A Novel Method for Calcium Carbonate Deposition in Wood That Increases Carbon Dioxide Concentration and Fire Resistance

In this study, a novel method for calcium carbonate deposition in wood that increases carbon dioxide concentration and fire resistance is proposed. The method promoted the mineralization of radiata pine wood microstructure with calcium carbonate by using a process consisting in the vacuum impregnation of wood with a calcium chloride aqueous solution and the subsequent sequential diffusion of gaseous ammonium and carbon dioxide. In the most favorable conditions, the method yielded a weight gain of about 20 wt.% due to mineralization, which implied the accumulation of 0.467 mmol·g−1 of carbon dioxide in the microstructure of wood. In addition, a weight gain of about 8% was sufficient to provide fire resistance to a level similar to that achieved by a commercially available fire-retardant treatment. The feasibility of retaining carbon dioxide directly inside the wood microstructure can be advantageous for developing wood products with enhanced environmental characteristics. This method can be a potential alternative for users seeking materials that could be effective at supporting a full sustainable development.

Hermetic Storage Technology for Food Grains: New Beginning of Organic and Safe Storage for Farmers and Consumers: A Review

The moisture content of grains, oxygen and carbon dioxide concentration in storage environment affects the storage life of food grains. The moisture content affects on storability of food grains severely, hence the storage structures must be provided with sufficient protection from moisture exchange between grain and atmosphere. The insect and pests grows very fast in presence of oxygen and moisture in the storage environment. The humid climate provides favorable conditions to moulds and insects to grow in most of the food grains and oilseeds. The grains exposed to these favorable environment further not useful for human consumptions. Many harmful chemicals like aflatoxins are formed in oilseeds and cereals. The emerging hermatic storage is highly effective technology to prevent the spoilage of grains without use of any harmful fumigants and chemicals, hence it is popularly known as organic storage technology. In this technology the flow of oxygen and water from external environment is fully controlled by impermeable, triple layer hermatic plastic bags.

Energy capture and carbon assimilation.

This chapter focuses on energy capture and carbon assimilation of fruit trees. It discusses the factors affecting photosynthesis and respiration, including temperature, carbon dioxide concentration, nutrient supply, water availability, oxygen, and carbohydrates.

A Sensitivity Analysis for Thermal Performance of Building Envelope Design Parameters

Sensitivity analysis is crucial in building energy assessments. It is used to determine the major variables influencing building thermal performance, using both observational research and energy simulation models. This study investigates the most influential envelope design parameters on the thermal performance of a typical residential building in Budapest, Hungary. Sensitivity analysis is used in conjunction with the IDA-Indoor and Climate Energy (IDA-ICE 4.8) simulation tool to assess the effects of 33 envelope design parameters for energy consumption and carbon dioxide concentrations. The input parameters include thickness, materials, density, specific heat and thermal conductivity of the basement, exterior floor, interior floor, exterior wall, interior wall, roof, ground slab, glazing type, and infiltration rate. The results show that exterior floor materials have the biggest impact on annual delivered energy for heating and cooling, whereas the density of all structural elements and thickness of the basement, exterior floors, interior floors, and walls have minimal effects on energy consumption. It is also shown that the impact of all investigated parameters is not sensitive to the carbon dioxide concentration in the building. The authors consider that the findings of the paper assist designers to assess the performance of existing buildings and more efficiently generating alternative solutions in the energetic retrofitting of existing and energy design of new residential buildings.

Numerical Model Development of the Air Temperature Variation in a Room Set on Fire for Different Ventilation Scenarios

Statistics show that most fires occur in civil residential buildings. Most casualties are due to the inhalation of hot air loaded with smoke, leading to intoxication with substances harmful to the human body. This research aimed to develop a CFD model that relates the operation of the sprinkler system to the operation of the ventilation system through the air temperature in a specific point close to the sprinkler position. A real-scale experiment was carried out, and a CDF model was developed. Several parameters of the CFD model (thermal conductivity of the experimental test room walls, numerical grid elements’ dimensions, burner heat release rate variation) were imposed to the model, so that the resulting entire time variation of the temperature next to the sprinkler location corresponds to the real measured variation. Two other experiments were used to validate the numerical model. Besides the air temperature, at this point, other essential parameters were determined in the entire experimental space: indoor air temperature, visibility, oxygen concentration, and carbon dioxide concentration. We found that if the ventilation rate increases, the indoor temperatures in that specific point decrease, and the sprinkler is activated later or, in some cases, it might never be activated. However, this conclusion is not valid for the entire analyzed space, as the ventilation system alongside the natural air movement imposes specific air speed and specific temperature distribution inside the analyzed space.

Carbon Dioxide Sensing with Langmuir–Blodgett Graphene Films

Graphene has become a material of choice for an increasing number of scientific and industrial applications. It has been used for gas sensing due to its favorable properties, such as a large specific surface area, as well as the sensitivity of its electrical parameters to adsorption processes occurring on its surface. Efforts are ongoing to produce graphene gas sensors by using methods that are compatible with scaling, simple deposition techniques on arbitrary substrates, and ease of use. In this paper, we demonstrate the fabrication of carbon dioxide gas sensors from Langmuir–Blodgett thin films of sulfonated polyaniline-functionalized graphene that was obtained by using electrochemical exfoliation. The sensor was tested within the highly relevant concentration range of 150 to 10,000 ppm and 0% to 100% at room temperature (15 to 35 °C). The results show that the sensor has both high sensitivity to low analyte concentrations and high dynamic range. The sensor response times are approximately 15 s. The fabrication method is simple, scalable, and compatible with arbitrary substrates, which makes it potentially interesting for many practical applications. The sensor is used for real-time carbon dioxide concentration monitoring based on a theoretical model matched to our experimental data. The sensor performance was unchanged over a period of several months.

The Effects of Carbon Dioxide Concentration on Residents in the Area of a Cement Plant in Perak, Malaysia

Nowadays, concrete is used extensively in construction. The cement factory must generate massive amounts of cement each year in order to deliver enough concrete. Carbon dioxide emitted during the cement manufacturing and raw materials transportation processes contributes to air pollution and greenhouse gas emissions, deteriorating air and water quality and posing health risks to residents. Hence, the purpose of this research is to investigate the effects of carbon dioxide absorption on local residents and their buildings. Therefore, the objectives of this paper are to determine the influence of carbon dioxide absorption on local residents’ health as well as the consequences on structures. A total of 375 questionnaires were distributed throughout the Perak cities of Kampar, Malim Nawar, and Kota Bharu. This research were conducted in Malaysia in 2019. It was decided to adopt convenience sampling. This paper’s findings are separated into two (2) sections: effects on local residents’ health, structures, and environment. According to the Pearson Correlation data, there are several dead cases, as well as locals suffering from cancer and other respiratory problems. The concrete, timber, and metal frames, as well as other faults on the door and windows, have all deteriorated significantly. To preserve human health and the environment, the government should tighten the rule on pollution discharge compliance, and all plant owners should be accountable for building a buffer zone and installing industrial air filters surrounding their factories.

Estimates of Late Albian atmospheric CO2 based on stomata of Pseudofrenelopsis from Jilin Province, Northeast China

Stomata characteristics of two extinct conifer Cheirolepidiaceae species, Pseudofrenelopsis gansuensis and Pseudofrenelopsis dalatzensis were used to reconstruct the atmospheric carbon dioxide concentration levels during the late Albian of Cretaceous. A sequence of fossil samples was collected from 5 beds in the Dalazi Formation in Zhixin and Luozigou basins of Jilin Province, northeastern China. The stomatal index was used to estimate the palaeo-pCO2. The average stomatal index value of the two species was 4.1 and the atmospheric CO2 content was ∼1200 ppmv by the average of Recent standardization and Carboniferous standardization. During the short interval of 104.8±0.5 Ma to 104.0±0.4 Ma in the late Albian, the atmospheric CO2 contents present a deceasing tendency, and the highest value was ∼1300 ppmv in the Luozigou Basin. In addition, the higher atmospheric CO2 values of late Albian likely linked to a “greenhouse climate” time of Oceanic anoxic event 1c (OAE1c).