Search Results (23)

Interpretations of the circumstances that formed the development of the Hermetic texts are still to be debated. However, these difficulties are not only philological in nature but also address the revelatory quality of the texts. The author of the sixteenth dialogue of the Corpus Hermeticum (CH) diminishes his work by claiming that the teachings contained in the treatise would actually only be understood properly if it were in the Egyptian language, not in its current form, Greek, because the Greek language is not able to reveal the truth conveyed by the divine power of the Egyptian language, but is only useful for logical debates and joking. The role of the written word, as well as its connection to oral initiation in Hermetism, is examined first in this paper. Second, we look at how the book and Egyptian writing mediating the teachings is portrayed as a sacred item in Hermetic initiation texts, as well as its importance in the initiation process. Finally, we examine the peculiar claim of the author of the sixteenth treatise of Corpus Hermeticum that, despite all this, it is possible to misuse Hermetic texts if they are translated, specifically, into the Greek language in which we can read most of them today. In studying CH XVI, I propose that Hermetic authors try to retain the famous character of the works by highlighting their Egyptian origin. They claim that Hermetic teachings can only lead to initiation in their original form but if they are translated into any language, they lose their divine power. Full article

An alternative conductive ink based on carbon nanotubes (CNTs) was developed using a platinum-catalyzed silicone elastomer and isopropyl alcohol (IPA). The inclusion of IPA in the conductive CNT ink facilitated the optimization of its mechanical strength, electrical conductivity, and viscosity. Compared to conventional silicone rubber-based conductive polymers that often solidify in a few hours at room temperature or with heating, this liquid composite of CNT particles and IPA exhibited a prolonged duration of up to several months in a hermetic environment, maintaining chemical stability even with the elastomer and its curing agent. The gradual evaporation of IPA initiates a well-known cross-linking process, leading to stretchability and electrical conductivity derived from the silicone elastomer and CNT particles, respectively. The relationship between the mechanical strength and electrical conductivity of the hardened conductive CNT ink was studied, which helped determine the optimized concentration of CNT particles in the conductive CNT ink. Subsequently, a piezoresistive sensor was designed, fabricated, and evaluated. The conductive CNT ink-based piezoresistive sensor showed high sensitivity and good repeatability with respect to a wide range of external forces. The effect of the concentration of CNT particles on the viscosity of the conductive CNT ink was also investigated, providing a better understanding of the entanglement of CNT particles within the silicone elastomer. A coating test using the conductive CNT ink with a paper cutting machine demonstrated its potential for adaptation to various printing techniques, including screen printing. The proposed conductive CNT ink, characterized by a simple chemical composition, facile fabrication process, use of non-toxic elements, high electrical conductivity, and stretchability, combined with an extended duration, has the potential to be applied for multiple purposes, such as various types of flexible and wearable electronics. Full article

Millet (Pennisetum glaucum (L.) R. Br.) is the most widely consumed cereal in Niger. Although its production lasts six months, consumption is year-round, requiring effective and safe storage solutions. Post-harvest losses of millet can reach up to 17% after several months of storage. Chemical pesticides are commonly used in large warehouses, but concerns over misuse and health risks have driven interest in safer alternatives. This study assessed the effectiveness of traditional and improved storage methods in controlling Trogoderma granarium Everts, an emerging pest of millet in large warehouse facilities. Three storage methods were tested: (i) a hermetic Purdue Improved Crop Storage (PICS) bag; (ii) chemical pesticide Phostoxin; and (iii) an untreated ordinary polypropylene bag as a control. Naturally infested millet obtained from a large warehouse was assessed for each treatment at the start and end of a six-month storage period. Two insect pests were identified, T. granarium and Tribolium sp. Initial infestation levels were 60 larvae and 0.47 adults per 500 g. After six months, the control showed a 1.7-fold increase in T. granarium larvae, a 2.96-fold increase in its adults, and a 3.19-fold increase in Tribolium sp. adults, resulting in 19.15% weight loss. In contrast, PICS and Phostoxin treatments maintained initial pest levels with no weight loss. These results suggest that hermetic storage is a safe, effective, and chemical-free alternative for preserving millet in large warehouses. Full article

Strawberries are highly perishable despite their popularity, as their limited shelf life compromises both freshness and market value. The study investigated the effects of 1-methylcyclopropene (1-MCP), modified atmosphere packaging (MAP), and their combined treatments on the quality and flavor of strawberries during cold storage and simulated shelf life. 1-MCP was applied by enclosing strawberry fruits in a hermetically sealed container and exposing them to 250 nL/L 1-MCP at 20 °C for 18 h. Three initial MAP gas compositions were tested: MAP1 (5% O₂, 15% CO₂, 80% N₂), MAP2 (10% O₂, 10% CO₂, 80% N₂), and MAP3 (15% O₂, 5% CO₂, 80% N₂), with MAP1 identified as optimal based on strawberry postharvest quality metrics. The results showed that all treatments could inhibit the deterioration of strawberry quality, and the 1-MCP + MAP treatment had the best fresh-keeping effect. Untargeted Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified 85 volatile compounds, and sensory correlation analysis revealed that 1-MCP + MAP-treated strawberries maintained the highest consumer acceptability, with odor characteristics closely resembling those of pre-storage controls. Further studies demonstrated that the combined treatment uniquely suppressed the generation of fatty acid oxidation-derived volatiles while stabilizing critical aroma-active esters, thereby decelerating flavor degradation. Collectively, these findings highlight the potential of 1-MCP + MAP as a postharvest strategy to delay the postharvest senescence of strawberries and maintain their storage quality. GC-MS provided a scientific method for the flavor quality evaluation of this preservation technology. Full article

The paper presents a study of changes in selected physicochemical properties of honeys during their refrigerated storage at 8 ± 1 °C for 24 weeks. On the basis of the study of primary pollen, the botanical identification of the variety of honeys was made—rapeseed, multiflower and buckwheat honey. The samples were stored for 24 weeks in dark, hermetically sealed glass containers in a refrigerated chamber (8 ± 1 °C, 73 ± 2% relative humidity). The comprehensive suite of analyses comprised sugar profiling (ion chromatography), moisture content determination (refractometry), pH and acidity measurement (titration), electrical conductivity, color assessment in the CIELab system (ΔE and BI indices), texture parameters (penetration testing), rheological properties (rheometry), and microscopic evaluation of crystal morphology; all data were subjected to statistical treatment (ANOVA, Tukey’s test, Pearson correlations). The changes in these parameters were examined at 1, 2, 3, 6, 12, and 24 weeks of storage. A slight but significant increase in moisture content was observed (most pronounced in rapeseed honey), while all parameters remained within the prescribed limits and showed no signs of fermentation. The honeys’ color became markedly lighter. Already in the first weeks of storage, an increase in the L* value and elevated ΔE indices were recorded. The crystallization process proceeded in two distinct phases—initial nucleation (occurring fastest in rapeseed honey) followed by the formation of crystal agglomerates—which resulted in rising hardness and cohesion up to weeks 6–12, after which these metrics gradually declined; simultaneously, a rheological shift was noted, with viscosity increasing and the flow behavior changing from Newtonian to pseudoplastic, especially in rapeseed honey. Studies show that refrigerated storage accelerates honey crystallization, as lower temperatures promote the formation of glucose crystals. This accelerated crystallization may have practical applications in the production of creamed honey, where controlled crystal formation is essential for achieving a smooth, spreadable texture. Full article

The cowpea is a vital crop for low-resource farmers in the Sahel, but post-harvest losses due to insect pests remain a major challenge. Callosobruchus maculatus (Fabricius, 1775), is the primary pest responsible for most of the damage to stored cowpeas. Recently, Trogoderma granarium (Everts, 1898) was found infesting cowpeas in large warehouses in Niger. This study evaluated hermetic storage bags to manage both common and emerging insect pests. Treatments included (i) the Purdue Improved Crop Storage (PICS) hermetic bag; (ii) a woven polypropylene (PP) bag with a polyethylene (PE) liner and Phostoxin; and (iii) a woven PP bag without Phostoxin (control). Naturally infested cowpea grains were obtained from the Office des Produits Vivriers du Niger (OPVN) warehouse in Maradi, Niger. Infestation levels were assessed using 12 samples of 500 g each, randomly collected from each treatment at the start and end of the trial. Major pests identified were C. maculatus, T. granarium, and Tribolium sp., with initial populations of 0.83, 0.44, and 0.83 adults per 500 g of cowpea, respectively. After six months of storage, pest densities in the control increased significantly: 232-fold for C. maculatus, 7.4-fold for T. granarium, and 2.7-fold for Tribolium sp.; resulting in a 38.5% weight loss. In contrast, both the Phostoxin and the PICS hermetic bags effectively suppressed pest populations, preventing weight loss. This study confirms the efficacy of hermetic storage, such as the PICS bag, in protecting cowpeas from both common and emerging pests. Full article

Hermetic glass-to-metal sealing (GMTS) technology combines metal and glass and can be used to construct vacuum tubes; electric discharge tubes; semiconductor diodes; reed switches; and pressure-tight glass-to-metal windows, optical windows, and lenses in electronics or electronic systems. The hermetic and mechanically strong seals engineered using GTMS are highly reliable, making them suitable for deployment in harsh environments and for applications requiring high performance. However, it has always been challenging to precisely and robustly join glass and metal due to the significant disparities in their properties. In this study, the laser transmission welding of borosilicate glass and aluminum alloy using a pulsed Nd:YAG laser to achieve hermetic glass–metal seals was experimentally investigated. This research focused on various processing parameters and the influence of surface conditions on bonding quality. Three different types of surfaces—a polished surface, a surface subjected to preoxidation, and a laser-modified surface—were compared. To evaluate the weld strength, shear-tensile separation forces were measured. The analysis of fracture and separation encompassed detailed examinations of the weld morphology, microstructure, and elemental composition. The results revealed that increasing the laser welding energy initially enhanced the weld strength until a saturation point was reached. Among the three different surface treatments tested, the laser surface modification of aluminum alloy yielded the highest weld strength. The maximum achieved bond force exceeded 35.38 N, demonstrating the feasibility of using cost-effective pulsed laser welding for glass-to-metal sealing. The results were significantly better than those from previous research in which aluminum alloy surfaces were pretreated using microarc oxidation. Full article

Grain quality is largely driven by grain infrastructure (technology) and handling practices (application of knowledge on handling). The use of inappropriate infrastructure and inappropriate handling protocols poses food safety and health-related risks. This review provides evidence for the link between drying and storage operations in the context of preserving grain quality. The purpose of this study was to evaluate the close grain quality relationship between drying and storage, with an appraisal of operations in Africa. This study further benchmarked successful and scalable models in Africa to infer guidance for promotion of optimal and effective drying and storage initiatives. While open-sun drying is undoubtedly the most adopted approach to grain drying for the rural-poor farmers, this study revealed greater success in grain storage, especially with the breakthrough at the introduction and adoption of small-scale hermetic storage technologies. Upon assessment of the cob, WFP Zero Food Loss Initiative, and AflaSight models implemented in Rwanda and Uganda, this study suggests: (i) the adoption of system thinking; (ii) the use of sustainable approaches such as gender inclusion, sustainable financing options, and use of existing infrastructures along-side novel interventions; and (iii) enabling policies and political will as strategic pathways for successful implementation of improved grain-quality interventions during drying and storage. In the short term, grain handlers must develop appropriate grain management protocols during open-sun drying to limit the impact of drying-related grain quality deterioration. Consortia-based implementation of the three models evaluated in this review could improve grain quality, food security and safety, and market linkages with premium grain markets, fostering economic growth and transformation. Full article

Seed quality declines during storage depending on relative humidity, temperature, and oxygen concentration. Low-oxygen atmospheres significantly enhanced the germination and vigor of seeds during storage in laboratory-scale experiments. Low-oxygen atmospheres include self-modified atmospheres, where gas composition changes due to microbial respiration and oxidative processes, as well as modified atmospheres, where gas composition is initially altered from an external source without further adjustments. However, the potential of low-oxygen atmospheres to preserve the quality of maize (Zea mays) seeds in bags of 25–50 kg capacity, like those employed by seed companies and small-scale farmers, remains underexplored, hindering a broader adoption of this storage technology. Our study assessed the feasibility of applying low-oxygen atmospheres for seed storage on the pilot scale, i.e., hermetic containers of 25 kg capacity made of polyethylene and polyamide, under controlled conditions. We first evaluated the ability of the hermetic containers to maintain low oxygen levels over time. Then, we compared the germination and vigor of seeds stored in the hermetic containers under modified and self-modified atmospheres with those stored in traditional poly-paper bags under normal atmospheric conditions. The seeds had 14% moisture content (wet basis) and were stored at 25 °C and 10 °C. Maintaining low oxygen levels in polyethylene–polyamide bags was feasible. Moreover, at 25 °C, modified and self-modified atmospheres maintained higher germination values (95.8% and 94.4%, respectively) compared to traditional storage (68.3%), and both were as effective as refrigeration (97.6%). However, refrigeration was better for preserving seed vigor, with radicle emergence values of 85.2% in self-modified atmospheres and 78.9% in modified atmospheres, compared to 65.0% and 61.2%, respectively, at 25 °C. In conclusion, the advantages of modified atmospheres observed in laboratory-scale studies are achievable on a larger scale with a proper container design, advancing the prospects for the practical application of this technology for the seed industry and small farmers. Full article

There is a constant demand for higher equipment parameters, such as the pressure of a sealing medium and shaft rotation speed. However, as the parameters increase, it becomes more difficult to ensure hermetization efficiency. The rotor of a multi-stage machine rotates in non-contact seals. Seals’ parameters have a great influence on vibration characteristics. Non-contact seals are considered to be hydrostatodynamic supports that can effectively dampen rotor oscillations. The force coefficients of gap seals are determined by geometric and operational parameters. A purposeful choice of these parameters can influence the vibration state of the rotor. It is shown for the first time that the initially dynamically flexible rotor, in combination with properly designed seals, can become dynamically rigid. Analytical dependencies for the computation of the dynamic characteristics are obtained. The resulting equations make it possible to calculate the radial-angular vibrations of the rotor of a centrifugal machine in the seals and construct the amplitude–frequency characteristics. By purposefully changing the parameters of non-contact seals, an initially flexible rotor can be made rigid, and its vibration resistance increases. Due to this, the environmental safety of critical pumping equipment increases. Full article

Increasing concerns about air quality due to fossil fuel combustion, especially nitrogen oxides (NO_x) from marine and diesel engines, necessitate advanced monitoring systems due to the significant health and environmental impacts of nitrogen dioxide (NO₂). In this study, a gas detection system based on the principle of the non-dispersive infrared (NDIR) technique is proposed. Firstly, the pyroelectric detector was developed by employing an ultra-thin LiTaO₃ (LT) layer as the sensitive element, integrated with nanoscale carbon material prepared by wafer-level graphics technology as the infrared absorption layer. Then, the sensor was hermetically sealed using inert gas through energy storage welding technology, exhibiting a high detectivity (D*) value of 4.19 × 10⁸ cm·√Hz/W. Subsequently, a NO₂ gas sensor was engineered based on the NDIR principle employing a Micro Electro Mechanical System (MEMS) infrared (IR) emitter, featuring a light path chamber length of 1.5 m, along with integrated signal processing and software calibration algorithms. This gas sensor was capable of detecting NO₂ concentrations within the range of 0–500 ppm. Initial tests indicated that the gas sensor exhibited a full-scale relative error of less than 0.46%, a limit of 2.8 ppm, a linearity of −1.09%, a repeatability of 0.47% at a concentration of 500 ppm, and a stability of 2% at a concentration of 500 ppm. The developed gas sensor demonstrated significant potential for application in areas such as industrial monitoring and analytical instrumentation. Full article

In recent years, there has been significant interest in quantum technology, characterized by the emergence of quantum computers boasting immense processing power, ultra-sensitive quantum sensors, and ultra-precise atomic clocks. Miniaturization of quantum devices using cold atoms necessitates the employment of an ultra-high vacuum miniature cell with a pressure of approximately 10⁻⁶ Pa or even lower. In this study, we developed an ultra-high vacuum cell realized by a miniature ion pump using a high-efficiency plasma source. Initially, an unsealed miniature ion pump was introduced into a vacuum chamber, after which the ion pump’s discharge current, depending on vacuum pressures, was evaluated. Subsequently, a miniature vacuum cell was fabricated by hermetically sealing the miniature vacuum pump. The cell was successfully evacuated by a miniature ion pump down to an ultra-high vacuum region, which was derived by the measured discharge current. Our findings demonstrate the feasibility of achieving an ultra-high vacuum cell necessary for the operation of miniature quantum devices. Full article

Hermetic storage methods are effective at protecting grain against insect pests. Biotic and abiotic factors influence oxygen depletion during hermetic storage. We investigated the dual effects of temperature and initial pest infestation level on oxygen depletion during airtight storage. Glass jars filled with cowpea grain were infested (25 or 50 adult cowpea bruchids), then hermetically sealed and stored at 20, 30, or 40 °C for 30 days. Oxygen depletion, relative humidity, and temperature were monitored. Germination, grain moisture content, grain damage and weight loss, and adult emergence were assessed. Oxygen depletion varied by temperature and insect infestation level. However, 30 °C was the optimum temperature for oxygen depletion (reaching 5% or less in 10 days) regardless of insect infestation level. No changes were observed in germination and grain moisture content, minimal grain damage, or weight loss (<1%). Only at 20 °C were adult insects able to survive after 30 days and emerged 45 days post-treatment under normoxia. Therefore, hermetic storage containers should remain closed for more than 30 days to minimize re-infestation of grain in areas where average ambient temperatures rarely exceed 23 °C. Further research is needed to assess the effect of low temperatures on oxygen depletion and insect survival in hermetic storage beyond 30 days. Full article

Microwave-assisted heat moisture treatment (MWT) was applied to quinoa grains, a nutritious gluten-free pseudocereal of great interest in food product development, to achieve the physical modification of the quinoa flour. The effect of treating quinoa grains at different initial water contents (WC; 10%, 20%, and 30%) in two operational systems was compared: one open at atmospheric pressure and variable WC (V system), and the other in hermetic containers at constant WC (C system). The morphological structure of the obtained flours and their techno-functional, rheological, and thermal properties were evaluated. MWT proved to be effective in modifying these properties, the main effects probably being caused by protein denaturation and aggregation, and intragranular molecular rearrangements of starch, with disruption of short-range molecular order and even the partial collapse of starch granules in the samples treated at the highest WC. The greatest differences were observed for the 20 and 30% WC treated-samples, particularly when using C system, which increased their water absorption capacity and decreased their foaming, emulsion, and gel-forming capacities. Based on these results, the control of WC and its evolution during MWT of quinoa grains appears to be a viable and effective approach to adapt flour functionality to the needs of food production, allowing a wider range of flour properties depending on the MWT conditions. Full article

The study was conducted to test whether radicle emergence (RE) would correlate with the storage potential of ten seed lots of watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai) hybrid cultivars (>98% normal germination). The RE test was performed by frequent counting radicle emergence (2 mm) percentage between 34 h and 60 h after germination was set up at 25 °C in the dark. Seed longevity was hermetically determined by artificial storage of seeds (air and waterproof) at 17 ± 0.3% of seed moisture and at 35 ± 2 °C over 63 days. Twelve seed samples were taken out during aging, and seed survival curves were constructed based on normal germination percentages conducted at 25 °C for seven days in the dark. The seed longevity criterion was P₅₀ (time for the germination to fall to 50%), which was determined through probit analysis by using survival curves. Correlation analysis showed that RE counts at 42 h during germination were highly correlated (p < 0.01) with initial seed quality, Ki (r = 0.7538), and the half-viability period, P₅₀ (r = 0.7936). Pre-storage normal germination percentages of seed lots were not related to longevity. Results showed that the RE vigor test has the potential to predict longevity in highly germinating hybrid watermelon seed lots. Full article