Atmospheric Effects Research Articles

The Influence of Store Atmosphere and Price on Sales Levels Through Purchasing Decisions As A Mediator

This study aims to examine how much influence the store atmosphere and prices have on the level of sales of coffee from Hati Pariaman through purchasing decisions as an intervening variable. Methods of data collection through surveys and distributing questionnaires, with a sample of 100 respondents. The analytical method used is SEM analysis using smartpls. The research results obtained based on hypothesis testing obtained that there is a significant influence of store atmosphere on purchasing decisions. There is a significant effect of prices on purchasing decisions. There is a significant influence store atmosphere on the level of sales. There is a significant effect of prices on the level of sales. There is a significant influence of purchasing decisions on the level of sales. Purchase decisions mediate the effect of store atmosphere on sales levels. Purchasing decisions mediate the effect of prices on sales levels.

A Dining Career Ladder: Customers’ Motivation of Visiting Internet-Famous Restaurants

ABSTRACT Customers visiting internet-famous restaurants enjoy unique dining experiences. However, few studies have explored customers’ motivation for visiting internet-famous restaurants. Integrating different motivational theories, this study proposes a dining career ladder to conceptualize customers’ initial motivations to visit internet-famous restaurants, and their (un)varying motivations when they gain increasing experience. With reflections from 27 participants, we found that dining career ladder consists of four levels, from the primary level of physiological needs (dine out and relaxation, gourmet food), to stimulation and novelty (curiosity and novelty seeking, effect of unique atmospherics, and restaurant online reputation), belongingness and socialization (social occasions and bandwagon effect), and self-esteem and recognition (fear of missing out). Customers have multidimensional motivations for going to restaurants initially, but they show a descending pattern of motivations moving from higher level of needs to lower levels by concentrating on physiological needs when they accumulate negative experiences. Dining companions play a role in customers’ motivations to visit internet-famous restaurants.

The extended transmission of cold atmospheric plasma-induced anticancer effects between cells

Abstract The application of cold atmospheric plasma (CAP) in cancer therapy has recently received extensive attention. However, researchers have mainly studied the effects of CAP on plasma-irradiated cancer cells and have not determined whether CAP affects surrounding or distant non-irradiated cancer cells. Here, the viability and intracellular ROS levels of plasma-irradiated and non-irradiated cancer cells were monitored in vitro. Our results showed that CAP may induce plasma-irradiated cancer cells (A549 cells, A375 cells, J82 cells and HT29 cells) to secrete soluble factors into the cell culture medium, which can transmit plasma-induced anticancer effects from plasma-irradiated cancer cells to non-irradiated cancer cells. Our research confirmed that plasma-induced anticancer effects can be transmitted between cancer cells.

Methylotrophic bacteria from rice paddy soils: mineral-nitrogen-utilizing isolates richness in bulk soil and rhizosphere.

Methanol, the second most abundant volatile organic compound, primarily released from plants, is a major culprit disturbing atmospheric chemistry. Interestingly, ubiquitously found methanol-utilizing bacteria, play a vital role in mitigating atmospheric methanol effects. Despite being extensively characterized, the effect of nitrogen sources on the richness of methanol-utilizers in the bulk soil and rhizosphere is largely unknown. Therefore, the current study was planned to isolate, characterize and explore the richness of cultivable methylotrophs from the bulk soil and rhizosphere of a paddy field using media with varying nitrogen sources. Our data revealed that more genera of methylotrophs, including Methylobacterium, Ancylobacter, Achromobacter, Xanthobacter, Moraxella, and Klebsiella were enriched with the nitrate-based medium compared to only two genera, Hyphomicrobium and Methylobacterium, enriched with the ammonium-based medium. The richness of methylotrophic bacteria also differed substantially in the bulk soil as compared to the rhizosphere. Growth characterization revealed that majority of the newly isolated methanol-utilizing strains in this study exhibited better growth at 37°C instead of 30 or 45°C. Moreover, Hyphomicrobium sp. FSA2 was the only strain capable of utilizing methanol even at elevated temperature 45°C, showing its adaptability to a wide range of temperatures. Differential carbon substrate utilization profiling revealed the facultative nature of all isolated methanol-utilizer strains with Xanthobacter sp. TS3, being an important methanol-utilizer capable of degrading toxic compounds such as acetone and ethylene glycol. Overall, our study suggests the role of nutrients and plant-microbial interaction in shaping the composition of methanol-utilizers in terrestrial environment.

Improving atmospheric correction for KOMPSAT-3A by optimizing the 6SV look-up table

ABSTRACT We present techniques for enhancing the look-up table (LUT) method, using the Second Simulation of a Satellite Signal in the Solar Spectrum Vector (6 SV) model for atmospheric correction (AC) and accurate surface reflectance (SR) computation across the multispectral (MS) KOMPSAT-3A channels. We improved the LUT-based SR accuracy using three interpolation and prediction methods for AC coefficients: minimum curvature surface (MCS), six-dimensional linear interpolation (6D), and a deep neural network (DNN). When assessed based on the solar zenith angle (SZA) and aerosol optical depth (AOD), MCS had limitations interpolating atmospheric effects, particularly at shorter wavelengths. The DNN method had high predictive ability for atmospheric effect variability with an increased SZA, but struggled to predict minor changes at low SZAs. In comparison, the 6D method, operating in real-time and considering all AC input variables, consistently retrieved high-quality SR across all MS channels. Our findings offer insights into each method’s strengths and limitations, guiding future remote sensing research and applications.

Catalytic pyrolysis of wood dust for monophenol over macroalgal biochar-based catalyst: Effects of activation agents and atmospheres during catalyst synthesis on its performance

After introducing heteroatoms into the carbon material skeleton, the performance of carbocatalyst during catalytic pyrolysis of biomass for monophenol production is significantly improved. Algae, as a carbon source with intrinsic nitrogen content, is well-identified as a suitable raw material for preparing heteroatom-doped carbocatalyst. The present study aimed to investigate the effects of different alkaline activation agents (KOH/NaOH) and gas atmospheres (N2/CO2) during the carbonization-activation synthesis process of macroalgal biochar-based catalysts (MBBCs) on their properties and performances. Characterizations of carbocatalysts were carried out via BET and XPS analyses to investigate the porous structures and surface functional groups. Results showed that CO2, as a weakly oxidizing atmosphere, can promote the formation of porous structure of MBBCs. However, the promotion is not as strong as that of chemical activation agents (KOH/NaOH). Furthermore, KOH can promote the formation of porous structure more strongly than NaOH, but NaOH can substantially enhance the formation of surface oxygen‑nitrogen groups compared to KOH. All the MBBCs exhibited the increment of monophenols in the bio-oil obtained from catalytic pyrolysis of wood dust, especially phenol, o-cresol, and p-cresol. Amongst, the biochar-based catalyst activated with NaOH in CO2 atmosphere was the most effective one in promoting monophenols content (up to 59.46 %). Compared with the control group (without catalyst), the phenol content was increased from 5.03 % to 19.40 %. Moreover, it is found that the catalytic performance was positively correlated with the CO species percentage on the surface of MBBCs. The macroalgal biochar-based catalyst has an excellent catalytic performance, which is of great significance for achieving the complete utilization of algae and thereby improving the quality of catalytic pyrolysis products.

Wave setup estimation at regional scale: Empirical and modeling-based multi-approach analysis in the Mediterranean Sea

Wave setup is a physical process that induces a temporal increase of the mean water level due to wave dissipation by bottom friction and breaking in the surf zone, extending over tens to hundreds of meters in the cross-shore direction. Wave setup contribution to coastal sea level solely induced by wind and atmospheric effects can increase by more than 100% under extreme events and conditions favouring its formation. It is therefore crucial to consider this phenomenon when assessing sea-level-related coastal hazards. Previous studies estimated the wave setup effect by means of numerical modeling and empirical formulations at regional and global scale. Such analyses require either high computational capacity to implement high-resolution numerical models over large domains, and/or accurate information on coastal morphological features from global or regional databases. Although the Mediterranean Sea is a fetch-limited environment, waves generated from extra-tropical cyclones are powerful enough for wave setup to develop, and subsequently for a potential significant wave setup contribution to extreme coastal sea level. Through the use of both numerical and empirical methods, we investigate the uncertainty associated to wave setup representation on the frequency and magnitude of coastal extreme sea levels occurring on sandy beaches in the Mediterranean Sea. Wave setup values are compared at beach scale between process-based modeling and empirical approaches, showing highly variable results. We also quantify the impact of wave setup on return levels of coastal sea level extremes using reconstructed sea levels. We employ various methods to calculate the wave setup component. Results show high spatial dispersion, with clear differences between the numerical and empirical approaches, especially in regions prone to the development of energetic waves. The total inter-method dispersion of 100-year return levels is often higher than 30 cm for average values of 62.4 cm. We emphasize the important limitations related to wave setup modeling (i.e., its underestimation) at large scale, and call for caution when applying empirical formulations (generally developed from local studies) at regional to global scale, which can lead to unrealistic wave setup values.

Effects of various cold plasma atmospheres and external influencing factors on the adsorption of formaldehyde gas by bamboo-based carbon microfibers

To effectively enhance the adsorption performance of gaseous formaldehyde (HCHO) by bamboo-based carbon microfibers (BCMFs), the active oxygen (O) and nitrogen (N)-containing functional groups were rapidly introduced by cold plasma. The effects of plasma time, plasma atmospheres including oxygen (O2), nitrogen (N2), air, and argon (Ar) as well as ambient temperature, flow rate, and initial concentration of gaseous HCHO on the adsorption performance of BCMFs were comprehensively investigated. The typical kinetic, isothermal, and thermodynamic models were also evaluated. The O2-plasma activated BCMFs showed the most serious etching effects among four atmospheres. The adsorption capacities were ranked as BCMF-800-N-10 (203.87 mg g−1) > BCMF-800-Ar-10 (166.26 mg g−1) > BCMF-800-Air-10 (151.28 mg g−1) > BCMF-800-O-10 (144.21 mg g−1), which were 112.99%, 73.69%, 58.04%, and 50.66% higher than the control, respectively. The O–CO and pyrrolic N groups were more easily formed onto BCMF-800-N-10. The Langmuir and the Freundlich models displayed the excellent fitting properties. The optimal kinetic model tended to transfer to the pseudo-second-order from the pseudo-first-order after cold plasma modification. The BCMFs activated by plasma showed a synergistic single/multi-layer adsorption mechanism with a complex physicochemical adsorption. The HCHO adsorption performance was positively correlated with its concentrations but negatively correlated with environmental temperature.

Semi-wet synthesis of high-performance Li1.6Mn1.6O4 for selective lithium extraction from Salt Lakes Brine

Among the manganese-based lithium-ion sieves, Li1.6Mn1.6O4 has a high theoretical lithium adsorption capacity as a spinel ion sieve material. Small particle size orthogonal phase purity LiMnO2 powders were prepared by a semi-wet method and calcined in air at 400 °C to obtain Li1.6Mn1.6O4 a lithium-ion sieve precursor. The synergistic effects of oxygen atmosphere, heat treatment conditions and lithium/manganese molar ratio on the crystal structure of LiMnO2 and the lithium adsorption/desorption characteristics of Li1.6Mn1.6O4 were comprehensively investigated with XRD, SEM, TEM, XPS, Raman, DTA-TG and capacity retention study. Notably, when the initial lithium/manganese molar ratio was set at 1.1, and the sample underwent a calcination at 120 °C for 48 h under carefully controlled deoxygenation conditions, we observed the exclusive presence of the desired orthorhombic phase in the LiMnO2 sample. In contrast, when the synthesis conditions deviated from the optimized parameters led to the presence of the monoclinic phase of Li2MnO3. This highlights the sensitivity of Li1.6Mn1.6O4 properties to the synthesis conditions. The results of adsorption-desorption cycles show that the ion sieve Li1.6Mn1.6O4 prepared by heat treatment of ordered o-LiMnO2 is more stable, the structural stability of Li1.6Mn1.6O4 were characterized by high-temperature in-situ XRD experiments during heating from 30 to 800 °C. The equilibrium adsorption capacity was 34 mg g−1 in Qarhan Salt Lake brine at 10th cycle, and a remarkably low Mn dissolution loss rate of 0.6 %. The results have significant potential to advance the development of high-performance adsorbent in the Li-Mn-O system and contribute to the advances in lithium separation technology.

Effect of process atmosphere on microstructure, melt pool, texture, precipitate characteristics, and mechanical properties of laser powder bed fusion Fe-12Cr-6Al

This study investigates the impact of atmospheres (Ar and N2) on Fe-12Cr-6Al alloy fabricated using laser powder bed fusion (L-PBF) in terms of melt pool shape/size, microstructure, precipitate characteristics, and mechanical properties. The sample built in the N2 atmosphere exhibited lower porosity, wider melt pools, and no Al2O3 agglomeration. Oxygen content decreased from 0.012 to 0.0045 (wt.%), and nitrogen content increased from 0.013 to 0.02 (wt.%). The Ar-printed sample had a yield strength (YS) of 232 ± 15 MPa, ultimate tensile strength (UTS) of 286 ± 10 MPa, and total elongation (TE) of 6.4 ± 1.3 %, while the N2-printed sample showed significant improvements of the mechanical properties: YS of 315 ± 11 MPa, UTS of 401 ± 11 MPa, and TE of 7.8 ± 1.1 %. Therefore, N2 might be considered to replace Ar as a cost-effective shielding gas for FeCrAl alloys, with improved properties.

Influence of Temperature and Gas Atmosphere on the Thermal Decomposition of (NH4)6Mo7O24.4H2O

This study investigates the effects of gas atmosphere and synthesis temperature on the thermal decomposition of (NH4)6Mo7O24.4H2O. Samples were synthesized in a CVD furnace at temperatures of 450, 550, and 650 °C, using different gases: H2, O2, and Ar, individually. The resulting samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), and optical absorbance. XRD results revealed the formation of MoO3 in all samples produced in an O2 atmosphere. However, in samples synthesized in an inert atmosphere (Ar), a mixture of MoO3 and Mo4O11 phases was detected. The same phase mixture was observed in samples produced at 450 and 550 °C in an H2 atmosphere. However, in samples synthesized in H2 at 650°C, MoO2 mixed with Mo4O11 was formed. Raman and FTIR spectroscopy confirmed the results obtained by XRD, and these two techniques were also used to compare samples synthesized at 550 °C in different environments. The VSM results indicate a paramagnetic response in the analyzed samples, and there is also an increase in magnetization as the percentage of the Mo4O11 phase increases. Absorbance measurements were also performed and further confirm expected changes in sample composition.

Fe site regulation and activity deciphering by selective phase transformation in the confined FeNi nanoparticles for oxygen evolution reaction

Given its initially low activity and difficulty in active phase formation, Fe site regulation is rarely touched in FeNi-based oxygen evolution reaction (OER) catalysts. Herein, the Fe sites regulation and activity deciphering are demonstrated by selective phase transformation taking nitrogen-doped carbon confined FeNi nanoparticles derived from Fe2Ni-MIL-MOF pyrolysis as an example; driven by the reduction atmosphere and Kirkendall effect assisted by melamine pyrolysis, some Fe and Ni sites were separated to form metallic Fe and FeNi alloy and the subsequent fluorination process induced the ionic compound FeF2 formation rather than NiF2, offering a good platform to evaluate the influence of active Fe phase for OER catalysis. Theoretical calculations combined with ex-situ and in-situ spectral characterization techniques proved the complete convention of FeF2 into a high-valent and reactive intermediate state of FeOOH. Considering the stable metallic state of Ni, the largely improved catalytic performance could be attributed to the Fe site regulation and the subsequent synergistic catalysis effect. Compared to the traditional iron-based catalyst, theoretically, the electronic structure of FeF2 was more conducive to the active FeOOH phase formation and significantly lowered the reaction energy barrier for OER. By addressing the aforementioned problems, low overpotential and good stability for OER catalysts were realized. The current work showed valid proof of the FeNi-based catalysts regulation via Fe sites for energy-relevant catalysis reactions.

Experimental evaluation of atmospheric plasma treatment effects on different textures of CFRP composite for aircraft applications

This article examines the impact of Atmospheric Plasma Treatment (APL) on the chemical composition and fracture properties of various textured surfaces (tool and bag side) of carbon fiber/epoxy (CFRP) composites utilized in aircraft applications. For this purpose, parameters of atmospheric plasma (APL) surface treatment were evaluated in comparison to chemical cleaning and peel-ply applications, taking into account its effects on surface properties and adhesive bond strength. A comprehensive variety of surface characterization techniques were utilized to analyze surface modifications, including water and diiodomethane contact angle measurements for assessing surface hydrophilicity, Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR) and X-ray Photoelectron Spectroscopy (XPS) for analyzing chemical composition and functional groups, and Profilometry, Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) for evaluating surface topography and morphology. Experimental results indicated that the reduction in the contact angle following plasma treatment correlated with the elevated oxygen concentration and the presence of polar functional groups (e.g. -OH, -NH2, -NH3, C=O, O-C=O) on the composite surface. Plasma treatment, especially at low nozzle speeds, increased surface roughness on the bag side surfaces. This prevented adhesive penetration and led to gas entrapment, resulting in adhesive failure mode and reduced single lap shear strength for the bag side. In contrast, on the tool side surfaces, the plasma treatment led to a remarkable 19.7% enhancement in shear strength, highlighting its effectiveness.

Physically Based Real‐Time Rendering of Atmospheres using Mie Theory

AbstractMost real‐time rendering models for atmospheric effects have been designed and optimized for Earth's atmosphere. Some authors have proposed approaches for rendering other atmospheres, but these methods still use approximations that are only valid on Earth. For instance, the iconic blue glow of Martian sunsets can not be represented properly as the complex interference effects of light scattered at dust particles can not be captured by these approximations. In this paper, we present an approach for generalizing an existing model to make it capable of rendering extraterrestrial atmospheres. This is done by replacing the approximations with a physical model based on Mie Theory. We use the particle‐size distribution, the particle‐density distribution as well as the wavelength‐dependent refractive index of atmospheric particles as input. To demonstrate the feasibility of this idea, we extend the model by Bruneton et al. [BN08] and implement it into CosmoScout VR, an open‐source visualization of our Solar System. In a first step, we use Mie Theory to precompute the scattering behaviour of a particle mixture. Then, multi‐scattering is simulated, and finally the precomputation results are used for real‐time rendering. We demonstrate that this not only improves the visualization of the Martian atmosphere, but also creates more realistic results for our own atmosphere.

Arctic Thin Ice Detection Using AMSR2 and FY-3C MWRI Radiometer Data

Thin ice with a thickness of less than half a meter produces strong salt and heat fluxes which affect deep water circulation and weather in the polar oceans. The identification of thin ice areas is essential for ship navigation. We have developed thin ice detection algorithms for the AMSR2 and FY-3C MWRI radiometer data over the Arctic Ocean. Thin ice (<20 cm) is detected based on the classification of the H-polarization 89–36-GHz gradient ratio (GR8936H) and the 36-GHz polarization ratio (PR36) signatures with a linear discriminant analysis (LDA) and thick ice restoration with GR3610H. The brightness temperature (TB) data are corrected for the atmospheric effects following an EUMETSAT OSI SAF correction method in sea ice concentration retrieval algorithms. The thin ice detection algorithms were trained and validated using MODIS ice thickness charts covering the Barents and Kara Seas. Thin ice detection is applied to swath TB datasets and the swath charts are compiled into a daily thin ice chart using 10 km pixel size for AMSR2 and 20 km for MWRI. On average, the likelihood of misclassifying thick ice as thin in the ATIDA2 daily charts is 7.0% and 42% for reverse misclassification. For the MWRI chart, these accuracy figures are 4% and 53%. A comparison of the MWRI chart to the AMSR2 chart showed a very high match (98%) for the thick ice class with SIC > 90% but only a 53% match for the thin ice class. These accuracy disagreements are due to the much coarser resolution of MWRI, which gives larger spatial averaging of TB signatures, and thus, less detection of thin ice. The comparison of the AMSR2 and MWRI charts with the SMOS sea ice thickness chart showed a rough match in the thin ice versus thick ice classification. The AMSR2 and MWRI daily thin ice charts aim to complement SAR data for various sea ice classification tasks.

A Path-Planning Method for UAV Swarm under Multiple Environmental Threats

To weaken or avoid the impact of dynamic threats such as wind and extreme weather on the real-time path of a UAV swarm, a path-planning method based on improved long short-term memory (LSTM) network prediction parameters was constructed. First, models were constructed for wind, static threats, and dynamic threats during the flight of the drone. Then, it was found that atmospheric parameters are typical time series data with spatial correlation. The LSTM network was optimized and used to process time series parameters to construct a network for predicting atmospheric parameters. The state of the drone was adjusted in real time based on the prediction results to mitigate the impact of wind or avoid the threat of extreme weather. Finally, a path optimization method based on an improved LSTM network was constructed. Through simulation, it can be seen that compared to the path that does not consider atmospheric effects, the optimized path has significantly improved flightability and safety.

The relationship between exercise commitment and college students' exercise adherence: The chained mediating role of exercise atmosphere and exercise self-efficacy

ObjectiveThis study aims to explore the mechanisms underlying exercise commitment, exercise atmosphere, exercise self-efficacy, and exercise adherence among college students, as well as the impact of gender differences on these mechanisms. MethodsUsing a stratified cluster sampling method, 984 college students (aged 19.74 ± 1.25 years) from six universities in Anhui, Shandong, and Shaanxi provinces were randomly selected, with 403 male students and 581 female students. They had completed the Exercise Commitment Scale (ECC), Physical Exercise Atmosphere Scale (PEAS), Exercise Self-Efficacy Scale (ESES), and Exercise Adherence Scale (EPS). The study variables were analyzed in sequence for reliability and validity, correlation analysis, regression analysis, structural equation model testing, and bias-corrected percentile Bootstrap testing using SPSS 23.0 software and Hayes' (2013) Process plug-in. ResultsExercise commitment significantly positively predicted exercise adherence (β = 0.796, p < 0.01), exercise commitment significantly positively predicted exercise environment and exercise self-efficacy (β = 0.645, p < 0.01, β = 0.356, p < 0.01), exercise environment significantly positively predicted exercise self-efficacy and exercise adherence (β = 0.344, p < 0.01, β = 0.144, p < 0.01), and exercise self-efficacy significantly positively predicted exercise adherence (β = 0.934, p < 0.01). The mediating role of exercise environment in the relationship between exercise commitment and exercise adherence does not exist in male college students, while it exists in female college students. ConclusionsExercise atmosphere and exercise self-efficacy play a mediating role between exercise commitment and exercise adherence, with a total mediating effect value of 0.796. This study indicates that exercise commitment not only directly predicts exercise adherence, but also indirectly predicts exercise adherence through the chained mediating effects of exercise atmosphere and exercise self-efficacy. The above-mentioned mediating effect exists in female college students, while some mediating effects do not exist in male college students, thus gender has a significant impact on this mediating effect.

Combustion characteristics of millimeter-sized aluminum particles in fluidized bed under various O2/CO2/H2O atmospheres

Aluminum is an attractive alternative fuel, but it burns very inefficiently due to the formation of a dense Al2O3 layer which prevents O2 from diffusion to the surface of Al particles. In previous experiments, the combustion of millimeter-sized Al (mAl) particles in the fluidized bed has achieved a substantial increase in the combustion efficiency, but further improvements are still needed. In this study, the effects of reaction atmosphere on the fluidized combustion of mAl particles were investigated. The experiments with different O2/H2O/CO2 concentrations were conducted. The experimental results indicate that the combustion efficiency of mAl particles in fluidized bed increases as the mole fraction of O2, H2O or CO2 increases, and the highest combustion efficiency can reach 38.7%. After the analysis of the oxide film on the surface of aluminum particles, it was found that it is easier to generate the unstable θ-Al2O3 under CO2 atmosphere, and it is easier to generate the unstable γ-Al2O3 and θ-Al2O3 under H2O atmosphere. The unstable Al2O3 film is more likely to be abraded in the fluidized bed, which leads to the effective improvement of the combustion efficiency.

Fade Duration Analysis on a Ka-Band Link Operating in the Tropical Region

Communication systems are rapidly shifting towards higher frequencies due to congestion experienced at lower frequencies and the growing demand for higher data transmission rates within the network. However, it has been observed that as frequency increases, the susceptibility of the system to weather-related factors, particularly adverse weather conditions like rain, becomes more pronounced. This has raised significant concerns regarding the dependability of satellite communication links. This research investigates the dynamic characteristics of signal degradation caused by atmospheric effects, specifically focusing on the impact of rain fade. The study involves an analysis of fading duration using a year's worth of data extracted from Measat-5, operating at a beacon frequency of 20.199 GHz and positioned at an elevation angle of 68.8°. Such data is useful when developing a fade mitigation technique (FMT) that mitigates the disruptive effects caused by heavy rainfall, ultimately leading to an enhancement in both signal quality and overall signal availability.

Site Diversity Mitigation Technique for Satellite Services for Ku and Ka-band in Tropical Region

The demand for satellite communication has increased which led to spectral congestion. Recently, the satellite services use Ku and Ka-band as additional spectrum for satellite communication services. Ku and Ka-band are categorized as high frequency range which is around 12 to 14 GHz and 20 to 30 GHz respectively. However, the higher frequency will affect the quality of services and lead to signal impairment. This is mainly caused by the atmosphere effect which is oxygen, liquid water, and precipitation. But among the list, rain causes most signal fading due to the scattering and depolarization. The aim of this research is to study the site diversity as mitigation techniques operating at Ku and Ka-band for enhancing the gain of the signal and calculating diversity gain. There are modelling of diversity gain that has been proposed by previous researchers namely Hodge, Panagopolous, ITU-R, X.Yeo and Semire models which were validated in different climate regions respectively. By using all previous modelling of diversity gain, it will also compare with the measured local diversity gain. Suitable modelling that can be used in this tropical region has been proposed by improving the mathematical model that will be suitable in the tropical regions. This is important for encouraging the finding of new theories for the future broadcasting systems to decrease the power loss during the rain fade.