scholarly journals In Situ Monitoring of Drying Process of Masonry Walls

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6190
Author(s):  
Łukasz Cieślikiewicz ◽  
Piotr Łapka ◽  
Radosław Mirowski
Keyword(s):  
Energy Consumption ◽  
Moisture Content ◽  
Thermal Behavior ◽  
Specific Energy Consumption ◽  
Masonry Wall ◽  
In Situ Monitoring ◽  
Drying Process ◽  
Final State ◽  
The Mean

The in situ hygro-thermal behavior of a wet masonry wall during its drying process is presented in this paper. The considered wall is a part of a basement of a historic building that was subjected to renovation works. The building is located in the City of Łowicz (Poland). The drying process was implemented by applying the thermo-injection method and a novel prototype of the drying device used for this method. The dedicated acquisition system was developed to in situ monitor parameters of the drying process. The air temperature and relative humidity in various locations in the basement, temperatures and moisture contents at several points of the wet wall as well as the electrical parameters of the drying device were registered. Based on variations of the monitored parameters, the hygro-thermal behavior of the wall during drying was studied. After 6 days of drying, the wall temperature in the drying zone was increased to approximately 40–55 °C, while the moisture content was reduced to the mean level of 3.76% vol. (2.35% wt.). These wall parameters allowed for effective impregnation of the wall with the hydrophobic silicone micro-emulsion, which created horizontal and vertical waterproofing. Moreover, the specific energy consumption during the drying process defined as energy consumption divided by the mean volumetric moisture content drop (MC) between the initial and final state in the wall and by the length of the dried wall section was estimated to be 11.08 kWh/MC%/m.

scholarly journals Efficiency Comparison between Two Masonry Wall Drying Devices Using In Situ Data Measurements

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7137
Author(s):  
Piotr Łapka ◽  
Łukasz Cieślikiewicz
Keyword(s):  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy Consumption ◽  
Masonry Wall ◽  
The Novel ◽  
In Situ Data ◽  
Content Change ◽  
In Situ Investigation ◽  
Efficiency Comparison

In this paper, an in situ investigation and comparison of energy consumption and efficiency of two devices for implementation of the thermo-injection masonry wall drying method are presented. The following drying devices were considered: the currently used device (CUD) and the novel prototype device (NPD) with optimized control of the operating parameters. The historic building subjected to the drying and renovation was located in the city of Łowicz (Poland). The temperature and relative humidity of the air in several points in the basement and the temperature and moisture content at various locations in the considered masonry wall segments, as well as the electrical parameters for both devices, were measured in the real time and registered by applying a dedicated data acquisition system. The specific energy consumption during drying, defined as the energy consumption divided by the length of the drying wall section and by the mean volumetric moisture content change in the wall, was equal to 16.58 and 10.44 kWh/m/moisture content vol.% for the CUD and NPD, respectively. Moreover, the moisture content in the wall decreased by an average of 2.13 and 3.22 vol.% for the CUD and NPD, respectively, while the temperature of the wall surface in the drying zone was increased to approximately 35–40 °C and 40–65 °C for the CUD and NPD, respectively. The obtained results showed that the NPD was much more efficient than the CUD and that the building renovation process may be more environmentally friendly by applying more efficient drying devices and strategies.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

IN SITU MONITORING OF MEAN BLOOD OXYGEN SATURATION USING EXTENDED MODIFIED LAMBERT BEER MODEL

2015 ◽  
Vol 27 (01) ◽  
pp. 1550004 ◽  
Author(s):  
Audrey K. C. Huong ◽  
Xavier T. I. Ngu
Keyword(s):  
Oxygen Saturation ◽  
In Situ Monitoring ◽  
Blood Oxygen ◽  
Optical Monitoring ◽  
Hypertension Status ◽  
Blood Oxygen Saturation ◽  
Fitting Procedure ◽  
Arterial Blood ◽  
The Mean

We present the use of Extended Modified Lambert–Beer model for optical monitoring of mean blood oxygen saturation ( S m O 2) via a fitting procedure. This work focuses on the absorption characteristics of hemoglobin derivatives in the wavelength range of 520–600 nm to give the best estimates of S m O 2. The study of the feasibility of applying this analytic method to skin oximetry is via spectroscopy data collected from fingertips of four healthy volunteers both at rest and during arterial blood occlusion condition. The results revealed a decrease in the mean of mean and standard deviation of S m O 2 value of fingertips from 94.5 ± 2.19% when volunteers were at rest to 56.76 ± 5.8% during the arterial blood occlusion measurement. The larger variation in the value estimated for blood occlusion condition could be a result of differences in volunteers' physical fitness and hypertension status. These estimated S m O 2 values agreed reasonably well with the value reported in most of the previous studies. This work concluded that the proposed technique can potentially be used as a complementary technique to clinical assessment of skin grafts and burnt skin.

scholarly journals The prediction model of moisture content’s stabilization during tobacco strip drying process

2018 ◽  
Author(s):  
Mingjian Zhang ◽  
Feng Huang ◽  
Qing Chen ◽  
Le Wang ◽  
Haisheng Wang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Probability Distributions ◽  
Chemical Properties ◽  
Mean Value ◽  
Drying Process ◽  
Variance Model ◽  
Initial Stage ◽  
The Mean ◽  
Agriculture Products ◽  
Physical And Chemical

A mathematical model was established to predict the mean value and variance of tobacco strip during drying processing, based that the physical and chemical properties of tobacco strip as agriculture products show probability distributions. The results show that the model can predict the mean value of moisture content at different times, and there is a certain deviation in predicting the variance of moisture content at initial stage of drying process. However, the prediction value of the variance of tobacco strip is much more accurate while the moisture content is between 8% and 10%, which is the interval of quality requirements.Keywords: tobacco strip; drying; mean value;variance model.  

Exergy and Energy Analysis, Drying Kinetics and Mathematical Modeling of White Mulberry Drying Process

2014 ◽  
Vol 10 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Hosain Darvishi ◽  
Mohammad Zarein ◽  
Saied Minaei ◽  
Hamid Khafajeh
Keyword(s):  
Mathematical Modeling ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Microwave Power ◽  
Specific Energy Consumption ◽  
Drying Kinetics ◽  
Improvement Potential ◽  
White Mulberry

Abstract The energy and exergy analysis, drying characteristics and mathematical modeling of the thin-layer drying kinetics of white mulberry using microwave drying were investigated. Results indicated that values of exergy efficiency (33.63–57.08%) were higher than energy efficiency (31.85–55.56%). Specific energy consumption increased with increasing microwave power while improvement potential decreased. The specific energy consumption and improvement potential varied from 3.97 to 6.73 MJ/kg water and 0.71 to 2.97 MJ/kg water, respectively. Also, energy efficiency decreased with decrease in moisture content and microwave power level. The best exergy and energy aspect was obtained by drying at 100 W microwave power. Drying took place mainly in warming up, constant rate and falling rate periods. The Page model showed the best fit to experimental drying data. Effective diffusivity increased with decreasing moisture content and increasing microwave power. It varied from 1.06 × 10−8 to 3.45 × 10−8 m2/s, with an energy activation of 3.986 W/g.

Compression characteristics and the influencing factors of sweet sorghum straw: Experimental study

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9429-9443
Author(s):  
Xiaoxue Du ◽  
Hanping Mao ◽  
Chunguang Wang
Keyword(s):  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Sweet Sorghum ◽  
Specific Energy Consumption ◽  
Test Scheme ◽  
Compression Process ◽  
Cutting Length ◽  
Compression Characteristics ◽  
Sorghum Straw

The rheological properties of the compression process of sweet sorghum straw were studied. The selected experimental factors comprised of the compression density, cutting length, compression speed, and moisture content, and specific energy consumption were selected as the evaluation index of the compression characteristics. The Box-Behnken test scheme was used to analyze the response surface test. The results showed that the selected compression model and specific energy consumption model of the sweet sorghum straw compression process were obtained. The primary factors contributing to energy consumption were the cutting length, moisture content, and compression density. The optimal parameters were as follows: a compression density of 500 kg/m3, a cutting length of 20 mm to 30 mm, a moisture content of 60.06%, and a specific energy consumption of 66 kJ/kg. The results provided methods for reducing the total energy consumption of the compression process and a theoretical basis for the compression and bundling of sweet sorghum.

scholarly journals Desain dan Uji Kinerja Alat pengering Hybrid Dengan Efek Cerobong Tipe Tumpukan untuk Pengeringan Biji Kopi Arabika

2020 ◽  
Vol 7 (3) ◽  
pp. 163-170
Author(s):  
Irwansyah Irwansyah ◽  
Leopold Oscar Nelwan ◽  
Dyah Wulandani
Keyword(s):  
Water Vapor ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
The Sun ◽  
Drying Method ◽  
Arabica Coffee ◽  
Coffee Beans ◽  
Chimney Effect

Artificial drying method for arabica coffee beans requires a large consumption of electrical energy. Electricity is needed to rotate the blower which functions to circulate hot air to the dryer so that it can evaporate some of the water contained in the coffee beans. Most of the arabica coffee producing areas in Aceh province have not been reached by the electricity network so the use of artificial dryers cannot be used. To overcome this obstacle, the air flow circulation system with chimney effect can be used to drain dry air. The aim of this research is to design a chimney effect hybrid dryer which is heat source from solar and biomass energy, to test the performance of the dryer and compare it with the sun drying method. Parameters observed were temperature, moisture content and specific energy consumption of solar radiation and biomass. Dryer capacity is 5 kg of arabica coffee beans. The results showed that the chimney effect hybrid dryer can be used to dry 5 kg of coffee beans. The drying show that drying temperature on the dryer chamber ranged between 37.3-60.9°C. To reduce the moisture content of coffee beans from 52.5 to 12.8% bb, it was take 16-17 hours, while the sun drying method takes up to 46 hours (6 days). The total specific energy consumption of hybrid dryer was 57.1 MJ/kg of water vapor, while the specific energy consumption of the drying method was 59.4 MJ/kg of water vapor.

scholarly journals CO2 Concentration and Occupants’ Symptoms in Naturally Ventilated Schools in Mediterranean Climate

Buildings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 197 ◽  
Author(s):  
Jesica Fernández-Agüera ◽  
Miguel Ángel Campano ◽  
Samuel Domínguez-Amarillo ◽  
Ignacio Acosta ◽  
Juan José Sendra
Keyword(s):  
Mediterranean Climate ◽  
Co2 Concentration ◽  
Building Envelope ◽  
In Situ Monitoring ◽  
Building Stock ◽  
Air Infiltration ◽  
The Mean ◽  
The Impact ◽  
Different Levels

A large part of the school building stock in Andalusia lacks ventilation facilities, so that the air renewal of the classrooms is achieved through the building envelope (air infiltration) or the opening of windows. This research analyses the airtightness of the classrooms in Andalusia and the evolution of CO2 concentration during school hours through in situ monitoring. Pressurization and depressurization tests were performed in 42 classrooms and CO2 concentration was measured in two different periods, winter and midseason, to study the impact of the different levels of aperture of windows. About 917 students (11–17 years of age) were surveyed on symptoms and effects on their health. The mean n50 values are about 7 h−1, whereas the average CO2 concentration values are about 1878 ppm, with 42% of the case studies displaying concentrations above 2000 ppm with windows closed.

Optimal Design for Rice Straw Briquetting Process Based on Experiments

2016 ◽  
Author(s):  
Yu Wang ◽  
Yu Sun ◽  
Kai Wu ◽  
Xianfei Xia
Keyword(s):  
Experimental Data ◽  
Energy Consumption ◽  
Moisture Content ◽  
Rice Straw ◽  
Lower Energy ◽  
Optimization Design ◽  
Specific Energy Consumption ◽  
Agricultural Crop ◽  
Technological Parameters ◽  
Test Platform

Ineffective utilization of agricultural crop straw is a big problem in agricultural developing countries. In this study, optimization design was carried out for the rice straw briquetting process based on experiments. A briquetting test platform designed by the authors was used to measure the specific energy consumption, extrusion pressure, as well as the density and compressive strength of the products made by rice straw under different technological parameters. These parameters included moisture content, temperature, pressure and pressing speed. Finally, optimal technological parameters were provided based on the experimental data. Results show that, lower energy consumption and better products quality are achieved when the moisture content is within 15% ∼ 20%, the temperature is within 110 °C ∼ 120 °C, the pressure is within 50 MPa ∼ 60 MPa and the pressing speed is within 40 mm/min ∼ 60 mm/min.

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