Geochemical Changes Associated with High-Temperature Heat Storage at Intermediate Depth: Thermodynamic Equilibrium Models for the DeepStor Site in the Upper Rhine Graben, Germany

The campus of the Karlsruhe Institute of Technology (KIT) contains several waste heat streams. In an effort to reduce greenhouse gas emissions by optimizing thermal power consumption on the campus, researchers at the KIT are proposing a ‘DeepStor’ project, which will sequester waste heat from these streams in an underground reservoir during the summer months, when the heat is not required. The stored heat will then be reproduced in the winter, when the campus’s thermal power demand is much higher. This paper contains a preliminary geochemical risk assessment for the operation of this subsurface, seasonal geothermal energy storage system. We used equilibrium thermodynamics to determine the potential phases and extent of mineral scale formation in the plant’s surface infrastructure, and to identify possible precipitation, dissolution, and ion exchange reactions that may lead to formation damage in the reservoir. The reservoir in question is the Meletta Beds of the Upper Rhein Graben’s Froidefontaine Formation. We modeled scale- and formation damage-causing reactions during six months of injecting 140 °C fluid into the reservoir during the summer thermal storage season and six months of injecting 80 °C fluid during the winter thermal consumption season. Overall, we ran the models for 5 years. Anhydrite and calcite are expected mineral scales during the thermal storage season (summer). Quartz is the predicted scale-forming mineral during the thermal consumption period (winter). Within ~20 m of the wellbores, magnesium and iron are leached from biotite; calcium and magnesium are leached from dolomite; and sodium, aluminum, and silica are leached from albite. These reactions lead to a net increase in both porosity and permeability in the wellbore adjacent region. At a distance of ~20–75 m from the wellbores, the leached ions recombine with the reservoir rocks to form a variety of clays, i.e., saponite, minnesotaite, and daphnite. These alteration products lead to a net loss in porosity and permeability in this zone. After each thermal storage and production cycle, the reservoir shows a net retention of heat, suggesting that the operation of the proposed DeepStor project could successfully store heat, if the geochemical risks described in this paper can managed.

Dynamics of the Apple Fruit Microbiome after Harvest and Implications for Fruit Quality

The contribution of the apple microbiome to the production chain of apple was so far largely unknown. Here, we describe the apple fruit microbiome and influences on its composition by parameters such as storage season, storage duration, storage technology, apple variety, and plant protection schemes. A combined culturing and metabarcoding approach revealed significant differences in the abundance, composition, and diversity of the apple fruit microbiome. We showed that relatively few genera contribute a large portion of the microbiome on fruit and that the fruit microbiome changes during the storage season depending on the storage conditions. In addition, we show that the plant protection regime has an influence on the diversity of the fruit microbiome and on the dynamics of pathogenic fungal genera during the storage season. For the genus Neofabraea, the quantitative results from the metabarcoding approach were validated with real-time PCR. In conclusion, we identified key parameters determining the composition and temporal changes of the apple fruit microbiome, and the main abiotic driving factors of microbiome diversity on apple fruit were characterized.

The results of consumer preference testing of popular apple cultivars at the end of the storage season

The results from 23 tasting sessions of experienced evaluators that took place during the last decade in May are presented in 4 periods which lasted 5 years except for the first one, which was seven-years long. The winner of the first testing period was ‘Bohemia’, ‘Meteor’ was the winner of the second period and ‘Admiral’ was the top rated in the remaining two testing periods. Across all the years, ‘Meteor’ had the highest total punctual value, but it was only about 0.4 points higher than ‘Admiral’. In the next sequence, they were followed by the cultivars ‘Andera’, ‘Rubin’ and ‘Andego’. In the aroma evaluation, ‘Andera’, ‘Gold Bohemia’ and ‘Topaz’ were the best. ‘Admiral’, ‘Gold Bohemia’ and ‘Andera’ were the top rated in flesh consistency. ‘Admiral’, ‘Angold’ and ‘Andera’ were the best in juiciness. ‘Gold Bohemia’, ‘Admiral’ and ‘Meteor’ had the highest values of the general taste. ‘Admiral’, ‘Angold’ and ‘Meteor’ were the most attractive.

Effectiveness of hermetic maize grain storage technology in limiting aflatoxin exposure in women and children from smallholder farming areas

The longitudinal study assessed the effectiveness of hermetic storage technology in limiting aflatoxin exposure among women aged 15-45 years and children under five years of age from households in selected smallholder farming areas of Zimbabwe. Exposure levels were determined by measuring aflatoxin M1 (AFM1) in urine samples from women and children every three months during the 2015/2016 storage season for nine months. After extraction and immunoaffinity column clean up, AFM1 was determined by high performance liquid chromatography. Generally, the proportion of AFM1 positive urine samples from women increased throughout the grain storage season from 5.4% (n=23) (geometric mean (GM) 1.62 μg/l) at harvest to 75% (n=315) (GM 48.35 μg/l) nine months later (range <limit of quantification (LOQ)-217.29 μg/l). In urine samples from children, AFM1 positive samples increased from 2.2% (n=4) (GM 0.78 μg/l) at harvest to 72.5% (n=98) (GM 22.81 μg/l) nine months later (range <LOQ- 135.00 μg/l). Urinary AFM1 was significantly higher in samples from participants using conventional storage (GM 62.28 μg/l; range <LOQ-217.29 μg/l) compared with samples from participants using hermetic technology (GM 31.95 μg/l; range <LOQ-157.71 μg/l. There was no significant difference in AFM1 concentrations in urine samples from participants consuming grain from metal silos and hermetic bags (P>0.05) hence the two technologies are equally effective in limiting exposure to aflatoxins in humans. The study concluded that aflatoxin exposure levels among women and children from small-holder farming areas increase throughout the postharvest season and the use of hermetic storage technology resulted in up to 33.2% decrease in frequency of detection and 48.7% decrease in levels of AFM1 compared to conventional storage technologies. Thus hermetic grain storage can be an effective technology recommended for limiting aflatoxin exposure in smallholder farming populations.

INFLUÊNCIA DA ÉPOCA DE ESTOCAGEM NA QUALIDADE DA BIOMASSA FLORESTAL PARA A GERAÇÃO DE ENERGIA

Este trabalho objetivou determinar a época de estocagem ideal para a melhoria da qualidade da biomassa florestal para geração de energia. O experimento foi realizado em Lages, SC, entre outubro de 2003 e fevereiro de 2005. Foram avaliados 4 lotes de toras com casca de Pinus taeda e Eucalyptus dunnii, em pilhas, com amostragem nas seguintes condições: material recém-colhido, com dois, quatro e seis meses de estocagem. O lote 1 foi armazenado entre outubro (2003) e maio (2004), o lote 2, de janeiro a agosto de 2004, o lote 3, de maio a novembro de 2004 e o lote 4, de agosto de 2004 a fevereiro de 2005. As propriedades avaliadas foram: teor de umidade na base úmida, poder calorífico superior e líquido. A época de estocagem teve influência sobre a qualidade energética da biomassa durante a estocagem, com alterações na umidade e poder calorífico líquido. Para ambas as espécies, as melhores épocas de estocagem foram entre agosto e fevereiro (lote 4) e outubro e maio (lote 1), com as maiores perdas de umidade e maiores ganhos energéticos. Portanto, a biomassa florestal colhida na saída do inverno ou início da primavera, que permaneceu sob estocagem durante o verão até o início do inverno, apresentou melhor qualidade energética.Palavras-chave: Energia; Pinus taeda; Eucalyptus dunnii. AbstractInfluence of the storage season over the quality of wood fuel. This study aimed to determine the optimal storage season for improving the quality of forest biomass for energy generation. The experiment was carried out in Lages, Brazil, between October 2003 and February 2005. 4 lots of Pinus taeda and Eucalyptus dunnii logs were stocked, in piles, with samples collected from the freshly harvested material, with two, four and six months of storage. The lot 1 was stored between October (2003) and May (2004), lot 2 (January-August (2004)), lot 3 (May-November (2204)) and 4 (August (2004)-February (2005)). The evaluated properties were as follows: moisture content on wet basis, gross and net calorific value. The storage season had influence on the biomass quality, with changes in moisture content and net calorific value. For both species, the best storage season was between August and February (lot 4) and from October to May (lot 1), with the greatest loss of moisture and higher energy savings. Therefore, forest biomass harvested in late winter or early spring, which remained in storage during the summer up to early winter had a better energy quality.Keywords: Energy; Pinus taeda; Eucalyptus dunnii

Effect of 1-MCP treatment on apple biochemical content and physiological disorders

The research was conducted with the apple ( Malus domestica ) cultivars Krameri Tuviõun and Talvenauding at the Estonian Agricultural University during 2003–2005. The aim was to study the effect of 1-methylcyclopropene (1-MCP) treatment (1 ppm, at room temperature, 24 h) on the biochemical content and physiological disorders of apples and on external quality after 4 months of storage. The apples were stored in a normal atmosphere at 2–5°C and 80–85% RH. In the first storage season 1-MCP treatment did not improve apple quality in general; only the peel background colour of treated apples remained greener. In the second storage season 1-MCP treatment influenced the biochemical content of the apples and improved apple quality: treated fruits were firmer (increase from 4.7 kg/cm 2 to 8.1 kg/cm 2 ) and contained more vitamin C; also, the SSC decreased and the loss of titratable acids was delayed. Consequently fruit spoilage decreased by 30%.

Contamination of Apple Fruit with Diphenylamine During Storage

Apple fruit are treatmented with diphenylamine (DPA) in the form of a postharvest dip to prevent the development of storage scald. However, DPA residues have been detected on apples not treated with DPA, which is problematic in markets where DPA residues are not acceptable. The objective of this study was to identify sources of DPA contamination and evaluate the effectiveness of ozone to reduce contamination. Concentrations of DPA in the atmosphere of commercial storage rooms was monitored during the storage season and the adsorption of DPA onto wood and plastic bin material, plastic bin liners, foam insulation, and apple fruit was assessed. DPA was sampled from headspace with solid phase micro extraction using 65 μm polyacrylate micro fibers and analyzed using GC-MS. The effectiveness of gaseous treatments of 300 and 800 ppb ozone to reduce DPA contamination on apple fruit and bin material was also determined. DPA was found to volatilize from treated apples and bins into the storage room air, where it was adsorbed onto storage room walls, bins, bin liners and other fruit. DPA was found in the atmosphere of storage rooms containing apples that were not treated with DPA. Wood and plastic bin material, bin liners, and foam insulation all had a high affinity for DPA and were determined to be potential sources of contamination. Ozone reacted with DPA and following gaseous ozone treatments, off-gassing of DPA from wood and plastic bin material and bin liners was reduced. However, ozone was not effective in removing all DPA in contaminated materials and was ineffective in removing DPA from contaminated apples. Due to the pervasive and persistent nature of DPA, fruit should be handled and stored in facilities where DPA is not used to prevent contamination of fruit.

Changes in Antiplatelet Activity, Pungency, and Percent Solids of Four Diverse Onion (Allium cepa) Lines During Cold Storage

Raw onion extract contains organosulfur compounds that prevent aggregation of platelets in human blood plasma and influence onion pungency. An increase in antiplatelet activity has the potential of reducing cardiovascular diseases. Accumulating organosulfur compounds directly influences pyruvic acid concentrations and may determine antiplatelet activity. Organosulfur compounds are volatile and may change concentration during storage. A study was conducted to evaluate antiplatelet activity, pyruvic acid content, and percent solids during cold storage. Two low-pungency lines (8155B and Exhibition) and two high-pungency (W420B and W434B) lines were grown in replicated plots at two Wisconsin locations in 1994 and 1995. Bulbs were evaluated for antiplatelet activity, percent solids, and pyruvic acid content at 40-day intervals after onion harvest. We found significant differences for antiplatelet activity and pyruvic acid content among dates of sampling and lines. Averaged over lines antiplatelet activity increased by 73% and 29% over 160 days in storage during the 1994–95 and 1995–96 storage seasons, respectively. Mean pyruvic acid concentrations increased 27% for the 1994–95 storage season and decreased 27.5% for the 1995–96 storage season. There were no significant changes for solids during storage for both years. These data indicate that antiplatelet activity increases during storage, which may be beneficial for human health. Since onions are often stored for long periods of time before sale, an increase in antiplatelet activity may be an added benefit for this crop.

Development of a Sensory Descriptive Profile for `Gala' Apple

`Gala' is an early maturing apple variety that has a distinctive aroma and flavor. Its storage season is short and flavor volatile production is reduced following controlled atmosphere (CA) storage. The aroma and flavor characters of `Gala' apples were identified by 10 trained panelists. A vocabulary of 13 descriptors for the aroma of whole and cut fruit and 16 descriptors for flavor were used to characterize the changes of apples stored in CA and/or regular atmosphere (RA) during five months. When compared to RA storage, intensity of fruity (pear, banana and strawberry) and floral characters decreased after 2.5 months in CA for whole and cut fruit aroma and flavor. During the entire storage period under CA, aroma of cut apples retained high vegetative and citrus characters but had a less intense anise aroma. Sourness, starchiness and astringency were significantly higher, however, sweetness was significantly lower. A musty note was perceived in whole apples stored in CA for 5 months. Differences in fruitiness of whole fruit and sourness only were found between fruit stored for 4 months in CA followed by 1 month in RA and fruit stored 5 months in CA. Relationships between panel ratings of specific characters and corresponding quantitative analysis will be discussed.