Drying Time Research Articles

An innovative Fuller’s earth-based film-forming formulation for skin decontamination, through removal and entrapment of an organophosphorus compound, paraoxon-ethyl

Organophosphorus compounds (OPs), such as VX, pose a significant threat due to their neurotoxic and hazardous properties. Skin decontamination is essential to avoid irreversible effects. Fuller’s earth (FE), a phyllosilicate conventionally employed in powder form, has demonstrated decontamination capacity against OPs. The aim of this study was to develop a formulation that forms a film on the skin, with a significant OP removal capacity (>95 %) coupled with sequestration capabilities, favorable drying time and mechanical properties to allow for easy application and removal, particularly in emergency context. Various formulations were prepared using different concentrations of polyvinyl alcohol (PVA), FE and surfactants. Their removal and sequestration capacity was tested using paraoxon-ethyl (POX), a chemical that simulates the behavior of VX. Formulations with removal capacity levels surpassing 95 % were mechanically characterized and cell viability assays were performed on Normal Human Dermal Fibroblast (NHDF). The four most promising formulations were used to assess decontamination efficacy on pig ear skin explants. These formulations showed decontamination levels ranging from 84.4 ± 4.7 % to 96.5 ± 1.3 %, which is equivalent to current decontamination methods. These results suggest that this technology could be a novel and effective tool for skin decontamination following exposure to OPs.

Nonlinear trends in signatures characterizing non-perennial US streams

Stream drying patterns – including duration, timing, and dry-down rates – affect aquatic ecosystems and nutrient exports in non-perennial streams. Because hydrologic processes are often nonlinear, changes in drying may also be nonlinear, but analyses of historical changes in stream drying to date have not characterized the frequency or functional forms of nonlinear change. Understanding the extent of nonlinear change in non-perennial streams is essential for advancing our fundamental knowledge of hydrological processes, aquatic ecosystems, and watershed functioning under a warming climate. This paper uses a polynomial-based trend detection technique (PolyTrend) to analyze the linear and nonlinear trend behaviors of three intermittency signatures (annual no-flow days specifying longer or shorter drying duration, day of first no-flow occurrence specifying timing of stream drying, and days from peak to no-flow specifying dry-down rates) at 540 non-perennial gage stations over 38 years (1980–2017) across the continental United States (CONUS). Additionally, we carried out a breakpoint analysis to characterize the discontinuities in the time series of each intermittency signature. Analysis of annual no-flow days shows that about 37 % of the total streamflow stations are drying for longer each year, whereas about 22 % are wetter for longer than in the past. The day of first no-flow occurrence analysis shows that 10 % of the streams are drying earlier, and 19 % are drying later. On the other hand, analysis of days from peak to no-flow shows that 14 % of streams are drying faster, and 17 % are drying more slowly. For all these metrics, among the significant trends, at least half of the relationships were nonlinear. For annual no-flow days, the breakpoint analysis shows more discontinuities in the second half of the analysis period (1999 to 2017) than in the first half, with more discontinuities in the Southern Great Plains than in other regions. The other two signatures demonstrate less frequent discontinuities in the second half of the analysis period, suggesting decreased nonlinear dynamics in recent years. Nonlinear no-flow duration trends are common in Mediterranean California, and the dry-down rate has increased in recent decades. Our findings indicate that nonlinear change in stream drying is widespread and must be accounted for in watershed planning and management.

Research on the production technology of rubber epoxy from concentrated natural rubber latex

The results of research on epoxidation technology from concentrated natural rubber latex (CNRL) and in-situ peroxyformic acid, which is synthesised from formic acid (FA) and hydrogen peroxide (HP), are presented in the article. The study investigated the influence of technological parameters of the epoxidation process, such as stabiliser content (nonylphenol ethoxylate, NP9), dry rubber content (DRC), isoprene, stirring speed, reaction time, reaction temperature, and molar ratios of hydrogen peroxide and isoprene (IP), on the epoxy resin content of the product. Research results have shown that the epoxidation reaction with NP9 at 10% takes from 2.5 to 20 hours under the following conditions: latex composition contains from 16 to 24% DRC, stirring speed 100 rpm, reaction temperature response 30 to 70 °C, HP/IP molar ratio changes from 0.7 to 1.3, FA/IP ratio is 0.2, the product was stable and without coagulation. The product was obtained with an epoxy content of 23.4 to 43.6%. This is the basis for building an epoxidized natural rubber (ENR) production process to create a series of natural rubber products that are renewable, environmentally friendly, low-cost, and have many industrial applications.

Effects of pretreatments involving ohmic heating and infrared radiation on the drying process of bananas using hot air

AbstractNowadays, the hot air drying process is the most widely used method for producing dried food and agricultural products due to its suitable investment and low operational costs. However, one of the disadvantages of drying with hot air is the prolonged drying time, which sometimes leads to serious damage to the quality characteristics of the resulting products, especially at high temperatures. Therefore, there is a need to find the most suitable conditions for producing high‐quality dried products. To conduct this experiment, after determining the desired number of samples, infrared preheating and ohmic heating were performed sequentially. In the first stage of preheating, the samples were placed in the ohmic heating device, and in the second stage, they were exposed to infrared radiation. Then, the samples were transferred to a hot air dryer for complete drying. The results showed that the antioxidant content increased with the increase in the thickness of the banana slices. Moreover, an increase in the drying temperature and the number of infrared lamps led to a reduction in the antioxidant content. The slices with less thickness and higher drying temperatures had the minimum phenol content. The maximum and minimum measured values of the total phenol content were 34.51 and 37.32, respectively. The range of variation in the solid soluble content was between 11.708% and 19.5437% Brix. In addition, at the same temperature values, an increase in the thickness of the banana slices resulted in a decrease in the solid soluble content of the samples. Furthermore, with an increase in the temperature for slices of the same thickness, the solid soluble content of the samples increased.Practical applicationsThe purpose of this research is to evaluate the effect of the thickness factors of the sample pieces, the temperature of the hot air dryer along with ohmic heating pretreatments, and the infrared lamps in the hot air dryer on the quality indicators of banana.

ІНТЕНСИФІКАЦІЯ СУШІННЯ ЯБЛУК ПРИ КОНВЕКТИВНОМУ ТА КОМБІНОВАНОМУ СПОСОБАХ ЗНЕВОДНЕННЯ

The paper examines the intensification of drying apple slices to low residual moisture content. It is proposed to use an energy-efficient multi-stage mode of convective drying at 80/60 °C and a combined multi-stage mode with IR radiation and IR convective heating (100 W) + 60 °C / 60 °C. The paper presents the temperature and kinetic curves and changes in drying speed for the studied dehydration regimes. A formula was obtained for determining the total duration of the process of drying apple slices using a combined method, and a dependence of the Rebinder number for the studied dehydration modes was constructed. Based on the experimental data analysis and generalization of research results, a method of determining the drying intensity based on the average moisture exchange and the average temperature of material heating per minute, at the first stage of drying and during the entire drying time, was proposed for the first time. The efficacy of the proposed modes is confirmed by a reduction in drying duration 1.9 times compared to the stationary mode at a coolant temperature of 60 °C. The obtained dried product is characterized by high recoverability (78–80%) and appropriate organoleptic properties.

Revealing the mechanism of post-harvest processing on rose quality based on dynamic changes in water content, enzyme activity, volatile and non-volatile metabolites

Existing studies on post-harvest processing of edible roses have mainly focused on processing techniques and physicochemical properties of the final dried products, with limited studies on how changes in metabolites during processing affect the quality of these products. This study investigated changes in water content and status, enzyme activity, phenolic compounds, and volatile and non-volatile compounds during processing and revealed the mechanisms by which post-harvest processing (drying without blanching (WBD) and drying with blanching (BD)) affects the quality of dried roses by establishing their correlations. Results showed that the blanching reduced the relative content of free water and water activity, thus reducing the subsequent drying time and enzyme activity. The BD method caused higher levels of phenolic compounds than the WBD method in terms of gallic acid, ellagic acid, epicatechin, and quercetin. The OPLS-DA analysis identified 6 differential volatiles out of 72 detected volatiles, contributing to the unique aroma of dried roses by activating olfactory receptors through hydrogen bonding and hydrophobic interactions. 58 differential metabolites were screened from 964 non-volatile metabolites. KEGG pathway analysis revealed that the changes in volatile and non-volatile metabolites induced by different processing methods were due to the effect of blanching on glutathione and fatty acid metabolism. These findings provide a comprehensive understanding of how post-harvest processing affects the quality of dried roses.

The Effect of Drying Time on the Antioxidant Properties of Single Black Garlic Powder

Black garlic is a processed product derived from fresh garlic that generally has a taste and aroma that is less preferred. A drying process is employed to increase the attractiveness of consuming black garlic. This study aims to assess the impact of the drying time on the antioxidant activity and content of antioxidant compounds such as phenolics, flavonoids, and tannins in single black garlic. The drying time is expected to yield a single black garlic powder that is more convenient for consumption, whether in capsule form or as an addition to food products. With low moisture content, single black garlic powder has a longer shelf life and high antioxidant activity, potentially commanding a higher market value. In this research, the drying time was carried out on a single black garlic using an oven for 6, 12, 18, and 24 hours. The analysis of the total phenolic content (TPC), entire tannin content (TTC), and total flavonoid content (TFC) was determined using a Uv-Vis spectrophotometer, and each component was measured concerning gallic acid equivalent for TPC, quercetin for TFC, and tannic acid for TTC. Antioxidant activity was determined using the DPPH method, and the outcomes were expressed as IC50 values. The research shows that the extended drying time leads to an augmentation of the antioxidant compound in black garlic. Drying for 24 hours produces significant outcomes, showing potent antioxidant activity with an IC50 value of 37,019 ppm (powerful antioxidant category), total phenolic content value is 44,785 ± 0,033 mgGAE/g, total flavonoid content value is 32,033 ± 0,008 mgQE/g, and total tannins content value is 74,884 ± 0,057 mgTAE/g. Statistical analysis using a one-way ANOVA showed a significant influence of drying time on TPC, TFC, and TTC (p < 0,05). The longer the drying time, the higher the antioxidant activity and the content of compounds acting as antioxidants in black garlic powder.

Experimental investigation, performance analysis, and optimization of hot air convective drying of date fruits via response surface methodology

A laboratory-scale hot air convective dryer (HACD) was used to dry date fruits surplus at 0.5 ± 0.02 kg kg−1 to a safe moisture level of 0.35 kg kg−1 under drying temperatures (T) of 50–70 °C with airflow rates (Q) of 0.18 and 0.28 m3 h−1. Kinetics, modeling, energy, economic feasibility, and color difference of the date fruits were analyzed and then optimized using response surface methodology (RSM) with two drying factors and eight responses. The drying time to reach the desired moisture level ranged from 9 to 28 h under different drying conditions. The proposed mathematical model expressed the moisture behavior over drying time with the highest R2 = 0.9998 and 0.9999, respectively, for 0.18 and 0.28 m3 h−1. Effective moisture diffusivity (Deff) was calculated using the starting accessibility parameter and varied between 9.9 × 10−8 and 3.3 × 10−7 m2 s−1. The energy analysis revealed that the specific energy consumption (SEC) varies between 22.04 and 43.05 kWh.kg−1 and the drying efficiency (η) are 16.91, 16.14, and 25.38% for 50, 60, and 70 °C, respectively. The RSM optimization using a multi-level design with two centurium points denoted the optimum responses for the highest drying temperature. The lowest payback period (Pb) of the drying system was estimated to be 0.45 years for T = 70 °C and Q = 0.28 m3 h−1. The optimum drying time, Deff, total energy consumption (Et), SEC, η, and total color change (ΔE) were estimated to be 9 h, 3.3 × 10−7 m2 s−1, 33.91 kWh, 22.04 kWh.kg−1, 27.69%, and 1.69, respectively.

Artificial neural network for drying behavior prediction of paddy in developed chamber fluidized–bed dryer

After rice is harvested, it must be dried before its products can be stored. Therefore, this paper presented a novel and simple method for improving paddy drying process in a column fluidized bed dryer. Additionally, artificial neural network methods were applied to predict the drying behavior. The experiments were conducted under two different drying chamber characteristics (a conventional chamber and a chamber fitted with nozzle) and four different air flow velocities (3.03, 3.52, 4.12 and 4.85 m/s) at a drying air temperature of 60 °C. The results showed that the chamber fitted with the nozzle reduced the drying time by approximately 67, 52 and 38 % at the air velocity of 3.52, 4.12 and 4.85 m/s, respectively. The specified experimental conditions and the calculated moisture content of the paddy in this work were used as input and output data for the artificial neural network, respectively, to predict drying characteristics. The artificial neural networks were developed with various parameters, including activation function, sampling type, split ratio, number of neurons and epoch number. The optimal model provided the root mean squared error of 0.111 and the coefficient of determination of 0.999. The best prediction was observed in the model using rectifier activation function with a split ratio of 0.85, epoch number of 1800, and 50 and 90 neurons in the first and second hidden layers, respectively.

Clinical Evaluation of the Safety and Tolerability of Film-Forming Sprays in Patients With Psoriasis and Eczema.

Background Treating dermatological pathologies under occlusion therapy is a popular adjunct, especially in thickened, lichenified areas of psoriasis where sustained contact with topical corticosteroids plays a pivotal role. Film-forming spray (FFS) can be a novel, alternate approach along with topical treatment in this area for carefully selected cases. This study aimed to evaluate the safety profile and physical characteristics of a novel formulation of an FFS in patients with psoriasis and eczema. Methods This open-label, multicentre, comparative study included subjects diagnosed with chronic plaque psoriasis requiring topical corticosteroid therapy or those with eczema necessitating its application and occlusion therapy. The study product was applied to two groups of subjects. For patients in group 1, the FFS was applied to the skin area affected by the dermatological condition, which was covered with ointment only. In the second group, the FFS was applied to the corresponding unaffected skin area. The FFS was applied for 60-90 seconds and was observed for two hours after the application. The subjects were evaluated for primary outcomes, including safety assessment, overall physical characteristics, and appearance of FFS from local skin effects. The secondary outcomes included physical appearance characteristics and overall patient satisfaction following the application of FFS at the target sites. Further statistical assessments were conducted using the SAS software version 9.4 (2023; SAS Institute Inc., Cary, North Carolina, United States). Result A total of 100 subjects were included in the study across 10 outpatient centers, of which 79% had psoriatic plaques and 21% had eczematous lesions. Primary outcomes showed a lack of appearance of clinical symptoms such as dryness, flakiness, or irritation. A total of 10% of subjects in group 1 had erythema, and 6% had a tingling sensation, which was transient and mild. The secondary outcomes showed that only 12% of subjects in Group 1 and 6% of subjects in Group 2 showed a feeling of stickiness at the application site. In group 1, 8% reported a cooling sensation, which disappeared in one and two minutes, and none experienced a cooling sensation in Group 2. The average drying time for FFS in subjects with dermatological conditions was 5.19 minutes compared to 1.51 minutes on unaffected skin. The film washability results indicated that 96% of subjects in group 1 reported complete removal in less than two minutes. At the end of the study period, the mean satisfaction scorewas8.99. No significant adverse events were reported in the patients. Conclusion This study highlights the potential application of a novel formulation of FFS as a safe and well-tolerated option for enhancing uniform skin coverage with the topical corticosteroid in patients affected with psoriasis and eczema.

Dielectric barrier discharge plasma pretreatment: A cleaner new way to improve energy efficiency and quality of wolfberry drying

Pulsed electric fields (PEF) and cold plasma (CP) show the potential to improve drying efficiency, but the understanding of their comparison and combined effects in PEF-driven dielectric barrier discharge (DBD) is lacking. This study aims to develop a non-chemical pre-treatment to improve drying efficiency and quality by exploring the effects of using PEF, atmospheric pressure plasma jet, and PEF-driven DBD for pre-treating wolfberry. Exploring the synergistic effects and mechanisms of PEF and CP in pre-treatment innovatively provided a new dimension for efficient drying. Results showed that DBD pre-treatment reduced the drying time by 50.6% and energy consumption by 46.0% compared to untreated wolfberry. DBD-pre-treated wolfberries showed better sensory quality and retained critical nutrients by reducing enzyme activities and drying time. DBD combined cold plasma etching and PEF cell disintegration to increase the surface area and pore volume of wolfberry. Furthermore, DBD affected the molecular and tissue structure, altering the binding state of water molecules.

Detecting abnormal cell behaviors from dry mass time series

The prediction of pathological changes on single cell behaviour is a challenging task for deep learning models. Indeed, in self-supervised learning methods, no prior labels are used for the training and all of the information for event predictions are extracted from the data themselves. We present here a novel self-supervised learning model for the detection of anomalies in a given cell population, StArDusTS. Cells are monitored over time, and analysed to extract time-series of dry mass values. We assessed its performances on different cell lines, showing a precision of 96% in the automatic detection of anomalies. Additionally, anomaly detection was also associated with cell measurement errors inherent to the acquisition or analysis pipelines, leading to an improvement of the upstream methods for feature extraction. Our results pave the way to novel architectures for the continuous monitoring of cell cultures in applied research or bioproduction applications, and for the prediction of pathological cellular changes.

Enhancing Wheat Sprout Attributes Using “Intensification of Vaporization by Decompression to the Vacuum”, an Innovative Drying–Texturizing Technology

Highly valued for their nutritional benefits, sprouts are characterized by high water content, which promotes microbial proliferation, potentially leading to toxicity and a reduced shelf life. To address this challenge, the present study explores the application of a novel drying–texturizing approach, named IVDV (Intensification of Vaporization by Decompression to the Vacuum), to sprouts. This technique would enable faster drying of the sprouts and better preservation of their nutritional content, compared to traditional hot-air drying. Using Response Surface Methodology, optimal IVDV parameters (saturated steam pressure P, processing time t, and water content W) for wheat sprouts were defined, with a focus on preserving vitamins, proteins, and lipids, and optimizing the expansion ratio. This optimization process identified optimal experimental conditions at 5.5 bars, a duration of 15 s, and 8.8% d.b. water content. Under these conditions, the use of IVDV endowed the expanded sprouts with a crunchier and more friable texture. In addition, it significantly improved the preservation of vitamins B6 and E by 412% and 42%, respectively, compared to traditional mild hot-air drying, without significantly affecting vitamin B2, proteins, and lipids. When combined with conventional hot-air drying, IVDV not only enhanced the preservation of the sprouts’ nutritional content but also reduced drying time and energy consumption. This marks a significant advancement in sprouts preservation techniques, paving the way for novel potential applications.

Technological and textural properties of gluten-free quinoa-based pasta (Chenopodium quinoa Wild)

Quinoa (Chenopodium quinoa Willd.) is an Andean grain with a perfect nutritional composition that, by diversifying its transformation, becomes an attractive alternative for consumers looking for a high-quality, healthy diet with a source of vegetable proteins. The objective of this work was to elaborate and evaluate the technological and textural properties of quinoa paste in its entirety through the Star-Shaped Composite Central Design (CCD) of 5 process variables: Water Temperature (°C), Water Quality (ml), Mixing Time (min), Drying Temperature (°C), and Drying Time (min), with 5 levels each. At the same time, the yield and good cooking quality were studied to optimize the process. In the model of the equation for the cooking time response, a negative and significant influence of drying temperature was shown. On the other hand, for cooking loss, dough gain, a* and b* values, and texture had high values if the drying time was increased. On the contrary, the L-value decreases, which is positively significant. Meanwhile, the swelling index was only significantly positive within the technological properties. In addition, it was found that the optimal conditions for producing quality pasta were 25 °C: 1150 ml: 30 min: 70 °C and 80 min, respectively, with a desirability of 0.883. When the pasta was prepared with quinoa, the cooking time was 7 min, the cooking loss was 2.46 g/g, the mass gain was 23.6 g/g, the cooking yield was 7.99%, the swelling index was 2.9%, water absorption was 135%, and protein was 12.71 g and 0. 21 Pa in texture, these results being consistent with cited research. Likewise, the whiteness was 51.97 for the values a* 2.41 and b* 12.45; all this analysis is reflected in the final yield of the process at 78%. In conclusion, the results indicated that, by optimizing the conditions in the production of gluten-free quinoa pasta, it is possible to obtain a gluten-free product with high added value, excellent cooking quality, adequate technological properties, texture, and color acceptable to the consumer.

Enhancing mangosteen peel drying: Impact of ethanol pre-treatment, vacuum pulsing, and blaching on process efficiency and bioactive compound levels

The processing of mangosteen yields a substantial volume of waste material. One efficient method for harnessing the potential of mangosteen peels is through their exposure to a drying process. This study investigated pre-treatment methods, ethanol (E), blanching (B), and vacuum pulsing (V), individually and in combination, to mitigate the effects of temperature during the drying of mangosteen peel. The mangosteen peels were dryied, three different models were employed to fit the experimental data: the empirical models of Page and Midilli, and a diffusive model with type I boundary conditions. The combination of pre-treatments (BE, BV, and BEV) at 80 °C significantly reduced drying time to 95 min. Furthermore, the pre-treatments led to reductions in the activation energy (Ea), enthalpy, and Gibbs free energy compared to the control sample (C), while entropy increased. The pre-treated samples exhibited a lighter reddish hue compared to the C sample. The pretreatments had significant effects on the levels of total phenolic compounds (TPC), anthocyanins (A), and flavonoids (F). The BEV sample exhibited notable increases, reaching up to 101% for TPC, 47% for A, and 97% for F at a drying temperature of 80 °C. The combination of pre-treatments B, E, and V resulted in the production of high-quality flour.

Comparative evaluation of drying methods for struvite produced from electrocoagulated source-separated urine: Implications for quality, energy and cost-effectiveness

Struvite precipitation from source-separated urine is crucial for waste utilization and sustainability. However, after precipitation, the high moisture content of struvite necessitates an additional drying process that can be costly and inefficient. In the present study, the performance of different drying methods—open sun drying, air drying, conventional drying (20–100 °C), and microwave drying (180–720 W) on the quality of struvite obtained from source-separated urine through electrocoagulation using Mg–Mg electrodes were evaluated. It was found that higher temperatures and power in the convective oven and microwave resulted in higher diffusivity (10−9-10−7 m2s−1), leading to reduced drying times. Different models were employed to comprehend the drying mechanism, and the one with the highest correlation coefficient (R2 = 0.99) and the lowest statistical values was selected. The key findings indicated that higher power and temperature levels were more cost-effective. However, characterization of the dried struvite using X-ray diffraction and Fourier-transformed infrared spectroscopy, disintegration of struvite crystals at temperatures above 60 °C in the conventional oven and 180 W in the microwave oven was observed. Based on the results, we conclude that sun drying is a cost-effective and environmentally friendly alternative for drying struvite without compromising its quality.

Solar drying of oregano leaves (Plectranthus amboinicus, Lour): Analysis of experimental performance under a tropical climate

Despite the multiple applications of the oregano ( Plectranthus amboinicus (Lour)), an important herbaceous plant because of its medicinal and culinary properties, limited research has been conducted on this species’ solar drying. Thus, the experimental drying of oregano leaves in a tropical climate was performed using direct and indirect solar drying and an electric oven in this research work. Also, mathematical modeling of the drying process, moisture diffusivity, activation energy, and colorimetric analysis (as a quality parameter) were accomplished to complement the experimental evaluation and understand the drying process behavior. The results show a shorter drying time obtained with the electric oven with 210 min reached at 65°C; however, the minimum solar drying time (250 min) was achieved with a maximum drying rate of 0.025 g water/g dry matter per minute and minimum final moisture between 0.28 and 0.13 g water/g dry matter was obtained with indirect solar dryer. Moreover, the models that better represented the experimental data were Modified Page, Page, and Logarithmic, with a maximum value of R2 obtained of 0.9980 corresponding to the Logarithmic model. Furthermore, a maximum effective diffusivity value of 1.81E-9 was obtained with direct solar dryer natural convection, while for the electric oven, were 1.14E-10, 2.280E-10, and 1.026E-09 for 45, 55, and 65°C, respectively. The activation energy for water diffusion in oregano leaves was 55.66 and 97.78 kJ/g mol for solar dryers and electric ovens, respectively, which were values very close to those reported in the literature. Finally, the colorimetric analysis exhibited a minimum color change value of 17.1 obtained for the indirect solar dryer, allowing better oregano preservation and maintaining its quality for the market, which makes it ideal for drying oregano in tropical climates and promotes solar drying use for sustainable growth of the region.

PROCESSING OF OLD SLUDGE DEPOSITS INTO COMPOSITE FUEL

An urgent problem in Ukraine is overcrowded sludge sites with outdated sludge deposits. Due to the food problem, the world needs to maximize the release of land areas that have been under technical use and reclaim them for agricultural land. Therefore, the processing of obsolete sludge deposits makes it possible to reuse land for activated sludge or for reclamation for other needs of the country. The paper sets the task of studying obsolete sludge deposits to create a technology for their processing. Due to the high ash content of old silt deposits, it was proposed to combine them with peat and biomass. This will reduce ash content by 1.5–2.0 times. Since the created composite granules and the sludge deposits themselves have a high moisture of 61–68 %, the drying kinetics was studied on a convective experimental stand to reduce it. The research results showed that composite granules have a drying time of 28–39 minutes to a moisture content of 6–7 %, which is 2.3–3.1 times faster than peat. The equilibrium moisture content of composite granules was determined to be 6–7 % and not exceeding the standard moisture content for fuel granules. The heat of combustion of obsolete sludge deposits, which is 11.8 MJ/kg, and the resulting composite granules based on them, was determined, which is quite high and, depending on the composition, is in the range of 13.4–15.5 MJ/kg. During the study of the combustion of a separate fraction of aged sludge deposits, it was found that the combustion process occurs in the upward convective flow of the oxidant behind the double boundary layer. It was determined that the combustion rate is independent of its size and is the same, but the mass affects the time of ignition. Further studies on the combustion of composite granules showed that the combustion rate of the granules is significantly lower than the combustion rate of the original biomass, but the combustion rate of a separate fraction of silt deposits prevails. Bibl. 32, Fig. 8, Tab. 1.

The Effect of the Periodic Drying Method on the Drying Time of Hazelnuts and Energy Utilization.

Hazelnut is a shelled fruit that is stored by drying and used as a snack or in industry. Since the hazelnut drying process is energy-intensive, there is a need for drying methods that will reduce the energy cost without lengthening the drying time. In this study, the effects of periodic drying of hazelnuts' energy recovery, oil, and protein content, as well as mass losses, were studied. Fresh Tombul hazelnuts (Corylus avellana L.) with a diameter of Ø 15-16 mm were dried in a tunnel dryer over 16 different periods by adjusting the drying time inside and waiting time outside the oven until the moisture content reached 6%. Drying experiments were carried out at 45 °C and three different air velocities. The increase in air velocity resulted in a reduction in the periodic drying time between 10% and 36%. The optimum drying in terms of drying time and energy utilization was realized at 0.5 m/s air velocity, with a 1.5 h working time and 0.5 h waiting time. During this period, drying time increased by 19% and energy utilization was 69%. For periodic drying, the increase in oven working time causes a decrease in energy utilization, while the increase in waiting time causes an increase in energy utilization and drying time. Periodic drying had no negative effect on hazelnut oil and protein content. Periodic drying is a suitable option for saving energy during hazelnut drying.

Effect of Solar Collector Geometry on Drying Time and Nutritional Properties of Levant Quality Hazelnuts

This study examines the impact of drying Levant hazelnut samples, including husk and shell, using hot air heated by solar panels at a constant speed of 6 m/s. The study also investigates the impact of collector irradiation absorption surface geometries on hazelnut drying time.
 A solar collector with four types of air duct geometry was used to dry hazelnuts. The radiation-absorbing surface of the air duct was manufactured flat, and three different trapezoidal geometries (30, 45 and 60 angles) were used. The mass losses of hazelnuts were measured and determined at regular intervals. In addition, the total phenolic content, the DPPH radical scavenging activity, the FRAP, the free fatty acid content, the peroxide value and the moisture content were measured. For the purpose of comparison, some of the products have been dried by means of unheated air at ambient temperature.
 The pre-drying process (withering process) to separate the hazelnuts from husk, only took 1.5 days (14 hours excluding night). In these systems, the shelled fresh hazelnuts, separated from the husk, fell below the equilibrium moisture content of 6% in 2 days (except for 18 hours at night). It was found that the most suitable collector geometry for all the parameters studied in the drying of hazelnuts with solar collectors was 45 degrees, and that other geometries could be used in terms of food properties.