bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of fractional forced KdV equation with Caputo–Fabrizio and Atangana–Baleanu–Caputo differential operators
Authors: AlBaidani Mashael M. , Aljuaydi Fahad , Alharthi N. S. , Khan Adnan , Ganie Abdul Hamid
Published: January 2024

It is essential for mathematicians, physicists, and engineers to construct fractional mathematical models for specific phenomena and develop numerical or analytical solutions for these models. In this work, we implement the natural decomposition approach with nonsingular kernel derivatives to investigate the solution of nonlinear fractional forced Korteweg–de Vries (FF-KdV) equation. We first investigate the FF-KdV equation under the Caputo–Fabrizio fractional derivative. The similar equations are then examined using the Atangana–Baleanu derivative. This approach combines the decomposition method with the Natural transform method. The series solution of the suggested equations is thus obtained using the natural transform. The key benefit of this novel approximate-analytical approach is that it may provide an analytical solution for the FF-KdV problem in the form of convergent series with simple computations. For each equation, three unique situations are chosen to demonstrate and test the viability of the proposed method. To guarantee the competence and dependability of the proposed method, the nature for various values of the Froude number Fr have been provided. The present approach is also used to calculate solutions at various fractional orders. The approximate series solution’s behavior for various fractional orders has been graphically displayed. The outcomes demonstrate that the methodology is simple to use and reliable when applied to numerous fractional differential equations.
Effect of a permanent-magnet-induced cusp field on a magnetic nozzle radio frequency plasma thruster
Authors: Nakahama Yugo , Takahashi Kazunori
Published: January 2024

A cusp magnetic field is formed upstream of a radio frequency antenna by using a permanent magnet (PM) array in a radio frequency plasma source attached to a diffusion chamber, while an expanding magnetic field configuration downstream of the source is maintained by placing a solenoid near the source tube’s exit, resembling a magnetic nozzle plasma thruster. The PM array is composed of 16 neodymium magnets and is designed to be movable axially, providing a movable axial location of the cusp field. The source is operated at a frequency of 13.56 MHz and an rf power of up to 2.6 kW in low-pressure argon. A force exerted on a target plate located downstream of the source is assessed by a pendulum target technique, showing that the force is increased if the cusp field is closer to the radio frequency antenna. The result is consistent with the previously reported result for the cusp field configuration applied by two sets of solenoids, while the present configuration can reduce the consumed electricity for the upstream solenoid.
Hard magnetic properties of Fe16N2 magnets
Authors: Saito Tetsuji , Yamamoto Hitoshi
Published: January 2024

Fe16N2 nanopowder composed of the α″-Fe16N2 phase exhibited a high saturation magnetization of 168 emu/g and a relatively high coercivity of 2.65 kOe under magnetic measurements with a DC magnetic field of 25 kOe at room temperature. A thermal study revealed that the α″-Fe16N2 phase in the Fe16N2 nanopowder was thermally stable up to 539 K. Fe16N2 nanopowder is, therefore, a prospective candidate for rare-earth-free magnets.
Enhancement of magnetoelectric coupling in laminate composites of textured Fe–Ga thin sheet and PZT
Authors: Liu Jiande , He Zhenghua , Mi Chengdong , Sha Yuhui , Zhu Xiaofei , Hao Hongbo , Chen Lijia , Zuo Liang
Published: January 2024

Magneto-mechano-electric (MME) generators consisting of piezoelectric and magnetostrictive materials can convert the stray magnetic noise to useful electric energy for the wireless sensor networks utilizing the magnetoelectric coupling effect and magnetic interactions. In this paper, a scalable engineering approach was proposed to fabricate the laminate MME generator composed of a PZT/Fe–Ga/PZT sandwich structure. The Goss-oriented Fe81Ga19 thin sheet with a large magnetostriction of 244 ppm was produced by a simple and low-cost approach, and the commercial polycrystalline piezoelectric ceramic products (PZT-5H) were used as the PZT layers. The effect of grain orientation, device structure, magnetic field amplitude, and resonance frequency on the electrical output of the PZT/Fe–Ga/PZT MME generator was investigated. The electrical output of the MME generator containing the Goss-oriented Fe81Ga19 thin sheet reached an AC voltage of 4.58 V and the ME coefficient of 76.33 V/cm·Oe under a low excitation magnetic field of 26 Oe at a low resonance frequency of 26 Hz. The MME generator with a Goss-oriented Fe–Ga layer shows 4.7 times higher output voltage and ME coupling coefficient than that with the no-oriented polycrystalline Fe–Ga layer, but only 81% of the latter’s resonance frequency. This is related to the significant increase in magnetostriction due to the texture transition after secondary recrystallization annealing at the temperature of 950 °C. This paper provides a very promising solution to meet the self-power supply needs of the Internet of Things utilizing low-value and low-frequency magnetic fields.
Effect of uniaxial stress on magnetic property of laminated amorphous sheets up to kilohertz range
Authors: Zhu Xueying , Li Yongjian , Dou Yu , Gao Jingming
Published: January 2024

Amorphous alloys are widely used as the core material for motors and transformers, which are subjected to stresses during manufacturing and operation processes. For instance, the compressive stress can influence the magnetic properties of amorphous alloys which leads to local overheating in the device and reduce the reliability. A high-frequency magnetizer with a stress application unit is designed and constructed to investigate the magnetic properties of amorphous alloys up to kilohertz range under stress conditions. The amorphous alloy sheets will fracture under stress because of their poor ductility and brittleness, so this paper uses laminated amorphous alloy sheets as the sample. The hysteresis loops and loss characteristics of amorphous alloys under stress ranging from 20 MPa tensile stress to 20 MPa compressive stress at a frequency of 50 Hz to 4 kHz are investigated. This research can provide data support for the design of cores in electromagnetic devices.
Advanced hybrid MRAM based novel GPU cache system for graphic processing with high efficiency
Authors: Han Shaopu , Jiang Yanfeng
Published: January 2024

With the rapid development of portable computing devices and users’ demand for high-quality graphics rendering, embedded Graphics Processing Units (GPU) systems for graphics processing are increasingly turning into a key component of computer architecture to enhance computability. The cache system based on traditional static random access memory (SRAM) plays a crucial role in GPUs. But high leakage, low lifetime and poor integration problems deeply plague the science and engineering field. In the paper, a novel magnetic random access memory (MRAM) based cache architecture of GPU systems is proposed for highly efficient graphics processing and computing accelerating, with the merits of high speed, long endurance, strong interference resistance, and ultra-low power consumption. Spin transfer torque-MRAM and spin orbit torque-MRAM are utilized in off-chip and on-chip caches, respectively. A controller design scheme with prefetching modules and optimized cache coherency protocols are adopted. After testing and evaluating with multiple loads, neural network models and datasets, the simulation results show that the proposed system can achieve up to 28%, 56%, and 66.45% optimizations mostly in terms of speed, energy and leakage power, respectively.
Structure and magnetic properties of nanocrystalline SmCo5 and SmCo3Cu2 prepared by using high-pressure torsion method
Authors: Wang Fei-Yang , Qi Ting-Ting , Wu Qiong , Ge Hong-liang , Si Ping-Zhan
Published: January 2024

Nanocrystalline SmCo5 and SmCo3Cu2 alloys were prepared by using high pressure torsion (HPT) method. The effect of severe plastic deformation of HPT on the structure and magnetic properties of the samples were investigated systematically. The grain size of SmCo5 and SmCo3Cu2 alloys was refined to the nanocrystalline regime or even amorphous state by HPT, depending on the number of the HPT rotation. Lamellar microstructures of the grains were observed in the samples after HPT for 2 turns of rotation. With increasing number of HPT rotation, a further structural refinement and an increasing coercivity were observed. The coercivity of the as-cast SmCo5 and SmCo3Cu2 alloys after HPT reached up to 0.5 and 1.64 T, respectively. This work demonstrates that HPT is a high efficiency method in producing bulk nanocrystalline magnetic materials.
Dynamic susceptibility of dipolar coupled magnetic vortices
Authors: Jales T. G. M. , Martins S. M. B. , Carriço A. S. , Dantas Ana L.
Published: January 2024

We report a calculation of the dynamic susceptibility of a pair of ferromagnetic circular nanocylinders stacked along the common axis, one on the other, and separated by a thin nonmagnetic spacer. Our theoretical model considers the dipolar energy without restrictions on dipolar sums, along with the anisotropy and exchange energies. Our results indicate that the nanocylinders dipolar interaction may affect the susceptibility spectrum. We have found, for instance, that a 30nm thick, 70nm diameter Fe nanocylinder holds a single magnetic vortex, and the planar susceptibility (χxx) spectrum displays two low-frequency peaks (at 0.37 and 1.00 GHz). We have also found that the χxx susceptibility spectrum of dipolar-coupled vortices in a pair of Fe nanocylinders with a 5 nm spacer exhibits peaks at 0.3, 0.7, 1.2, and 1.4 GHz. Furthermore, the relative weight of the peaks is controlled by the degree of spatial localization of these excitations.
Supplementary comparison of national measurement standards of gauge pressure in the range from 1 MPa to 10 MPa
Authors: Zuyev A , Bardonov A , Leontyev M , Dapkeviciene K
Published: January 2024

Main text

This report gives the results of the supplementary comparison COOMET.M.P-S1 for measurements of the gauge pressure within the range from 1 MPa to 10 MPa. This comparison was piloted by NSC "Institute of Metrology" (Kharkiv, Ukraine). The principle of comparison is to determine the transfer standard effective area of the piston according to the method of cross-float equilibrium of transfer standard and national standards NMI-participants comparisons piston-cylinder assemblies. All values agree with the reference values within the expanded uncertainties taken with coverage factor k = 2.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Modulating the density of silicon nanowire arrays for high-performance hydrovoltaic devices
Authors: Zhang Binbin , Zhang Bingchang , Sheng Guangshang , Gu Chenyang , Yu Jia , Zhang Xiaohong
Published: January 2024

Hydrovoltaic devices (HDs) based on silicon nanowire (SiNW) arrays have received intensive attention due to their simple preparation, mature processing technology, and high output power. Investigating the impact of structure parameters of SiNWs on the performance of HDs can guide the optimization of the devices, but related research is still not sufficient. This work studies the effect of the SiNW density on the performance of HDs. SiNW arrays with different densities were prepared by controlling the react time of Si wafers in the seed solution (t
seed) in metal-assisted chemical etching. Density of SiNW array gradually decreases with the increase of t
seed. HDs were fabricated based on SiNW arrays with different densities. The research results indicate that the open-circuit voltage gradually decreases with increasing t
seed, while the short-circuit current first increases and then decreases with increasing t
seed. Overall, SiNW devices with t
seed of 20 s and 60 s have the best output performance. The difference in output performance of HDs based on SiNWs with different densities is attributed to the difference in the gap sizes between SiNWs, specific surface area of SiNWs, and the number of SiNWs in parallel. This work gives the corresponding relationship between the preparation conditions of SiNWs, array density, and output performance of hydrovoltaic devices. Density parameters of SiNW arrays with optimized output performance and corresponding preparation conditions are revealed. The relevant results have important reference value for understanding the mechanism of HDs and designing structural parameters of SiNWs for high-performance hydrovoltaic devices.
The fastVFP code for solution of the Vlasov–Fokker–Planck equation
Authors: Bell A R , Sherlock M
Published: January 2024

We describe the fastVFP code for solution of the Vlasov–Fokker–Planck equation for non-local electron transport and the generation of magnetic field, especially for application to laser-produced plasmas. We describe the essential features of the code that make it fast and robust and suitable for inclusion as a transport package in a fluid simulation. We present a few sample results that demonstrate the abilities of the code.
Non-Maxwellian electron effects on the macroscopic response of a Hall thruster discharge from an axial–radial kinetic model
Authors: Marín-Cebrián Alberto , Bello-Benítez Enrique , Domínguez-Vázquez Adrián , Ahedo Eduardo
Published: January 2024

A 2D axial–radial particle-in-cell (PIC) model of a Hall thruster discharge has been developed to analyze (mainly) the fluid equations satisfied by the azimuthally-averaged slow dynamics of electrons. Their weak collisionality together with a strong interaction with the thruster walls lead to a non-Maxwellian velocity distribution function (VDF). Consequently, the resulting macroscopic response differs from a conventional collisional fluid. First, the gyrotropic (diagonal) part of the pressure tensor is anisotropic. Second, its gyroviscous part, although small, is relevant in the azimuthal momentum balance, where the dominant contributions are orders of magnitude lower than in the axial momentum balance. Third, the heat flux vector does not satisfy simple laws, although convective and conductive behaviors can be identified for the parallel and perpendicular components, respectively. And fourth, the electron wall interaction parameters can differ largely from the classical sheath theory, based on near Maxwellian VDF. Furthermore, these effects behave differently in the near-anode and near-exit regions of the channel. Still, the profiles of basic plasma magnitudes agree well with those of 1D axial fluid models. To facilitate the interpretation of the plasma response, a quasiplanar geometry, a purely-radial magnetic field, and a simple empirical model of cross-field transport were used; but realistic configurations and a more elaborate anomalous diffusion formulation can be incorporated. Computational time was controlled by using an augmented vacuum permittivity and a stationary depletion law for neutrals.
Radiative dynamics of laser-driven Li@C

n
embedded in quantum plasma
Authors: Bahar Mustafa Kemal
Published: January 2024

This work considers a guest Lithium atom (Li@C

n
) in an endohedral fullerene, embedded in a quantum plasma modeled by the more general exponential cosine screened Coulomb (MGECSC) potential, under the influence of a spherical confinement and laser radiation field. The system is examined in nonrelativistic form and the related wave equation is solved using the tridiagonal matrix method (TMM), thus obtaining the discrete-continuum spectrum and related wave functions. The numerical values of the relevant parameters in this process are physically accessible values. The effects of the plasma, laser field and endohedral cavity on the photoionization cross section (PCS) are analysed in detail. The shielding effect of the plasma medium and the pulsating effect of the laser field modify the effective potential energy of the system, affecting the localizations of the 2s and continuum states, causing various overlapping cases. Considering different values of the endohedral encompassement parameters, which means that different types of fullerenes are taken into account, overlapping cases occur for different spectra and wave functions. Scrutinising these overlappings, the confinement and Cooper resonances of the PCSs are analysed. This analysis provides many details for the radiative dynamics of an artificial system Li@C

n
. The relevant ranges and critical values of plasma, laser field, and endohedral encapsulation parameters in the formation process of these resonances and PCSs are explained, as well as the cross-section curves, resonance positions, effective photoelectron energy range, and general PCS behavior, which can be important for potential experiments in addition to other theoretical investigations.
Practical realisation of the kelvin by Johnson noise thermometry
Authors: Benz Samuel P , Coakley Kevin J , Flowers-Jacobs Nathan E , Rogalla Horst , Tew Weston L , Qu Jifeng , White D Rod , Gaiser Christof , Pollarolo Alessio , Urano Chiharu
Published: January 2024

Johnson noise thermometry (JNT) is a purely electronic method of thermodynamic thermometry. In primary JNT, the temperature is inferred from a comparison of the Johnson noise voltage of a resistor at the unknown temperature with a pseudo-random noise synthesized by a quantum-based voltage-noise source (QVNS). The advantages of the method are that it relies entirely on electronic measurements, and it can be used over a wide range of temperatures due to the ability of the QVNS to generate programmable, scalable, and accurate reference signals. The disadvantages are the requirement of cryogenic operation of the QVNS, the need to match the frequency responses of the leads of the sense resistor and the QVNS, and long measurement times. This review collates advice on current best practice for a primary JNT based on the switched correlator and QVNS. The method achieves an uncertainty of about 1 mK near 300 K and is suited to operation between 4 K and 1000 K.
Design of structured meshes of mining excavations based on variability trends of real point clouds from laser scanning for numerical airflow modeling
Authors: Wróblewski Adam , Kujawa Paulina , Wodecki Jacek , Ziętek Bartłomiej
Published: January 2024

Various technologies are used to acquire and process 3D data from mining excavations, such as Terrestrial Laser Scanning (TLS), photogrammetry, or Mobile Mapping Systems (MMS) supported by Simultaneous Localization and Mapping (SLAM) algorithms. Due to the often difficult measurement conditions, the data obtained are often incomplete or inaccurate. There are gaps in the point cloud due to objects obscuring the tunnel. Data processing itself is also time-consuming. Point clouds must be cleaned of unnecessary noise and elements. On the other hand, accurate modeling of airflows is an ongoing challenge for the scientific community. Considering the utilization of 3D data for the numerical analysis of airflow in mining excavations using Computational Fluid Dynamics (CFD) tools, this poses a considerable problem, especially the creation of a surface mesh model, which could be further utilized for this application. This paper proposes a method to create a synthetic model based on real data. 3D data from underground mining tunnels captured by a LiDAR sensor are processed employing feature extraction. A uniformly sampled tunnel of given dimensions, point cloud resolution, and cross-sectional shape is created for which obtained features are applied, e.g. general trajectory of the tunnel, shapes of walls, and additional valuable noise for obtaining surfaces of desired roughness. This allows to adjust parameters such as resolution, dimensions, or strengths of features to obtain the best possible representation of a real underground mining excavation geometry. From a perspective of Computational Fluid Dynamics (CFD) simulations of airflow, this approach has the potential to shorten geometry preparation, increase the quality of computational meshes, reduce discretization time, and increase the accuracy of the results obtained, which is of particular importance considering airflow modeling of extensive underground ventilation networks.
Life cycle assessment of a new smart label for intelligent packaging
Authors: Sokka L , Välimäki M , Väisänen K -L , Keskinen J , Hakola E , Mäntysalo M , Ollila J , Happonen T , Hakola L , Smolander M
Published: January 2024

Within the past years, there has been a growing demand for sustainable, cost-efficient on-line sensing of chemical and physical properties and locations of products. Measuring of products’ physical properties, such as temperature and humidity, could improve product safety and efficiency of logistic operations. In the future measurement of temperature of food items could also aid in reducing food wastage. The aim of this study was to calculate the life cycle environment impacts of a temperature logger, hereafter called smart label, primarily targeted for the monitoring of the packed food products. According to the results, the largest normalised impacts of the smart label production are resource use (both use of fossil fuels and use of minerals and metals), eutrophication and particulate matter formation. The main materials causing these impacts were the printed electronics inks and adhesives. In addition, energy used in the production, and plastics used as substrates had large impacts on the results. It should be noted that the present calculations have mainly been made on a laboratory scale. The impacts are likely to get smaller on an industrial scale with more efficient production. In the future, the label could potentially bring environmental benefits through product savings when used in products with high environmental load.
Advancing electron microscopy using deep learning
Authors: Chen K , Barnard A S
Published: January 2024

Electron microscopy, a sub-field of microanalysis, is critical to many fields of research. The widespread use of electron microscopy for imaging molecules and materials has had an enormous impact on our understanding of countless systems and has accelerated impacts in drug discovery and materials design, for electronic, energy, environment and health applications. With this success a bottleneck has emerged, as the rate at which we can collect data has significantly exceeded the rate at which we can analyze it. Fortunately, this has coincided with the rise of advanced computational methods, including data science and machine learning. Deep learning (DL), a sub-field of machine learning capable of learning from large quantities of data such as images, is ideally suited to overcome some of the challenges of electron microscopy at scale. There are a variety of different DL approaches relevant to the field, with unique advantages and disadvantages. In this review, we describe some well-established methods, with some recent examples, and introduce some new methods currently emerging in computer science. Our summary of DL is designed to guide electron microscopists to choose the right DL algorithm for their research and prepare for their digital future.
Bounds on 10th moments of (𝑥,𝑥³) for ellipsephic sets
Authors: Anderson Theresa , Hu Bingyang , Liu Yu-Ru , Talmage Alan
Published: January 2024

Let

A

\mathcal {A}

be an ellipsephic set which satisfies digital restrictions in a given base. Using the method developed by Hughes and Wooley, we bound the number of integer solutions to the system of equations
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartLayout 1st Row 1st Column Blank 2nd Column a m p semicolon sigma-summation Underscript i equals 1 Overscript 2 Endscripts left-parenthesis x Subscript i Superscript 3 Baseline minus y Subscript i Superscript 3 Baseline right-parenthesis equals sigma-summation Underscript i equals 3 Overscript 5 Endscripts left-parenthesis x Subscript i Superscript 3 Baseline minus y Subscript i Superscript 3 Baseline right-parenthesis 2nd Row 1st Column Blank 2nd Column a m p semicolon sigma-summation Underscript i equals 1 Overscript 2 Endscripts left-parenthesis x Subscript i Baseline minus y Subscript i Baseline right-parenthesis equals sigma-summation Underscript i equals 3 Overscript 5 Endscripts left-parenthesis x Subscript i Baseline minus y Subscript i Baseline right-parenthesis comma EndLayout">

a
m
p
;

∑

i
=
1

2

(

x
i
3

−

y
i
3

)

=

∑

i
=
3

5

(

x
i
3

−

y
i
3

)

a
m
p
;

∑

i
=
1

2

(

x
i

−

y
i

)
=

∑

i
=
3

5

(

x
i

−

y
i

)
,

\begin{equation*} \begin {split} & \sum _{i=1}^2 \left (x_i^3-y_i^3 \right )=\sum _{i=3}^5 \left (x_i^3-y_i^3 \right )\\ & \sum _{i=1}^2 (x_i-y_i)=\sum _{i=3}^5 (x_i-y_i), \end{split} \end{equation*}

with

x
,
y

∈

A

5

\mathbf {x, y} \in \mathcal {A}^5

. The fact that ellipsephic sets with small digit sumsets have fewer solutions of linear equations allows us to improve the general bounds obtained by Hughes and Wooley and also the corresponding efficient congruencing estimates. We also generalize our result from the curve

(
x
,

x
3

)

(x, x^3)

to

(
x
,
ϕ
(
x
)
)

(x, \phi (x))

, where

ϕ
\phi

is a polynomial with integer coefficients and

deg
⁡
(
ϕ
)
≥
3

\deg (\phi ) \ge 3

.
Refinements of the 2-dimensional Strichartz estimate on the maximum wave packet
Authors: Wang Hong , Zhang Lingfu
Published: January 2024

The Strichartz estimates for Schrödinger equations can be improved when the data is spread out in either physical or frequency space. In this paper we give refinements of the 2-dimensional homogeneous Strichartz estimate on the maximum size of a single wave packet. Different approaches are used in the proofs, including arithmetic approaches, polynomial partitioning, and the

l
2

l^2

Decoupling Theorem, for different cases. We also give examples to show that the refinements we obtain cannot be further improved when

2
≤
p
≤
4

2 \leq p \leq 4

and

p
=
6

p = 6

.
Convergence, finiteness and periodicity of several new algorithms of 𝑝-adic continued fractions
Authors: Wang Zhaonan , Deng Yingpu
Published: January 2024

Classical continued fractions can be introduced in the field of

p
p

-adic numbers, where

p
p

-adic continued fractions offer novel perspectives on number representation and approximation. While numerous

p
p

-adic continued fraction expansion algorithms have been proposed by the researchers, the establishment of several excellent properties, such as the Lagrange’s Theorem for classic continued fractions, which indicates that every quadratic irrationals can be expanded periodically, remains elusive. In this paper, we introduce several new algorithms designed for expanding algebraic numbers in

Q

p

\mathbb {Q}_p

for a given prime

p
p

. We give an upper bound of the number of partial quotients for the expansion of rational numbers, and prove that for small primes

p
p

, our algorithm generates periodic continued fraction expansions for all quadratic irrationals. Experimental data demonstrates that our algorithms exhibit better performance in the periodicity of expansions for quadratic irrationals compared to the existing algorithms. Furthermore, for bigger primes

p
p

, we propose a potential approach to establish a

p
p

-adic continued fraction expansion algorithm. As before, the algorithm is designed to expand algebraic numbers in

Q

p

\mathbb {Q}_p

, while generating periodic expansions for all quadratic irrationals in

Q

p

\mathbb {Q}_p

.
Classifying solutions of 𝑆𝑈(𝑛+1) Toda system around a singular source
Authors: Mu Jingyu , Shi Yiqian , Sun Tianyang , Xu Bin
Published: January 2024

Consider a positive integer

n
n

and

γ
1

>
−
1
,
⋯
,

γ
n

>
−
1

\gamma _1>-1,\cdots ,\gamma _n>-1

. Let

D
=
{
z
∈

C

:

|

z

|

>
1
}

D=\{z\in \mathbb {C}:|z|>1\}

, and let

(

a

i
j

)

n
×
n

(a_{ij})_{n\times n}

denote the Cartan matrix of

s
u

(
n
+
1
)

\frak {su}(n+1)

. Utilizing the ordinary differential equation of

(
n
+
1
)

(n+1)

th order around a singular source of

S
U

(
n
+
1
)

{SU}(n+1)

Toda system, as discovered by Lin-Wei-Ye [Invent. Math. 190 (2012), pp. 169–207], we precisely characterize a solution

(

u
1

,
⋯
,

u
n

)

(u_1,\cdots , u_n)

to the

S
U

(
n
+
1
)

{SU}(n+1)

Toda system
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartLayout Enlarged left-brace 1st Row 1st Column StartFraction partial-differential squared u Subscript i Baseline Over partial-differential z partial-differential z overbar EndFraction plus sigma-summation Underscript j equals 1 Overscript n Endscripts a Subscript i j Baseline e Superscript u Super Subscript j Superscript Baseline 2nd Column a m p semicolon equals pi gamma Subscript i Baseline delta 0 on upper D 2nd Row 1st Column StartFraction StartRoot negative 1 EndRoot Over 2 EndFraction integral Underscript upper D minus StartSet 0 EndSet Endscripts e Superscript u Super Subscript i Superscript Baseline d z logical-and d z overbar 2nd Column a m p semicolon greater-than normal infinity EndLayout for all i equals 1 comma midline-horizontal-ellipsis comma n">

{

∂
2

u
i

∂
z
∂

z
¯

+

∑

j
=
1

n

a

i
j

e

u
j

a
m
p
;
=
π

γ
i

δ
0

 on 
D

−
1

2

∫

D
∖
{
0
}

e

u

i

d

z
∧

d

z
¯

a
m
p
;
>
∞

for all

i
=
1
,
⋯
,
n

\begin{equation*} \begin {cases} \frac {\partial ^2 u_i}{\partial z\partial \bar z}+\sum _{j=1}^n a_{ij} e^{u_j}&=\pi \gamma _i\delta _0\text { on } D\\ \frac {\sqrt {-1}}{2}\,\int _{D\backslash \{0\}} e^{u_{i} }{d}z\wedge {d}\bar z &> \infty \end{cases} \quad \text {for all}\quad i=1,\cdots , n \end{equation*}

using

(
n
+
1
)

(n+1)

holomorphic functions that satisfy the normalized condition. Additionally, we demonstrate that for each

1
≤
i
≤
n

1\leq i\leq n

,

0
0

represents the cone singularity with angle

2
π
(
1
+

γ
i

)

2\pi (1+\gamma _i)

for the metric

e

u
i

|

d

z

|

2

e^{u_i}|{d}z|^2

on

D
∖
{
0
}

D\backslash \{0\}

, which can be locally characterized by

(
n
−
1
)

(n-1)

non-vanishing holomorphic functions at

0
0

.
The stable conjugation-invariant word norm is rational in free groups
Authors: Jaspars Henry
Published: January 2024

We establish the rationality of the stable conjugation-invariant word norm on free groups and virtually free Coxeter groups.
1770 Assessment of lying and standing blood pressure; an audit leading to an improved clinical effectiveness and quality improvement
Authors: Singh K , Sethi D
Published: January 2024

Introduction

Assessment of lying and standing blood pressure is commonly undertaken in geriatric medicine to make a diagnosis of orthostatic or postural hypotension. We carried out the audit to review the clinical practice and assess its adherence to the Royal College of Physicians (RCP) guidance on how to accurately measure the lying and standing blood pressure (Falls and Fragility Fracture Audit Programme).

Method

It was a prospective audit. The first audit cycle was conducted in July 2020 and the second cycle in April 2021

Results

During the first data collection, the practice was reviewed in 69 patients. 35 were female (age range 63-92 years) and 34 male (age range 72-95 years). The lying and standing blood pressures were measured in 27 patients. Only 4 were performed as per the RCP guidance. 34 team members (including doctors, nurses, healthcare assistants, etc.) were randomly surveyed on how to correctly measure lying and standing blood pressure. None were aware of the RCP guidance in this context. We delivered local presentations of the results of the audit and RCP guidance flyers were displayed on the bulletin boards in the department. During the second cycle, the practice was reviewed in 58 patients. 30 were female (aged 67-94 years) and 28 male (aged 68-96 years). The lying and standing blood pressures were measured in 32 patients, of which 20 were recorded according to the RCP guidance. There was an increase of adherence to the guidance from 14.8% to 62.5% after undertaking the aforementioned interventions.

Conclusions

Following dissemination of the RCP guidance on how to accurately measure the lying and standing blood pressures, we witnessed an improvement in the practice suggestive of an improved clinical effectiveness. Robustly evaluating a service followed by education of the staff can lead to enhanced clinical care and quality improvement.
1756 Improvement in the number of discharges prior to 3 p.m. using quality improvement methodology
Authors: England S , Guthrie K , Winfield A
Published: January 2024

Introduction

Under current nationwide clinical pressures, hospitals are running at full capacity. Late discharges can lead to poor flow throughout the hospital, overcrowding in the emergency department and out of hours transfers, leading to a poor patient experience and impacts on patient safety. Early morning and afternoon discharges create better flow and improve patient satisfaction, by being home in time for tea. The discharge collaborative within Leeds Teaching Hospitals NHS Trust is a multidisciplinary team (MDT) of junior doctors, pharmacists, nurses and discharge co-ordinators. The aim of the team is to improve discharges in the trust prior to 3 p.m. to 70%. Discharging patients earlier in the day is a complex multifactorial issue which requires an MDT approach.

Method

To understand this further a retrospective case note review was conducted to look at avoidable and unavoidable causes of delayed discharges. Each team also received a questionnaire, to discover their perceived barriers to early discharges. This was communicated to teams to empower them to develop their own solutions which were shared within the trust. Run charts of discharges before 3 p.m. are published for each ward in the hospital every two weeks, which is available to wards, but also monitored by the discharge collaborative. Changes to practice include; education of the medical team regarding importance of timely discharge, use of discharge boards, the increase use of discharge lounge, identifying ‘golden patients’ for early morning discharges, prioritisation of community discharges the previous day and achievement recognition for wards with the most improvement.

Results/Conclusions

Within the trust, several departments have improved their discharges prior to 3 p.m. through the improvements implemented from the discharge collaborative, including speciality and integrated medicine (SIM), oncology, and trauma services. This project resulted in two step improvements within the Trust with 40% of patients being discharged before 3 p.m.
1721 Enhancing the recognition of sensory impairment on the Care of the Elderly wards
Authors: Hackney A , Ball G , Brown J , Wharton C
Published: January 2024

Introduction

Although hearing loss is the foremost cause of years lived with disability in people over 70, it remains commonly under-recognised. Health of the UK signing deaf community is reportedly worse than the general population, often due to resulting undertreatment of associated co-morbidities including visual impairment, falls and dementia.

Local Problem

There is an estimated 21% prevalence of ≥25dBHL hearing loss within the Wolverhampton adult population, this increasing with age. A large number of inpatients admitted to the Older Adult Medicine (OAM) wards at New Cross Hospital have clinically evident sensory impairment, impacting upon interactions with healthcare staff. This project identified the current methods through which hearing and/or visual impairment is formally screened for and documented within the OAM Department of a large district general hospital, targeting interventions towards mitigating barriers faced in sensory assessment.

Methods and Intervention

Baseline and post-intervention documentation of sensory impairment was collected from admission and bedside notes of 23 inpatients during each cycle. A multidisciplinary focus group of medical, nursing and practice education facilitators identified a marked underutilisation of bedside alert signs (4%), prompting creation of a redesigned bedside poster with a greater focus on sensory aid functionality.

Results

60% of posters were utilised 10 days after introduction, with an increase from 4% to 36% in recording of known sensory impairment being observed. 100% and 25% of inpatients with correctly functioning hearing aids and spectacles were documented respectively. 100% of patients admitted through frailty intervention streams were assessed for sensory loss, compared to 0% admitted via the unselected medical take.

Conclusions

Improved bedside alert posters provided initial evidence as a sustainable improvement in supporting inpatients with sensory impairment. Incorporating positive lessons from frailty team practice will assist in developing future education sessions, highlighting intended sign usage and transferrable sensory assessment methods for involved healthcare teams.
2033 ``Polyclinics'' - a concept of multiple clinic attendance. A pilot quantitative and qualitative review
Authors: Stross M , Laraman J , Begum A , Punniamoorthy M
Published: January 2024

Introduction

The concept of “polypharmacy” is a well-recognised phenomenon, forming a keystone of any comprehensive geriatric assessment. We considered whether a similar concept could be applied to the number of outpatient clinics that patients may attend - a concept we have coined “polyclinic”. We recognise that older populations may have a greater number of comorbidities and, as a result, have more healthcare professionals inputting into their care. Similar to the potential detrimental effects of multiple medications, we were interested to explore if a similar detrimental effect may apply to patients attending multiple clinics. We also attempted to consider environmental and financial impacts. We approached this in both a quantitative and qualitative manner.

Method

A cohort was selected from all admissions to a subacute Geriatrics ward at University Hospital of Wales during the month of April 2023. National records were used to review the last decade of clinic attendances. For interviews every 4th patient was contacted

Results

66 patients (75% female) were identified with 3 exclusions. The average number of clinics attended was 18.4 with 0.36 new diagnoses being made per clinic and 0.69 interventions per attendance. Geriatric clinic attendance yielded both a higher average number of diagnoses and interventions (0.93 and 1.4 respectively). Patient feedback was limited to 8 patients and 7 next of kin. Feedback regarding ‘worthwhileness’ was very positive with ratings >8/10. Feelings about possible cutting back on clinics or virtual clinic attendance were mixed with concerns regarding suitability and access to technology

Conclusions

We identified several limitations to this pilot project but overall feedback was positive. This study does not have the scope to suggest that attending multiple clinics are detrimental but aims to raise the concept of “polyclinic” that may be overlooked, particularly in a comorbid population and considers potential patient impact and concerns.
2011 Review of the requirement and impact of the medicine for the Elderly Major Trauma Service in South-East Scotland
Authors: Quarm M L , Johnston C S , Kilgour A H M
Published: January 2024

Introduction

It is well established that older adults with hip fracture benefit from comprehensive geriatric assessment (CGA), but there is less evidence for its use in major trauma. Since 2012 Major Trauma Centres (MTCs) have opened across the UK, with varying access to CGA. We report the requirement and impact of CGA in a MTC in its first year of opening.

Methods

We reviewed all adult patients admitted under the South-East Scotland MTC included in the Scottish Trauma Audit Group (STAG) database from 1st November 2021 – 31st October 2022. We compared: patients under 65y, patients ≥65y who did not undergo CGA, and patients ≥65y who underwent CGA. Outcomes were: review by ED consultant within one hour of presentation, trauma team activation, injury severity score (ISS), CGA within 7 days when CFS≥5, and mortality at 30 days.

Results

1323 patients were identified (mean age 63.7y, SD20.9): <65y (n=690, 45.5y, SD14.0), ≥65y without CGA (n=401, 77.2y, SD8.2), and ≥65y with CGA (n=289, 84.6y, SD 7.3). The commonest mechanism of injury in all three groups was fall from standing height (29.1%, 59.6%, and 73.4% respectively). ED consultant review within 1 hour occurred in 37%, 25% and 18% of cases, with trauma team activation occurring in 32%, 18% and 7%. Average ISS were: 13, 12 and 11, and commonest sites of injury in those over 65 were external (e.g. skin), chest and limb. CGA was undertaken within 7 days in 95.1% of those with a documented CFS≥5. Mortality at 30 days was 2.9%, 12% and 8%.

Conclusions

A fifth of patients admitted to our MTC in the first year were older adults with CFS≥5. These patients were under-triaged at several stages despite comparable average ISS across groups. CGA may reduce 30-day mortality. We recommend further research into the benefit of CGA within MTCs.
1883 The Psychological Impact of Hospital Discharge on the Older Person
Authors: Hussein Y , Edwards S , Patel H P
Published: January 2024

Introduction

Older people often require hospitalisation but prolonged length of stay and deconditioning in the acute setting is associated with adverse outcomes. 35% of older people do not recover functionally after discharge. Less is known on the psychological impact and coping mechanisms of vulnerable older people after discharge. Our aim was to explore factors signalling psychological vulnerability in older patients, post-discharge to inform better discharge planning.

Methods

A systematic search for studies reporting poor discharge outcomes in older people was performed in Medline, CINAHL, PsycInfo between 2010-2022. The search terms were ’older patients >65 year’, ‘post-discharge’, ’psychological distress’, ’loneliness’, ‘anxiety’, ‘depression’, and ‘length of hospital stay’. Exclusion criteria included COVID-19 disease, dementia (+/- severe cognitive impairment), individuals aged <65 and those under palliative care services.

Results

1,666 records were identified of which 878 were excluded as they were outside of our date limits or were not in English Language. 681 were excluded after application of exclusion criteria and 699 were excluded because of insufficient details. 31 duplicates were removed leaving 38 articles that were assessed for eligibility. 7 of these reports were found suitable, comprising of 1,131 patients. Three highly relevant themes identified relating to post-discharge outcomes across all studies were social isolation, lack of support, depression, apathy and fear, which led to further psychological distress. Older patients with tendency toward depressive symptoms had an increase likelihood of death.

Conclusion

It appears discharge processes fail to address psychological factors that permit successful transition from hospital. Pre-discharge screening of psychological symptoms and coping ability may assist in identifying older patients who are at risk of mental as well as subsequent physical deterioration. Better knowledge of positive and negative predictors of a successful transition from hospital to home would enable more holistic, effective, and inclusive discharge planning processes for older people.
1724 Age is just a number: Cardiac resynchronisation therapy in older patients has comparable outcomes to those that are younger
Authors: Safdar N Z , Kamalathasan S , Gupta A , Wren J , Bird R , Papp D , Latto R , Ahmed A , Palin V , Gierula J , Witte K K , Straw S
Published: January 2024

Introduction

Older people may be less likely to receive cardiac resynchronisation therapy (CRT) for the management of chronic heart failure. We aimed to describe differences in clinical response, complications, and subsequent outcomes following CRT implantation in older patients when compared to those that were younger.

Methods

We conducted a retrospective cohort study of consecutive patients implanted with CRT between March 2008 and July 2017. We recorded complications, symptomatic and echocardiographic response, hospitalisations for heart failure, and all-cause mortality comparing patients aged <70, 70-79, and ≥80 years.

Results

During the study period, 574 patients (median age 76 years [IQR 68-81], 73.3% male) received CRT. Patients aged ≥80 years had worse symptoms at baseline and were more likely to have co-morbidities. Although the provision of guideline-directed medical therapy for heart failure was less optimal in those ≥80 years old, left ventricular function was similar at baseline. Older patients were less likely to receive CRT-defibrillators (which were twice as likely to require generator replacement) compared to CRT-pacemakers. Complications were infrequent and not more common in older patients. Age was not a predictor of symptomatic or echocardiographic response to CRT (67.2%, 71.2%, and 62.6% responders in patients aged <70, 70-79, and ≥80 years, respectively; p=0.43) and time to first heart failure hospitalisation was similar across all groups (p=0.28). Finally, estimated 10-year survival was lower for older patients (49.9%, 23.9%, and 6.8% for patients aged <70, 70-79, and ≥80 years, respectively; p<0.001).

Conclusions

The benefits of CRT were consistent in selected older patients (≥80 years) despite a greater burden of co-morbidities and less optimal provision of guideline-directed medical therapy. These findings support the use of CRT in an aging population.
1903 Barriers perceived by medical students when considering a career in geriatric medicine
Authors: Fisher G , True S
Published: January 2024

Introduction

Despite the UK’s increasing life expectancy, and increase in the elderly population, there is an overwhelming lack of Geriatricians in the UK; as of 2022, there is only 1 consultant Geriatrician per 8,031 individuals over the age of 65 (BGS, 2023). To meet the complex care needs of this population, there must be a focus on increasing the interest that doctors have towards Geriatric Medicine, with the overall aim being to recruit more doctors into the speciality.

Method

The aim of this review was to investigate what factors medical students perceive as barriers to pursuing a career in Geriatric Medicine and then, from identifying these, generate a set of comprehensive suggestions as to how to tackle these barriers at a medical school level to increase the interest and ultimately uptake of Geriatric Medicine. The qualitative review contains literature published between 2003 and 2023 accessed using MedLine.

Results

Six themes were identified in answering our question: (a) high emotional burden, (b) caring for patients with complex needs, (c) negative preconceptions of non-clinical factors (prestige, salary, career progression), (d) negative influence of clinical educators, (e) lack of intellectual stimulation and (f) lack of exposure to the speciality and the elderly.

Conclusion

The barriers perceived by medical students when considering Geriatrics as a speciality are complex and multifaceted; these barriers must be tackled promptly in order to secure the next generation of Geriatricians. We suggest that this work can be used as a foundation for further qualitative studies with UK medical students to investigate barriers that are specific to UK students. From this, interventional courses designed to increase Geriatric Medicine uptake could be developed to strengthen the UK Geriatric Medicine workforce.