britain; and the reintroduction of wild boar, beaver, wolf, and lynx. It also highlights the role of international relations and geopolitics in biodiversity conservation.
Enchanted realism
Authors: Tansman Alan
Published: September 2023

That the power of language was in a degenerated condition relative to the past has been the accepted poetic wisdom in every period of Japanese literary history. Lived language was always a shadow of some earlier, more vibrant way of writing. In the 1880s, a modern literary language—a language of realism—was being formed with the by now familiar goal of becoming a transparent medium; but now, its object was the revelation of the alienated modern self. Still, the prosaic quality of realism elicited dismay. How was the beauty of language to be salvaged? How was a writer to create a language that was a pellucid opening to the world of things, but that also reached beyond that world; how could one craft a language that was both quotidian and enchanted? These were perennial challenges throughout Japanese literary history.