Relative Humidity Values Research Articles

Hydrothermal Evaluation of Vernacular Housing: Comparing Case Studies of Waste PET Bottles, Stone, and Adobe Houses

This work shows the humidity and thermal evaluation of different case studies of houses. The analyses focused on room prototypes and houses built in different regions of Querétaro, México. Three different climatic zones were included with the evaluations of houses and prototypes. The assessments of internal and external parameters in residential buildings are also shown. The internal parameter measurements were done with hydro-thermometers and thermography images. Six structures were evaluated, one of the conventional housing materials and five of alternative or vernacular materials. The predicted mean vote (PMV) and the predicted percentage dissatisfied (PPD) were determined using the average temperature and relative humidity values, and they were considered to be dynamic because they can change depending on many factors. The six dwelling insulating properties were associated with their construction materials, design, location, and other factors. The six houses have many differences, but considering their behavior in their location, the two floor porous stone house got the best results. On the contrary, the flagstone house with a gabled roof of galvanized sheets had a cold perception despite many advantageous elements, failing to provide comfort in such a cold location. Contrasting these with other adobe constructions, the analyzed one had low thermal insulation, which was explained by its characteristics. PET and adobe uninhabited prototypes had medium to cold perceptions. The PET prototype has excellent and adjustable insulations, both on temperature and RH, considering the passive illumination and ventilation of its glass bottle skylights.

Initial Corrosion Behaviors of Fe20Cr25NiNb Stainless Steel in High Temperature Environment with Different Relative Humidity Values

Initial Corrosion Behaviors of Fe20Cr25NiNb Stainless Steel in High Temperature Environment with Different Relative Humidity Values

Research on Methane Measurement and Interference Factors in Coal Mines.

The detection of methane has always been an important part of coal mine safety. In order to improve the methane measurement accuracy in coal mines and to determine the influence of environmental interference factors on the measurement results, we designed a spherical, experimental chamber simulating the on-site environment of an underground coal mine containing methane, in which various environmental interference factors can be superimposed. The simulation chamber can generate a uniform and controllable dust environment, a controllable methane environment with concentrations below that which would trigger an alarm, controllable humidity, and environments characterized by other interference factors. Based on computational simulations of the experimental chamber with varying dust-particle-concentration distributions using a single particle size, an optimal design for the chamber has been realized in terms of the rapid mixing of dust and the flow field. Finally, we constructed an underground methane concentration measurement system for coal mines and assessed the influences of different dust concentrations and relative humidity values on the performance of methane measurements, providing a means for improving the measurement accuracy of underground coal mine, spectral, absorption-type methane sensors.

Molecular Changes in Spider Viscid Glue As a Function of Relative Humidity Revealed Using Infrared Spectroscopy.

Spider aggregate glue can absorb moisture from the atmosphere to reduce its viscosity and become tacky. The viscosity at which glue adhesion is maximized is remarkably similar across spider species, even though that viscosity is achieved at very different relative humidity (RH) values matching their diverse habitats. However, the molecular changes in the protein structure and the bonding state of water (both referred to here as molecular structure) with respect to the changes in RH are not known. We use attenuated total reflectance-infrared (ATR-IR) spectroscopy to probe the changes in the molecular structure of glue as a function of RH for three spider species from different habitats. We find that the glue retains bound water at lower RH and absorbs liquid-like water at higher RH. The absorption of liquid-like water at high RH plasticizes the glue and explains the decrease in glue viscosity. The changes to protein conformations as a function RH are either subtle or not detectable by IR spectroscopy. Importantly, the molecular changes are reversible over multiple cycles of RH change. Further, separation of glue constituents results in a different humidity response as compared to pristine glue, supporting the standing hypothesis that the glue constituents have a synergistic association that makes spider glue a functional adhesive. The results presented in this study provide further insights into the mechanism of the humidity-responsive adhesion of spider glue.

THE INFLUENCE OF DIFFERENT FACTORS ON THE MAISOTSENKO CYCLE EFFECTIVENESS

An important problem in the heat industry is the significant cost of energy resources for air conditioning. Therefore, energy-efficient refrigeration systems based on renewable energy sources and evaporative air cooling, as well as air-conditioning systems according to the Maisotsenko cycle using psychrometric energy of the environment are of great importance. This paper presents the results of experimental and numerical research of the influence of various factors on the efficiency of indirect evaporative heat and mass transfer apparatus on the M-cycle on the basis of a new unit cell.
 An experimental stand of a heat and mass transfer apparatus with vertically arranged plate channels was developed for experimental research. Experimental studies of heat and mass transfer in the new unit cell were conducted in a wide range of Reynolds numbers 200…1200, temperature 16… 30 °С, relative humidity 30… 50 %. The calculated study was performed using a modified ε-NTU method. Studies have shown that the thermodynamic efficiency of a wet bulb thermometer at a Reynolds number below 500 exceeded one. According to the results of computational studies, the influence of cell length and surface intensification of dry channels on thermodynamic efficiency was determined. Shown the effect of changes in thermodynamic efficiency in the range of 86…94 % increase in efficiency by 1 % leads to an increase in cell length by 7 %. The value of the enhancement factor increases with increasing air flow regime, so when the heat and mass transfer surface area increases by 50 % and the Reynolds number 200, the thermodynamic efficiency increases by 14 %, and with the Reynolds number 800 – by 28 %. The dependence of the thermodynamic efficiency of the cells at the dew point on the relative humidity of the inlet air have a maximum, which with increasing Reynolds number shifts toward larger values of relative humidity.
 Unlike traditional air conditioning devices, the M-cycle heat and mass exchanger does not use a steam compression cycle, so energy costs are spent only on the operation of the fan to pump air, which is a more environmentally friendly and energy efficient way of air conditioning.

Measurements of Some Meteorological Variables at a Tropical Location in Nigeria

This study observed six meteorological variables at a tropical location from 2016 to 2019. The measurement was performed at the meteorological station (7.55 0N; 4.56 0E) of Obafemi Awolowo University, Ile-Ife, Nigeria. The variables that were measured are: incoming solar radiation, net radiation, air temperature, surface temperature, relative humidity and wind speed. The results obtained showed that the maximum daytime monthly mean values of the incoming solar radiation (S) and net radiation (Rn) were recorded in March (782.0 and 545.4 Wm-2, respectively), which is the transition month from dry to wet season. The minimum daytime monthly mean values of S and Rn were recorded in August (443.9 and 330.4 Wm-2, respectively) which is the cloudiest month of the year at the study location. The daily air and surface temperatures (Ta and Ts, respectively) varied between 16.4 and 37.8 0C; 17.7 and 49.7 0C, respectively. The daytime maximum values peaked at about 15:00 LT with the maximum monthly mean values recorded in February (36.3 and 47.7 0C, respectively) and the daytime minimum monthly mean values recorded in August (28.9 and 33.3 0C, respectively). The daily values of relative humidity (Rh) ranged between 29 % and 98 % with a mean value of 47 %. The diurnal trend of wind speed (u) recorded at the study location ranged between 0.48 ms-1 to 2.10 ms-1.

RH simulation model for canvas paintings protected by an aluminium backplate and an additional hygroscopic layer

To protect a canvas easel painting, a common conservation strategy is to add a back plate at the stretcher, creating a closed air void. This plate protects not only from dust but mainly from temperature and relative humidity (RH) variations in the room and moisture changes in the wall on which it is hanging. The addition of hygroscopic layers can reduce the amplitude and change phase of humidity oscillations. This paper proposes a new mathematical model that can be used to predict moisture levels within the canvas when this conservation strategy is applied. The model is compared against the temperature and RH detailed experimental data, captured and shown in the latest paper by Padfield et al. Back protection of canvas painting. Our paper presents values of T, RH and mixing ratio (MR) obtained at the different layers of an easel painting, protected and unprotected, with cotton and without it, submitted to different room and wall temperature and RH cycles. The experimental results show a phase displacement between the canvas temperatures and the corresponding RH values in the canvas air boundary layer. In some cases this phase shift, which is an unexpected behaviour, allows RH and temperatures to achieve their maximum value at the same time. The purpose of the model is to simulate the RH response at the different air boundary layers inside the air void, such as the canvas, the aluminium back plate, and the hygroscopic cotton protection, produced by cyclic variations of temperature in the room or the wall. The model is built simulating four interrelated processes: the canvas permeation flow, the air infiltration rate between room and void, the equilibrium moisture content (EMC) and the vapour sorption rate for the canvas and the cotton. A key innovation of the model is the dependence between EMC, sorption rate, and RH condition, which captures the counter-intuitive behaviours observed in the data. The model results agree with the experimental results. The developed tool allows the interpretation of the processes involved and to extend the simulations to other cases, materials, and conditions.

Climate change impact on water balance of quasi-closed lagoons in the North-Western Black Sea coast

The paper studies the impact of regional climate changes that occurred in the past and are expected to occur in the near future on the components of the annual fresh water balance of quasi-closed lagoons in the North-Western Black Sea coast. Currently these lagoons have no permanent connection with the sea. However, there are some episodic connections via artificially created channels, ducts and other waterworks. The value of insufficiency of the studied lagoons' annual fresh water balance is used as an indicator of their ecosystems' sensitivity to climate change. Action plans must be created and implemented for the lagoons that are the most sensitive to changes in regional climatic conditions in order to achieve and maintain their "good" environmental quality status.
 The climate-induced changes of meteorological parameters in the North-Western Black Sea coast that determine the components of the lagoons' water balance are estimated for two periods: the current one from 2000 to 2018 (based on the observations made at coastal meteorological stations) and the near-future one of 2021-2050 which is compared to the 1961-1990 period (based on the data of the Climate Cadastre of Ukraine). The expected climatic conditions in the near future (2021-2050) were determined by the RCM simulations of the Euro-CORDEX project for the RCP4.5 climate change scenario.
 The research evaluates the components of the lagoons' fresh water balance (precipitation reaching the lagoons' water surface, fresh water inflow from the catchments, evaporation from the lagoons' water surface) and identifies the residuals (shortages) of annual balance. It uses the "climate-runoff" hydrological model for the above climatic periods to determine the fresh water inflow into the lagoons through the watercourses of their catchment areas. The annual evaporation layer from the lagoons' water surface was evaluated using the long-term average monthly values of temperature and relative humidity for each of the periods.
 It was established that the climatic changes that occurred earlier and those expected in the current century caused and will cause the increasing insufficiency of the annual fresh water balance of quasi-closed lagoons in the North-Western Black Sea coast. This can threaten salinization, shallowing or even disappearance of some lagoons. Thus new strategies for water and environmental management of such lagoons must be developed. In terms of vulnerability to climate changes leading to significant annual insufficiency of fresh water balance (if there are no other water sources, e.g. water from the sea), lagoons are ranked in the following order: Kuialnytskyi Lagoon, Dofinivskyi Lagoon, Budatskyi Lagoon (if there is no water inflow from the Dnistrovskyi Lagoon), the Tuzla group of lagoons, Sasyk Lagoon, Tyligulskyi Lagoon, Hadzhybeisky Lagoon (if there is no anthropogenic runoff).

Statistical analysis of atmospheric parameters, noise temperature and digital terrestrial television signal strength over Jos metropolis, Plateau state, Nigeria

The study of the relationship between the Received Signal Strengths (RSS) from Unity TV (786 MHz) located at Rayfield (9.84 o North 8.89 o East), Jos, Plateau State and some atmospheric parameters with noise temperature has been done using two years half-hourly data. The measurement was carried from 5 am and 9 pm daily. The analysis was carried out using the regression, co-integration and Granger causality models. The results show that the RSS is higher in the morning hours (5.00 am–9.00 am) late in the evening (6.30 pm–9.00 pm) but lower between 9.00 am and 6.30 pm. This might be due to the “dusty” atmosphere and low reflection of ionosphere in the day time which causes signal attenuation within the day time. The correlation coefficients from the coefficient of determination (R squared) of 0.88, 0.004, 0.838. 0.25, 0.867, and 0.112, are −0.94, −0.07, 0.92, −0.50, −0.93, −0.334 for atmospheric temperature, pressure, relative humidity, wind speed, noise temperature and rainfall respectively. It means all the independent variables except relative humidity are inversely proportional with the RSS. Also, the higher R2 values for atmospheric temperature, relative humidity and noise temperature respectively, indicates higher correlation between RSS and these parameters. It can be inferred that the models are suitable for predicting Unity TV (UTV) signal strength and that of other TV stations in Jos and environs, using T, RH and NT as inputs. The results also showed that there is a co-integration and Granger Causal relationship between the parameters and RSS.The result will find applications to the Nigeria Broadcasting Commission in the assigning of frequencies taking atmospheric parameters into considerations, Radio Engineers and Scientists, Satellite link designers, and mobile communication experts for the link budget design and appropriate equipment deployment based on the atmospheric condition on the geographical areas.

Indoor air quality analysis in naturally ventilated university training laboratories: a health risk assessment

The indoor air quality (IAQ) of eleven naturally ventilated training laboratories was analysed to evaluate the health risk to occupants. IAQ evaluation included analysis of physical (temperature (T) and relative humidity (RH)), chemical (CO2, CO, O3, total volatile organic compounds (TVOC), and particulate matter (PM)) and microbiological (fungi and bacteria) pollutants. Monitoring was carried out in labs used for teaching different academic disciplines (biology, chemical, ecology, and computers) during two periods of the academic year. Ventilation rates (VR), air change per hour (ACH) in every lab, and the hazard quotients for each of the chemical pollutants and the accumulated (HQ and HI) were calculated. Environmental comfort was not fully satisfactory considering the RH and CO2 values, especially during hours with higher occupancy. Coarse particles and bacteria were generated indoor related to human activity. At chemical and biological laboratories, TVOC concentrations were sometimes above the recommended value, and all the labs presented VR below the European guideline’s recommendations. Results from this study show natural ventilation is not enough to get an adequate IAQ, although no significant non-carcinogenic risk was estimated. However, installation of complementary ventilation systems would be advisable to avoid health risk by acute short-term exposure.Graphical abstract

Variability of soybean yield and seed quality depending on environmental hydrothermal factors

Variability of soybean yield and seed quality depending on environmental hydrothermal factors

Evaluating Corrosion Behaviour of Copper Under Deliquescent Drying/Wetting Cycles in Humid Air Condition

Most nuclear safety agencies around the world agree that deep geological repositories (DGRs) constructed hundreds of meters below ground in stable host rock formations are viable solutions to safely isolate used nuclear fuel. In Canada, the DGR design involves storing used nuclear fuel in sealed copper coated used fuel containers (UFC) surrounded by highly compacted bentonite blocks (HCB) ~500 m underground. Shortly after emplacement, heat generated by radioactive decay of the used fuel will warm the UFC and its surroundings, desiccating the HCB and decreasing moisture on the container surface. As water vapour is driven from the UFC surface, the presence of minor amounts of dissolved salts may cause droplet formation prior to complete evaporation, during which deposits of salts may be left behind on the UFC. Later, as conditions evolve and the relative humidity increases and the temperature decreases, condensation of liquid water on the UFC surfaces will produce droplets again, due to the deliquescence of minor salt deposits. In either the wetting or the drying scenario, secondary spreading and spatial separation of anodic and cathodic reactions and consequent non-uniform corrosion could be possible, due to the droplet geometry.To investigate this scenario, the quartz crystal microbalance (QCM) technique is being used. The QCM initially consists of a quartz plate, covered by gold electrodes on both sides where a layer of copper is deposited on the crystal by using magnetron sputtering. In this technique, the change in the resonance frequency of a vibrating quartz crystal is correlated to its mass change due to the corrosion process. To investigate the effect of salts and their deliquescence behaviours, different salts (NaCl, CaCl2, and MgCl2) and CR10-E simulated groundwater were loaded on the copper surface using an inkjet printer, and then corrosion tests were performed at different temperatures and relative humidity (RH) values. In parallel, a set of long-term vapour-phase corrosion tests was performed on wrought and cold-sprayed copper coupons at 75 °C and different RH values. As part of the post-experiment analysis, the corrosion products were analyzed using a suite of surface analysis techniques, including optical microscopy, Raman spectroscopy, and scanning electron microscopy (SEM).The results from QCM experiments at RH values below salts deliquescence point showed a low mass change that could correlate with less corrosion in comparison to the experiments at RH values above salts deliquescence point. It’s worth noting that even at RH values below the deliquescence point of the salts, a trace of corrosion was observed which could be indicative of the presence of monolayers of water on the surface. The results obtained from NaCl and CR10-E exposure conditions showed higher mass change and therefore higher corrosion in comparison to CaCl2 and MgCl2 salts. As for the long-term vapour-phase corrosion tests, Raman spectroscopy confirmed the presence of CuO and Cu2O on the surface as corrosion products. Further surface characterizations and mass loss measurements are underway to determine the extent of corrosion on the copper coupons.

Highly Ordered Supramolecular Assembled Networks Tailored by Bioinspired H-Bonding Confinement for Recyclable Ion-Transport Materials

Highly Ordered Supramolecular Assembled Networks Tailored by Bioinspired H-Bonding Confinement for Recyclable Ion-Transport Materials

Thermodynamic modelling of perchlorate/chloride and perchlorate/chlorate deliquescence at Mars-relevant temperatures

Perchlorate (ClO4−) salts were discovered on Mars and are known to absorb water vapor from the atmosphere and deliquesce into the aqueous phase. Other species such as chlorides (Cl−) and chlorates (ClO3−) were also identified; these species can affect the deliquescence of perchlorates. Here we generate phase diagrams of perchlorate/chloride and perchlorate/chlorate binary mixtures for K, Na, Mg and Ca in the temperature range 223–273 K. Using a new approach based on thermodynamic modelling of evaporation, we determined the deliquescence relative humidity (the minimum relative humidity at which a salt converts into a liquid by absorbing atmospheric water vapor) and the eutonic relative humidity (the minimum relative humidity at which two salts are in equilibrium with liquid) for binary salt mixtures. Our modelling results show that the deliquescence relative humidity values of all salt mixtures is always lower than that of each individual end-member salt at a fixed temperature, typically a few percent lower. The closer the eutonic is to one of the end-member, the smaller the decrease in relative humidity compared to the pure pole. Thus, only eutonics which are far from both poles exhibit a significant drop in relative humidity. Moreover, the eutonic relative humidity always increases with decreasing temperature, which does not favor liquids in the dry and cold Martian environment. Finally, the increased stability of water ice at the lowest temperatures always reduces or even eliminates the stability of liquids. Therefore, the favorable temperature and relative humidity conditions under which binary salt liquid mixtures exist are generally not significantly improved compared to single salts.

Indoor Temperature and Relative Humidity Dataset of Controlled and Uncontrolled Environments

The large volume of data generated with the increasing development of Internet of Things applications has encouraged the development of a large number of works related to data management, wireless communication technologies, the deployment of sensor networks with limited resources, and energy consumption. Different types of new or well-known algorithms have been used for the processing and analysis of data acquired through sensor networks, algorithms for compression, filtering, calibration, analysis, or variables being common. In some cases, databases available on the network, public government databases, data generated from sensor networks deployed by the authors themselves, or values generated by simulation are used. In the case that the work approach is more related to the algorithm than to the characteristics of the sensor networks, these data source options may have some limitations such as the availability of databases, the time required for data acquisition, the need for the deployment of a real sensors network, and the reliability or characteristics of acquired data. The dataset in this article contains 4,164,267 values of timestamp, indoor temperature, and relative humidity acquired in the months of October and November 2019, with twelve temperature and humidity sensors Xiaomi Mijia at the laboratory of Control Systems and Robotics, and the De La Salle Museum of Natural Sciences, both of the Instituto Tecnológico Metropolitano, Medellín—Colombia. The devices were calibrated in a Metrology Laboratory accredited by the National Accreditation Body of Colombia (Organismo Nacional de Acreditación de Colombia—ONAC). The dataset is available in Mendeley Data repository.

Indoor air quality and diversity of fungi inside and outside residences of children with a history of allergy in Cuba

Several investigations suggest that the exposure to fungal allergens during childhood may increase the risk of sensitisation in children genetically predisposed to allergy. The objective of this study was to evaluate the quality and diversity of fungal propagules in indoor air, specifically in the bedrooms of children with a family history of allergy. The indoor and outdoor air was sampled from 44 bedrooms of children with a family history of allergy during the years 2018 and 2019 in Havana, Cuba. Inside the bedrooms, the presence of humidity problems, visible fungal growth, and the quality of ventilation was examined, while the values of temperature and relative humidity were recorded. Moreover, a distribution analysis of the genera detected was carried out and the Sørensen coefficient of similarity was calculated. In addition, the relationship between the outdoor and indoor air concentrations of each residence was determined. The concentrations of fungal propagules in the indoor air of the bedrooms were between 20 and 1330 colony-forming unit (CFU)/m3. According to the analysed limit values, 18 bedrooms can be classified as having poor indoor air quality. Cladosporium, Aspergillus, Penicillium, and Curvularia were the most frequent genera of the 19 identified in the study. There was a similarity between the indoor and outdoor air mycobiota in 15.9% of the rooms. The detection of these allergenic fungal genera is an alert for children in the sampled homes, mainly for those that were classified as poor indoor air quality according to the examined standards.

Dependencies of the indoor climate on the course of the seasons and derivation of regressions from long-term measurements.

A building's indoor climate is an essential input variable for a variety of building physics computational models, simulations, and analyses. Precise knowledge of the indoor climate is necessary to minimize the risk of mold or moisture damage and is required to ensure minimum heat insulation standards in buildings. Detailed data are especially necessary for the progressive application of transient calculations, for example, concerning thermal comfort or energy consumption. While the properties of building materials and the (local) outdoor climate are known, only rudimentary information about the dynamic indoor climate is available. Most existing information in the literature about indoor climate is fairly general and forgoes a differentiation between climatic region, occupancy profile, and the utilization of rooms. In this paper, we report on indoor climate measurements in naturally ventilated apartments over a period of 1year. The measurement results complement the existing data to provide accurate indoor climate data in buildings. The measured values of indoor temperature and relative humidity serve to derive the dew point temperature and moisture load whereby dynamic time-dependent regression functions are determined for these parameters. The evaluations are carried out separately according to room use. The comparison of living rooms and bedrooms indicates a great influence of room use on the indoor climate in residential buildings. The determined indoor climate model can be used for the planning of buildings and simulations. The classification into living rooms and bedrooms makes it possible to take user behavior into account more realistically in building physics simulations. The minimum thermal insulation in residential buildings can also be checked and designed based on realistic data. The prediction interval describes the limits in which residential rooms are free of damage with a high probability. In this way, the indoor climate model describes an approach to examine and evaluate simulation results regarding condensation risk and mold damage in naturally ventilated rooms.

The Effect of Humidity and Temperature on Indoor and Outdoor COVID-19 Infections

Environmental conditions and their association with COVID-19 have significantly attracted scientists’ attention. The current study links COVID-19 with climate indicators by comparing two configurations: indoor infections in a University of Duhok (UOD) building and outdoor infections within the boundaries of the Duhok Governorate (DG). The collected data included temperature and relative humidity (RH) and confirmed cases for indoor and outdoor configurations over 5 and 11 months, respectively. For the indoor infections, data were collected over the period of 5 weekdays, while for the outdoor infections, they were collected on the days when statistics were published. The prospective cross-section design was used for different statistical analyses. The overall indoor infections were very low, and the maximum values for RH and temperature were approximately <24% and <20°C, respectively; in the one-sample t-test, the results were significantly correlated ( p value <0.05) with the confirmed COVID-19 cases. For outdoor infections, using the correlation bivariate method, the study found that the RH and temperature results significantly correlated ( p value <0.05) with the confirmed COVID-19 cases. However, for indoor configuration, other than for Tmax, the results were not associated. As for the outdoor infections, the RH and temperature averages were high enough to put in groups to employ the one-way repeated ANOVA and general linear model with the same results. The means of the RHlow, RHmedium, and RHh groups were significantly correlated ( p value <0.05) with COVID-19. However, the means of the medium RH and high RH groups were not significantly associated with the increasing outdoor infections. This study will contribute to the reduction of overall COVID-19 infections.

Determination of Variability in Ambient Conditions During Cold Storage of Aronia Fruits

In this research, temperature and relative humidity in a cold store with an evaporative cooling system were investigated during one-month cold storage of Aronia melanocarpa Nero fruits. Ambient temperature and relative humidity were measured by sensors at 36 points for different levels (top, medium and base level). The research was carried out in accordance with the randomized plot design for the purpose of storing Aronia melanocarpa in a cold store at +3oC for 1 month. The results were evaluated by using variance analyses and descriptive statistics. In addition, spatial variability maps were created for evaluating of temperature and relative humidity variation at different levels. Variation of the temperature was determined between 3.40oC and 5.32oC for top level, 3.80oC and 5.49oC for middle level and 3.92oC and 5.51oC for base level at 3oC storage temperature. Coefficient of variations was determined as 11.47% for top level, 11.48% for middle level and 7.10% for bottom level for temperature. The relative humidity values were changed between 74.00% and 88.09%. Mean coefficient of variation of the relative humidity varied between 3.22% and 4.43%. According to the results; distributions of the temperature and relative humidity for different levels were not uniform. Reason of high variability between measurement of the temperature and the relative humidity for different levels in the cold store was the distribution of the cold air. The cold air was ventilated by an evaporator and distributed according to the design of the cold store (dimensions, shape, and materials) and placement of fruit cases. Different storage conditions were determined at different levels in the cold store during storage of Aronia fruits in this research. In addition, there is generally one temperature/relative humidity sensor located back of the door inside the cold store used to control the cooling system. Measurement of the temperature and relative humidity from one point in a cold store is not enough to give an idea about the ambient conditions of the cold store. When storing agricultural products, the use of more temperature/relative humidity sensors in the cold store will enable the actual situation of the temperature and relative humidity values to be taken into account to control the operation of the cooling system. Additional cold air distribution systems such as ventilator, air curtains and placement of fruit cases may help to improve air distribution and decrease the spatial variability of the storage conditions in the cold store.

Impact of Short-Term Atmospheric Heat Transfer on the Survival of Granary Weevil in Stored Winter Wheat

The granary weevil Sitophilus granarius L. is a pest causing substantial damage to stored wheat worldwide, against which the elaboration of sustainable control methods has recently been gaining importance. Our objective was to assess the efficacy of a rapid atmospheric convection heat transfer method against S. granarius under laboratory conditions. We examined the changes in adult mortality and progeny survival triggered by heat and the effect of this on the quality parameters of treated wheat items. The insecticidal efficacy, achieved by the treatment of infested grains, was also analyzed at 37, 47, 67, 87, and 107 °C for 5, 6, and 7 min under 40% and 60% rh exposure to atmospheric heating with the progeny production assessed 45 days after the treatment. The quality parameters of the treated wheat were analyzed by a germination test and NIR grain analysis. Our findings showed that adequate eradication of S. granarius was obtained at 107 °C for 5 min of exposure under suboptimal (40% rh) relative humidity values. At 60% relative humidity, mortality averages were more dispersed, and efficacies above the expected 95% occurred over longer exposures. The progeny-suppression effect from short-term heating was affirmed. The atmospheric convection heat transfer method, under the applied temperature and exposure time combinations, did not induce detectable changes in the quality parameters or the germination ability of the treated wheat. Overall, our findings indicated that the use of short-term heating for the post-harvest protection of cereals is feasible, which may contribute to the realization of residuum-free pest management and provide an effective and sustainable technique in integrated pest management.