bluuebunny/crossref_metadata_2025 huggingface dataset:
Erinnern als interkulturelles Handeln am Beispiel des Shanghaier Exils
Authors: Tong Xin , Zhang Fan
Published: February 2022

Dieser Beitrag rückt den sozial-kommunikativen Prozesscharakter von Erinnern in den Blick und untersucht kommunikative Erinnerungspraktiken in der deutschen und chinesischen Gesellschaft. Im Kontext der kulturwissenschaftlichen Gedächtnis- und Exilforschung werden die Exil-Diskurse in Deutschland und China exemplarisch anhand des Beispiels des Erinnerns an die Zuflucht der Juden in China neu reflektiert, indem eine kulturvergleichende bzw. komparatistische Perspektive profiliert wird. Dabei soll ein kommunikativer Erinnerungsprozess bezüglich des Refugiums in der Stadt Shanghai aufgezeigt werden, der über geografische und kulturelle Grenzen transzendiert und auf einen profunden deutsch-chinesischen Austausch in multiplen Bereichen hinweist. Hierbei wird erkenntlich, dass das Erinnern an das Shanghaier Exil über den jüdischen Kontext hinausgehend mit weiteren deutschen und chinesischen kollektiven Erinnerungen korreliert und Dialoge zwischen Ländern sowie Kulturen fördert.
Distribution network regional opportunity maintenance model design considering total supply capability upgrade of distributed power
Authors: Shen Haitian , Li Changyu , Chen Xiaofeng , Yu Qian , Shentu Jianpan , Hou Siwei
Published: February 2022

Because the existing maintenance models are not statistically analyzed, the maintenance effect is not ideal. Therefore, a distribution network area opportunistic maintenance model considering the total supply capability promotion of distributed generation is designed to achieve the total supply capability promotion and reduce the network loss rate after maintenance. Considering multiple time scales, the distribution network total supply capability model is constructed, and the improved repetitive power flow algorithm is used to count the model; taking the total supply capability model as the reliability basis of the distribution network system, and the maximum power supply capacity as the goal, the regional opportunistic maintenance model of total supply capability promotion is constructed, and the model is used to determine the area to be repaired, fully considering the reliability requirements of the distribution system, and combining with the node depth coding technology and the simulation Genetic algorithm optimizes the network structure, realizes the network reconfiguration, and completes the model solution. Through the analysis of the actual data, using this model to repair the regional equipment of distribution network can obtain good maintenance results. After the completion of maintenance, the network loss rate is low, but the total supply capability is high, which has good maintenance effect.
Research on topology adaptive method of distributed feeder automation based on IEC 61850
Authors: Zhao Ruifeng , Lu Jiangang , Chen Jinrong , Guo Wenxin , Liang Yongliang
Published: February 2022

Distributed feeder automation (FA) needs to automatically recognize the changes in the feeder topology in real-time and has to configure the application topology of the corresponding distributed functions. This paper analyzes the application topology’s requirements when implementing distributed FA for the feeder equipped with a smart terminal unit (STU) and a fault passage indicator (FPI). Based on IEC 61850, the functional logic node and topology configuration of intelligent electronic devices (IEDs) are studied. The application topology identification and data flow dynamic binding methods for fault location, fault isolation, and power supply restoration are proposed. A case study verifies the effectiveness of the proposed method.
Effects of konjac glucomannan on pasting, rheological, and structural properties of low-amylose rice starch
Authors: Yue Yuxi , Ren Bingxi , Zhong Kai , Wu Yanping , Bu Qian , Gao Hong
Published: February 2022

Blend of starch and polysaccharide is a secure and feasible modifying method for starch. Effects of konjac glucomannan (KGM) on pasting, retrogradation, rheological and structural properties of low-amylose rice starch were evaluated. KGM addition reduced the pasting temperature, breakdown and setback values, but raised the peak viscosity. When KGM concentration increased, the storage and loss moduli showed an upward trend. Fourier transform infrared spectroscopy (FTIR) showed redshifts at 3450 and 1640 cm−1 and suggested the formation of intermolecular hydrogen bond between KGM and starch molecules. X-ray diffraction (XRD) indicated that KGM decreased the relative crystallinity from 11.88 to 3.10%. Scanning electron microscopy (SEM) of KGM induced samples showed looser network structures, and confocal laser scanning microscopy (CLSM) detected less cloud-like blurry pastes surrounding around the starch ghosts. KGM addition suppressed the starch retrogradation. These results could be used to broaden the application of KGM in the food industry.
The effects of rotational and traverse speeds and SiC particles on the microstructure and mechanical properties of AA 5052 in friction stir welding
Authors: Sharabeyani Sattar , Daei Sorkhabi Amir Hossein
Published: February 2022

In this paper, the effect of variations in the traverse and rotational speeds of the welding tool on mechanical properties of friction stir welding of AA 5052 plates have been investigated. For this purpose, variations of microstructure, tensile properties and hardness of metals joined at rotational speeds of 500, 800 and 1000 rpm and traverse speeds of 41.5, 80 and 125 mm min−1 have been studied. The results showed that the average grain size of the welded joint reduced with increasing rotational and traverse speeds, because of more intensive dynamic recrystallization. Micro-hardness and ultimate tensile strength increased with increasing rotational speed. The effects of adding of SiC particles on the microstructure and mechanical properties at optimum rotational and traverse speeds were examined.
Influence of hot extrusion on the microstructure and mechanical properties of Al2O3/7075 aluminum matrix composites
Authors: Tu Kai , Yan Hong , Xiong JunJie , Wei ZhiFan , Hu Zhi , Wan JianPing , Wang ZhiLu
Published: February 2022

The influence of hot extrusion on the microstructure and mechanical properties of Al2O3/7075 aluminum matrix composites was investigated via optical microscopy, scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, transmission electron microscopy and tensile testing. The results indicate that the yield strength, tensile strength, and elongation of the as-extruded composites respectively reached 244.4 MPa, 360.3 MPa, 11.0 %, which increased by 20.24, 33.28 and 507.73 %, compared to those of the as-cast composites. The hot extrusion process grants the composites fine compactness and significantly improves the distribution of Al2O3 particles in the composite. The eutectic phase at the grain boundaries was crushed into small fragments under shear force after hot deformation. Moreover, high dislocation density near the Al2O3 particles and grain boundaries was observed in the extruded composite. The failure mode of the as-cast material was quasi-cleavage fracture, while the failure mode of the as-extruded material was primarily ductile fracture.
Radiation synthesis and characterization of polymeric wet adhesives for attracting and trapping insects
Authors: Elhady Muhamed A. , Mousaa Issa M. , Awadallah-F Ahmed
Published: February 2022

Diverse wet adhesives were prepared from oleic acid (OA), polyvinyl pyrrolidone (PVP), and cis-1,4-polyisoprene (PI) at different ratios for attracting and trapping insects. The ratios of (PVP-PI)/OA were 1:2, 1:1 and 2:1 (g/g). The ratio between PVP and PI was 9 to 1 (g/g). The blends were irradiated with doses from 10 to 50 kGy. Adhesion properties, water sorption, Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy were conducted. The results show that the adhesion of all wet adhesives was augmented by increasing the irradiation dose up to 20 kGy. The best wet adhesive composition was 2:1, which contained a high concentration of oleic acid. The wet adhesives of (PVP-PI)/OA were tested to attract and trap flies and mosquitoes.
Fabrication of magnetic core–shell Fe nanowires by electrochemical deposition
Authors: Cao Xiaoming , Mukhtar Aiman , Gu Liyuan , Wu Kai Ming
Published: February 2022

Highly-ordered Fe nanowires (NWs) were successfully electrodeposited in a laboratory made anodic aluminum oxide template with a diameter of 30 nm. The as prepared Fe NWs were used as a substrate to prepare core–shell Fe@Fe3O4 NWs after annealing and hydrogen reduction at high temperature. The phase transformation of the oxide shell of electrodeposited Fe NWs took the form Fe2O3 → α-Fe2O3 → Fe3O4. Transmission electron microscopy images revealed that the surface of Fe@Fe
x−1O
x
NWs was smooth and orderly, and the oxide layer was dense and uniform. The magnetic analysis of Fe@Fe
x−1 O
x
nanowires was carried out using a vibrating sample magnetometer. It was found that Fe@Fe3O4 nanowires manifested the characteristics of super-paramagnetism in the direction perpendicular to the nanowires due to smaller coercive force, and they can be suitable material for future biomedical applications.
Analysis of the evolution of Mg2Si precipitates during continuous cooling and subsequent re-heating of a 6061 aluminum alloy with differential scanning calorimetry and a simple model
Authors: Falkinger Georg , Reisecker Christian , Mitsche Stefan
Published: February 2022

In Al–Mg–Si alloys the presence of β-Mg2Si precipitates crucially affects strength and recrystallization during hot deformation and annealing. This work contributes to the understanding of the evolution of β-Mg2Si precipitates throughout a typical production process by investigating a continuous cooling and re-heating sequence with differential scanning calorimetry at varying rates. A simple model for nucleation and growth with improved numerical properties is presented and validated with the help of the calorimetric curves. The model, which is designed for future implementation in a finite element software, is shown to be very suitable for predicting the phase formation during cooling but limited for predicting the phase dissolution during re-heating.
Effects of alloying elements on the microstructure and mechanical properties of as-cast Cr12MoV cold-working die steel
Authors: Fang Kai , Guo Xun , Huang Feng , Zhou Jianxin , Xu Qingyan , Qin Xunpeng
Published: February 2022

A group of orthogonal experiments were conducted to investigate the effects of alloying elements on the microstructure and mechanical properties of as-cast Cr12MoV cold-working die steel. The results indicate that the solidification structures are mainly composed of equiaxed grains with reticular eutectic carbides precipitated at grain boundaries. While Mo has little effect on grain size, the structures could be effectively refined by V and Ce, and Ce addition is beneficial for breaking up the grain boundary eutectic networks. The compressive yield strength and micro-hardness increase with increasing V content and decreasing Ce content. For Mo, the yield strength and micro-hardness reach their maximum values at 0.5 wt.% and 0.9 wt.% respectively. Overall, considering the grain size number, micro-hardness and yield strength, the optimal contents of Mo, V and Ce are given.
Analysis of Mixing in Corotating Twin Screw Extruders through Numerical Simulation
Authors: Avalosse T. , Rubin Y.
Published: February 2022

Mixing is a major ingredient in many industrial processes to obtain desired and uniform material properties. Nowadays, many materials, pigments, additives, gas or reactants, are mixed to create new products combining the characteristics of different raw materials to obtain specific product properties. The quality of the mixing, i.e. the uniformity of the mixture, is a key issue that will determine the morphology and the properties of the resulting compound [1, 2]. An insight in the physics of mixing is therefore necessary in order to achieve a good quality of mixing or maintain it when scaling equipment, for example.

Such information can now be obtained through the numerical simulation of the transient flow in extruder components. To improve greatly the ease of obtaining such information, a new technique introduced in a finite elements software is presented. This technique simplifies the meshing, reduces the meshes needed and eliminates complex remeshing algorithms to simulate flow in screws, pumps and mixing devices.

This technique is validated versus traditional simulation methods (i.e. conforming meshes). 3-D transient numerical simulations of two twin screw extruder configurations are then presented. A further quantitative comparison of their mixing behavior is developed as statistical information (of the RTD, deformations, dispersion, etc.) can be obtained to compare both configurations in a synthetic and quantitative way.
The Adjustable Grooved Feed Extruder
Authors: Rauwendaal C. , Sikora J.
Published: February 2022

Grooved feed extruders have been around since about the 1960s. These extruders offer considerable advantages over conventional extruders, such as higher throughput, better stability, and the ability to process very high molecular weight polymers. There are some important disadvantages as well, for instance, higher motor load, wear is more likely, high pressures in the grooved region, and the screw design has to be adapted.

The disadvantages of the grooved feed extruder disappear when the grooved feed extruder is made with a mechanism that allows adjustment of the groove depth. This paper will report on the development of grooved feed extruders that incorporate an adjustment mechanism that allows the depth of the grooves to be changed, during actual operation, from zero to full depth. Operational data from actual extrusion experiments are presented.
Hydrolytic Depolymerization of Polyethylene Terephthalate by Reactive Extrusion
Authors: Yalçinyuva T. , Kamal M.R. , Lai-Fook R.A. , Özgümüs S.
Published: February 2022

Continuous hydrolytic depolymerization of polyethylene terephthalate (PET) resin at high temperature and pressure was carried out in a co-rotating twin screw extruder. In this novel process, hydrolysis is achieved by injection of saturated steam at high pressure. Optimum conditions occur at relatively low screw speeds and water/PET ratios. Hydrolysis extent was measured using carboxyl end group titration, and by determination of molecular weights using NMR and GPC analysis. Low molecular weight products are obtained at low residence times in the extruder, suggesting high depolymerization rates. This is supported by the results of a simple kinetic model.
Single and Double Bubble Tubular Film Extrusion of Polybutylene Terephthalate
Authors: Song K. , White J. L.
Published: February 2022

An experimental study of film formation and structure development of polybutylene terephthalate (PBT) in single and double bubble tubular film extrusion processes is presented. PBT was found largely stable in the first stage. In the second stage, the bubble was unstable and biaxial inflation was achieved only with a blow-up ratio of one. The sources of second bubble instabilities were related to the crystalline nature of the first bubble being inflated in the second stage. The structure and properties in the films varied substantially with processing conditions. While the first bubble had poorly ordered α-structure, the double bubble possessed oriented polymorphic texture. The second deformation that induced high film-line stress favored the formation of a stable β phase. The mechanical behavior of the films reflected the crystal perfection as well as orientation in the films.
Mechanical Properties of Isotactic Polypropylene with Oriented and Cross-hatched Lamellae Structure
Authors: Kech A. , Ludwig H.-C. , Möginger B. , Eyerer P. , deClaville Christiansen J.
Published: February 2022

The mechanical properties of injection moulded unreinforced isotactic, polypropylene depend on the crystalline structure and lamellae orientation. Push-pull processing is an injection moulding technique that allows the user to produce parts with oriented structures. Mostly applied for short fibre reinforced thermoplastics in order to align fibres parallel to the flow direction, this technique can also be used to orient the polymeric matrix of LCP and polypropylene. A comparison of mechanical properties as well as investigations on morphology between the samples produced using conventional injection moulding and push-pull processing are presented trying to improve the knowledge about this so far rather unknown technique.
Modification of self-reinforced composites (SRCs) via film stacking process
Authors: Jakob Fabian , Pollmeier Joshua , Bisevac Sinan , Heim Hans-Peter
Published: February 2022

This work presents the mechanical behavior of self-reinforced composites (SRCs) manufactured and modified via film stacking. For modification, interleaved films made of polypropylene (PP), a thermoplastic elastomer and a polyolefin engage were combined in different ways to induce the elastic modifier into the matrix material. The content of modifier was also varied in two ways. First, the films were produced out of a single material and second out of a compound. So, the same content of modifier was implemented in two different ways. It is shown that, in case of this research, only the kind of modifier and the content but not the way of implementation are responsible for the mechanical behavior of SRCs. It is shown that the modification can adjust the tensile strength, tensile stiffness and impact properties in a broad range. It is also shown that different mechanical properties of the composite can be predicted by a regression model that uses the Shore A hardness and the content of modifier.
Non-isothermal viscoelastic melt spinning with stress-induced crystallization: numerical simulation and parametric analysis
Authors: Wang Rui , Hao Kuangrong , Wang Huaping , Wang Chaosheng , Chen Lei , Xie Ruimin
Published: February 2022

This paper considers a model of melt spinning with stress-induced crystallization, where the melt uses the Phan Thien-Tanner model, and the solid adopts the rubber elastic model. We design a computationally efficient algorithm for solving the model. The temperature, radius, and birefringence profile in low-speed and high-speed spun PET fibers were predicted and compared with the published experimental data. The simulation results are consistent with the experimental data from the literature. Then a parametric analysis is conducted to investigate the effects of operating conditions on the spinning dynamics and reveal the relationship between the operating conditions and the final properties. The change of take-up speed has a significant influence on the crystallinity and birefringence of the fiber.
Effect of the amount of oxazoline compatibilizer on the mechanical properties of liquid crystalline polymer/polypropylene blends
Authors: Takasuka Shogo , Takahashi Tatsuhiro
Published: February 2022

The effect of the amount of 2,2′-Bis(2-oxazoline) on the spectral, thermal, morphological, and tensile properties of polypropylene (PP)/liquid crystalline polymer (LCP)/maleic anhydride grafted PP (PP-g-MAH) blends was investigated. A wholly aromatic LCP having a low melting point, namely a AL-7000 copolyester was used, because it also uses a compatibilizer with a low decomposition temperature. As the amount of 2,2′-Bis(2-oxazoline) increased, the dispersibility of the LCP improved and the tensile properties were improved, but when it was added in excess, a loss in function was observed. In particular, when 0.5 wt% of 2,2′-Bis(2-oxazoline) were added, the tensile strength and elastic modulus were the highest, and cohesive fracture (fracture within the matrix, not at the PP/LCP interface) was observed in the scanning electron microscope image.
Study of distributive mixing in a journal bearing flow geometry
Authors: Mostafaiyan Mehdi , Wießner Sven , Heinrich Gert
Published: February 2022

We implicitly assess the distributive mixing of generalized Newtonian fluids with shear-thinning behavior in a journal bearing flow geometry. For this purpose, we firstly develop a finite element code to calculate the flow field parameters. Our numerical algorithm splits the viscous stress tensor into arbitrary Newtonian stress and a source term, which grows gradually during the iterative solution. Therefore, we get a better converging solution than the Picard method, especially for highly shear-thinning fluids. Secondly, considering two inert fluids in the mixing domain, we employ a Lagrangian-Eulerian approach to predict the shape of the interface between two fluids. The results of our numerical analysis provide us the required information to evaluate three implicit mixing criteria: the concentration variance, the striation thickness, and the mean strain function. Then we conduct a parametric study to investigate the effects of different parameters (geometry and rheology) on the distributive mixing state. In addition, we discuss which mixing criteria provide a better evaluation for distributive mixing.
Exploring the applicability of a simplified fully coupled flow/orientation algorithm developed for polymer composites extrusion deposition additive manufacturing
Authors: Wang Zhaogui
Published: February 2022

Prior literature employed a finite element based fully coupled algorithm that solved the flow/orientation coupling effects in extrusion deposition additive manufacturing, i.e., a key component for identifying the material properties of solidified deposited polymer composites. However, the complex iterative solution protocol reduces the computational capability of the algorithm. This paper simplifies the finite element based fully coupled algorithm by employing a scalar representation of the fourth order orientation tensor affected viscosity tensor. The revised code predicts similar fiber orientation results as compared to a related prior study. With the simplified fully coupled algorithm, effects of material deposition rate and fiber aspect ratio on a 2D planar large area extrusion deposition flow are explored, where the power law rheology model is employed for the flow simulation. Computed results show that an increased material deposition rate reduces the extrudate-swell ratio of the melt front and varies the local fiber orientation of the deposited bead especially near the flow region in contact with the substrate. Higher fiber aspect ratio enhances the principal fiber alignment of the extrusion and deposition flows, where the maximum local difference of the principal A
11 component is 23% with increasing fiber aspect ratio from 10 to 25.
Prophylactic management of radiation-induced mucositis using herbal mouthwash in patients with head and neck cancer: an assessor-blinded randomized controlled trial
Authors: Kongwattanakul Sirikorn , Petchann Nutjaree , Petroch Petcharat , Thanthong Saengrawee , Tungfung Sunanta , Chamchod Sasikarn , Pitiporn Supaporn , Nantajit Danupon
Published: February 2022

Objectives

Radiation-induced mucositis (RIOM) is one of the most common side effects from head and neck radiotherapy. Several reagents have been introduced to manage the symptom; however, there is still a limited number of effective reagents. Herbal mouthwashes with payayor (Clinacanthus nutans Lindau) and fingerroot (Boesenbergia rotunda) were tested their efficacies in preventing and reducing severity of RIOM in comparison with normal saline with sodium bicarbonate.

Methods

One hundred twenty patients with head and neck cancer undergoing radiotherapy participated in the study and were randomly assigned into three treatment groups using block randomization method. The participants were assigned one of the three mouthwashes for use throughout their radiotherapy course and were assessed for their mucositis scores from week one to six into their radiotherapy course as well as at one-month follow-up. Body mass index was also measured for comparison of nutritional status.

Results

The two mouthwashes were similarly effective in prophylaxis of RIOM in term of severity. The averaged mucositis scores were less than two for all groups. For the onset of RIOM, both herbal mouthwashes could slightly delay the symptom but not statistically significant. Patients’ body mass index across the three treatment groups was also comparable. The patients were largely satisfied with all the mouthwashes with no clear preference on any of them.

Conclusions

Prophylactic treatment of RIOM using herbal mouthwashes could substitute the current standard of normal saline with bicarbonate. A different formulation of the two herbs could potentially improve the prophylactic outcome.

Trial Registration No

NCT03359187.
Nilpotent groups with balanced presentations
Authors: Hillman Jonathan A.
Published: February 2022

We show that if a nilpotent group 𝐺 has a balanced presentation and Hirsch length

h
⁢

(
G
)

>
3

h(G)>3

, then

β
1

⁢

(
G
;
Q
)

=
2

\beta_{1}(G;\mathbb{Q})=2

.
There is one such group which is torsion-free and of Hirsch length

h
=
4

h=4

, and none with

h
=
5

h=5

.
We also construct a torsion-free nilpotent group 𝐺 with

h
⁢

(
G
)

=
6

h(G)=6

and

β
2

⁢

(
G
;
F
)

=

β
1

⁢

(
G
;
F
)

\beta_{2}(G;F)=\beta_{1}(G;F)

for all fields 𝐹.
Research on intelligent interactive music information based on visualization technology
Authors: Liao Ningjie
Published: February 2022

Combining images with music is a music visualization to deepen the knowledge and understanding of music information. This study briefly introduced the concept of music visualization and used a convolutional neural network and long short-term memory to pair music and images for music visualization. Then, an emotion classification loss function was added to the loss function to make full use of the emotional information in music and images. Finally, simulation experiments were performed. The results showed that the improved deep learning-based music visualization algorithm had the highest matching accuracy when the weight of the emotion classification loss function was 0.2; compared with the traditional keyword matching method and the nonimproved deep learning music visualization algorithm, the improved algorithm matched more suitable images.
The impact of self-efficacy on nonoperative treatment of atraumatic shoulder pain
Authors: Grandizio Louis C. , Choe Lisa J. , Follett Lisa , Laychur Andrew , Young Amanda
Published: February 2022

Context

Atraumatic shoulder pain is frequently encountered in primary care and surgical clinics. With increased recognition of the biopsychosocial model, there has been an increased emphasis on identifying patient factors associated with less effective coping strategies such as pain catastrophizing. It remains uncertain what impact self-efficacy has on the response to nonoperative treatment of shoulder pain.

Objectives

Our purpose is to determine the influence of patient coping strategies (self-efficacy) on the outcome of nonoperative treatment of atraumatic shoulder pain. We hypothesize that higher levels of self-efficacy are associated with increased self-reported function after nonoperative treatment.

Methods

We conducted a retrospective case-control study for a consecutive series of patients seen in our clinic with nonoperatively managed atraumatic shoulder pain. Baseline demographics and range of motion were recorded. Patients completed the Simple Shoulder Test (SST), PROMIS Pain Interference (PI), and PROMIS Self-Efficacy for Managing Symptoms (SE). After 3 months of nonoperative treatment, patients were placed into two groups: patients who clinically improved (Group 1) and those that did not (Group 2), with clinical improvement defined as an increase of 2 or greater on the SST.

Results

Seventy-eight patients returned for follow-up and completed all questionnaires. There were no statistically significant differences for age, sex, or tobacco use between the two groups. Half of the patients in our series had symptoms for >12 months, with rotator cuff syndrome being the most frequent diagnosis (40.0%). Patients in Group 1 had significantly higher PROMIS SE scores (42 vs. 39, p=0.0094) at initial evaluation. At 3-month follow-up, patients in Group 1 also had significantly lower Numeric Pain Rating Scale (NPRS) scores (4.5 vs. 6.5, p=0.0067), compared to Group 2.

Conclusions

Patients who experience clinical improvement with nonoperative treatment of atraumatic shoulder conditions demonstrate higher self-efficacy than patients who fail to improve. Guiding patients with atraumatic shoulder pain and low self-efficacy toward interventions aimed at improving coping strategies, rather than addressing musculoskeletal factors alone, may contribute to the goal of improving outcomes.
Tort Theory and Restatements: Of Immanence and Lizard Lips
Authors: Engstrom Nora Freeman , Green Michael D.
Published: February 2022

This Essay gingerly enters the tort theory “wars” that torts scholars have been debating for many decades. Is the essence of tort law instrumentalism in some form, including most notably in providing appropriate incentives to minimize the costs of accidents, as Guido Calabresi normatively proposed and William Landes and Richard Posner descriptively claimed? Or, on the other hand, is tort law simply about the injurer and victim and the just manner for allocating the victim’s loss—blind to any collateral consequences?

We address these debates from our perspective as Restatement Reporters, honing in on the question of what role tort theory plays in our work. Our answer is virtually none. There are two independent and sufficient reasons for this conclusion. First, we are deeply skeptical that there is an immanent meta-theory that explains tort law or guides its development. Instead, we think tort law is a hodgepodge, influenced by public policy, culture, administrative concerns, evidentiary lacunae, technological developments, and random events. These eclectic and shifting forces influence what tort law is and how it evolves with the felt needs of any given era. Tort law, in short, is built from the bottom up, not the top down and is far too messy to be the product of intelligent design. Beyond that, even if there were such a force at tort law’s heart, that force would still have little influence on our work. The doctrinal level at which Restatements operate and the case law that fuels the production of Restatements—ground level law—is a disjunction from theory, which operates at 30,000 feet. This disjunction means that the latter is of little assistance when it comes to addressing the quotidian matters important to tort law and Restatements. Whether tort law is entirely instrumental or solely about corrective justice cannot answer the question of whether parents should have immunity from tort suits by their children. The answer to that question must be found in the case law, not in Kant.
Revisiting taxonomic disparities in the genus Naemorhedus: new insights from Indian Himalayan Region
Authors: Joshi Bheem Dutt , Singh Vinaya Kumar , Singh Hemant , Bhattacharjee Saurav , Singh Ashutosh , Singh Sujeet Kumar , Chandra Kailash , Sharma Lalit Kumar , Thakur Mukesh
Published: February 2022

Gorals are distributed in varied ranges of habitats in South and South–East Asia, and the existence of the number of species in the genus Naemorhedus has been greatly debated from time to time. A school of thought supports the presence of three species, while a recent genetic study recognizes five species of goral throughout their distribution range. However, the unavailability of DNA sequences of gorals from India left a gap in understanding the species occurrence in Indian Himalayan Region (IHR). We revisited goral taxonomy by sequencing mitochondrial Cytochrome b gene (∼404 bp) and control region (∼225 bp) of 75 Himalayan gorals from Western and Central Himalayas in India. Based on various species delineating methods, we suggest that Himalayan goral (N. goral) is a highly diverged species and possibly exists into two subspecies, i.e. N. g. bedfordi in Western Himalayas and N. g. goral in the Central Himalayas. We validate the presence of plausibly six species of gorals across the distribution and recognize N. griseus and N. goral are two distinct species considering the observed discrepancy in the available sequences. We also propose that goral populations distributed in Western and Central Himalayas may be considered as two evolutionary significant units (ESUs). This recognition will bring concentrated efforts in further exploring the natural populations and ecological information required for prioritizing conservation and management of Himalayan goral.
Unbiased estimation of the gradient of the log-likelihood for a class of continuous-time state-space models
Authors: Ballesio Marco , Jasra Ajay
Published: February 2022

In this paper, we consider static parameter estimation for a class of continuous-time state-space models. Our goal is to obtain an unbiased estimate of the
gradient of the log-likelihood (score function), which is an estimate that is unbiased even if the stochastic processes involved in the model must be discretized in time. To achieve this goal, we apply a doubly randomized scheme, that involves a novel coupled conditional particle filter (CCPF) on the second level of randomization. Our novel estimate helps facilitate the application
of gradient-based estimation algorithms, such as stochastic-gradient Langevin descent. We illustrate our methodology in the context of stochastic gradient descent (SGD) in several numerical examples and compare with the Rhee–Glynn estimator.
Festigkeitsnachweis unter Mixed-Mode-Beanspruchung
Authors: Richard Hans Albert
Published: February 2022

Die im Jahr 2001 erschienene FKM-Richtlinie „Bruchmechanischer Festigkeitsnachweis“ [1] enthält wichtige Hinweise und Regeln zur bruchmechanischen Beurteilung von mechanisch beanspruchten Bauteilen mit Fehlern wie z.B. Rissen. Dabei werden insbesondere Risse betrachtet, bei denen sich infolge Bauteilbelastung oder Bauteilgeometrie symmetrische Spannungsfelder in der Umgebung der Rissspitze ergeben (Mode I-Beanspruchung von Rissen). Liegen jedoch unsymmetrische Spannungsfelder in der unmittelbaren Umgebung des Risses vor, spricht man von Mixed-Mode-Beanspruchung. Dabei können in Sonderfällen auch reine Mode II (lokale ebene Schubbeanspruchung des Risses) und reine Mode III (lokale nichtebene Schubbeanspruchung des Risses) auftreten. Die bruchmechanische Behandlung von Mixed-Mode-Rissproblemen ist zwar etwas komplexer als die Betrachtung von reinen Mode I-Rissproblemen, der Erkenntnisstand für Fälle mit unsymmetrischer Rissbeanspruchung ist in den letzten Jahren aber so weit gewachsen,zdass sich dieser in die Konzepte der FKM-Richtlinie integrieren lässt. Wie ein bruchmechanischer Festigkeitsnachweis bei Mixed-Mode-Beanspruchung von Rissen aussehen kann, wird in diesem Beitrag dargestellt.
Bruchmechanisches Bewerten dünnwandiger Strukturen
Authors: Zerbst Uwe , Schödel Manfred
Published: February 2022

In Ergänzung der europäischen SINTAP-Prozedur wird eine spezielle Option zum bruchmechanischen Bewerten dünnwandiger Strukturen vorgeschlagen, bei der die Grundgleichungen von SINTAP mit dem CTOD-δ5-Konzept verknüpft werden. Das Konzept ist mit Normvorschlägen der ASTM und ISO zum Ermitteln bruchmechanischer Kennwerte für Strukturen mit geringer Dehnungsbehinderung kompatibel. Als dünnwandig werden Strukturen definiert, bei denen das Verhältnis aus Risstiefe oder Ligamentlänge zu Probendicke mindestens vier beträgt. Die experimentelle Validierung an drei Aluminium-Legierungen sowie zwei ferritischen und einem austenitischen Stahl unter Zug-, Biege- und biaxialer Zugbelastung ergab konservative Vorhersagen der Maximallast und der Risswachstumscharakteristik für die Plattendicken größer als 5 mm und annähernd exakte Vorhersagen für die Plattendicken von 1,6, 2,5 und 3mm.
Alterungsprüfung transparenter Kunststoffdächer
Authors: Schulz Ulrich , Tjandraatmadja Grace
Published: February 2022

Um die Lebensdauer von transparenten Kunststoffdächern voraussagen zu können, werden für die am häufigsten eingesetzten Polymere, Polymethylmetacrylat (PMMA) und Polycarbonat (PC), materialspezifische künstliche Bewitterungsmethoden mit vertretbarer Untersuchungsdauer vorgestellt. Sie berücksichtigen diejenigen für jeden Werkstoff charakteristischen Wetterepisoden, die zur schnellsten Alterung führen, dem Worst-Case-Szenarium. Ein für alle Polymerwerkstoffe geeignetes Bewitterungsverfahren ist nicht sinnvoll.
Bestimmung der elastischen Eigenschaften von Festkörpern – Teil 1
Authors: Beckmann Jörg , Rehmer Birgit , Finn Monika , Glaubitz Steffen
Published: February 2022

Für die Berücksichtigung mechanischer Belastungen unterhalb der Streckgrenze ist im Rahmen einer zuverlässigen Bauteilauslegung die Kenntnis der elastischen Konstanten von besonderer Bedeutung. Für die experimentelle Bestimmung des Elastizitätsmoduls wurde eine Vielzahl von Verfahren entwickelt, die zum Teil werkstoffspezifisch Eingang in die Normung gefunden haben. Prinzipiell können diese Verfahren in zwei Gruppen unterteilt werden: die statischen und die dynamischen Prüfverfahren. Die statischen Verfahren beruhen auf der direkten Messung des Spannungs-Dehnungs-Zusammenhangs während einer mechanischen Belastung im elastischen Verformungsbereich (Zug, Biegung, Druck). Die dynamischen Verfahren basieren auf der Schwingungsanregung eines Prüfkörpers und der Analyse der resultierenden Schwingungen (Resonanzmethode oder Impulsanregungsmethode) oder auf der Messung der Ultraschallausbreitungsgeschwindigkeit. Stellvertretend für die dynamischen Verfahren wird im ersten Teil dieses Beitrages die Resonanzmethode vorgestellt. Der zweite Teil dieses Beitrages fasst die werkstoffabhängigen Ergebnisse der E-Modulbestimmung mit statischen Verfahren im Zug- und Biegeversuch zusammen.
Some relations between elastic and physical parameters of pure metals
Authors: Buch Alfred
Published: February 2022

The present contribution shows that a correlation between the rating of elastic moduli E [tension], G [torsion] and B [for hydrostatic compression] and that of the latent fusion heat for metallic elements exits in subgroups. It was shown that for pairs of metals with close E-values and close values of atomic mass and volume parameters, also the bulk moduli B are close. However when the mass-parameter of the second metal of the pair is evidently smaller, than also its B-modulus is much smaller for this metal. Therefore is the Young’s modulus a better measure of bond force magnitude than the bulk modulus.
Correlation between magnitude sequence of Young’s moduli and physical properties of pure metals
Authors: Buch Alfred
Published: February 2022

In the case of consecutive increase of the atomic number AN the sequence of Young’s modulus E, of latent fusion heat L cal/cc and of the reciprocal atomic volume (1/V) is mostly similar. The magnitude sequence of metals melting points is sometimes different than that of the E-modulus.
Measurement and control of copper and tin coatings
Authors: Runje Biserka , Alar Željko , Rede Vera
Published: February 2022

Comparison of thickness measurement for selectively applied copper and tin coatings on printed circuit boards was performed by use of destructive and non-destructive methods. The analysis of measurement results was performed by applying criterion of critical difference of repeatability and reproducibility according to international standard ISO 5725-(1-6):1994. Comparison of results for measuring ranges on the basis of critical difference of reproducibility, shows that results of measurement for copper and tin coatings obtained by using different methods are mutually comparable. In measuring tin coating, repeatability of measurement results was achieved and that means that results obtained in very strict conditions are comparable.
Einsatz von Computertomographie in der Reverse-Engineering-Technologie
Authors: Bartscher Markus , Hilpert Uwe , Goebbels Jürgen , Weidemann Gerd , Puder Holm , Jidav Horia-Nicolae
Published: February 2022

Unter vollständigem Reverse-Engineering (RE) versteht man die physische Rekonstruktion eines Bauteils ohne Kenntnis seiner Konstruktionsdaten. Am Anfang einer vollständigen Reverse-Engineering-Prozesskette steht das Originalbauteil, am Ende seine physische Kopie. Sollen auch innere Bauteilgeometrien erfasst werden, ist Computertomographie (CT) mit Röntgenstrahlen ein wesentlicher Bestandteil dieser Prozesskette. In diesem Beitrag wird am Beispiel eines Zylinderkopfes – einer historischen Motorkomponente eines Horch 853 Automobils von 1935–37 – eine vollständige RE-Prozesskette dargestellt und der Einfluss der verschiedenen Prozessschritte auf die Rekonstruktion des Originalteils untersucht. Die Prozesskette besteht aus der Bestimmung von äußeren und inneren Geometrien durch optische und CT-Messtechnik, der Verschmelzungder Ausgangsmessdaten zu einem einzigen Multisensordatensatz und dem Erstellen des virtuellen Modells, d. h. eines geeigneten Konstruktionsdatensatzes als Ausgangsbasis für die Fertigung der Bauteilkopien. Die Fertigung baut hier auf weiteren abgeleiteten Datensätzen auf, die gießtechnische sowie Bearbeitungsmodifikationen enthalten. Durch die notwendige Adaption an moderne Fertigungstechniken beinhaltet die Rekonstruktion eines historischen Bauteils immer auch eine partielle Umkonstruktion. Der originale Zylinderkopf diente als Vorlage für ein virtuelles Modell, von dem mehrere Kopien aus unterschiedlichen Materialien (Grauguss, Aluminium) angefertigt wurden. Der Beitrag stellt die angewandte, optimierte Prozesskette dar.
Omni-directional and broadband acoustic anti-reflection and universal acoustic impedance matching
Authors: Im Ku , Park Q-Han
Published: February 2022

The mechanism of the perfect anti-reflection of acoustic waves, regardless of frequency and incident angle, is presented. We show that reflections at a planar interface between two different acoustic media can be removed by adding a nonlocal metamaterial that compensates for the impedance mismatch. The properties required of a nonlocal metamaterial are explicitly specified through spatio-temporally dispersive mass density and bulk modulus. We analyze the characteristics of spatio-temporal dispersion according to the thickness of the matching layer. We discuss the issue of the total internal reflection caused by conventional matching layers and explain how our nonlocal matching layer avoids this. The practical design of our nonlocal layer using metamaterials is explained. The omni-directional frequency-independent behavior of the proposed anti-reflection matching layer is confirmed through explicit numerical calculation using the finite element method, and comparisons made to the conventional quarter-wave matching layer approach.
Terahertz 3D bulk metamaterials with randomly dispersed split-ring resonators
Authors: Okatani Taiyu , Sunada Yuto , Hane Kazuhiro , Kanamori Yoshiaki
Published: February 2022

While optical systems using terahertz wave are expected to achieve beneficial applications, at present, the materials of the optical elements that compose them must be selected from limited choices. In this study, we propose a three-dimensional bulk metamaterial in which metal microstructures are dispersed in the bulk resin randomly. A bulk metamaterial was designed and fabricated, in which split-ring resonators known as typical metamaterials were dispersed in cyclo-olefin polymer. In the fabrication method, a resin sheet containing split-ring resonators was first prepared and then diced into resin grains containing a single split-ring resonator. Finally, they were filled in a mold and solidified with a resin solution to obtain the target bulk metamaterial. The optical properties of the fabricated bulk metamaterial were measured by terahertz time-domain spectroscopy. The measurement results confirmed that the refractive index deviated from the original refractive index of the cyclo-olefin polymer due to the resonance of split-ring resonators, suggesting that the proposed bulk metamaterials could be used as a new optical material in the terahertz band.
Probing the long-lived photo-generated charge carriers in transition metal dichalcogenides by time-resolved microwave photoconductivity
Authors: Herman Artur P. , Zelewski Szymon J. , Misztal Kamil , Kudrawiec Robert
Published: February 2022

Understanding the dissociation of excitons into long-lived free charge carriers is a crucial issue when considering the applications of transition metal dichalcogenides (excitonic semiconductors) oriented toward the use of solar energy (such as photovoltaics or photocatalysis). In our work, long-lived carriers have been observed by time-resolved microwave photoconductivity (TRMC) for the first time in both atomically thin and bulk MoS2, MoSe2, WS2, and WSe2 crystals. The lifetime of majority carriers is close to microseconds and can even reach several microseconds due to different contribution of surface and defect states, as well as surface band bending (bulk). The three components depend on the material and vary from sample to sample, therefore determining the dynamics of the TRMC signal. The rise time of TRMC signal was found to be in the range of 0.1–0.2 μs and as it depends on the studied material it can be speculated that it is related to the dissociation time of excitons captured by traps.
All-metallic high-efficiency generalized Pancharatnam–Berry phase metasurface with chiral meta-atoms
Authors: Cai Jixiang , Zhang Fei , Pu Mingbo , Chen Yan , Guo Yinghui , Xie Ting , Feng Xingdong , Ma Xiaoliang , Li Xiong , Yu Honglin , Luo Xiangang
Published: February 2022

Metasurfaces based on the Pancharatnam–Berry (PB) phase have attracted significant attention in the domains of subwavelength optics and electromagnetics. Conventional theory predicts that the PB phase is exactly twice the rotation angle of the anisotropic meta-atoms. Differently, a recent advance has demonstrated that the generalized PB phase representing multiple times of the rotation angle could be obtained with high-fold rotational symmetry meta-atoms, but it suffers from the low cross-polarization conversion efficiency (the theoretical upper limit of 25%) that impedes its further applications, especially for meta-atoms with rotational symmetry ≥3. Here, we verify that the chiral meta-atoms with high-fold rotational symmetries could produce the generalized PB phase. Besides, the all-metallic configuration is utilized to design C2, C3, and C5 chiral catenary meta-atoms to improve their efficiency and bandwidth. The equivalent air waveguide with low loss between two adjacent meta-atoms is formed to analyse the higher performances of the all-metallic scheme for the realization of the generalized PB phase compared with the metal–insulator–metal and all-dielectric C3 meta-atoms. As a proof of concept, four metadevices including two spin-Hall metadevices and two holograms are experimentally demonstrated and their maximum efficiency could exceed 83% in simulation. This work could provide a high-efficiency platform for the study of the generalized PB phase in linear and nonlinear optics.