scholarly journals Effect of Environmental Conditions on Performance of Corrugated Sheet Boxes Manufacturing Process

2019 ◽  
Vol 8 (2S7) ◽  
pp. 339-343
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Environmental Conditions ◽  
Performance Test ◽  
Mechanical Performance ◽  
Sheet Material ◽  
Climatic Conditions ◽  
Atmospheric Conditions ◽  
Severe Condition ◽  
Moisture Content Level

Corrugated sheet material is very sensitive to the environmental conditions, especially moisture. The present study focuses on the mechanical behavior of corrugated sheet box board at different humidity and temperature conditions. The objective of this study is to study the important properties of corrugated sheet boxes at different climatic conditions and also to study the influence of the properties of corrugated sheet paper on the properties of corrugated board and box at various environmental conditions. The mechanical performance test carried out under controlled atmospheric conditions where the temperature (0C) range was studied from 200C to 500C and the relative humidity (Rh) range was studied from dry condition 30% Rh to severe condition 90% Rh. The results tested showed that the maximum compressive load of empty corrugated sheet box sealed exposed to moisture content decreased with the increase of temperature and relative humidity. In general it is observed in paper, corrugated sheet board and boxes that have optimum combined properties are obtained at moisture content level at 7-8% and hence moisture content of 7-8% may be the ideal value for corrugated sheet paper used in corrugated packaging industry

scholarly journals Svalbard reindeer (Rangifer tarandus platyrhynchus) antler characteristics reflecting the local environmental conditions

2019 ◽  
Vol 46 (1) ◽  
pp. 16-23
Author(s):  
Jan Kavan ◽  
Veronika Anděrová
Keyword(s):  
Environmental Conditions ◽  
Rangifer Tarandus ◽  
Well Being ◽  
Climatic Conditions ◽  
High Mountain ◽  
Atmospheric Conditions ◽  
Individual Subject ◽  
Svalbard Reindeer ◽  
Invasive Method ◽  
Antler Size

AbstractA new non-invasive method based on picture analysis was used to estimate the conditions in Svalbard reindeer populations. The well-being of an individual subject is often expressed through visual indices. Two distinct reindeer populations were compared based on their antler parameters. Relative antler size and number of tines are variables supposed to reflect correspondingly the environmental conditions of sedentary populations within the growing season. The occurrence areas of two studied populations are distinctly isolated – separated with high mountain ridges, glaciers and fjords. The population in Petuniabukta occupies a sparsely vegetated region with harsh climatic conditions, whereas Skansbukta represents an area with continuous tundra vegetation cover, milder climatic conditions and, consequently, also a longer vegetation season. These environmental factors probably caused significant differences in the relative antler size and number of tines in the studied species. The Skansbukta population exhibited a larger relative antler size and higher number of tines than the population in Petuniabukta (both parameters differed significantly, p < 0.01). This difference reflects concisely the different environmental conditions of both locations. A comparison of Skansbukta population antler characteristics between years 2017 and 2018 did not reveal significant changes, most probably due to very similar atmospheric conditions in these two years (in terms of air temperature).

Effect of the Environmental Conditions of Tropical Climates on the Performance Parameters of a Gas Turbine Power Generation Plant

2020 ◽  
Author(s):  
J. Fajardo ◽  
D. Barreto ◽  
T. Castro ◽  
I. Baldiris
Keyword(s):  
Power Plant ◽  
Relative Humidity ◽  
Gas Turbine ◽  
Output Power ◽  
High Temperatures ◽  
Environmental Conditions ◽  
Thermal Efficiency ◽  
Specific Work ◽  
Atmospheric Conditions ◽  
Compressor Inlet

Abstract It is known that high temperatures adversely affect the performance of gas turbines, but the effect of the combination of atmospheric conditions (temperature and relative humidity -RH-) on the operation of this type of system is unknown. In this work the effects of atmospheric conditions on the energy and exergy indicators of a power plant with gas turbine were studied. The indicators studied were the mass flow, the specific work consumed by the compressor, specific work produced by the turbine, the combustion gas temperature, the NO concentration, the net output power, the thermal efficiency, the heat rate, the specific consumption of fuel, the destruction of exergy and exergy efficiency. Among the results, it is noted that for each degree celsius that reduces the temperature of the air at the compressor inlet at constant relative humidity on average, the mass flow of dry air increases by 0.27 kg/s, the specific work consumed by the compressors decreases by 0.45%, the output power increases by 1.17% and the thermal efficiency increases by 0.8%, the exergy destruction increases by 0.72% and the exergy efficiency increases by 0.81%. In addition, humidity changes relative to high temperatures are detected more significantly than at low temperatures. The power plant studied is installed in Cartagena, Colombia and since it is not operating in the design environmental conditions (15 °C and 60% relative humidity) it experiences a loss of output power of 6140 kW and a drop in thermal efficiency of 5.12 %. These results allow considering the implementation of air cooling technologies at the compressor inlet to compensate for the loss of power at atmospheric air conditions.

Neoseiulus baraki (Acari: Phytoseiidae) survival and walking in response to environmental stress

2019 ◽  
Vol 24 (3) ◽  
pp. 487 ◽  
Author(s):  
Vaneska Barbosa Monteiro ◽  
Girleide Vieira França ◽  
Manoel Guedes Correa Gondim Jr ◽  
Debora Barbosa Lima ◽  
Jose Wagner Silva Melo
Keyword(s):  
Relative Humidity ◽  
Environmental Stress ◽  
Survival Time ◽  
Environmental Conditions ◽  
Walking Speed ◽  
Tracking System ◽  
Climatic Conditions ◽  
Stress Factors ◽  
Neoseiulus Baraki ◽  
Increasing Temperature

Living organism is exposed to the influence of various environmental conditions. These environmental conditions can trigger stress and compromise the fitness of the organism. As living organisms, phytoseiid mites are frequently exposed to a range of environmental stressors. In the present study, we attempted to explore the responses of the Neoseiulus baraki to environmental stress factors (temperature and humidity). Initially, the effect of different temperature (18–33 °C) and relative humidity (10–95%) levels on the survivorship of unfed N. baraki females was evaluated. Next, we estimated the walking parameters (distance traveled and average walking speed) with a computerized tracking system and we tested how N. baraki is constrained in their effective displacement by their ability to walk and survive in absence of food. The proportion of surviving N. baraki as well as mean survival time decreased significantly with increasing temperature. The opposite trend was observed to relative humidity. The distance covered by N. baraki reduced with increasing temperature (when only taking the temperature dependence of the survival time but not of walking speed and neither the tortuosity of the walking path) ranged from 550 m at 18 ºC to 100 m at 33 ºC. Under climatic conditions representative for the Tropics (27 ºC and 75 % RH) N. baraki was able to survive up to 1.5 days (36 h) without feeding and covered 0.9 m in 10 min as displacement estimated by walking.

scholarly journals Soil compaction of various Central European forest soils caused by traffic of forestry machines with various chassis

2015 ◽  
Vol 24 (3) ◽  
pp. e038 ◽  
Author(s):  
Michal Allman ◽  
Martin Jankovský ◽  
Valéria Messingerová ◽  
Zuzana Allmanová ◽  
Michal Ferenčík
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Compaction ◽  
Soil Moisture Content ◽  
Standard Test ◽  
Primary Objective ◽  
Climatic Conditions ◽  
Moisture Content Level ◽  
European Forest

<p><em>Aim of study: </em>The primary objective of this paper was to compare the effects of different types of forestry machine chassis on the compaction of the top layers of soil and to define the soil moisture content level, at which machine traffic results in maximum compaction.</p><p><em>Area of study:</em> Measurements were conducted in eight forest stands located in Slovakia and the Czech Republic. The soil types in the stands subjected to the study were luvisols, stagnosols, cambisols, and rendzinas.</p><p><em>Material and Methods:</em> The measurements were focused on tracked and wheeled (equipped with low pressure tyres) cut-to-length machines, and skidders equipped with wide and standard tyres. The bulk density of soil was determined from soil samples extracted from the ruts, the centre of the skid trail, and the undisturbed stand. To determine soil moisture content, at which the soil is the most susceptible to compaction, the Proctor standard test was employed.</p><p><em>Main results:</em> The moisture content for maximal compaction fluctuated from 12% to 34.06%. Wheeled machines compacted the soil to 1.24 – 1.36 g.cm<sup>-3</sup> (30.3 – 35.4 % compaction) in dried state. Bulk density of soil in stands where tracked machine operated was lower, ranging from 1.02 to 1.06 g.cm<sup>-3</sup> (25.3 % compaction).</p><p><em>Research highlights:</em> All wheeled machines caused the same amount of soil compaction in the ruts, despite differences in tyres, machine weight, etc. Maximum compaction caused by forestry machines occurred at minimal moisture contents, easily achievable in European climatic conditions.  </p><p><strong>Keywords:</strong> soil compaction; bulk density; soil moisture content limits; cut-to-length machines; skidders.</p>

Dynamic moisture sorption and hygroexpansion of Populus euramericana Cv. under two cyclic hygrothermal conditions

Holzforschung ◽  
2016 ◽  
Vol 70 (12) ◽  
pp. 1191-1199 ◽  
Author(s):  
Tiantian Yang ◽  
Erni Ma ◽  
Jianhui Zhang
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Environmental Conditions ◽  
Moisture Sorption ◽  
Longitudinal Direction ◽  
Measured Data ◽  
Populus Euramericana ◽  
Dimensional Changes ◽  
Unit Change ◽  
Condition B

Abstract Poplar (Populus euramericana Cv.) specimens, 20 mm in radial (r) and tangential (t) directions with thicknesses of 4 mm and 10 mm along the longitudinal direction, were subjected to cyclic environmental conditions, in the course of which the relative humidity (RH) changed sinusoidally between 75% and 45% at 20°C (condition A), or the temperature (T) was changed sinusoidally within 5–35°C at 60% RH (condition B). Moisture content (MC), as well as the t- and r-dimensional changes were measured as a response to the dynamic environmental conditions. The measured data also changed sinusoidally but they lagged behind the triggering original RH or T data. This effect was much higher under condition A than under condition B. The observed equivalent RH and T changes at different ΔMCs or Δts served for comparison of the responses to RH and T, and the former were less pronounced than the latter. MC and t-dimensional changes per unit change of RH were greater than those per unit change of T but still lower than static values. In summary, the effects of dynamic RH change are larger than those of T, especially concerning MC responses compared to dimensional changes.

Déformations générées dans les bétons sous l'influence des conditions climatiques

1991 ◽  
Vol 18 (6) ◽  
pp. 1088-1092 ◽  
Author(s):  
Gérard Ballivy ◽  
Brahim Benmokrane ◽  
Omar Chaallal
Keyword(s):  
Experimental Study ◽  
Relative Humidity ◽  
Strain Gauge ◽  
Environmental Conditions ◽  
Structural Integrity ◽  
Climatic Conditions ◽  
Strain Gauges ◽  
Volume Changes ◽  
Environmental Agents ◽  
Concrete Blocks

This paper presents the results of an experimental study of strains generated in concrete by variations in climatic conditions. Three 0.16 m3 concrete blocks, instrumented with vibrating wires strain gauges, were exposed to various environmental conditions (drying–wetting) during approximately 3 years and strains were measured. The study shows that concrete strains induced by environmental agents acting alone can reach levels that may jeopardize the structural integrity of concrete structures exposed to similar conditions, when the boundary conditions cannot accommodate the resulting extensive volume changes. Key words: environmental conditions, relative humidity, temperature, drying, wetting, vibrating wires strain gauge, concrete strains.

Observations on the microclimate of the fleece

1957 ◽  
Vol 8 (3) ◽  
pp. 281 ◽  
Author(s):  
IEB Fraser
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Climatic Conditions ◽  
Wetting And Drying ◽  
Total Moisture Content

The reaction of the fleece to moisture has been studied in terms both of relative humidity of the microclimate and of fleece moisture. The processes of wetting and drying of the fleece are by no means consistent or uniform, and behaviour varies with differing climatic conditions. Measurement of fleece moisture on the basis of relative humidity and total moisture content has shown that fleece types that are susceptible to bacterial discoloration retain moisture for a longer period than do fleece types that are generally immune from such discoloration. The effect is more marked in hogget than in adult fleeces. The importance of sensitivity of the skin to water and the part played by this in the realization of susceptibility are also discussed.

scholarly journals The dependence of soil CO2 fluxes on atmospheric conditions during sub-periods of soil respiration

2015 ◽  
Vol 76 (2) ◽  
pp. 129-143
Author(s):  
Krzysztof T. Wroński ◽  
Barbara Przybylska
Keyword(s):  
Relative Humidity ◽  
Soil Respiration ◽  
Temperature Dependence ◽  
Climatic Conditions ◽  
Dry Forest ◽  
Co2 Fluxes ◽  
Atmospheric Conditions ◽  
Soil Co2 ◽  
Model Research ◽  
The Relationship

Abstract Soil respiration was measured on rusty soil in a dry forest near Łódź. A two-year series of soil respiration measurements was divided into characteristic sub-periods, and the relationship between soil CO2 emissions to selected aspects of climatic conditions was examined. The temperature dependence of soil CO2 fluxes is linear from March to June and exponential during the period of June to March. Dividing the year into a phase of growth and a phase of decline and modelling soil respiration for each of these sub-periods separately does not significantly improve the accuracy of the model. Research shows that soil respiration responds with a delay of three days to changes in temperature and relative humidity, but with a 17-day delay to changes in precipitation.

scholarly journals Effect of Extreme Climate on Topology of Railway Prestressed Concrete Sleepers

Climate ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 17 ◽  
Author(s):  
Dan Li ◽  
Sakdirat Kaewunruen
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Prestressed Concrete ◽  
Vital Role ◽  
Climatic Conditions ◽  
Time Dependent ◽  
Railway Infrastructure ◽  
Time Dependent Behaviour ◽  
The Impact ◽  
Dependent Behaviour

Railway networks are exposed to various environmental conditions. It is thus critical that infrastructure components can tolerate such effects by design. Railway sleepers are a critical safety component in ballasted track systems. Prestressed concrete is currently the most common material for railway sleepers due to its superior advantages in structural performance, low maintenance, sustainability, and construction. In practice, many prestressed concrete sleepers are installed in harsh environments that are subject to various changes in climate. Environmental conditions are, therefore, one of the most critical phenomena affecting the time-dependent behaviour of prestressed concrete sleepers. Hence, the impact of climate changes on the serviceability of railway infrastructure needs to be thoroughly investigated. Temperature and relative humidity are crucial aspects that have not been sufficiently studied so far with reference to prestressed concrete sleepers embedded in track systems. This study aims to investigate the effects of extreme climatic conditions on the performance and time-dependent behaviour of prestressed concrete sleepers using contemporary design approaches. The issue concerning the effects of climate uncertainties on creep and shrinkage is rigorously investigated on the basis of both environmental temperature and relative humidity. The outcome indicates that environmental conditions play a vital role in the time-dependent behaviour of prestressed concrete sleepers. The insights will be essential for assessing the long-term serviceability of prestressed concrete sleepers that have been installed in railway lines and are subjected to extreme environmental conditions.

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