Development and application of ab initio electron dynamics on traditional and quantum compute architectures

Electron dynamics processes are of utmost importance in chemistry. For example, light-induced processes are used in the field of photocatalysis to generate a wide variety of products by charge transfer, bond breaking, or electron solvation. Also in the field of materials science, more and more such processes are known and utilized, for example, to design more efficient solar cells. Even the formation of bonds in molecules is an electron dynamics process. Through experimental progress, it is now even possible to trigger specific processes and chemical reactions with special laser pulses. To study all these processes, computer-aided simulations are an indispensable tool. Depending on the size of the molecules considered and the desired accuracy, however, the underlying quantum-mechanical properties result in numerical formulas whose computation far exceeds the capabilities of even modern supercomputers. In this thesis, three projects are presented to demonstrate modern use cases of electron dynamics and show how recent developments in computer technology and software design can be used to develop more efficient and user-friendly programs. In the first project, the inter-Coulombic decay (ICD), an ultrafast energy transfer process, between two isolated chemical structures is investigated. After the excitation of one structure, the energy is transferred to the other, which is ionized as a result. The process has already been shown experimentally in atoms and molecules and is studied here for quantum dots, focusing on systems with more quantum dots and higher dimensions for the continuum than in previous studies. These elaborate studies are made possible by implementing computationally intensive program parts of the Heidelberg MCTDH program used on graphics processing units (GPUs). The performed studies show how the ICD process behaves with multiple partners as well as which competing decay processes occur and thus provide relevant information for the development of technologies based on quantum dots such as quantum dot qubits for use in quantum computers. Electron dynamics processes are not only relevant in the development of new quantum computers, but conversely, quantum computers can also provide the ability to perform electron dynamics with significantly more interacting electrons and a smaller error than it would ever be possible with traditional computers. In another project, therefore, a quantum algorithm was developed that could enable such simulations and their analysis in the future. The quantum algorithm was implemented in the dynamics program Jellyfish, which was also developed in the context of this dissertation. The program is based on a graphical user interface oriented on dataflow programming, which simultaneously leads to a modular structure. The resulting modules can be combined flexibly, which allows Jellyfish to be used for a wide variety of applications. In addition to dynamic algorithms, novel analysis methods were developed and demonstrated on laser-driven electronic excitations in molecules such as hydrogen, lithium cyanide, or guanine. Thus, the generation of electronic wave packets as well as transitions between electronic states were studied in an explicitly time-dependent manner and the formation of the exciton in such processes was described qualitatively by means of densities as well as quantitatively by so-called exciton descriptors such as exciton size or hole and particle position. Thus, in summary, this dissertation presents both new insights into electron dynamic processes and new possibilities for more efficient simulation of these processes using GPU implementations and quantum algorithms. The developed dynamics program Jellyfish offers the potential to be used in many further studies in this area and to be extended to allow for example simulations with a continuum like in the ICD calculations in the future

Three-Electron Dynamics of the Interparticle Coulombic Decay in Doubly Excited Clusters with One-Dimensional Continuum Confinement

A detailed analysis of the electronic structure and decay dynamics in a symmetric system with three electrons in three linearly aligned binding sites representing quantum dots (QDs) is given. The two outer A QDs are two-level potentials and can act as (virtual) photon emitters, whereas the central B QD can be ionized from its one level into a continuum confined on the QD axis upon absorbing virtual photons in the inter-Coulombic decay (ICD) process. Two scenarios in such an ABA array are explored. One ICD process is from a singly excited resonance state, whose decay releasing one virtual photon we find superimposed with resonance energy transfer among both A QDs. Moreover, the decay-process manifold for a doubly excited (DE) resonance is explored, in which collective ICD among all three sites and excited ICD among the outer QDs engage. Rates for all processes are found to be extremely low, although ICD rates with two neighbors are predicted to double compared to ICD among two sites only. The slowing is caused by Coulomb barriers imposed from ground or excited state electrons in the A sites. Outliers occur on the one hand at short distances, where the charge transfer among QDs mixes the possible decay pathways. On the other hand, we discovered a shape resonance-enhanced DE-ICD pathway, in which an excited and localized B∗ shape resonance state forms, which is able to decay quickly into the final ICD continuum

Animal Welfare during Transport and Slaughter of Cattle: A Systematic Review of Studies in the European Legal Framework

Literature related to European transport and slaughter processes were included in this systematic review. The publication period is limited to the past twelve years since the European Animal Welfare Transport Regulation was enacted in 2009. Three different databases were used. The final screening resulted in the inclusion of 19 articles in this review. When handling cattle during transport and slaughter, personnel have an important impact and may inflict stress on the animals. Other factors, such as the group composition and health status prior to transport, can have a strong negative effect on animal welfare. At the abattoir, constructional conditions and the resulting environmental influences can have a negative impact on welfare as well. These include increased noise levels due to the lack of noise dampening and changing light conditions. Stress in cattle can be assessed, e.g., by measuring stress hormones or heart rate. Effective stunning is an important welfare-relevant step in the slaughtering process. Some signs of unconsciousness, such as immediate body collapse or absence of the corneal reflex, can be easily assessed. Expertise and continuous training of all personnel involved are important measures in stress reduction

Streptococcus suis in German pig holdings—conventional and molecular detection

Streptococcus suis (S. suis) is a zoonotic agent worldwide. Pigs are the main reservoir, mostly asymptomatic. Humans get the infection by contact and consumption of contaminated meat and meat products. In this study, samples from 38 pig carcasses fit for human consumption from 17 holdings were arbitrarily selected. From each carcass, seven tissue samples were taken and examined for the presence of S. suis, using conventional microbiology and PCR. In addition, virulence-associated factors (epf, arcA, sly, mrp) were tested with PCR. More isolates were PCR-positive for S. suis as compared to conventional testing, mostly in samples from the heart and from the mandibular lymphnodes. All isolates were epf negative, combinations of arcA, sly and mrp were found in some isolates. Six isolates were positive for arcA and mrp, five for arcA and sly. For three isolates the triple combination arcA + mrp + sly was found. These isolates originated from different pigs

Impact of Procedures and Human-Animal Interactions during Transport and Slaughter on Animal Welfare of Pigs: A Systematic Literature Review

Animal welfare during the transport and slaughter of pigs is in the interests of consumers and producers. All procedures and human-animal interactions on the day of slaughter are potentially stressful for the pigs. Good handling practices—calm handling and a handling set to the individual needs of the pigs—and management of the animals provide the maximum animal welfare at slaughter, but only by avoiding or minimizing any further external stressors in addition to the transport and the slaughter itself. By conducting a systematic literature review, we wanted to find out which procedures and human-animal interactions were found by researchers to have an impact on welfare during pig transport and slaughter. Direct human-animal contact and the management of transport and slaughter procedures were identified as major influencing factors. As the animal welfare-sensitive areas of stunning, control of stunning, and bleeding are highly important, personnel should be trained regularly to ensure good practices and animal welfare. Deficient handling and procedures in the transport/slaughter processes can be critically scrutinized and corrected only when personnel are sufficiently educated. Knowledge of best handling practices is necessary to reflect on our own and other personnel’s behaviour and to maintain awareness of animal welfare. Animal suffering caused by humans is not acceptable

Intertextuality in the Legal Papers of Karl Kraus: A Scholarly Digital Edition

Projektberich

A comparative survey of veterinarians, equine owners, and equine keepers regarding the knowledge and implementation of legal requirements in Germany for the use and documentation of veterinary medicines in equines intended for slaughter

In Europe, equines destined for human consumption (hereafter called slaughter equines) are subject to the same restrictions of usage of veterinary drugs as other food-producing animals, with amendments regulated in the so-called ‘positive list’, Regulation (EC) No. 1950/2006. Due to the complex legal requirements for drug administration in slaughter equines, it might be that specific knowledge regarding the legislation of slaughter equines may be insufficient among veterinarians, equine owners, and equine keepers. To study this assumption, three target group-specific surveys were conducted in 2021. Answers from 153 equine treating veterinarians, 170 equine owners, and 70 equine keepers were included in the analysis. In total 68.4% (91/133) of the participating veterinarians, the regulations of the ‘positive list’, Regulation (EC) No. 1950/2006, were ‘rather complicated’ to ‘complicated’. Among the participating veterinarians, 38.4% (58/151) did not or could not answer correctly how to proceed if a slaughter equine is scheduled to receive phenylbutazone, usage of which is prohibited in all livestock by Regulation (EU) No. 37/2010. Simultaneously, 56.2% (86/153) of the participating veterinarians named phenylbutazone as the, or one of the, most often used non-steroidal anti-inflammatory drugs. Altogether, 41.2% (70/170) of participating equine owners and 42.9% (30/70) of equine keepers did not know under which circumstances an equine can legally be slaughtered for human consumption. In total, 34.3% (24/70) of the equine keepers classified their knowledge of national regulations for animal keepers regarding the documentation of drug usage in equines as ‘poor’ to ‘nonexistent’. This lack of knowledge in all three surveyed groups, combined with the complex legal regulations regarding the usage and documentation of drugs in slaughter equines, could result in missing and false documentation, treatment of slaughter equines with prohibited substances and therefore pose a risk factor for drug residues in equine meat

Three electron dynamics of the interparticle Coulombic decay with two dimensional continuum confinement

In a pair of self assembled or gated laterally arranged quantum dots, an electronically excited state can undergo interparticle Coulombic decay. Then, an electron from a neighbor quantum dot is emitted into the electronic continuum along the two available dimensions. This study proves that the process is not only operative among two but also among three quantum dots, where a second electron emitting dot causes a rate increase by a factor of two according to the predictions from the analytical Wigner Weisskopf rate equation. The predictions hold over the complete range of conformation angles among the quantum dots and over a large range of distances. Electron dynamics was calculated by multiconfiguration time dependent Hartree and is, irrespective of the large number of discrete variable representation grid points, feasible after having developed an OpenACC graphic card compilation of the progra

Modeling of interventions for reducing external Enterobacteriaceae contamination of broiler carcasses during processing

This article presents a mathematical model for the Enterobacteriaceae count on the surface of broiler chicken during slaughter and how it may be affected by different processing technologies. The model is based on a model originally developed for Campylobacter and has been adapted for Enterobacteriaceae using a Bayesian updating approach and hitherto unpublished data gathered from German abattoirs. The slaughter process in the model consists of five stages: input, scalding, defeathering, evisceration, washing, and chilling. The impact of various processing technologies along the broiler processing line on the Enterobacteriaceae count on the carcasses’ surface has been determined from literature data. The model is implemented in the software R and equipped with a graphical user interface which allows interactively to choose among different processing technologies for each stage along the processing line. Based on the choice of processing technologies the model estimates the Enterobacteriaceae count on the surface of each broiler chicken at each stage of processing. This result is then compared to a so-called baseline model which simulates a processing line with a fixed set of processing technologies. The model calculations showed how even very effective removal of bacteria on the exterior of the carcass in a previous step will be undone by the cross-contamination with leaked feces, if feces contain high concentrations of bacteria

Hepatitis E virus cross-contamination on the surface of porcine livers after storage in Euro meat containers in a German pig abattoir

Hepatitis E virus (HEV) is a foodborne zoonotic pathogen and known as the causative agent of hepatitis E in humans. The specific role of porcine liver as a vehicle for human HEV infections has been highlighted in different studies. Nevertheless, gaps of knowledge still exist regarding possible HEV cross-contamination both at consumer and production level. Furthermore, people working in the food production industry, e.g. veterinarians and abattoir employees, are exposed to an increased risk of HEV infection. The aim of the present study was to investigate HEV cross-contamination on the surface of porcine liver in a German abattoir. The sample set included 250 samples of porcine liver parenchyma and the corresponding 250 superficial layer samples of the same livers, which were analyzed for the presence of HEV ribonucleic acid (RNA). Afterwards, the initial status of the tested liver parenchyma was compared with the occurrence of HEV RNA in the corresponding superficial layer. HEV RNA was detectable in 34% (85/250) of superficial layer samples, with 58% (49/85) of the samples originated from initially HEV negative livers. To our knowledge, this is the first study that provides an insight in the potential of HEV cross-contamination at abattoir level in Germany. Furthermore, it could be identified that the joint storage of livers in Euro meat containers has a significant impact on the presence of HEV RNA on the surface of porcine liver