Terms Of Stability Research Articles

Impact of total ionizing dose on the alpha-soft error rate in FDSOI 28 nm SRAMs

Synergy effect of total ionizing dose (TID) on alpha-soft error rate (α-SER) in FDSOI 28 nm SRAM has been experimentally characterized using a dedicated setup combining alpha-particle irradiation (241Am solid source) in vacuum chamber and 10 keV X-ray irradiation. Measurements have been performed on a 3 Mbit single-port SRAM cut powered at 1 V. Irradiations up to 125 krad(Si) have been achieved and their impact on the α-SER has been characterized from the cumulated number of bitflips as a function of the exposition time to the alpha-source. Modelling and simulation have been used to link transistor threshold voltage variations to SRAM cell stability in terms of static noise margin (SNM), critical charge (Qcrit) and finally estimated SER, in good agreement with experimental results.

Dynamic formation of preferentially lattice oriented, self trapped hydrogen clusters

A series of MD and DFT simulations were performed to investigate hydrogen self-clustering and retention in tungsten. Using a newly develop machine learned interatomic potential, spontaneous formation of hydrogen platelets was observed after implanting low-energy hydrogen into tungsten at high fluxes and temperatures. The platelets formed along low miller index orientations and neighboring tetrahedral and octahedral sites and could grow to over 50 atoms in size. High temperatures above 600 K and high hydrogen concentrations were needed to observe significant platelet formation. A critical platelet size of six hydrogen atoms was needed for long term stability. Platelets smaller than this were found to be thermally unstable within a few nanoseconds. To verify these observations, characteristic platelets from the MD simulations were simulated using large-scale DFT. DFT corroborated the MD results in that large platelets were also found to be dynamically stable for five or more hydrogen atoms. The LDOS from the DFT simulated platelets indicated that hydrogen atoms, particularly at the periphery of the platelet, were found to be at least as stable as hydrogen atoms in bulk tungsten. In addition, electrons were found to be localized around hydrogen atoms in the platelet itself and that hydrogen atoms up to 4.2 Å away within the platelet were found to share charge suggesting that the hydrogen atoms are interacting across longer distances than previously suggested. These results reveal a self-clustering mechanisms for hydrogen within tungsten in the absence of radiation induced or microstructural defects that could be a precursor to blistering and potentially explain the experimentally observed high hydrogen retention particularly in the near surface region.

Deep Deltoid Ligament Reconstruction Utilizing Suture Augmentation via an Arthroscopically- Assisted Approach: A Novel Technique and Case Series

Category: Trauma; Arthroscopy Introduction/Purpose: Deltoid ligament rupture is a common occurrence in the setting of acute ankle fractures. The indications for surgical restoration of the deltoid ligament complex vary considerably throughout the literature. If medial ankle instability exists after ankle fracture fixation, repair or reconstruction of the deltoid ligament complex may be performed, which is traditionally done via an open approach. While the superficial deltoid is easily accessed with an open approach, the deep deltoid ligament is extremely difficult to visualize. We present a novel technique for reconstruction of the deep deltoid ligament complex utilizing suture augmentation via an arthroscopically-assisted approach and present our outcomes. With this method, the deep deltoid ligament disruption is easily visualized and reconstructed in a minimally invasive manner through an accessory anteromedial arthroscopy portal. Methods: This is a technique guide and retrospective case series. Data was obtained via chart review including pre-operative, intraoperative, and post-operative follow ups. Variables such as age, weight, body mass index (BMI), sex, side, history of previous ankle surgery, preoperative ambulatory status, length of hospital stay, as well as disposition were documented. Radiographs were reviewed for evidence of restoration of the medial clear space as well as hardware position and bony union. In addition, a technique guide was developed using expert surgeon experience and opinion while using this novel technique. Results: 7 patients who underwent this novel technique were reviewed with an average follow up time of six months (3-8 months). All patients suffered bimalleolar or trimalleolar equivalent fractures. Patients were indicated for deep deltoid ligament reconstruction if medial ankle instability existed intraoperatively with valgus stress testing under fluoroscopy. Medial clear space decreased from a mean 11mm preoperatively to 3.3mm postoperatively. 6 patients returned to ambulation without brace by three months postoperatively. One patient demonstrated increased medial clear space measured at 6.6mm postoperatively and residual pain on follow up, but was treated conservatively and able to progress to weight bearing as tolerated by 6 months. One patient developed a keloid scar that required a steroid injection. No postoperative infections occurred. Conclusion: Deep deltoid ligament reconstruction utilizing suture augmentation via an arthroscopically-assisted approach should be considered in patients who have residual medial ankle instability after ankle fracture fixation. This novel technique allows visualization of the deep deltoid ligament complex and reconstruction in a minimally invasive manner via an accessory anteromedial arthroscopy portal. Our short term outcomes demonstrate success in restoring ankle function and radiographic parameters of the medial clear space. Further studies are needed to evaluate long term postoperative functional outcomes, stability, and development of post-traumatic arthritis.

Zinc Oxide-Encapsulated Copper Nanowires for Stable Transparent Conductors.

Cu nanowire (NW)-based transparent conductors are considered to be highly promising constituents of next-generation flexible transparent electronics. However, the fast oxidation of copper under ambient conditions hinders the use of Cu NWs. Herein, we demonstrate a low-cost and scalable approach for preparing a ZnO shell on the surface of Cu NWs under ambient conditions. The covered ZnO shells enhance the oxidative stability of Cu NWs. The optical and electrical properties of ZnO@Cu NWs remain similar to the original performance of the Cu NWs (for example, before encapsulating: 13.5 Ω/sq. at 84.3%, after encapsulating: 19.2 Ω/sq. at 86.7%), which indicates that encapsulation with a ZnO shell enables the preservation of the transparency and conductivity of Cu NW networks. More importantly, the ZnO@Cu NWs exhibit excellent stability in terms of long-term storage, hot/humid environments, and strong oxidizing atmosphere/solution.

Solvent-free synthesis of ZrO2 nanoparticles/nitrogen-rich two-dimensional carbon nanosheet composites as efficient catalysts for ORR

An innovative, high-performance, non-noble-metal-based oxygen reduction reaction (ORR) catalyst must be developed utilizing a new and cost-effective technique. ZrO2 has the merits of high stability, low toxicity, good catalytic activity, and low enthalpy for atomic oxygen adsorption. However, the poor conductivity restricts its application as an ORR catalyst. Here, we successfully prepared ZrO2 nanoparticles / nitrogen-rich two-dimensional carbon nanosheet composites as ORR catalysts using a straightforward, solvent-free, one-step pyrolysis approach. Due to the unique component and structure characteristics, ZrO2@N-C-900 demonstrates remarkable ORR performances in alkaline electrolytes, such as high half-wave potential (0.82 V vs. RHE), higher current density (JL = 6.4 mA cm−2), and outstanding long term stability (95 % for 36,000 s). Especially, when used in a Zn-air battery, ZrO2@N-C-900 exhibited a power density of 148 mW cm−2, exceeding that of 20 % Pt/C.

Determining the area of a technical system stability in fuzzy sets terms

Ensuring the stability of the technical systems functioning, including those in water transport, is an important area for the application of mathematical methods, including probabilistic and mathematical-statistical methods. The stochastic nature of disturbances affecting complex systems and worsening the level of stability of the latter should be reflected in the implemented human-machine control loops. One of the directions here is the accounting and use of (usually competing) expert assessments, on the one hand, and a reasonable definition of stability indicators, a choice from a variety of possibilities, on the other hand. From a general point of view of management theory, the method of using expert assessments developed in the paper can be considered as an integral part of the risk management problem that is being developed so far, mainly for economic systems and using only financial criteria. The concept of the minimum allowable efficiency of a technical system is introduced in the paper. On its basis, an approach in which the indicator of the stability of a technical system is linked to a system-wide criterion indicator of the quality of its functioning is implemented. The corresponding mathematical model as a problem of mathemati- cal programming is formulated. Approaches to its solution including for the nonconvex multiextremal case are discussed. A feature of the proposed approach to the definition of the integral indicator of the stability of the dynamics of a technical system is the use of expert assessments in determining the probable range of changes in the controlled variables of the optimization model, implemented as a mathematical programming problem, which logically leads to the use of fuzzy set theory. With the non-linearity of the objective functions and restrictions that arise in this case, the gradient method of searching for a conditional optimum is effective.

Shifting cultivation and logging change soil organic carbon functional groups in tropical lowland rainforests on Hainan Island in China

Recent evidence has demonstrated that tropical forest secondary succession has significant influences on soil organic C (SOC) storage. However, the changes in the SOC functional groups with forest restoration are still uncertain. In this study, the stock and functional groups of SOC in tropical forest recovery after two types of disturbance were measured, and the key influencing factors were analyzed. The SOC stocks were significantly higher in the young-secondary forests after shifting cultivation and in the clear cut forests than in the old-growth forests. However, the shifting cultivation and logging practices significantly increased the ratio of carbohydrate C to N-alkyl/methoxyl C (CC/MC), indicating that the decomposition degree of SOC in the old-growth forests was higher. The proportion of aromatic C in soil was higher in the young-secondary forests after shifting cultivation than in the old-growth forests. The proportion of aromatic C in litter and fine roots, the α-diversity of soil fungal and bacterial communities, and soil phosphorus were positively correlated with soil aromatic C between the shifting cultivation secondary and old-growth forests. The proportion of O-alkyl C in soil was higher in the logged forests than in the old-growth forests. The proportion of O-alkyl C in litter was positively correlated with O-alkyl C in soil between the logged and old-growth forests. Our results suggest that the labile O-alkyl C functional group recovers more rapidly after logging practices, and restoration after shifting cultivation increases the labile carbohydrate C functional group and aromaticity in tropical lowland rainforests. However, SOC has greater chemical stability in terms of the decomposition degree in tropical old-growth forests.

Drone-Based Monitoring and Mapping for LMO Confined Field Management under the Ministry of Environment

The objective of this study was to devise effective safety management systems for enclosed living modified organism (LMO) fields regulated by the Ministry of Environment (MOE), achieved through an assessment of the impact of LM crops on the surrounding flora. A combination of conventional survey methods and cutting-edge drone-based monitoring systems was employed, with a keen focus on their efficacy. Our investigation spans three distinct zones (forest, non-forest, and enclosed field), involving vegetation surveys, biodiversity index analyses, and drone-powered aerial observations to study topographical shifts. Over time, wild plants adjacent to the enclosed LMO field exhibited stability in terms of species composition. Nevertheless, disparities in growth patterns emerged across various areas. Predominantly, herbs thrived in enclosed and non-forest areas, while trees and shrubs flourished in forested regions. Annual plants predominantly populated the non-forest regions, whereas perennials dominated the forested areas. To this end, drones captured aerial photographs of a 31.65-hectare expanse with 40% coverage overlap, furnishing a real-time vegetation map that transcends the capacities of conventional methods. By combining vegetation surveys, drone-generated vegetation mapping, and dynamic monitoring of topographical changes, our research endeavors to facilitate the formulation of a robust safety management framework for LMO confined fields overseen by the MOE. This holistic approach aspires to prevent ecosystem contamination and establish a resilient, enduring system that averts LMO leakage, thereby safeguarding the environment.

Investigating the Correlation Between Drug Physical Properties and Physical Characteristics and Drug Entrapment Efficiencies of Chitosan-TPP Nanoparticles

Chitosan nanoparticles (NPs) have been the subject of intensive research. This study aimed to determine how different drug characteristics such as molecular weights, drug solubility in the processing medium, and drug ionization/charge state affected chitosan NPs particularly their percentage entrapment efficiency (% EE) and mean hydrodynamic diameters (MHDs). Drugs with varying molecular weights but of similar aqueous solubilities were chosen and were dissolved in a 2% chitosan-acetic acid solution. Chitosan NPs were formed using by ionic gelation technique using sodium tripolyphosphate (TPP) at specific concentration and volume ratios of chitosan to TPP. NPs containing Enalapril and Paracetamol displayed better short-term stability in terms of MHDs. A direct relationship between MHDs of NPs and chitosan concentrations was found. In comparison, at both low and high admixed drug concentrations and at high chitosan concentration, larger NPs sizes were associated with the lower molecular weight drug (Paracetamol). However, the study did not demonstrate a direct relationship between NPs characteristics such as MHDs and drugs molecular weights. The ZP of Paracetamol-loaded NPs was lowest at high drug concentrations at all chitosan concentrations compared to other drugs-loaded NPs. When compared to drugs with high and low molecular weights, medium molecular weight Atenolol showed the highest % EE. This clearly indicated that there was no direct correlation between drug molecular weight and % EE, but rather other factors influenced on % EE. Nevertheless, an inverse linear relationship with high correlation coefficients was only found when % EE was plotted against each drug molecular weight divided by the ratio of drugs solubilities in acetic acid to their employed concentrations, however the correlation was inconsistent between drugs of varying molecular weights.

3D hydroxylated Ti3C2Tx MXene nanonet architecture supported Pt catalysts for efficient hydrogen evolution

Ti3C2Tx MXene nanonets (MNNs) with 3D fibrous architecture were obtained from Ti3C2Tx MXene nanoplates (MNPs) via surface modifying of alkalization in concentrated KOH solution, which was further combined with carbon nanotube and used as catalyst supports for Pt nanoparticles. By controlling the treatment time of alkalization, the lamellar surface of MNPs was getting into fibration in different extent. The catalytic performances toward hydrogen evolution reaction (HER) of a series of Pt-loaded MNNs catalysts were investigated, in which 1 %Pt-MNNs-9 composite catalyst presented the best hydrogen evolution performance. In detail, 1 %Pt-MNNs-9 with 1 wt.% of Pt loading exhibits an overpotential of 60 mV at 10 mA·cm−2, which is much lower than 1 % Pt-MNPs (274 mV). It also keeps stable performance for long term stability. The enhanced catalytic activity is probably due to the fact that, Ti3C2Tx MNNs with 3D architecture not only possesses abundant sites to anchor Pt nanoaprticles, but also facilitates the mass and charge transfer, which are significantly beneficial to catalytic reaction. The 3D architecture MXene fibers are expected to have widespread applications including but not limited to energy storage/conversion, and catalytic fields.

Possibilities and limitations of α-relaxation data of amorphous freeze-dried cakes to predict long term IgG1 antibody stability

The value of correlating global α-relaxations with long term protein stability after freeze-drying is inconsistently reported. This study aims to clarify whether and to what extend the long term stability of a freeze-dried protein formulation can be predicted with this method. For this purpose, the α-relaxation parameter τβ [h] of freshly prepared freeze-dried products is obtained by isothermal microcalorimetry. The concept is, that molecular movements in the amorphous matrix are strongly reduced in cakes with longer relaxation time and the product should therefore be more resistant against aggregation. To increase τβ in comparison to a conventional freeze-drying cycle, aggressive drying cycles including structural collapse of the product as well as tempering protocols after freeze-drying are applied. The τβ values are correlated with the aggregation rate of a freeze-dried IgG1 monoclonal antibody measured with high performance size exclusion chromatography. The antibody was used in its market formulation and 6 further compositions. A weak correlation between α-relaxation times and IgG1 aggregation was found. A higher mobility level through increased residual moisture helped to improve the correlation.

Antimalarial drug discovery against malaria parasites through haplopine modification: An advanced computational approach.

The widespread emergence of antimalarial drug resistance has created a major threat to public health. Malaria is a life-threatening infectious disease caused by Plasmodium spp., which includes Apicoplast DNA polymerase and Plasmodium falciparum cysteine protease falcipain-2. These components play a critical role in their life cycle and metabolic pathway, and are involved in the breakdown of erythrocyte hemoglobin in the host, making them promising targets for anti-malarial drug design. Our current study has been designed to explore the potential inhibitors from haplopinederivatives against these two targets using an in silico approach. A total of nine haplopine derivatives were used to perform molecular docking, and the results revealed that Ligands 03 and 05 showed strong binding affinity compared to the control compound atovaquone. Furthermore, these ligand-protein complexes underwent molecular dynamics simulations, and the results demonstrated that the complexes maintained strong stability in terms of RMSD (root mean square deviation), RMSF (root mean square fluctuation), and Rg (radius of gyration) over a 100 ns simulation period. Additionally, PCA (principal component analysis) analysis and the dynamic cross-correlation matrix showed positive outcomes for the protein-ligand complexes. Moreover, the compounds exhibited no violations of the Lipinski rule, and ADMET (absorption, distribution, metabolism, excretion, and toxicity) predictions yielded positive results without indicating any toxicity. Finally, density functional theory (DFT) and molecular electrostatic potential calculations were conducted, revealing that the mentioned derivatives exhibited better stability and outstanding performance. Overall, this computational approach suggests that these haplopine derivatives could serve as a potential source for developing new, effective antimalarial drugs to combat malaria. However, further in vitro or in vivo studies might be conducted to determine their actual effectiveness.

Gas sensing with Nb(V) doped nanocrystalline TiO2: Sensitivity and long-term stability study

The work addresses the problem of long- term stability of metal oxide materials gas sensor performance and deals with Nb(V) doped nanocrystalline TiO2 which is characterized by reasonable response values for practical application alongside with the absence of response decay during continuous operation. The TiO2 nanomaterials containing up to 4 at% Nb were synthesized using flame spray pyrolysis. Materials are investigated by XRD and EPR methods. The sensor properties were studied by in situ electrical conductivity measurements. Nb(V) reduces the electrical resistance of TiO2 due to the formation of oxygen vacancies and increase in conduction electron concentration, but this effect is limited by the appearance of a significant number of charge traps. Pure TiO2 tended to transform into rutile phase during annealing in the analyte gas mixture, while Nb stabilized the anatase phase. Both pure and doped TiO2 demonstrate stable sensor performance in long-term, however slow growth of baseline resistance and sensor response are observed which is, according to EPR data, connected with slow processes of defect annealing and intergrain contact formation.

Increasing Performance of Spiral-Wound Modules (SWMs) by Improving Stability against Axial Pressure Drop and Utilising Pulsed Flow.

Spacer-induced flow shadows and limited mechanical stability due to module construction and geometry are the main obstacles to improving the filtration performance and cleanability of microfiltration spiral-wound membranes (SWMs), applied to milk protein fractionation in this study. The goal of this study was first to improve filtration performance and cleanability by utilising pulsed flow in a modified pilot-scale filtration plant. The second goal was to enhance membrane stability against module deformation by flow-induced friction in the axial direction ("membrane telescoping"). This was accomplished by stabilising membrane layers, including spacers, at the membrane inlet by glue connections. Pulsed flow characteristics similar to those reported in previous lab-scale studies could be achieved by establishing an on/off bypass around the membrane module, thus enabling a high-frequency flow variation. Pulsed flow significantly increased filtration performance (target protein mass flow into the permeate increased by 26%) and cleaning success (protein removal increased by 28%). Furthermore, adding feed-side glue connections increased the mechanical membrane stability in terms of allowed volume throughput by ≥100% compared to unmodified modules, thus allowing operation with higher axial pressure drops, flow velocities and pulsation amplitudes.

Synthesis of ZnO@VC for enhancement of synergic photocatalytic degradation of SMX: Toxicity assessment, kinetics and transformation pathway determination

Nanocomposite-based photocatalytic degradation of sulfamethoxazole (SMX) is frequently used for wastewater treatment. However, applying various nanoparticles led to different removal efficiencies and levels of environmental toxicity. Herein, we synthesized and characterized ZnO@VC to enhance the photocatalytic degradation of SMX. Effects of SMX concentration, catalyst dosage, pH, water matrix and role of reactive oxygen specious (ROS) were evaluated. Results confirmed 97.69±0.95% (5 mg L−1 SMX/0.05 g L−1 catalyst) removal efficiency followed pseudo-first-order kinetic. Higher SMX concentration and higher catalyst dosage reduced degradation efficiency because of the prevention of catalyst active-sites and limiting light availability. SMX removal efficiency was slightly reduced in synthetic wastewater (SWW) and tap water (TW) by anions scavenging ROS. Due to pH reliance of SMX anionic-density, the degradation efficiency was positively and negatively impacted by acidic and basic environment, and pH values below and over the catalyst point of zero charge (PZC), respectively. Quenching test revealed that some specious of ROS play more important role in photocatalytic degradation of SMX. Two degradation pathways of SMX photocatalytic decomposition were described. The synthesized catalyst showed good stability in terms of reusability. The results revealed that ZnO@VC with high detoxification ability (97%) could be a promising photocatalyst for treatment of antibiotics from water and wastewater.

A Study on the Effect of Temperature Variations on FPGA-Based Multi-Channel Time-to-Digital Converters.

We describe a study on the effect of temperature variations on multi-channel time-to-digital converters (TDCs). The objective is to study the impact of ambient thermal variations on the performance of field-programmable gate array (FPGA)-based tapped delay line (TDL) TDC systems while simultaneously meeting the requirements of high-precision time measurement, low-cost implementation, small size, and low power consumption. For our study, we chose two devices, Artix-7 and ProASIC3L, manufactured by Xilinx and Microsemi, respectively. The radiation-tolerant ProASIC3L device offers better stability in terms of thermal sensitivity and power consumption compared to the Artix-7. To assess the performance of the TDCs under varying thermal conditions, a laboratory thermal chamber was utilized to maintain ambient temperatures ranging from -75 to 80 °C. This analysis ensured a comprehensive evaluation of the TDCs' performance across a wide operational range. By utilizing the Artix-7 and ProASIC3L devices, we achieved root mean square (RMS) resolution of 24.7 and 554.59 picoseconds, respectively. Total on-chip power of 0.968 W was achieved using Artix-7, while 1.997 mW of power consumption was achieved using the ProASIC3L device. We worked to determine the temperature sensitivity for both FPGA devices, which could help in the design and optimization of FPGA-based TDCs for many applications.

Metasurface-based terahertz wideband linear polarization converter

We designed a linear polarization converter based on metasurface and simulated its functionality. It has a broad bandwidth and operates in the terahertz frequency range (0.4–1.2 THz). The polarization converter consists of a polyimide substrate, a metal grating and a bimetallic split ring resonator. In a bimetallic split ring resonator, the gaps between the rings are rotated by 90° from one another. The structure is simulated by commercial software CST STUDIO SUITE. The results show that the device successfully converts the polarization of terahertz wave from y to x. This structure also has high stability in terms of incidence angle and operates efficiently in the range of 0° to 45°.This kind of polarization converter has a wide application prospect in satellite communication, radar detection, 3D imaging of displays, and other fields.

Determination of the Dynamics of Thunderstorms Through the Dry Adiabatic Lapse Rate and Environmental Lapse Rate

This research aims to determine the types of thunderstorms formed in the thickness of the cloud (determine the Dry adiabatic lapse rate (DALR) and Environmental lapse rate (ELR)) in the case of precipitation during the day. Data were taken by Temperature, Dew point, Atmospheric Pressure, and Height from re-analysis by the (ECMWF) for the heights (0-18000) m, the levels of pressure (1000-100) mbar, low cloud cover data, and the characteristic days ((18, 24, 27) February, 28 April, and 25 November) of the year 2018 for Baghdad station were chosen to obtain the largest possible number of clouds and their diversity to use them in calculating the cloud cover and weather stability in terms of calculating the daily change, temperature, dew point in addition to calculating the low cloud cover with altitude and atmospheric instability. The Sigma Plot program was used in this research to determine the base of clouds and thunderstorms. The change in temperature, Dew point, clouds base, and altitude was determined, then the cloud thickness, types, and classification were calculated. The clouds found are strong thunderstorm clouds characterized by thickness and height, such as the clouds of Nimbostratus (Ns) and Cumulonimbus (Cb).

Throughput-Aware Dynamic Task Offloading Under Resource Constant for MEC With Energy Harvesting Devices

With the explosive increase of Internet of Things (IoT) devices, an increasing number of computation-intensive applications are emerging in IoT system. However, most IoT devices are limited by size and location, equipped with low-performance CPUs and low-capacity batteries, which cannot go well with computation-intensive applications. Mobile edge computing (MEC) is considered as a promising solution to provide computation-intensive and latency-sensitive services in IoT system, but it is still challenging to improve the throughput and extend the battery life of IoT devices under communication constraints. This paper focuses on the task offloading problem for an MEC system with multiple energy harvesting (EH) devices. To accommodate the system dynamics and ensure the system stability in terms of task queue and battery level, we apply Lyapunov optimization theory, and design a computation tasks maximum offloading algorithm to maximize the system throughput. The algorithm can determine the offloading decision in real-time without knowing any statistical information about the system. We first give a series of mathematical analysis to verify the system stability and discuss the performance of the algorithm. In addition, a number of simulation experiments are conducted to present the efficiency of the algorithm.

Using Hydrogel Beads as a Blood Model in Optical Coherence Tomography

Abstract Optical Coherence Tomography (OCT) is a standard imaging procedure in ophthalmology. OCT Angiography is a promising extension, allowing for fast and non-invasive imaging of the retinal vasculature analyzing multiple OCT scans at the same place. Local variance is examined and highlighted. Despite its introduction in the clinic, unanswered questions remain when it comes to signal generation. Multiphase fluids like intralipid, milk-water solutions and human blood cells were applied in phantom studies shedding light on some of the mechanisms. The use of hydrogel beads allows for the generation of alternative blood models for OCT and OCT Angiography. Beads were produced in Hannover, their size was measured and their long term stability was assessed. Then, beads were shipped to Karlsruhe, where OCT imaging resulted in first insights. The hydrogel acts as a diffusion barrier, which enables a clear distinction of bead and fluid when scattering particles were added. Further on, the scattering medium below the bead showed increased signal intensity. We conclude that the inside of the bead structure shows enhanced transmission compared to the plasma substitute with dissolved TiO2 surrounding it. Beads were found clumped and deformed after shipping, an issue to be addressed in further investigations. Nevertheless, hydrogel beads are promising as a blood model for OCT Angiography investigations, offering tunable optical parameters within the blood substitute solution.