scholarly journals Case study of fungal growth on newly cast concrete floors

2021 ◽  
Vol 2069 (1) ◽  
pp. 012016
Author(s):  
SM Kristensen ◽  
AP Koch ◽  
JK Sheard ◽  
U Thrane
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Fungal Growth ◽  
Moisture Barrier ◽  
Technological Institute ◽  
Apartment Complex ◽  
Building Process ◽  
Cast Concrete

Abstract In several cases, the Danish Technological Institute has experienced widespread fungal growth on newly cast concrete floors, with a moisture barrier and floating wooden flooring. The reason for fungal growth is usually due to an inadequate drying period. Existing recommendations require that the relative humidity (RH) of air in equilibrium with the concrete, measured in the middle of the concrete, should not exceed 85-90% RH. In this study, six randomly picked apartments in a newly built apartment complex, were chosen for a case study of fungal growth and moisture on newly cast concrete. The study demonstrates that at least some pecies of fungi can grow very well on newly cast concrete if the surface is dusty and moist. The study also demonstrates that a few samples on the surface will often be representative for the whole floor. The study finds that there is a need to revise the existing guidelines for acceptable moisture content in the concrete before mounting the floor. This might have an impact on the entire building process and/or the design of the floor construction. The study also finds that there is a need for a guideline for measuring moisture and fungal growth on newly cast concrete floors.

Effect of Temperature and Relative Humidity during Transportation on Green Coffee Bean Moisture Content and Ochratoxin A Production

2007 ◽  
Vol 70 (1) ◽  
pp. 164-171 ◽  
Author(s):  
HECTOR A. PALACIOS-CABRERA ◽  
HILARY C. MENEZES ◽  
BEATRIZ T. IAMANAKA ◽  
FREDERICO CANEPA ◽  
ALDIR A. TEIXEIRA ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ochratoxin A ◽  
Fungal Growth ◽  
Effect Of Temperature ◽  
Coffee Bean ◽  
Green Coffee ◽  
Final Destination ◽  
Coffee Beans ◽  
Environmental Variations

Changes in temperature, relative humidity, and moisture content of green coffee beans were monitored during transportation of coffee from Brazil to Italy. Six containers (three conventional and three prototype) were stowed in three different places (hold, first floor, and deck) on the ship. Each prototype was located next to a conventional container. The moisture content of the coffee in the container located on the first floor was less affected by environmental variations (0.7%) than that in the hold and on the deck. Coffee located in the hold showed the highest variation in moisture content (3%); in addition, the container showed visible condensation. Coffee transported on the deck showed an intermediary variation in moisture (2%), and there was no visible condensation. The variation in coffee moisture content of the prototype containers was similar to that of the conventional ones, especially in the top layers of coffee bags (2 to 3%), while the increase in water activity was 0.70. This suggests that diffusion of moisture occurs very slowly inside the cargo and that there are thus sufficient time and conditions for fungal growth. The regions of the container near the wall and ceiling are susceptible to condensation since they are close to the headspace with its high relative humidity. Ochratoxin A production occurred in coffee located at the top of the container on the deck and in the wet bags from the hold (those found to be wet on opening the containers at the final destination).

scholarly journals Nature-inspired wax-coated jute bags for reducing post-harvest storage losses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kennedy Odokonyero ◽  
Adair Gallo ◽  
Himanshu Mishra
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Developing World ◽  
Fungal Growth ◽  
Seed Storage ◽  
Water Repellency ◽  
Security Threat ◽  
Post Harvest ◽  
Storage Losses ◽  
Jute Bags

AbstractPost-harvest storage of grains is crucial for food and feed reserves and facilitating seeds for planting. Ironically, post-harvest losses continue to be a major food security threat in the developing world, especially where jute bags are utilized. While jute fabrics flaunt mechanical strength and eco-friendliness, their water-loving nature has proven to be their Achilles heel. Increased relative humidity and/or precipitation wets jute, thereby elevating the moisture content of stored seeds and causing fungal growth. This reduces seed longevity, viability, and nutritional value. To address this crucial weakness of jute bags, we followed a nature-inspired approach to modify their surface microtexture and chemical make-up via alkali and wax treatments, respectively. The resulting wax-coated jute bags (WCJBs) exhibited significant water-repellency to simulated rainfall and airborne moisture compared to control jute bags (CJBs). A 2 months-long seed storage experiment with wheat (Triticum aestivum) grains exposed to 55%, 75%, and 98% relative humidity environments revealed that the grains stored in the WCJBs exhibited 7.5–4% lesser (absolute) moisture content than those in the CJBs. Furthermore, WCJBs-stored grains exhibited a 35–12% enhancement in their germination efficacy over the controls. This nature-inspired engineering solution could contribute towards reducing post-harvest losses in the developing world, where jute bags are extensively utilized for grain storage.

CATFISH DRYING (Clarias Batraclus) USING ‘TEKO BERSAYAP’ SOLAR DRYER

2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Time ◽  
Ambient Relative Humidity ◽  
Solar Dryer

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.

Assessment of Potential Damage Factor: A Case Study of St. Paul’s Cathedral, Kolkata

2021 ◽  
Vol 6 (1) ◽  
pp. 53-68
Author(s):  
Chiradeep Basu ◽  
Subarna Bhattacharyya ◽  
Anirban Chaudhuri ◽  
Shaheen Akhtar ◽  
Akash Chatterjee ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Nitrogen Concentration ◽  
Building Design ◽  
Airborne Microorganisms ◽  
Air Movement ◽  
Fungal Load ◽  
Heritage Building ◽  
Central Pollution Control Board ◽  
Potential Damage

Damaging factors such as airborne microorganisms, relative humidity, ventilation, temperature and air pollutants are the major concerns of the tropical climate of Kolkata, India where our study site, 172-year-old St. Paul’s Cathedral is located. In this context, the aim was to develop an equation to assess the management priority and which factors would be more responsible for potentially damaging the heritage building. The temperature varied from 28°C to 31°C, relative humidity was recorded 72% over a period of 14 days in the prayer hall whereas almost constant temperature (27°C) and relative humidity (55%) were recorded in crypt. Air movement was recorded 0.5–3 m s−1 in both crypt and prayer hall. Sulphur dioxide and oxide of nitrogen concentration were lower than the standard mentioned by the Central Pollution Control Board, India. The fungal load was lower inside the crypt (237 CFU m−3) than in the prayer hall (793 CFU m−3). Calculated potential damage for prayer hall and crypt was found to be 48.75% and 37.08%, respectively. Results revealed that microbial load and relative humidity were the potent factors for damage to the building. Continuous air movement, that is, ventilation and building design here played significant roles. The Heritage Conservation Committee can use the data for better management.

Algorithms to predict moisture content of grain using relative humidity time-series

2020 ◽  
Author(s):  
Charles B. Delahunt ◽  
Wenbo Wang ◽  
Simon Ghionea ◽  
Andrew Miller ◽  
Austin Chan ◽  
...  
Keyword(s):  
Time Series ◽  
Relative Humidity ◽  
Moisture Content

Determination of readiness for laying based on material moisture, corresponding relative humidity, and water release

2020 ◽  
Vol 62 (10) ◽  
pp. 1033-1040
Author(s):  
Christoph Strangfeld ◽  
Sabine Kruschwitz
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Embedded Sensors ◽  
Residual Water ◽  
Floor Covering ◽  
Water Release ◽  
Content Determination ◽  
Two Samples ◽  
Moisture Content Determination

Abstract The moisture content of the subfloor has to be determined before installation to avoid damage to the floor covering. Only if readiness for layering is reached, can an installation without damage be expected in all cases. In general, three approaches exist to measure residual water content: determination of moisture content, determination of water release, or determination of the corresponding relative humidity. All three approaches are tested under laboratory conditions at eight screed types including two samples thicknesses in each case. Moisture content and water release are measured by sample weighing, the corresponding relative humidity is measured by embedded sensors. All three approaches are compared and correlated. The evaluations show only a weak correlation and, in several cases, contradicting results. Samples are considered ready for layering and not ready for layering at the same time, depending on the chosen approach. Due to these contradicting results, a general threshold for a risk of damage cannot be derived based on these measurements. Furthermore, the experiment demonstrates that the measurement of corresponding relative humidity is independent of the screed type or screed composition considered. This makes humidity measurement a potentially very promising approach for the installation of material moisture monitoring systems.

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