An effective method of bulk materials moisture measurement using capacitive sensors

When we speak about capacitance moisture meters for bulk materials we have to face with different values of dielectric permittivity for different bulk materials in dehydrated state, what causes a method error that can be named ‘type uncertainty’. Besides, different varieties of the same material have different values of dielectric permittivity, which depend from geographical origin, processing conditions etc. It can be hardly predicted automatically and type uncertainty can be compensated only in separate situations with the help of preliminary calibration. Main tasks of the research are to develop new comparison principle of moisture measurement with better accuracy due to effective compensation of physical, chemical and granulometric composition influence on the result of moisture measurement, develop new primary and secondary instrument transducers. Moisture sensor consists of four measuring capacitors. Two of them should be filled with a sample, which moisture content should be determined, and other pair of measuring capacitors should be filled with a same substance, but previously dehydrated. Mathematical models, developed to take into account granulometric composition of a bulk material were used to carry out a comparison analysis for three types of instrument measuring transducers. Obtained results proved that suggested principle of moisture measurement provides effective compensation of granulometric composition influence. Developed measuring principle had been experimentally tested what helped to confirm that it provides two times better compensation of different physical and chemical composition for different materials in comparison with the direct comparison method.     

Viability modelling of seeds and sensitivity analysis under fluctuating temperature and moisture content

This study presents the sensitivity analysis of Ellis and Roberts (1980a, 1980b) viability model as this is derived from the contribution of moisture content, seed temperature and time step variables. The analysis revealed significant increase in sensitivity of viability regarding the time variable for Δt<72min which is often adopted in computational modelling. For Δt>720min, the moisture content variable exhibited increasing sensitivity of viability, but to a lesser degree than this of the time variable. Also, in all the tested cases, the temperature variable exhibited the least contribution to the viability sensitivity. Furthermore, a modification in the viability model is proposed incorporating the concept of effective values of seed temperature and moisture content to more appropriately reproduce the fluctuating behaviour of the actual storage conditions. Finally, an improved version of the effective temperature and moisture content variables based on the improved viability model is proposed.     

Dennettia tripetala: Hot aqueous dried plant part and selected chemical components of the plant as biopreservative in the storage of Vigna unguiculata grains

The identification of bioactive components and biopreservative effect of Dennettia tripetala hot aqueous fruit extract were studied. The identified bioactive components of the aqueous extract included methaqualone (51.53%), [1,2-Benzenedicarboxylic acid, 4-methyl-5-(1-methylethyl)-, dimethyl ester] (10.46%), [2,1,3-Benzoselenadiazole, 4,6-dichloro-] (4.53%), [o-Xylene] (0.54%), and [Ethane, 1,1-bis(p-chlorophenyl)-] (0.57%). The extract was able to preserve Vigna unguiculata grains for thirty weeks without insect-pests infestation and significant degradation in nutritional, biological value and functional characteristics. The biopreservation effect of the extract could be attributed to the presence of [1,2-Benzenedicarboxylic acid,4-methyl-5-(1-methylethyl)-, dimethyl ester]; and [Ethane, 1,1-bis(p-chlorophenyl)]. The study showed the feasibility of hot aqueous extraction of bioactive compounds from D. tripetala and application as postharvest biopreservative for cowpea grains. Preservation of the grains could improve food security and enhance food safety in nations where cowpea are consumed, exported or imported.     

弯曲菌噬菌体在家禽生产中的防控进展

弯曲菌感染是引起细菌性肠胃炎的主要原因之一,在世界范围内是常见的食源性人畜共患致病菌.家禽被证明是弯曲菌的重要储存库,同时也是人类弯曲菌病的主要感染源.弯曲菌的多重耐药性问题严重,人类弯曲菌病的发病率居高不下,对公共卫生造成威胁.因此,寻找一种安全的抗生素替代品已经成为了目前亟待解决的问题.噬菌体是环境中普遍存在的细菌...     

Spatiotemporal evaluation of red flour beetle (Tribolium castaneum) dispersion under the effect of climate and topography in South Korea

Control of Tribolium castaneum, a stored product insect pest, requires analysis of the post-introduction dispersion pattern to determine the most effective time and place for preventive measures. However, the indoor habitat characteristics of T. castaneum limit the choice of tools that can be used for spatiotemporal evaluation of its dispersion. In this study, we evaluated potential T. castaneum distribution in South Korea in response to climate change and predicted its likely dispersion pattern from major grain-importing ports by considering seasonal wind status and location of agricultural facilities. Climatic suitability for T. castaneum was evaluated by recording the locations of indoor cultivation areas, and the dispersal range of T. castaneum from major grain-importing areas was estimated by considering flight direction and distance along with seasonal wind patterns. The results showed that climatic suitability for the insect would increase with climate change, and a high potential for dispersion could be expected during the summer. This study proposes data that can assist in decision making for T. castaneum control as well as a model-based methodology applicable for evaluating a stored product insect.