The tropospheric scintillation prediction of earth-to-satellite link for Bangladeshi climatic condition

The performance of earth-to-satellite link largely depends on various environmental factors like rain, fog, cloud, and atmospheric effects like ionospheric and tropospheric scintillation. In this paper, the tropospheric scintillation of Bangladesh, a subtropical country, is predicted based on measured climatic parameters, like relative humidity, temperature. In this prediction, ITU scintillation model are used. Four major cities, named Dhaka, Chittagong, Rajshahi and Sylhet, of Bangladesh are selected for prediction of scintillation. From the simulation result, Rajshahi is found to be the most badly affected region by the scintillation fade depth (SFD), which is followed by Chittagong and the SFD is minimum in Dhaka and Sylhet. The difference in SFDs among the considered cities does not vary heavily. It is also found that the SFD varies from 3 dB to 13 dB depending on the frequency in used. Moreover, higher scintillation is found in rainy season of Bangladesh. During this period, the scintillation becomes double of the average figure.

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Exposure Assessment of Airborne Bacteria Emitted from Swine Manure Composting Plant

Processes ◽

10.3390/pr9081283 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1283

Author(s):

Ki-Youn Kim

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Swine Manure ◽

Airborne Bacteria ◽

Particulate Matters ◽

Distribution Characteristics ◽

E Coli ◽

Enterococcus Spp ◽

Staphylococcus Spp ◽

Rotary Type

This study was performed to investigate the distribution characteristics of airborne bacteria emitted from swine manure composting plants. The types of swine manure composting plants selected for the survey in this study were as follows: screw type, rotary type, and natural dry type. Mean levels of airborne bacteria in swine manure composting plants were 7428 (±1024) CFU m−3 for the screw type, 3246 (±1407) CFU m−3 for the rotary type, and 5232 (±1217) CFU m−3 for the natural dry type, respectively. Based on the results obtained from this study, the swine manure composting plant operated by screw type showed the highest concentration of airborne bacteria, followed by the natural dry type and rotary type. The monthly concentration of airborne bacteria was the highest in August and the lowest in November, regardless of the type of swine manure composting plant. The respirable size of airborne bacteria accounted for about 50% of the total. The ratio of respirable to the total quantity of airborne bacteria was 50%. The correlation relationships between airborne bacteria and environmental factors (temperature, relative humidity, particulate matters, and odor) were not found to be significant in the swine manure composting plants. The predominant genera of airborne bacteria identified were Micrococcus spp., Staphylococcus spp., Escherichia(E-coli) spp., Enterococcus spp., and Enterobacteriaceae spp.

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EFFECTS OF ENVIRONMENT ON GROWING HYDROPONICS MAIZE FODDER USING LOW-COST GREENHOUSE CULTIVATING UNIT FOR LIVESTOCK PRODUCTION.

10.36106/ijsr/0431788 ◽

2021 ◽

pp. 71-72

Author(s):

Adamu, B. ◽

Abdullahi, S. ◽

Saidu, S. G ◽

Yustus Sunday Francis

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Production System ◽

Low Cost ◽

Factors Affecting ◽

Production Water ◽

Fodder Production ◽

Food Requirement ◽

Greenhouse Cultivation ◽

Near Future

The term 'Hydroponics' was derived from Greek words 'hydro' means water and 'ponics' means labor. Hydroponic is a modern agricultural technique that uses nutrient solution rather than soil solution for fodder production. As population increases the food demand also increased, the existing system of agriculture will not be able to meet the food requirement in the near future due to environmental challenges in the industry. The major environmental factors affecting the hydroponics production system are; Temperature, relative humidity, and light. The objectives of this studies are to examine the hydroponics greenhouse technologies, impact of environmental factors on hydroponics greenhouse cultivation and challenges of growing on hydroponics greenhouse system. This study revealed that hydroponics greenhouse cultivation is a better option for improved fodder production, water utilization, palatability and digestibility.

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Evaluation of Atmospheric Effects on Interferograms Using DEM Errors of Fixed Ground Points

Sensors ◽

10.3390/s18072336 ◽

2018 ◽

Vol 18 (7) ◽

pp. 2336 ◽

Cited By ~ 1

Author(s):

Takashi Nonaka ◽

Tomohito Asaka ◽

Keishi Iwashita

Keyword(s):

Phase Noise ◽

Atmospheric Effects ◽

Sar Images ◽

Single Pass ◽

Digital Elevation ◽

Total Phase ◽

Disaster Monitoring ◽

The Difference ◽

Elevation Model ◽

Interferometric Sar

High-resolution synthetic aperture radar (SAR) data are widely used for disaster monitoring. To extract damaged areas automatically, it is essential to understand the relationships among the sensor specifications, acquisition conditions, and land cover. Our previous studies developed a method for estimating the phase noise of interferograms using several pairs of TerraSAR-X series (TerraSAR-X and TanDEM-X) datasets. Atmospheric disturbance data are also necessary to interpret the interferograms; therefore, the purpose of this study is to estimate the atmospheric effects by focusing on the difference in digital elevation model (DEM) errors between repeat-pass (two interferometric SAR images acquired at different times) and single-pass (two interferometric SAR images acquired simultaneously) interferometry. Single-pass DEM errors are reduced due to the lack of temporal decorrelation and atmospheric disturbances. At a study site in the city of Tsukuba, a quantitative analysis of DEM errors at fixed ground objects shows that the atmospheric effects are estimated to contribute 75% to 80% of the total phase noise in interferograms.

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Droplet and Aerosol Suspension Times in Ambient Air in Confined Spaces and Transmission of COVID-19: Influence of Environmental Factors

Journal of Scientific Research ◽

10.3329/jsr.v13i2.50273 ◽

2021 ◽

Vol 13 (2) ◽

pp. 495-506

Author(s):

M. R. Islam ◽

S. H. Naqib

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Ambient Air ◽

Confined Space ◽

Natural Processes ◽

Confined Spaces ◽

Potential Source ◽

Aerosol Droplet ◽

Exhaled Air ◽

Mode Of Transmission

The COVID‑19 pandemic, alternatively known as the coronavirus pandemic, is an unfolding pandemic of coronavirus disease 2019 (COVID‑19) across the entire globe in an unprecedented proportion. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2. The mode of transmission of COVID-19 is a subject of intense research. The airborne transmission is one prime possibility. Breathing and talking are natural processes which generate exhaled particles. The exhaled air is an aerosol/droplet composed of naturally produced particulates of varying size. The duration over which the aerosols/droplets are suspended in the air is an important factor. Long suspended aerosols/droplets are potential source of transmission, particularly in confined spaces. We have calculated times of suspension by considering various environmental factors, namely, the ambient temperature and relative humidity in a confined space, in this work. Both temperature and relative humidity affect the suspension time of the exhaled aerosols/droplets with varying degree. The effects of environmental factors are significant for aerosols, particularly for those with small radii. We have discussed the possible implications of our findings in this paper.

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Environmental Factors Affecting the Diversity and Photosynthetic Pigments of Trentepohlia Species in Northern Thailand’s Chiang Dao Wildlife Sanctuary

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.8912 ◽

2020 ◽

Vol 89 (1) ◽

Author(s):

Santi Saraphol ◽

Srunya Vajrodaya ◽

Ekaphan Kraichak ◽

Anchalee Sirikhachornkit ◽

Nuttha Sanevas

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Photosynthetic Pigments ◽

Dominant Species ◽

Winter Season ◽

Morphological Identification ◽

Wildlife Sanctuary ◽

Total Carotenoids ◽

Carotene Content ◽

Factors Affecting

This study addressed the environmental factors that affect Trentepohlia spp. in the Chiang Dao Wildlife Sanctuary at altitudes of 399 to 1,503 meters above sea level (m a.s.l.) during the rainy, winter, and summer seasons. Species were identified using characteristic morphological identification. The influence of environmental factors on the algae was analyzed using a statistical program, and seasonal changes in the quantity of photosynthetic pigments in the dominant species were evaluated. The average relative humidity was 69.34 ± 12.90%, the average temperature was 26.23 ± 3.79 °C, and the average light intensity was 139.78 ± 42.21 µmol photon m−2 s−1. Thirteen species were found: Trentepohlia chapmanii, Trentepohlia sp. 1, Trentepohlia sp. 2, Trentepohlia sundarbanensis, Trentepohlia sp. 3, Trentepohlia rigidula, Trentepohlia sp. 4, Trentepohlia effusa, Trentepohlia monilia, Trentepohlia abietina, Trentepohlia sp. 5, Trentepohlia aurea, and Trentepohlia umbrina. The largest number of species (seven to nine) were found at lower altitudes, from 473 to 517 m a.s.l. Species diversity was greatest in the winter season (13 species). Species found at low attitude were grouped together (Group 1) and had the greatest diversity, and the remaining species were divided into Groups 2, 3, and 4. Environmental factors had both positive and negative influences on the species, especially T. chapmanii, which was found below 1,003 m a.s.l., and T. monilia, which was found in areas with a high relative humidity of 74.50% to 83.93%. The ratio of the total carotenoids to chlorophyll of T. rigidula, the dominant species, was relatively high at 4.96:1, and the β-carotene content (46.89 %w/w) was highest during winter.

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Investigation of monthly variations in the efficiencies of photovoltaics due to sunrise and sunset times

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v18.i1.pp310-317 ◽

2020 ◽

Vol 18 (1) ◽

pp. 310

Author(s):

Armstrong O. Njok ◽

Julie C. Ogbulezie ◽

Manoj Kumar Panjwani ◽

Raja Masood Larik

Keyword(s):

Relative Humidity ◽

Solar Energy ◽

Electrical Energy ◽

Time Of Day ◽

Peak Efficiency ◽

Pv Module ◽

Average Relative Humidity ◽

The Difference ◽

Monthly Variations ◽

Different Levels

The effect of time of day and month on the efficient conversion of solar energy to electrical energy using a polycrystalline (PV) module in calabar was studied. A KT-908 precision digital hygrometer and thermometer, and a M890C+ digital multimeter were used in the process. Results obtained shows that photovoltaic produce different levels of peak efficiencies at different times of the day for different months due to the difference in sunrise and sunset times for the months. The results also indicated that photovoltaics will be more efficient in months with low average relative humidity couple with low panel temperature. A peak efficiency of 77% at 12:30 in the month of April was observed before dropping to 73% at 12:00 in the month of May, indicating that there might be further drop in efficiency as we proceed further into the year. Results also show that photovoltaics are more efficient before noon in the month of May than in April while the reverse will be observed in the afternoon.

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Seed Storage and Germination Performance in Knema attenuata - an Endemic Medicinal Tree of Western Ghats, India

Journal of Non Timber Forest Products ◽

10.54207/bsmps2000-2021-u31w16 ◽

2021 ◽

Vol 27 (3) ◽

pp. 162-166

Author(s):

Abdul Azeez Hussain ◽

◽

Ramachandra Kurup Rajvikraman ◽

Keyword(s):

Seed Germination ◽

Relative Humidity ◽

Moisture Content ◽

Seed Bank ◽

Tree Species ◽

Western Ghats ◽

Climatic Condition ◽

Seed Storage ◽

Medicinal Tree

Detailed study on seed storage and germination trailed in Knema attenuata (Wall. ex Hook. f. & Thomson) Warb.– the IUCN Red Listed ‘least concern’ medicinal tree species revealed that seeds were of recalcitrant nature. Viability of the seeds could be maintained for a longer period of up to 6 months with 47% Moisture content (mc) when kept in closed polycarbonate bottles at seed bank condition [20±20C Temp. and 40% Relative Humidity (RH)]. The 55% seed germination under normal climatic condition could be enhanced to a much higher percentage (75±5) inside the mist house chamber (34±30C Temp. and 70-80% RH).

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Mid-Holocene drylands: A multi-model analysis using Paleoclimate Modelling Intercomparison Project Phase III (PMIP3) simulations

The Holocene ◽

10.1177/0959683619854512 ◽

2019 ◽

Vol 29 (9) ◽

pp. 1425-1438

Author(s):

Shanshan Liu ◽

Dabang Jiang ◽

Xianmei Lang

Keyword(s):

Relative Humidity ◽

Potential Evapotranspiration ◽

Aridity Index ◽

Phase Iii ◽

Collective Effects ◽

Model Data ◽

Intercomparison Project ◽

The Difference ◽

Paleoclimate Modelling Intercomparison Project ◽

Paleoclimate Modelling

This study examines changes in aridity levels during the mid-Holocene (approximately 6000 cal. yr ago) using multi-model simulations from the Paleoclimate Modelling Intercomparison Project Phase III. Overall, there is little difference in the total area of drylands from the preindustrial period; global drylands are 8% wetter than during the preindustrial period as measured by an aridity index; and 16% of preindustrial drylands convert to a wetter climate subtype, double the sum of zones that are replaced by a drier category. Considerable variations are present among regions with major contractions of each dryland subtype from northern Africa to South Asia and the main expansions of arid, semiarid, and dry subhumid climates in southern hemisphere continents. The difference in precipitation is the leading factor of the aforementioned changes. The second factor is the altered potential evapotranspiration as mainly induced by relative humidity, which contributes to additional aridity changes in a same direction as precipitation does. The collective effects of precipitation and relative humidity account for more than 80% of the dryland variations. In comparison, the simulated aridity change is in reasonable agreement with reconstructions, while there are model–data discrepancies for Australia and uncertainties across proxies for southern Africa.

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Thermal Performance Comparison between Single and Double Storey Terrace Houses in Melaka, Malaysia

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.835.416 ◽

2016 ◽

Vol 835 ◽

pp. 416-422

Author(s):

Fahanim Abdul Rashid ◽

Asrul Mahjuddin Ressang Aminuddin ◽

Norafida Ab. Ghaffar

Keyword(s):

Relative Humidity ◽

Thermal Comfort ◽

Case Studies ◽

Thermal Performance ◽

High Energy ◽

Performance Comparison ◽

Building Envelope ◽

The Difference ◽

Economic Developments ◽

Housing Typology

Over the past decade many studies were conducted to investigate the thermal performance of terraced houses in Malaysia. It was found that this housing typology failed to address the need for thermal comfort and alternatives to the narrow frontage with deep plan have been proposed with simulated good thermal performance. Although this is good progress for new generation of terraced houses, millions of units of terraced houses are still in use and new units with the outdated existing plans continued to get built due to consistently very high demand due to progressive urbanisation and rapid economic developments. Therefore, it is imperative that the thermal comfort issue for existing terraced houses is dealt with and through this paper a comparison between single and double storey terraced houses is made through analysis of indoor environmental monitoring (ambient temperature, relative humidity and air velocity) of two (2) selected case studies in Merlimau, Melaka. Contrary to popular belief, it is found that there is no statistical difference between both sets of indoor temperature and relative humidity between the case studies. This finding is indicative of the consistent and stable temporal temperature highs and lows in a 24 hour cycle despite the difference in indoor volume and distance between the ground floor and the roof cavity. Much of the reason is due to the materiality of the terraced houses construction and unsealed and uninsulated building envelope. Therefore, further research into improving the thermal performance of existing terraced houses of any typology have to be conducted to allow thermal comfort and to reduce reliance on high energy consuming air-conditioning.

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EFFECT OF ENVIRONMENT ON BROMOBUTYL RUBBER–STEEL ADHESION

Rubber Chemistry and Technology ◽

10.5254/rct.19.80455 ◽

2019 ◽

Vol 93 (2) ◽

pp. 429-444 ◽

Cited By ~ 2

Author(s):

Essi Sarlin ◽

Ari Rosling ◽

Mari Honkanen ◽

Mari Lindgren ◽

Mira Juutilainen ◽

...

Keyword(s):

Sulfuric Acid ◽

High Temperature ◽

Relative Humidity ◽

Environmental Factors ◽

Adhesive Layer ◽

Metal Structure ◽

Adhesive System ◽

Metal Interface ◽

Weakest Link ◽

Industry Sectors

ABSTRACT Optimizing the maintenance cycles of rubber-lined components is of great importance. Especially for the industry sectors operating under demanding conditions, challenges in the lifetime evaluation of rubber linings may cause apparent premature failures. Thus, understanding the effect of environmental factors on the performance and durability of rubber linings, as well as on the weakest links of the structure in certain environments, is essential. The performances of bromobutyl rubber and rubber–steel interfaces after exposure to different environments, namely, high temperature (95 °C), moisture (95% relative humidity and immersion), and sulfuric acid (solution with 75 g/L of acid) were investigated. The weakest link of the rubber–metal structure and, consequently, the location of the fracture were mostly within the adhesive layer or at the primer–metal interface. However, the most degraded component of the adhesive system depends on the aging environments.

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