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Abstract Energy optimization of factory operations has gained increasing importance over recent years since it is understood as one way to counteract climate change. At the same time, the number of research teams working on energy-optimized factory operations has also increased. While many tools are useful in this area, our team has recognized the importance of a comprehensive framework to combine functionality for optimization, simulation, and communication with devices in the factory. Therefore, we developed a framework that provides a standardized interface to research energy-optimized factory operations with a rolling horizon approach. The optimization part of the framework is based on the OpenAI gym environment. The framework also provides connectors for multiple communication protocols including Open Platform Communication Unified Architecture and Modbus via Transmission Control Protocol. These facilities can be utilized to implement rolling horizon optimizations for factory systems easily and directly control devices in the factory with the optimization results. In this article, we present the framework and show some examples to prove the effectiveness of our approach.

Abstract Nations and companies are forced to reduce CO2 emissions and decelerate global warming. In this development, the transition of the heating sector is still in its infancy despite the relatively large share of thermal energy in the total energy consumption. Industrial companies can contribute significantly to reduce CO2 emissions by using waste heat through connecting their industrial energy supply system (IESS) to a district heating system (DHS). This paper focuses on emission reduction potential of an (industrial) heat transfer station (HTS) regarding energy flexibility and sector coupling required for the successful integration of industrial waste heat. To optimize the operating behaviour of the HTS, a data and optimization model is integrated into a digital twin (DT) based on reference architecture model for industry 4.0 (RAMI4.0). Within the DT, the information, functional and business layer are modeled. The effects of operating the HTS supported by central modules of the DT are evaluated on one year’s data of an IESS of a real industrial site. The results show a potential operating cost reduction by 6 % for the IESS and increases in profits of 1.3 % for the DHS. Scope 2 emissions can be reduced by 25 % for the IESS and 180 % for the DHS respectively, strongly depending on emission factors and allocation methods.

Abstract Both rising and more volatile energy prices are strong incentives for manufacturing companies to become more energy-efficient and flexible. A promising approach is the intelligent control of Industrial Energy Supply Systems (IESS), which provide various energy services to industrial production facilities and machines. Due to the high complexity of such systems widespread conventional control approaches often lead to suboptimal operating behavior and limited flexibility. Rising digitization in industrial production sites offers the opportunity to implement new advanced control algorithms e. g. based on Mixed Integer Linear Programming (MILP) or Deep Reinforcement Learning (DRL) to optimize the operational strategies of IESS.This paper presents a comparative study of different controllers for optimized operation strategies. For this purpose, a framework is used that allows for a standardized comparison of rule-, model- and data-based controllers by connecting them to dynamic simulation models of IESS of varying complexity. The results indicate that controllers based on DRL and MILP have a huge potential to reduce energy-related cost of up to 50% for less complex and around 6% for more complex systems. In some cases however, both algorithms still show unfavorable operating behavior in terms of non-direct costs such as temperature and switching restrictions, depending on the complexity and general conditions of the systems.

The impact of cooling rate during high-pressure gas quenching on the fatigue performance of low-pressure carburized spur gears was studied for steel grades 20MnCr5 and 17NiCrMo6-4. The results show an increased fatigue limit by 10 to 11% when applying a slower cooling rate for both steel grades. Moreover, for 20MnCr5 the slower cooled gears show an increase in compressive residual stresses by 130 MPa compared to the faster cooling, although no significant difference was observed for 17NiCrMo6-4. It is also seen that the cooling rate affects the core hardness for both steel grades, while other properties like surface hardness, case-hardness depth and martensite variant pairing were unaffected. The results for the retained austenite content and average martensite unit size show no clear effect of the cooling rate. The possible influence of different carbon distributions after quenching for the two used cooling rates on the carbide precipitation and fatigue limit is discussed.

A novel approach for the correlation of local martensite tetragonality determined by electron backscatter diffraction and carbon distribution by atom probe tomography (APT) is presented. The two methods are correlated by site-specific sample preparation for APT based on the local tetragonality. This approach is used to investigate the local carbon distribution in high carbon steel with varying local martensite tetragonality. Regions with low tetragonality show clear agglomeration of carbon based on statistical nearest neighbour (NN) analysis, while regions with high tetragonality show only small elongated agglomerations of carbon and no significant clustering using NN analysis. The APT average bulk carbon content shows no quantitative difference between regions with low and high tetragonality, indicating that no significant long-range diffusion of carbon has taken place.

Abstract In addition to renewable energy sources, the transition of the German energy system will increasingly involve the use of decentralized combined heat and power plants (CHP). In order to use this promising technology cost-optimally, modeling approaches must be developed that enable optimization of the systems. Mixed integer linear programming (MILP) is a powerful tool for solving mathematical optimization problems. However, to reduce the computing time the model formulation requires compelling simplifications in relation to reality. The aim of this paper is to present a modeling approach for a combined heat and power plant that depicts dynamic power changes more accurately than existing approaches. Power gradients are mapped by differentiating between the control signal of the CHP unit and the actually generated power output for thermal and electrical power. Finally, the accuracy of the modeling approach is examined in a field test and evaluated according to the accuracy achieved.

The increasing share of volatile, renewable energies, such as wind and solar power, leads to challenges in the stabilization of power grids and requires more flexibility in future energy systems. This article addresses the flexibilization of the consumer side and presents a simulation-based method for the technical and economic investigation of energy flexibility measures in industrial steam supply systems. The marketing of three different energy-flexibility measures—bivalence, inherent energy storage and adjusting process parameters—both at the spot market and at the balancing power market, are investigated from a technical as well as an economic point of view. Furthermore, the simulation-based methodology also considers pressure and temperature fluctuation induced by energy-flexibility measures. First, different energy-flexibility measures for industrial steam supply systems are introduced. Then, the physical modeling of the steam generation, distribution, and consumption as well as measure-specific control strategies will be discussed. Finally, the methodology is applied to a steam supply system of a chemical company. It is shown that the investigated industrial steam supply system shows energy-flexibility potentials up to 10 MW at peak and an annual average of 5.6 MW, which highly depend on consumer behavior and flexibility requirements.

This study explores the impact of digitalization on the performance of insurance intermediaries, who still play a key role in the revenue generation of insurance companies. By using an interdisciplinary approach, this study is the first to examine the extent and type of digital technologies used by intermediaries, their impact on performance with respect to revenue, productivity, and interaction with clients, and the role of digital stress in this context. The research is exploratory, which is why a research model with many variables and relationships between them was built. The quantitative multivariate method of Partial Least Squares Structural Equation Modeling (PLS-SEM) was applied as it allows the simultaneous estimation of models with multiple dependent variables and their interconnections. In this context, data collected in 2022 from 671 insurance intermediaries from Germany, whose demographic distribution in the sample is representative of the German insurance market, were analyzed. The findings show that insurance intermediaries use many digital technologies compared to other industries, particularly those that create added value in their daily work. Empirical evidence also showed that using digital technologies positively affects performance but induces perceived digital stress. As this study reveals, the latter diminishes the positive effects on performance. Technology optimism, technological skills, and organizational support reduce the severity of stress. This means that insurers can start here to support intermediaries to mitigate the performance-limiting effects. This study adds to the insurance literature by providing a broader understanding of how insurance intermediaries deal with digitalization and what it means for their performance.

Abstract To evaluate the long-term posterior capsule opacification (PCO) formation, and glistening rate of the HOYA Vivinex (XY1) IOL compared to Alcon AcrySof (SN60WF). In this prospective, multicentric, randomized, paired-eye, open-label study, we included 87 subjects that underwent cataract surgery with IOL implantation, with 67 patients completing the 3-year follow-up. The completer population consisted of 32 subjects implanted with XY1 and 35 implanted with SN60WF. Primary endpoints consisted of the evaluation of glistenings and measurement of PCO. Secondary outcomes included Best Corrected Distance Visual Acuity (BCVA), Contrast Acuity (CA), uncorrected visual acuities, subjective refraction, medical and lens complication rates, adverse events, and optical/visual symptoms. Follow-up visits occurred at 6-months, 1-, 2- and 3-years. At 3-years follow-up, mean PCO score was 0.121 ± 0.193 for eyes implanted with Vivinex versus 0.239 ± 0.463 for AcrySof (p = 0.026). The Vivinex IOL showed statistically significantly lower glistening occurrence through 3-years postoperatively (0.14 ± 0.26) compared to AcrySof (1.79 ± 1.43; p

Abstract Background The ongoing expansion of the cosmetic armamentarium of facial rejuvenation fails to uncover the inherent risks of cosmetic interventions. Informed consent to all risks of cosmetic filler injections and potential sequelae, including ocular and neurological complications, should be carefully ensured. We present two cases of complications following facial hyaluronic acid filler injections. Case presentations Case 1: A 43-year-old woman presented with monocular vision loss of the left eye, associated ptosis, ophthalmoplegia, periocular pain and nausea, cutaneous changes of the glabella region and forehead, and sensory impairment in the left maxillary branch dermatome (V2) after receiving a hyaluronic acid (HA) filler injection into the left glabellar area. On ophthalmological examination, an ophthalmic artery occlusion (OAO) was diagnosed upon identification of a “cherry-red spot”. Magnetic resonance imaging (MRI) revealed a left ischemic optic neuropathy. Supportive therapy and hyaluronidase injections were initiated. A follow-up MRI of the head performed two months after presentation corresponded to stable MRI findings. The patient had irreversible and complete vision loss of the left eye, however, the ptosis resolved. Case 2: A 29-year-old woman was admitted to hospital a few hours after a rhinoplasty and cheek augmentation with hyaluronic acid, presenting with acute monocular vision loss in the right eye, retrobulbar pain, fatigue and vomiting. In addition, the patient presented a harbinger of impending skin necrosis and a complete oculomotor nerve palsy on the right side, choroidal ischemia and vision impairment. Supportive treatment and hyaluronidase injections into the ischemic tissue were initiated. A small scar at the tip of the nose, vision impairment and an irregular pupillary margin on the right side persisted at follow-up. Conclusion These two case reports and the literature review emphasize the pathophysiological mechanisms leading to potentially devastating complications. In order to reduce the risk of vision loss secondary to cosmetic filler injections, practitioners should possess a thorough knowledge of anatomy and preventive strategies.

Purpose: The use of a non-diffractive extended-depth-of-focus (EDOF) intraocular lens (IOL) with slight myopia of −0.5 D on the non-dominant eye increases the spectacle independence and has good subjective tolerance with optical phenomena comparable to those of a monofocal IOL. This case report describes the course of a myopic patient who underwent refractive lens exchange, didn't tolerate mini-monovision and received IOL exchange therefore. Observations: A healthy, 62-year-old male with myopia of approximately −5 D underwent refractive lens exchange with a non-diffractive EDOF-IOL on both eyes with slight myopia on the non-dominant left eye (mini-monovision). The operation was performed without any complications, postoperative treatment was due to the clinic's standard procedure. Two weeks postoperative the patient presented with uncorrected distance visual acuity of 0.0 logMAR, a subjective refraction of −0.25/−0.25/142° and corrected distance visual acuity of 0.1 logMAR on the right eye. On the left eye, distance visual acuity was 0.4 logMAR with a subjective refraction of −0.5/−0.75/9° (intended mini-monovision) and corrected distance visual acuity of 0.0 logMAR. Binocular distance visual acuity was 0.0 logMAR. The patient complained about the occurrence of optical phenomena at dim light while driving a car and subjective reduced visual acuity. After an IOL exchange on the left eye with the implantation of the same type of non-diffractive EDOF-IOL aimed for emmetropia, the patient was symptom-free and reported no more subjective complaints. Conclusions: Despite the satisfying subjective and objective visual outcome which is proven in multiple studies, the subjective perception of a mini-monovision with a non-diffractive EDOF-IOL can vary individually. A preoperative assessment of the patient's needs and tolerance of a mini-monovision is crucial for a satisfying postoperative outcome.

Abstract Studying anterior lens capsule cutting edge profiles from femtosecond laser-assisted capsulotomy procedures performed before and after lens fragmentation. Twenty eyes (10 patients) with age-related cataract underwent femtosecond laser-assisted surgery (FLACS) using the Ziemer Z8 platform. First step of laser surgery was either capsulotomy (group first) or fragmentation (group second). One eye of each patient was assigned randomly, the second eye treated with the different sequence of procedures. After anterior capsule removal, tissue was fixed in cacodylate-buffered solution and cutting-edge profiles were analysed using scanning electron microscopy (SEM). All cases had cataract grade 2 and 3 based on LOCS III grading. SEM analysis showed more smooth edges in the first group, especially in cases with pseudoexfoliation (P = 0.037); more tags and bridges and a significant number of staggered cutting patterns (7 out of 10 cases) in the second group. All cases evolved the same microgroves with “valleys and mountains “ as signs of the photodisruption process. Femtosecond laser capsulotomy should be performed before lens fragmentation minimizing the rate of cutting errors. Especially in eyes with advanced cataract, as intracapsular pressure may increase due to lens fragmentation without anterior capsular opening.

Purpose: Filler injections for aesthetic purposes are very popular, but can have far-reaching and irreversible consequences. This report describes the course of a patient with devastating complications after glabellar hyaluronic acid injection, their pathomechanism, management and outcome. Observations: A healthy, 43-year-old woman underwent her first hyaluronic acid injection in the glabella and went blind on her left eye immediately thereafter. Massaging of the injection area and observation were performed, before she presented with swelling of the left forehead and upper lid, ptosis, complete ophthalmoplegia and blindness in our hospital. Immediate massaging of the globe and systemic therapy including acetylsalicylic acid, tinzaparin sodium and cortisone was initiated and hyaluronidase injections in the injection area were performed. In the further course, the patient developed necrotic and hemorrhagic skin and mucosal lesions, lagophthalmos, anterior and posterior segment ischemia and globe hypotonia with consecutive globe deformation. In the follow-up of 2.5 months, lid swelling, lagophthalmos and ptosis resolved and keratopathy improved but blindness, skin lesions and strabismus with reduced eye motility were still present and madarosis and early enophthalmos were detected. Conclusions and Importance: The outcome of ophthalmic artery occlusion after hyaluronic acid filler injection is poor. Sufficient knowledge about facial anatomy, the implementation of filler injections and the management of complications is essential for the practitioner. The patient should be clarified about potential and even rare risks of these procedures.

A 23-year-old male patient presented with very mild visual disturbances, but a distinct prominence of the optic discs, more pronounced in the right than in the left eye. The ophthalmic symptoms initially seemed trivial, but a large-scale interdisciplinary workup later identified them as the presenting symptoms of sarcoidosis affecting lung and eyes. A standard steroid monotherapy successfully caused regression of the ophthalmic findings.

Diabetic retinopathy (DR) is an inflammatory condition that affects the posterior of the eye; yet, there are limited published data on techniques measuring the expression of growth and inflammatory factors (GIF) from the posterior segment. The purpose of the current study was two-fold: to sample the vitreous fluid from the eyes of patients with DR and assess the expression of GIF. As DR is an inflammatory disease, the second objective of this study was to determine the relationship between the status of DR and the expression of vitreous GIF. This non-randomized clinical trial was approved by BfARM for the analysis and evaluation of 12 eyes from patients with diabetic macular edema. Vitreous sampling was performed before treatment with fluocinolone acetonide and the extracted vitreous material was examined for the determination of GIF including interleukins 6 (IL-6) and 8 (IL-8), interferon gamma-inducible protein (IP-10), monocyte chemoattractant protein-1 (MCP-1), placental growth factor (PIGF), pigment epithelium-derived factor (PEDF), VEGF (vascular endothelial growth factor) and intercellular adhesion molecule (CD54). These were linearly compared with the grade of inflammation in the vitreous assessed via DR score and ART. Additionally, all eyes were grouped based on their diabetic retinopathy status. All cytokine levels, except MCP-1 and PEDF, were numerically higher in DME patients with proliferative DR than those with non-proliferative DR. DR grade was found to linearly correlate with the expression of CD54 (p = 0.02, rho = 0.64), IL-8 (p = 0.03, rho = 0.64) and PIGF (p = 0.007, rho = 0.76). A correlation was found between ART and CD54 (p = 0.02, rho = 0.66) and also between ART and IL-8 (p = 0.04, rho = 0.60). A trend was found between ART and PIGF (p = 0.08, rho 0.52). For IL-6, there appeared to be a trend with DR grade (p = 0.14, rho = 0.45) and ART (p = 0.09, rho = 0.51). Proliferative DR was shown to be associated with a significant higher expression of CD54, IL-8 and PIGF, thus suggesting that they are potentially important in defining and monitoring the effectiveness of a patients' therapy. Vitreous probes may be helpful in deciding which therapy to administer (i.e. anti-VEGF or corticosteroid or both) based on the expression of GIF. Registry EudraCT number: 2016-004488-38; DRKS-ID: DRKS00014915.

Myopia is the most common refractive error. Surgical correction with laser is possible. LASIK and SMILE are the techniques currently most used. Aim of the study was to compare changes in corneal volume and thickness after the respective laser treatment. 104 eyes of 52 patients were matched based on refractive error into two equally sized groups, either treated with LASIK or SMILE. Measurements were obtained from the Scheimpflug camera (Pentacam) preoperatively and at 3 and 12 months postoperatively. 3 months postoperatively, the flapless SMILE procedure resulted in a significant overall greater loss of corneal volume (P < 0.01) and corneal thickness (P < 0.01) compared to LASIK. No significant difference was found when comparing the 3 to 12-months values in each group. Within the currently used ranges of refractive error correction, loss in central corneal thickness and corneal volume with SMILE is higher in comparison to LASIK. As greater loss in corneal volume and thickness might contribute to higher level of corneal instability maximum ranges of refractive error correction with SMILE should not supersede those set currently for LASIK until more long-term results on corneal ectasia are available for SMILE.

Purpose: To report a case of autoimmune keratitis in a patient with mycobacterium tuberculosis (MBT). Methods: An 84-year-old male with pulmonary tuberculosis (TB) was admitted with chronic, non-healing bilateral ulcerations of the inferior peripheral cornea associated with stromal and subconjunctival nodules. Results: Clinical examination revealed circumscribed peripheral corneal ulceration with whitish nodules in adjacent stromal and subconjunctival tissue. Microbiological cultures of the corneal tissue were negative for MBT and other microbial pathogens; however, enzyme-linked immunosorbent assay (ELISA) of blood and corneal samples showed significantly elevated levels of IgM and IgA against MBT. In addition to systemic anti-tuberculosis therapy, the patient was treated topically with Polyspectran® eye drops, Dexamethasone eye drops, and Bepanthen® ointment, for 2 weeks. Both eyes showed dramatic improvement after 2 weeks. Conclusion: The present report demonstrates that MBT is able to initiate delayed autoimmune response within the corneal tissue during an intensive phase of anti-tuberculosis treatment. Keywords: Ocular tuberculosis, Scrofulous keratitis, Phlyctenule, Autoimmune response

To investigate whether adenosine diphosphate (ADP)-induced platelet hyperaggregability is associated with nonarteritic anterior ischemic optic neuropathy (NAION) or retinal vein occlusion (RVO). We retrospectively reviewed thrombophilia screening data of patients with NAION or RVO without a history of arterial hypertension, diabetes mellitus, hyperlipidemia, obesity, and cigarette abuse. Patients with a positive family history for thromboembolism were not excluded. Platelet aggregation (area under the curve, AUC) after induction of 0.5, 1.0, and 2.0 µmol of ADP was estimated in 25 NAION and RVO patients and compared with 25 healthy controls. We observed significantly greater platelet aggregation post 0.5 (P = 0.002) and 1.0 (P = 0.008) µmol of ADP among NAION and RVO patients compared with healthy controls. Platelet hyperaggregability was significantly more prevalent in patients than in controls (56% vs. 8%; P = 0.0006). Our results suggest that in NAION and RVO patients without a history of arterial hypertension, diabetes mellitus, hyperlipidemia, obesity, and cigarette abuse, platelets are significantly hyperreactive after induction of very low concentrations of ADP when compared with healthy individuals. This hyperreactivity is particularly evident in patients with a family history of thromboembolism.

Introduction. For management of complicated retinal detachments, a pars plana vitrectomy with temporary silicone oil (SO) fill is the method of choice. According to literature, the retinal redetachment rate varies between 70% with around 36% in our own group (retrospective data analysis, n=119 eyes). Methods. The main goal was to reduce the retinal redetachment rate. Standard operating procedures (SOPs) and evaluation protocols (EVALPs) were developed to prospectively analyse risk factors. Lab analysis of SO was performed, and the role of surgical experience was evaluated and investigated with Eyesi®. Results. We achieved a significant reduction of the retinal redetachment rate (to 6.80%, n=101, p=0.002). After surgery with SO injection, neither further membrane peeling (in 16.5%) nor retinal laser coagulation (in 100%) during revision surgery had a significant effect on the reattachment rate (p=0.167, p=0.23), while extensive additional laser coagulation reduced visual acuity (p=0.01). A 3-port approach had to be set up to complete SO removal. A difference in success rate depending on surgical experience was confirmed, and the performance in Eyesi correlated with that in the patients’ eye. Conclusions. A SOP- and EVALP-based management and new strategies to secure the surgical performance seem to be essential for successful surgery.

Introduction. To evaluate the impact of the eye lens status and oil side effects on the outcome of vitreoretinal surgery in retinal detachment with proliferative vitreoretinopathy (PVR) and a temporary silicone oil tamponade (SOT). Methods. 101 eyes were analyzed retrospectively and 103 eyes prospectively in regard to their retinal reattachment success rate and key factors for the outcome. Subgroup analysis of 27 eyes with Scheimpflug lens photography (SLP) before and after retinal reattachment service with SOT was performed. For SLP (65% phakic eyes) a Pentacam densitometry reference body with 3 mm diameter was chosen and 3 segments (anterior/mid/posterior) were evaluated separately after a quality check. Results. The retinal reattachment rate was highest in the prospective pseudophakic group (p=0.039). Lens transparency loss occurred earlier in middle aged patients than in younger patients. Besides the nucleus, layers posterior and anterior to it showed specific transparency changes. The emulsification rate was higher when eyes had been operated on in the anterior chamber before retinal reattachment service. Conclusions. Retinal reattachment surgery seems to benefit from preoperative cataract removal. We found significant lens changes in the nucleus as well as in the layers anterior and posterior to it. This corresponds to the histology of the lens epithelium published before.

PURPOSE:To evaluate the efficacy of the virtual reality training simulator Eyesi to prepare surgeons for performing pars plana vitrectomies and its potential to predict the surgeons' performance. METHODS:In a preparation phase, four participating vitreoretinal surgeons performed repeated simulator training with predefined tasks. If a surgeon was assigned to perform a vitrectomy for the management of complex retinal detachment after a surgical break of at least 60 hours it was randomly decided whether a warmup training on the simulator was required (n = 9) or not (n = 12). Performance at the simulator was measured using the built-in scoring metrics. The surgical performance was determined by two blinded observers who analyzed the video-recorded interventions. One of them repeated the analysis to check for intra-observer consistency. The surgical performance of the interventions with and without simulator training was compared. In addition, for the surgeries with simulator training, the simulator performance was compared to the performance in the operating room. RESULTS:Comparing each surgeon's performance with and without warmup trainingshowed a significant effect of warmup training onto the final outcome in the operating room. For the surgeries that were preceeded by the warmup procedure, the performance at the simulator was compared with the operating room performance. We found that there is a significant relation. The governing factor of low scores in the simulator were iatrogenic retinal holes, bleedings and lens damage. Surgeons who caused minor damage in the simulation also performed well in the operating room. CONCLUSIONS:Despite the large variation of conditions, the effect of a warmup training as well as a relation between the performance at the simulator and in the operating room was found with statistical significance. Simulator training is able to serve as a warmup to increase the average performance.