Conformality of atomic layer deposition in microchannels: impact of process parameters on the simulated thickness profile

Unparalleled conformality is driving ever new applications for atomic layer deposition (ALD), a thin film growth method based on repeated self-terminating gas-solid reactions. In this work, we re-implemented a diffusion-reaction model from the literature to simulate the propagation of film growth in wide microchannels and used that model to explore trends in both the thickness profile as a function of process parameters and different diffusion regimes. In the model, partial pressure of ALD reactant was analytically approximated. Simulations were made as function of kinetic and process parameters such as temperature, (lumped) sticking coefficient, molar mass of the ALD reactant, reactant’s exposure time and pressure, total pressure, density of the grown material, and growth per cycle (GPC) of the ALD process. Increasing the molar mass and the GPC, for example, resulted in a decreasing penetration depth into the microchannel. The influence of the mass and size of the inert gas molecules on the thickness profile depended on the diffusion regime (free molecular flow vs. transition flow). The modelling was compared to a recent slope method to extract the sticking coefficient. The slope method gave systematically somewhat higher sticking coefficient values compared to the input sticking coefficient values; potential reasons behind the observed differences are discussed.

On the Evaluation of Energy Dissipation at the Beginning of Fatigue

The slope method is a popular energy dissipation estimation method, which ignores the influence of heat exchange. Within the framework of the zero-dimensional thermal diffusion model, this paper presents a calculation method for evaluating the energy dissipation of materials in the initial stage of fatigue, which can be called the optimization method. Different from the slope method, this method takes the influence of thermal boundary conditions into consideration. Numerical simulation showed that the optimization method has the ability to accurately estimate energy dissipation in different experimental environments and is not sensitive to measurement noise. Compared with the popular slope method, the newly proposed optimization method has certain advantages in adaptability to different environments and flexibility in parameter selection. A case study was also carried out to study a high-cycle fatigue life of an aluminum alloy which demonstrated that results predicted by the proposed method matched the experimental data in the range of short fatigue life.

Extracting Four Solar Model Electrical Parameters of Mono-Crystalline Silicon (mc-Si) and Thin Film (CIGS) Solar Modules using Different Methods

Experimental measurements were done for characterizing current-voltage and power-voltage of two types of photovoltaic (PV) solar modules; monocrystalline silicon (mc-Si) and copper indium gallium di-selenide (CIGS). The conversion efficiency depends on many factors, such as irradiation and temperature. The assembling measures as a rule cause contrast in electrical boundaries, even in cells of a similar kind. Additionally, if the misfortunes because of cell associations in a module are considered, it is hard to track down two indistinguishable photovoltaic modules. This way, just the I-V, and P-V bends' trial estimation permit knowing the electrical boundaries of a photovoltaic gadget with accuracy. This measure gives extremely significant data to the plan, establishment, and upkeep of PV frameworks. Three methods, simplified explicit, slope, and iterative, are used to compute two solar models' parameters using MATLAB code. The percentage maximum power errors at (600 and 1000) W/m2 for both current-voltage and power-voltage values with the corresponding measured ones using the slope method are 0.5% and 3% for monocrystalline silicon copper indium gallium di-selenide, respectively. The iterative method is 5 % and 10% for monocrystalline silicon and copper indium gallium di-selenide. Finally, for the simplified explicit 8% and 9%, for monocrystalline silicon and copper indium gallium di-selenide, respectively. The slope method gives more close results with the corresponding measured values than the other two methods for the two PV solar modules used. Consequently, the slope method is less influenced by the meteorological condition.

Determination of Deoxygenation Rate of Citarum River Water using Long Term Technique

Citarum River is a large river located in West Java Province. The current condition of the Citarum River is highly polluted, especially in urban areas. Utilization of river water quality models is one of the popular methods to support river recovery. The deoxygenation rate is an important coefficient in the BOD-DO formula used in the water quality model. Usually, the deoxygenation rate is determined in laboratory in short term. A long term technique of laboratory test will likely gives better results. This study aims to determine the actual coefficient of the deoxygenation rate of the Citarum River water by using the long term technique. Sampling was carried out at 2 points which were considered to be able to represent the condition of the Citarum River. The laboratory analysis method used in the calculation of the deoxygenation rate uses the Thomas’ Slope Method and the empirical formula of Hydroscience. The results showed the value of the deoxygenation rate range using the Slope method as a whole that ranged from 0.33 to 0.56 per day. While the value of the deoxygenation rate ranges using the Empirical formula ranges from 0.37 to 0.46 per day. The overall BOD (La) range ranges from 44.03 to 55.03 mg/L. The value of the deoxygenation rate obtained from the long term technique give similar range to that of empirical formula result. It suggests that the long-term technique can improve the results of the short-term deoxygenation rate method.

Establishment of a murine, lipopolysaccharide-induced sepsis model for testing anaerobic exercise thresholds and early mobilization

Background: Several methods have been proposed to prevent post intensive care syndrome (PICS) after sepsis, including early mobilization, but controversy remains in mechanisms and outcomes. Translational studies are required to fully reveal the optimal exercise intensity during acute phase sepsis. The aim of this study is to establish a septic mouse model and and classify exercise intensi ties during the acute phase of sepsis. Methods: Adult, male C57/B6 mice received lipopolysaccharide (LPS) injections (20mg/kg). We recorded survival rates and metabolic changes, such as resting energy expenditure (REE) compared with controls up to 72h after LPS administration. We also observed vital signs (rectal temperature and weight change) and inflammation (TNF-αand IL-6). We detected exercise intensity via metabolic monitoring treadmill, analyzed the anaerobic threshold (AT) by V-Slope Method and classified the intensity levels according to American College of Sports Medicine (ACSM) guidelines.Result: Around 30% of the mice survived 72h after LPS induction with REE and rectal temperatures lowest at around 22-24h later (REE at 22h: 2.26±0.34 kcal/day p<0.05 vs. baseline; Rectal temperature at 24h: 29.17±0.48℃, p<0.05 vs. baseline). Gradual recovery was seen out to 72h. Blood concentrations of TNF-α were highest at the 12h timepoint (41.23±24.39 pg/ml, p<0.05 vs. baseline) and IL-6 was highest at 24h after LPS induction (1476.5±274.7 pg/ml, p<0.05 vs. baseline). Using the V‐Slope method, we observed the AT at each timepoint (6h:14m/min,12h: 9m/min, 24h:4m/min,36h:10m/min, 48h:16m/min,60h:20m/min,72h:22m/min) and classified these into very low intensity exercise training (VLIT), low intensity exercise training (LIT), or moderate intensity exercise training (MIT) at each timepoint. Conclusion: We classified exercise intensities out to 72h after sepsis recovery using a mouse model. These data may serve as a bridge to clinical studies to fill gaps in best practice for sepsis rehabilitation.