scholarly journals Determining the effect of synthetic-based varnish and impregnation on wood’s shear strength under cold climate conditions

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3377-3390
Author(s):  
Şemsettin Doruk
Keyword(s):  
Shear Strength ◽  
Ambient Temperature ◽  
Climatic Conditions ◽  
Wood Products ◽  
Cold Climate ◽  
Wood Preservation ◽  
Water Repellent ◽  
Wood Preservatives ◽  
Climate Conditions ◽  
Parallel Direction

Glue shear strength and wood preservatives play an important role in the longevity of engineered wood products. The effects of factors such as UV rays, humidity, and temperature on wooden materials are known. However, it is not known what effects sub-zero temperatures have on wood material and how wood preservatives play a role. This study determined the effects of synthetic-based varnish and impregnation on shear strength in cold climatic conditions. Variables including glue type, ambient temperature, tree type, and process type were investigated. Wood laminate test samples were produced for this purpose, and water repellent impregnation material and synthetic-based varnish were used as wood preservatives. Experimental samples were kept in a cold air cabinet at (-15 °C) and (-30 °C) temperature for 90 days. Samples kept in different temperature conditions were subjected to a pull experiment in a parallel (//) direction to the fibers under static load. As the ambient temperature decreased, the shear strength decreased (-15 °C: 8,960 N/mm2 ,-30 °C: 8,025 N/mm2 ) . When the performance of wood preservation elements were examined, it was determined that the varnish process (8,875 N/mm2) and the impregnation process (8,691 N/mm2) were not statistically significant, at 12% and 10%, respectively.

scholarly journals Improving the strength of sandy soils via ureolytic CaCO<sub>3</sub> solidification by <i>Sporosarcina ureae</i>

2018 ◽  
Vol 15 (14) ◽  
pp. 4367-4380 ◽  
Author(s):  
Justin Michael Whitaker ◽  
Sai Vanapalli ◽  
Danielle Fortin
Keyword(s):  
Shear Strength ◽  
Acid Rain ◽  
Climatic Conditions ◽  
Carbonate Precipitation ◽  
Biogeochemical Process ◽  
Climate Conditions ◽  
Sporosarcina Ureae ◽  
Microbially Induced Carbonate Precipitation ◽  
Environmental Durability ◽  
Hydrolysis Of

Abstract. “Microbially induced carbonate precipitation” (MICP) is a biogeochemical process that can be applied to strengthen materials. The hydrolysis of urea by microbial catalysis to form carbonate is a commonly studied example of MICP. In this study, Sporosarcina ureae, a ureolytic organism, was compared to other ureolytic and non-ureolytic organisms of Bacillus and Sporosarcina genera in the assessment of its ability to produce carbonates by ureolytic MICP for ground reinforcement. It was found that S. ureae grew optimally in alkaline (pH ∼ 9.0) conditions which favoured MICP and could degrade urea (units U mL−1 represent µmol min−1 mL OD600) at levels (30.28 U mL−1) similar to S. pasteurii (32.76 U mL−1), the model ureolytic MICP organism. When cells of S. ureae were concentrated (OD600 ∼ 15–20) and mixed with cementation medium containing 0.5 M calcium chloride (CaCl2) and urea into a model sand, repeated treatments (3 × 24 h) were able to improve the confined direct shear strength of samples from 15.77 kPa to as much as 135.80 kPa. This was more than any other organism observed in the study. Imaging of the reinforced samples with scanning electron microscopy and energy-dispersive spectroscopy confirmed the successful precipitation of calcium carbonate (CaCO3) across sand particles by S. ureae. Treated samples were also tested experimentally according to model North American climatic conditions to understand the environmental durability of MICP. No statistically significant (p < 0.05, n= 3) difference in strength was observed for samples that underwent freeze–thaw cycling or flood-like simulations. However, shear strength of samples following acid rain simulations fell to 29.2 % of control MICP samples. Overall, the species S. ureae was found to be an excellent organism for MICP by ureolysis to achieve ground strengthening. However, the feasibility of MICP as a durable reinforcement technique is limited by specific climate conditions (i.e. acid rain).

scholarly journals Validation of Thermal Models for Polycrystalline Photovoltaic Module Under Derna City Climate Conditions

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Mahmood Abdel hadi ◽  
Yasser Aldali ◽  
Ali N Celik
Keyword(s):  
Ambient Temperature ◽  
Linear Models ◽  
Theoretical Models ◽  
Climatic Conditions ◽  
Solar Irradiation ◽  
Photovoltaic Module ◽  
Cell Temperature ◽  
Climate Conditions ◽  
Quantitative Indicators ◽  
Temperature Correlations

The main objective of the present paper is to compare nine different cell temperature models available in the literature with data measured under real Derna city climatic conditions (a semi arid climate) for month of August. The study focuses on a comparison of nine theoretical models to calculate the cell temperature based on the experimental measurements such as the ambient temperature, irradiance, and wind speed in some of the models. The presently used models are explicit, depending on the easily measurable parameters and of wide applicability. Six statistical quantitative indicators are used to evaluate the cell temperature models analysed, namely, R2, RMSE, RRMSE, MAE, MBE and MARE. The cell temperature correlations presently studied, first order linear models depending on the ambient temperature, solar irradiation incident on the panel and voltage output, provide the most accurate cell temperature estimations at Derna city climatic conditions.

Ecological specificities of the interaction between animal breeding and climate changes, caused by greenhouse gas emissions

2017 ◽  
Vol 4 (3) ◽  
pp. 62-72
Author(s):  
O. Zhukorsky ◽  
O. Nykyforuk ◽  
N. Boltyk
Keyword(s):  
Greenhouse Gases ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Climatic Conditions ◽  
Animal Breeding ◽  
Gas Emissions ◽  
Climate Conditions ◽  
Emissions Inventory ◽  
Theoretical Substantiation ◽  
Global Problems

Aim. Proper development of animal breeding in the conditions of current global problems and the decrease of anthropogenic burden on environment due to greenhouse gas emissions, caused by animal breeding activity, require the study of interaction processes between animal breeding and external climatic conditions. Methods. The theoretical substantiation of the problem was performed based on scientifi c literature, statistical informa- tion of the UN Food and Agriculture Organization and the data of the National greenhouse gas emissions inventory in Ukraine. Theoretically possible emissions of greenhouse gases into atmosphere due to animal breeding in Ukraine and specifi c farms are calculated by the international methods using the statistical infor- mation about animal breeding in Ukraine and the economic-technological information of the activity of the investigated farms. Results. The interaction between the animal breeding production and weather-and-climate conditions of environment was analyzed. Possible vectors of activity for the industry, which promote global warming and negative processes, related to it, were determined. The main factors, affecting the formation of greenhouse gases from the activity of enterprises, aimed at animal breeding production, were characterized. Literature data, statistical data and calculations were used to analyze the role of animal breeding in the green- house gas emissions in global and national framework as well as at the level of specifi c farms with the consid- eration of individual specifi cities of these farms. Conclusions. Current global problems require clear balance between constant development of sustainable animal breeding and the decrease of the carbon footprint due to the activity of animal breeding.

PERSIAN GARDENS IN COLD AND DRY CLIMATE: A CASE STUDY OF TABRIZ’S HISTORICAL GARDENS

2016 ◽  
Vol 10 (3) ◽  
pp. 193
Author(s):  
Ahad Nejad Ebrahimi ◽  
Farnaz Nazarzadeh ◽  
Elnaz Nazarzadeh
Keyword(s):  
Comparative Study ◽  
Water Supply ◽  
Field Study ◽  
Cold Climate ◽  
Natural Substrate ◽  
Garden Design ◽  
Climate Conditions ◽  
North West ◽  
Special Expertise

Throughout history, gardens and garden designing has been in the attention of Persian architects who had special expertise in the construction of gardens. The appearance of Islam and allegories of paradise taken from that in Koran and Saints’ sayings gave spirituality to garden construction. Climate conditions have also had an important role in this respect but little research has been done about it and most of the investigations have referred to spiritual aspects and forms of garden. The cold and dry climate that has enveloped parts of West and North West of Iran has many gardens with different forms and functions, which have not been paid much attention to by studies done so far. The aim of this paper is to identify the features and specifications of cold and dry climate gardens with an emphasis on Tabriz’s Gardens.  Due to its natural and strategic situation, Tabriz has always been in the attention of governments throughout history; travellers and tourists have mentioned Tabriz as a city that has beautiful gardens. But, the earthquakes and wars have left no remains of those beautiful gardens. This investigation, by a comparative study of the climates in Iran and the effect of those climates on the formation of gardens and garden design, tries to identify the features and characteristics of gardens in cold and dry climate. The method of study is interpretive-historical on the basis of written documents and historic features and field study of existing gardens in this climate. The results show that, with respect to natural substrate, vegetation, the form of water supply, and the general form of the garden; gardens in dry and cold climate are different from gardens in other climates.

scholarly journals Relationship between Relative Maturity and Grain Yield of Maize (Zea mays L.) Hybrids in Northwest New Mexico for the 2003–2019 Period

Agriculture ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 290
Author(s):  
Koffi Djaman ◽  
Curtis Owen ◽  
Margaret M. West ◽  
Samuel Allen ◽  
Komlan Koudahe ◽  
...  
Keyword(s):  
New Mexico ◽  
Grain Yield ◽  
Sprinkler Irrigation ◽  
Growing Season ◽  
Climatic Conditions ◽  
Agricultural Science ◽  
Production Optimization ◽  
Science Center ◽  
Early Season ◽  
Climate Conditions

The highly variable weather under changing climate conditions affects the establishment and the cutoff of crop growing season and exposes crops to failure if producers choose non-adapted relative maturity that matches the characteristics of the crop growing season. This study aimed to determine the relationship between maize hybrid relative maturity and the grain yield and determine the relative maturity range that will sustain maize production in northwest New Mexico (NM). Different relative maturity maize hybrids were grown at the Agricultural Science Center at Farmington ((Latitude 36.69° North, Longitude 108.31° West, elevation 1720 m) from 2003 to 2019 under sprinkler irrigation. A total of 343 hybrids were grouped as early and full season hybrids according to their relative maturity that ranged from 93 to 119 and 64 hybrids with unknown relative maturity. The crops were grown under optimal management condition with no stress of any kind. The results showed non-significant increase in grain yield in early season hybrids and non-significant decrease in grain yield with relative maturity in full season hybrids. The relative maturity range of 100–110 obtained reasonable high grain yields and could be considered under the northwestern New Mexico climatic conditions. However, more research should target the evaluation of different planting date coupled with plant population density to determine the planting window for the early season and full season hybrids for the production optimization and sustainability.

A review on life cycle assessments of thermally modified wood

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kévin Candelier ◽  
Janka Dibdiakova
Keyword(s):  
Life Cycle ◽  
Environmental Impacts ◽  
Treated Wood ◽  
Single Step ◽  
Thermal Modification ◽  
Wood Products ◽  
Wood Preservation ◽  
Cumulative Energy ◽  
Thermally Modified Wood ◽  
Cumulative Energy Intake

AbstractThis review compiles various literature studies on the environmental impacts associated with the processes of thermal modification of wood. In wood preservation field, the wood modification by heat is considered as an ecofriendly process due to the absence of any additional chemicals. However, it is challenging to find proper scientific and industrial data that support this aspect. There are still very few complete studies on the life cycle assessment (LCA) and even less studies on the environmental impacts related to wood heat treatment processes whether on a laboratory or on an industrial scales. This comprehensive review on environmental impact assessment emphasizes environmental categories such as dwindling of natural resources, cumulative energy intake, gaseous, solid and liquid emissions occurred by the thermal-treated wood industry. All literature-based data were collected for every single step of the process of wood thermal modification like resources, treatment process, transport and distribution, uses and end of life of treated wood products.

scholarly journals Stochastic Simulation of Mould Growth Performance of Wood-Frame Building Envelopes under Climate Change: Risk Assessment and Error Estimation

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 333
Author(s):  
Lin Wang ◽  
Maurice Defo ◽  
Zhe Xiao ◽  
Hua Ge ◽  
Michael A. Lacasse
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Error Estimation ◽  
Ventilation Rate ◽  
Climatic Conditions ◽  
Cold Climate ◽  
Mould Growth ◽  
Frame Building ◽  
Wood Frame ◽  
Water Tightness

Previous studies have shown that the effects of climate change on building structures will increase the mould growth risk of the wood-frame building envelope in many circumstances. This risk can be controlled by wind-driven rain deflection, improving water tightness of the exterior facade, and improving cladding ventilation. However, the effectiveness of these risk mitigation strategies are subject to various uncertainties, such as the uncertainties of wall component properties and micro-climatic conditions. The objective of this paper is to apply stochastic hygrothermal simulation to evaluate the mould growth risk of a brick veneer-clad wood-frame wall with a drainage cavity under historical and future climatic conditions of Ottawa, a Canadian city located in a cold climate zone. An extensive literature review was conducted to quantify the range of stochastic variables including rain deposition factor, rain leakage moisture source, cladding ventilation rate and material properties of brick. The randomised Sobol sequence-based sampling method, one of the Randomized Quasi-Monte Carlo (RQMC) methods, was applied for risk assessment and error estimation. It was found that, under the climatic condition of Ottawa, limiting the amount of wind-driven rain to which walls are subjected is a more robust mitigation measure than improving cladding ventilation in controlling mould growth risk, the improving of water tightness of exterior façade is not as robust as wind-driven rain deflection and cladding ventilation, however, the reduction of rainwater penetration can reduce the mould growth risk at different levels of rain deposition factor and cladding ventilation rate.

Catchment-scale evaluation of pollution potential of urban snow at two residential catchments in southern Finland

2013 ◽  
Vol 68 (10) ◽  
pp. 2164-2170 ◽  
Author(s):  
Nora Sillanpää ◽  
Harri Koivusalo
Keyword(s):  
Snow Water Equivalent ◽  
Hydrological Cycle ◽  
Cold Climate ◽  
Road Maintenance ◽  
Catchment Scale ◽  
Small Surface ◽  
Climate Conditions ◽  
Snow Water ◽  
High Level ◽  
Mass Loads

Despite the crucial role of snow in the hydrological cycle in cold climate conditions, monitoring studies of urban snow quality often lack discussions about the relevance of snow in the catchment-scale runoff management. In this study, measurements of snow quality were conducted at two residential catchments in Espoo, Finland, simultaneously with continuous runoff measurements. The results of the snow quality were used to produce catchment-scale estimates of areal snow mass loads (SML). Based on the results, urbanization reduced areal snow water equivalent but increased pollutant accumulation in snow: SMLs in a medium-density residential catchment were two- to four-fold higher in comparison with a low-density residential catchment. The main sources of pollutants were related to vehicular traffic and road maintenance, but also pet excrement increased concentrations to a high level. Ploughed snow can contain 50% of the areal pollutant mass stored in snow despite its small surface area within a catchment.

scholarly journals The Potential of Solar Air Heating in the Turkish Industrial Sector

2018 ◽  
Vol 63 (1) ◽  
pp. 57-66
Author(s):  
Balázs Bokor ◽  
Hacer Akhan ◽  
Dogan Eryener ◽  
László Kajtár
Keyword(s):  
Solar Radiation ◽  
Energy Savings ◽  
Measurement Data ◽  
Industrial Sector ◽  
Climatic Conditions ◽  
Cold Climate ◽  
Conventional Heating ◽  
Industrial Building ◽  
High Solar Radiation ◽  
Mathematical Correlation

Transpired solar collector (TSC) systems are simple solutions for the preheating of ventilation air with solar energy. Their performance is a function of several environmental factors, so the climatic conditions of the location play an important role. In this paper, the effect of different climatic zones on the thermal performance of the TSC is investigated. To exclude other sources of influence, the same reference industrial building is examined in four Turkish locations (Antalya, Istanbul, Ankara and Sivas) representing different climatic conditions. RETScreen simulation is carried out for all four regions to obtain the drop of conventional heating requirement in case absorber azimuth of 0°, 45° and 90°. To illustrate the performance, temperature rise, heating energy savings and annual solar fraction are presented. Generally, it can be stated that a location with cold climate and high solar radiation at the same time benefits most from the use of a TSC system. A mathematical correlation has been found showing the solar fraction's dependence on solar radiation and heating degree days. Finally, simulation results have been compared to a set of measurement data from an industrial building's TSC system near Istanbul.

Sign in / Sign up

Export Citation Format

Share Document