Differential Effects of Abiotic Factors on the Insecticidal Efficacy of Diatomaceous Earth against Three Major Stored Product Beetle Species

This study evaluated the influence of temperature and relative humidity (RH) on the insecticidal effect of diatomaceous earth (DE) at two concentrations, 500 and 1000 ppm, on wheat, for the control of Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae), Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). These bioassays were carried out in all combinations of four temperature levels (15, 20, 25, and 30 °C), and two relative humidity levels (55 and 75%). Cryptolestes ferrugineus and O. surinamensis were found to be much more susceptible to the DE-treated wheat than T. confusum, but the increase of the DE dose increased the mortality level for all three species. Although the increase of temperature and the decrease of RH increased insect mortality in some of the combinations tested, the reverse was observed in some treatments, suggesting that there are considerable differential effects of these factors in DE efficacy. The increase of insect exposure from 1 to 21 days notably increased insect mortality, suggesting that exposure is a critical factor that may alleviate possible differential effects of certain abiotic conditions. The results of the present work provide data that illustrate the viability of the utilization of DE in stored product protection, as alternatives to chemical control methods.

Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section

In the present investigation, an analysis of the fire resistance of the steel-reinforced concrete-filled steel tubular columns with circular cross-sections was carried out by means of numerical simulation. The development of the study was carried out by means of numerical simulation to predict the behavior of the column against fire. The results of the numerical model are validated by comparing the temperature levels obtained through experimental tests. From the results obtained, it is shown that the increase in the contact area between the steel and the concrete reduces the average temperature of the column, which implies a greater resistance to fire. The fire resistance of the columns with the steel profile designs are between 3.4 - 3.6 times higher compared to the column only made of concrete, which is an indication of the excellent performance of the steel-reinforced concrete-filled steel tubular columns with circular cross- sections columns. In general, the methodology proposed in this research allows the analysis of the thermal physical phenomena of the different columns used for the construction of buildings.

Impact of Heat on the Different Stages of the Production of Local Beer “Tchoukoutou” Made from Sorghum

Tchoukoutou is a local alcoholic drink made from sorghum. The optimization and good quality of this drink depend on certain factors such as temperature that were the subject of our work. To carry out this study, we have set ourselves the general objective of structuring the production of Tchoukoutou. Specifically, the study aims to systematize the cooking of the wort, to verify the properties of the beer through tests and to produce a quality drink. An investigation was made on the influence of temperature on sorghum germination and wort cooking. The study of the effect of temperature on the germination of sorghum was carried out. It concerned four different temperature levels which are: 23 ° C, 26 ° C, 30 ° C and 35 ° C. A study of the influence of temperature on brewing was done with different varieties of sorghum and also at different temperature ranges: 78 ° C, 83 ° C, 89 ° C, and 92 ° C. The results showed that the ideal germination temperature is 30 ° C and for brewing it is 78 ° C. The soaking time during germination, for a good germination rate, is between 16h and 26h. In conclusion, the temperature factor is a parameter that should not be overlooked when making Tchoukoutou. Our study thus made will serve as a basis for subsequent studies in the same direction to achieve a standardized industrial production of Tchoukoutou.

A Comparative Study on the Temperature Effect of Solid Birch Wood and Solid Beech Wood under Impact Loading

In order to use wood for structural and load-bearing purposes in mechanical engineering, basic information on the impact behaviour of the material over a wide temperature range is needed. Diffuse porous hardwoods such as solid birch wood (Betula pendula) and solid beech wood (Fagus sylvatica) are particularly suited for the production of engineered wood products (EWPs) such as laminated veneer lumber (LVL) or plywood due to their processability in a veneer peeling process. In the frame of this study, solid birch wood and solid beech wood samples (300 × 20 × 20 mm3) were characterised by means of an impact pendulum test setup (working capacity of 150 J) at five temperature levels, ranging from −30 °C to +90 °C. The pendulum hammer (mass = 15 kg) was equipped with an acceleration sensor in order to obtain the acceleration pulse and deceleration force besides the impact bending energy. In both solid birch wood and solid beech wood, the deceleration forces were highest at temperatures at and below zero. While the average impact bending energy for solid birch wood remained almost constant over the whole considered temperature range, it was far less stable and prone to higher scattering for solid beech wood.

Effects of Temperature and Salinity on Seed Germination of Three Common Grass Species

Temperature and salinity significantly affect seed germination, but the joint effects of temperature and salinity on seed germination are still unclear. To explore such effects, a controlled experiment was conducted, where three temperature levels (i.e., 15, 20, and 25°C) and five salinity levels (i.e., 0, 25, 50, 100, and 200 mmol/L) were crossed, resulting in 15 treatments (i.e., 3 temperature levels × 5 salinity levels). Three typical grass species (Festuca arundinacea, Bromus inermis, and Elymus breviaristatus) were used, and 25 seeds of each species were sown in petri dishes under these treatments. Germination percentages and germination rates were calculated on the basis of the daily recorded germinated seed numbers of each species. Results showed that temperature and salinity significantly affected seed germination percentage and germination rate, which differed among species. Specifically, F. arundinacea had the highest germination percentage, followed by E. breviaristatus and B. inermis, with a similar pattern also found regarding the accumulated germination rate and daily germination rate. Generally, F. arundinacea was not sensitive to temperature within the range of 15–25°C, while the intermediate temperature level improved the germination percentage of B. inermis, and the highest temperature level benefited the germination percentage of E. breviaristatus. Moreover, F. arundinacea was also not sensitive to salinity within the range of 0–200 mmol/L, whereas high salinity levels significantly decreased the germination percentage of B. inermis and E. breviaristatus. Thus, temperature and salinity can jointly affect seed germination, but these differ among plant species. These results can improve our understanding of seed germination in saline soils in the face of climate change.

Behavior of Reactive Powder Concrete Beams Exposed to Fire

In this paper, the effect of direct fire flame and steel fiber ratio on some mechanical properties and behavior of the relationship between load and deflection of rectangular reinforced concrete beams under the influence of fire exposure was studied. Concrete specimens were exposed to fire at temperatures ranging from (25- 400 ºC). Three temperature levels of (200, 300, 400 ºC) where chosen for exposure duration of 2.0 hours. After conducting the test, it was found that increasing the proportion of steel fibers in percentages 0.5% to 1% and 1.5% decreases the mid-span deflection at service load by 33%, 50% and 37.5 and increases the ultimate load by 36.36%, 41.6% and 53% respectively. After the beams are exposed to fire, it was noticed that the maximum crack width increases with increasing fire temperature.

Effects of different temperatures on the growth and survival of mud crab (Scylla paramamosain) larvae

This study aimed to evaluate the effects of temperature on the growth and survival of mud crab (Scylla paramamosain) larvae in two stages including zoea-1 to megalopa (the first experiment) and megalopa to crablet-1 (the second experiment). Each experiment was conducted in a completely randomized design with four temperature levels (27, 30, 33, and 36℃) in triplicate. Stocking density of 200 ind./L for the first experiment and 4 ind./L for the second experiment. Fiberglass tanks of 500-L (containing 300-L and 250-L of 25‰ water for the first and second experiment, respectively) were used in the experiments. The results showed that S. paramamosain larvae at zoea-3 and zoea-4 died at 33℃ or above, while the highest survival rate of this stage was found at 27℃ (11.5%). The growth and larval stage index during the zoea to megalopa stage were significantly higher in 30℃ (p<0.05) compared to those in the 27℃ treatment. In the second experiment, the survival rates of crablet-1 were highest (72.9%) at 27℃ and lowest (34,7%) at 36℃. The growth rate of crablets at this stage increased with increased temperature. The highest carapace width and weight (3.41 mm and 0.030 g, respectively) were recorded at 36℃. The findings of this study suggested that mud crab larvae should be reared at the temperature range of 27-30℃ to maximize their production.

ANN Modeling to Analyze the R404A Replacement with the Low GWP Alternative R449A in an Indirect Supermarket Refrigeration System

Artificial neural networks (ANNs) have been considered for assessing the potential of low GWP refrigerants in experimental setups. In this study, the capability of using R449A as a lower GWP replacement of R404A in different temperature levels of a supermarket refrigeration system is investigated through an ANN model trained using field measurements as input. The supermarket refrigeration was composed of two indirect expansion circuits operated at low and medium temperatures and external subcooling. The results predicted that R449A provides, on average, a higher 10% and 5% COP than R404A at low and medium temperatures, respectively. Moreover, the cooling capacity was almost similar with both refrigerants in both circuits. This study also revealed that the ANN model could be employed to accurately predict the energy performance of a commercial refrigeration system and provide a reasonable judgment about the capability of the alternative refrigerant to be retrofitted in the system. This is very important, especially when the measurement data comes from field measurements, in which values are obtained under variable operating conditions. Finally, the ANN results were used to compare the carbon footprint for both refrigerants. It was confirmed that this refrigerant replacement could reduce the emissions of supermarket refrigeration systems.

Assessment of the Physicochemical Parameters of Bodo Creek, Rivers State, Nigeria: A Pre-spill, Post-spill and Post-clean-up Review

Water bodies are a source of ecosystem services such as water supply, production, recreation, and aesthetics. In 2008, two major oil spills took place in Bodo creek. A major challenge with the assessment and monitoring of an environment is the lack of baseline data. However, Bodo Creek has been studied extensively. This paper, therefore, reviews pre-spill, post-spill, and post-clean-up studies on physicochemical parameters in Bodo Creek. This paper revealed that the difference in the levels of the physicochemical parameters including pH, salinity, dissolved oxygen (DO), biochemical oxygen demand (BOD), and temperature in Bodo Creek, before and after the oil spill was not statistically significant (P > 0.05); other physicochemical parameters examined in this paper are alkalinity, total hardness, chemical oxygen demand (COD) and total dissolved solids (TDS). This paper also revealed that pH and temperature were higher in the post-cleanup study, while DO and conductivity were higher in the pre-cleanup study. BOD was significantly higher in the post-spill study than the pre-spill study, indicating a high level of pollution as a result of the oil spill. This review also shows that there are higher pH and temperature levels in post-clean-up studies than the pre-cleanup studies. Pre-clean-up DO and conductivity were higher than the levels in the post-clean-up study.

Temperature and creatine kinase changes during a 10-day taper period in sprinters

Objective.The aim of this prospective cohort study, performed during a 10-day training camp, was to analyze the effect of a series of successive speed-power training sessions on the concurrent circadian changes in resting leg skin temperature and blood creatine kinase (CK) levels and to determine the correlation between them. Approach. Seventeen elite sprinters, aged 22‒31 years, were examined. Every morning and evening, capillary blood samples were drawn to assay CK levels. Lower limb skin temperature was measured simultaneously, and thermal images were taken using an infrared camera. Main results. From the first day of the training camp, the base temperature levels began to drop to obtain a significant reduction from the 6th day (male) and from the 8th day (female) to the end of the camp . Simultaneously, CK levels increased in the male group from 8th to the end of the camp, but it did not change significantly in females. Regarding the circadian rhythm, the CK levels always rose during the day and declined during the night. The temperature decreased during the day and increased during the night until the 6th day. After that, the temperature changed oppositely till the end of camp, i.e. it increased during the day and decreased during the night. This could suggest that the training microcycle should last about a week because after this time there may be a disturbance in the temperature circadian rhythm and a significant CK accumulation Significance. Multi-day speed-power training induced a progressive reduction in resting skin temperature and an elevation in CK levels. It also altered the circadian rhythm of the body skin temperature, which may indicate that after about 6 days of regular exercise, physiological deregulation may occur.