Study on Critical Moisture Content of Unsaturated Evaporation

2014 ◽  
Vol 513-517 ◽  
pp. 2643-2646
Author(s):  
Hua Zhang ◽  
Wen Long Hu ◽  
Jin Lu Cao
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Measuring System ◽  
Evaporation Process ◽  
Critical Moisture Content ◽  
Whole Process ◽  
Critical Moisture ◽  
Three Stages ◽  
Soil Water Characteristic Curves ◽  
Water Contents

Thin layer evaporation tests of three types of soil were conducted by a newly designed humidity-controllable evaporation and penetration measuring system and lasted for 8 days. The whole process of sample mass variation from wet to dry was recorded in the laboratory. The critical moisture content and air-dried moisture content were obtained from evaporation curve, which divided the evaporation process of thin layer unsaturated soil into three stages, including stable rate stage, reducing rate stage and residual stage. The soil water characteristic curves of soils were predicted by Arya and Paris model, the results showed that the critical moisture contents of evaporation process were the same with the water contents corresponding to residue values of SWCC, it is significant to studying on unsaturated evaporation process.

scholarly journals Impact of fast and slow desiccation on Garcinia imberti seed and seedling vigour

2018 ◽  
Vol 5 (3) ◽  
pp. 95-102
Author(s):  
M Anto ◽  
C Anilkumar
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Germplasm Conservation ◽  
Seedling Vigour ◽  
Critical Moisture Content ◽  
Normal Seedling ◽  
Southern Western Ghats ◽  
Mean Germination Time ◽  
Critical Moisture ◽  
Activated Silica Gel

Garcinia imberti Bourd. endemic to the southern Western Ghats is classified as endangered by the IUCN (2018). The seeds as the sole means of propagation with initial moisture content (MC) of 62.8% are sensitive to desiccation. Studies on the responses of the seed to drying require ascertaining of the critical moisture content (CMC) as a basic requisite for germplasm conservation. Responses of G. imberti seeds to fast drying with activated silica gel (25 ± 2 °C, 6 ± 1% RH) and to slow drying under laboratory conditions (28 ± 2°C, 60 ± 2% RH) were evaluated for seed and seedling vigour. When the MC was reduced to 56% by 48 hours of slow drying or 6 hours of fast drying, 75 to 90% normal seedlings were produced respectively. In the case of fast dried seed (6 hours), seed associated parameters except mean germination time showed peak values with maximum germination and enhanced root length. Below the CMCs of 16.4 and 26.3% (fast and slow drying respectively), half of the tested seeds become non viable. Thus for germplasm conservation the present study proposes 6 hour’s of fast drying to retain viability and normal seedling development of G. imberti.

scholarly journals Testing methods of moisture content, critical moisture content, and germination of jamblang (Syzygium cumini (L.) Skeels) seed

2019 ◽  
Vol 8 (1) ◽  
pp. 47
Author(s):  
Miraz Nur Indraeni ◽  
Faiza Chairani Suwarno ◽  
Abdul - Qadir
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Seed Quality ◽  
Block Design ◽  
Syzygium Cumini ◽  
Critical Moisture Content ◽  
Testing Method ◽  
Randomized Complete Block Design ◽  
Final Count ◽  
Critical Moisture

Jamblang (Syzygium cumini (L.) Skeels) researches are still focused to identify the plant benefits, but that leads to efforts to obtain good seed quality hasn’t been done. This study aims to determine the moisture content testing method, the critical moisture content, and germination testing method (sowing media and first and final count of seed germination). Improving procedure for moisture content testing and identified the best media for germination testing was arranged in a Completely Random Design.  Determining jamblang seeds critical moisture content was arranged in a Randomized Complete Block Design. The experiments were repeated four times. Moisture content with slicing method obtained 49.57%. Jamblang seeds critical water content is 41.61% with 50% germination. The best method of germination was sand medium with fresh seeds (90%). The first count of jamblang seed germination occurs on 32 days after sowing and final count on 83 days after sowing.

scholarly journals Risk of Moisture in Diffusionally Open Roofs with Cross-Laminated Timber for Northern Coastal Climates

Buildings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Agnieszka Sadłowska-Sałęga ◽  
Krzysztof Wąs
Keyword(s):  
Moisture Content ◽  
Indoor Air ◽  
Oriented Strand Board ◽  
Layer System ◽  
Critical Moisture Content ◽  
Cross Laminated Timber ◽  
Safe Level ◽  
Roof Structure ◽  
Calculation Results ◽  
Critical Moisture

The paper is an attempt to answer the question whether the material-optimized roof construction using cross-laminated timber (CLT) is safe in terms of moisture content in the demanding northern costal climates. The proposed roof structure meets the strength requirements. The partition is diffusionally open, which facilitates moisture transport. However, there is a concern whether the applied layer system allows maintaining a safe level of moisture content below critical moisture content (CMC), which has been set at 20%. The article presents the annual hygrothermal calculation of the proposed roof slope for four locations of northern Europe and Greenland characterized by costal or subpolar climate. Four scenarios of indoor air relative humidity were considered: free floating, RHmin = 40%RH, RHmin = 50%, RHmin = 60%. In all cases, the minimum indoor temperature was 20 °C. The analysis was carried out using WUFI®Plus software. The calculation results showed that the moisture content did not exceed 20% in the CLT layer at any of the described locations. However, for the two coldest climates the assumed level of safety has been exceeded in the roof oriented strand board (OSB) sheathing.

Drying Characteristics of Chlorella pyrenoidosa Using Oven and its Evaluation for Bio-Ethanol Production

2020 ◽  
Vol 1007 ◽  
pp. 1-5
Author(s):  
Megawati ◽  
Astrilia Damayanti ◽  
Radenrara Dewi Artanti Putri ◽  
Irene Nindita Pradnya ◽  
Habib Faisal Yahya ◽  
...  
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Dry Weight ◽  
Chlorella Pyrenoidosa ◽  
Carbohydrate Content ◽  
Drying Characteristics ◽  
Influence Of Temperature On ◽  
Critical Moisture ◽  
Higher Temperature ◽  
Water Contents

The objective of this research is to study the influence of temperature on drying and changes in carbohydrate composition during the drying. Chlorella pyrenoidosa was dried in oven at various temperatures and initial weight 2 g. The initial moisture content of Chlorella pyrenoidosa was 487.2% dry weight and the composition was hemicellulose (62.76), cellulose (2.39), and lignin (0.46% dry weight). Every 5 min, the moisture content was recorded. The critical moisture contents of Chlorella pyrenoidosa at 50, 60, and 70 °C are 7.2, 3.9, and 3.1% dry weight, respectively. Meanwhile, the equilibrium water contents are 0.53, 0.32, and 0.12% dry weight, respectively. The carbohydrate content in Chlorella pyrenoidosa cell as a result FTIR analysis indicates that the higher temperature of drying the carbohydrate content increases. Drying of Chlorella pyrenoidosa at temperatures of 50, 60, and 70 °C will decrease moisture content without disturb carbohydrate molecule, so the carbohydrate content increases. Therefore, drying of Chlorella pyrenoidosa before converting become bio-ethanol will give benefit to increase the carbohydrate content and initial rupturing of it’s cell.

Understanding wet tear strength at varying moisture content in handsheets

TAPPI Journal ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 29-35
Author(s):  
ADELE PANEK ◽  
JOEL PANEK ◽  
JAMES FAUGHT ◽  
PETER W. HART
Keyword(s):  
Moisture Content ◽  
Kraft Pulp ◽  
Transition Point ◽  
Maximum Point ◽  
Critical Moisture Content ◽  
Tear Strength ◽  
Moisture Content Level ◽  
Critical Moisture ◽  
Type Data ◽  
Pulp Production

A laboratory study was conducted looking at the effects of moisture content on wet tear strength in handsheets. Three different wetting techniques were used to generate the wet tear (Elmendorf-type) data at varying moisture levels, from TAPPI standard conditions (dry) to over 60% moisture content (saturated). Unbleached hard-wood and softwood fiber from full-scale kraft pulp production were used. The softwood fiber was refined using a Valley beater to reduce freeness. Handsheets were made with a blend of hardwood and softwood and with refined softwood, without the addition of wet-end chemistry. The resulting grams-force tear data obtained from the test was indexed with basis weight and plotted versus both moisture content and dryness. As moisture content levels in the handsheets increased, the wet tear strength also increased, reaching a critical maximum point. This marked a transition point on the graph where, beyond a critical moisture content level, the tear strength began to decline linearly as moisture increased. This pattern was repeated in handsheets made from a blend of hardwood and softwood and from 100% refined softwood.

scholarly journals Pendugaan Umur Simpan Benih Padi (Oryza sativa L) Menggunakan Metode ASLT (Accelerated Shelf Life Testing) dengan Pendekatan Model Kadar Air Kritis

2019 ◽  
Vol 7 (2) ◽  
pp. 228
Author(s):  
I Putu Mas Pradnyana Wibawa ◽  
Ida Bagus Putu Gunadnya ◽  
I Made Anom Sutrisna Wijaya
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Oryza Sativa L ◽  
Initial Moisture Content ◽  
Total Solid ◽  
Rice Seed ◽  
Life Testing ◽  
Critical Moisture Content ◽  
Critical Moisture ◽  
Rice Seeds

Tujuan dari dilakukanya penelitian Ini adalah untuk menduga umur simpan benih padi menggunakan metode ASLT (Accelerrated Shelf Life Testing) dengan pendekatan model kadar air kritis. Adapun benih yang digunakan adalah benih varietas Ciherang dan varietas Inpari 30. Kemasan dari benih padi adalah plastic jenis Polipropilen (PP). Benih padi disimpan pada kondisi lingkungan (suhu 290C dan RH 75%). Pengamatan benih dianggap kritis ketika persentase daya berkecambah di bawah 80%. Ditemukan dari hasil pengukuran bahwa nilai permeabilitas kemasan (k/x) dari plastic PP adalah 0,013 gH2O/m2.day.mmHg. Pengamtan kadar air awal (Ma) adalah 13 %, kadar air kritis (Mc) adalah 29 %, total padatanya (WS) adalah 8,8 kg, dan perbedaan tekanan (?P) 1,15 mmHg. Sementara Inpari 30 memiliki nilai kadar air awal (Ma) 14%, kadar air kritis 29%, total padatannya (WS) 8,7 kg, dan ?P 0,9 mmHg.  Dari nilai tersebut dapat diduga umur simpan dua varietas benih bersertifikat yang dikemas dalam plastik PP dan disimpan pada suhu 29oC dan RH 75% adalah 156 hari (5,03 bulan) untuk varietas Ciherang dan 254 hari (8,19 bulan)  untuk 30 varietas Inpari.   The purpose of this study was to prediction the shelf life of certified rice seeds using the ASLT (Accelerated Shelf Life Testing) method based on the critical moisture content approach. The varieties of rice seeds used in this research were Ciherang and Inpari 30 varieties which packed with polypropylene (PP) plastic packaging. The rice seeds packages were stored at environmental condition (temperature of 29oC and RH of 75%). Observation on seeds germination was done daily until the seeds have a germination percentage below 80%. When the seeds under this condition, moisture content of the seeds was measured and refer as critical moisture content. It was found that the packaging permeability (k/x) of PP plastic was 0.013 g H2O/m2.day.mmHg. Observation on rice seed of Ciherang variety revealed that its values of initial moisture content (Ma) was 0.133 %, its critical moisture content (Mc) was 0.291 %, its total solid (Ws) was 8.8 kg, and pressure difference  (?P) was 1,15 mmHg. While, for Invary 30 variety the values of its shelf life parameters were as follows: Ma 0.144 %, Mc 0.293 %, Ws 8.7 kg, and ?P 0.9 mmHg. The prediction of shelf life the two certified rice seeds which were packed in PP plastic and stored at 29oC and RH of 75% were 156 days (5.03 months) for Ciherang variety and 254 days (8.19 months). ) for Inpari 30 variety.

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