Application of agro and non-agro waste materials for unfired earth blocks construction: A review

The production process of conventional building materials consumes a high amount of energy which has a negative impact on the environment. The use of locally available materials and upgradation of traditional techniques can be a good option for sustainable development. Consequently, earth has attracted the attention of the researchers as a building construction material for its availability and lower environmental impact. On the other hand, in developing countries waste disposal from the agricultural and industrial sectors raises another serious concern. The scientists have introduced such waste additives into the earth matrix to improve its performance. Therefore, the present paper reviews the state-of-the-art of research on the effects of these various agro and non-agro wastes in the production of unfired earth blocks. This study is divided into three sections: The first section outlines the different types of waste materials and earth blocks considered in the selected papers. The second part deals in depth with the test results of the different properties (density, water absorption, compressive strength, flexural strength and thermal conductivity) of unfired earth blocks containing waste materials. The last section analyses and compares the results with the current earth-building construction standards. The literature survey presents that the waste materials have a clear potential to partly replace earth by complying with certain requirements. Moreover, the application of such wastes for the development of building construction materials provides a solution that decreases energy usage as well as contributes to effective waste management. Future research on establishing guidelines and standards for the development and production of these sustainable unfired earth building materials is recommended

Influence of Sawdust Particle Sizes on the Physico-Mechanical Properties of Unfired Clay Blocks

Sawdust, which is a waste/by-product of the wood/timber industry, can be utilised as a valuable raw material in building material production due to its abundance and low cost. However, the application of sawdust in the manufacture of unfired clay blocks has received little investigation. Furthermore, the impact of different sawdust particle sizes on the properties of unfired clay blocks has not been studied. Therefore, this study screened sawdust at three different particle sizes: SP-a (212 μm < x < 300 μm), SP-b (425 μm < x < 600 μm) and SP-c (1.18 mm < x < 2.00 mm), to examine their effects on the physical and mechanical properties of unfired clay blocks. The density, linear shrinkage, capillary water absorption and flexural and compressive strengths were among the tests performed. Different sawdust percentages, i.e., 2.5%, 5%, 7.5% and 10% of the total weight of the clay, were considered. The tests results show that when sawdust was added to the mixture, the density of the samples reduced for all particle sizes. However, the linear shrinkage increased in SP-a samples but decreased in the other two particle size samples as the sawdust percentage increased from 2.5% to 10%. On the other hand, the capillary water absorption coefficient increased while the strength decreased with increasing sawdust content for all three groups. The highest compressive strength (CS) and flexural strength (FS) were achieved at 2.5% of sawdust content. Furthermore, it was observed that SP-b (CS—4.74 MPa, FS—2.00 MPa) samples showed the highest strength followed by SP-a (CS—4.09 MPa, FS—1.69 MPa) and SP-c (CS—3.90 MPa, FS—1.63 MPa) samples. Consequently, good-quality unfired clay blocks can be manufactured using sawdust up to 2.5% with particle sizes ranging between 600 and 425 μm

The Prevalence of Cognitive Impairment Among Adults With Incident Heart Failure: The “Reasons for Geographic and Racial Differences in Stroke” (REGARDS) Study

Background Cognitive impairment (CI) is estimated to be present in 25%–80% of heart failure (HF) patients, but its prevalence at diagnosis is unclear. To improve our understanding of cognition in HF, we determined the prevalence of CI among adults with incident HF in the REGARDS study. Methods and Results REGARDS is a longitudinal cohort study of adults ≥45 years of age recruited in the years 2003–2007. Incident HF was expert adjudicated. Cognitive function was assessed with the Six-Item Screener. The prevalence of CI among those with incident HF was compared with the prevalence of CI among an age-, sex-, and race-matched cohort without HF. The 436 participants with incident HF had a mean age of 70.3 years (SD 8.9), 47% were female, and 39% were black. Old age, black race, female sex, less education, and anticoagulation use were associated with CI. The prevalence of CI among participants with incident HF (14.9% [95% CI 11.7%–18.6%]) was similar to the non-HF matched cohort (13.4% [11.6%–15.4%]; P < .43). Conclusions A total of 14.9% of the adults with incident HF had CI, suggesting that the majority of cognitive decline occurs after HF diagnosis. Increased awareness of CI among newly diagnosed patients and ways to mitigate it in the context of HF management are warranted

Environmental control methods against wild and domestic species of Muridae family: A review

Rat and mice are the major pests which cause a large number of common diseases between humans and animals. Several methods have been used to combat these pests. A new environmental control method of rat is presented for urban, rural and natural areas in Iran. The results showed that keeping the rat away and improving residential areas are two of the most effective and less costly methods to prevent the rat. Removing water and food supplies in all cases reduces the population and damage caused by rat. © 2018, Malhotra Publishing House

A narrative review of studies on diazinon removal and detoxification from polluted water with emphasis on electrochemical process

Diazinon can be the source of contamination in the environment. Therefore, the aim of this study was to compare the efficiency of the electrochemical process in reducing diazinon from aqueous media. Eighty eight sources (articles) were selected focusing on these studies in Iran. The electrochemical processes used in the removal of pesticides, and in particular of diazinon, have been used more than the rest of the methods, and the removal of these pollutants is high. Biological methods have been considered in the removal of these materials. The results showed that electrochemical processes have the potential for removal of pesticides, including diazinon. Electrochemical and biological methods both have the potential to eliminate pesticides, which according to the conditions and possibilities can be considered. © 2018, Malhotra Publishing House

HUMAN HEALTH AND TRENBOLONE RESIDUE IN BOVINE MEAT

In recent years, hormones and hormone-like compounds have been frequently used in vegetable and livestock production to obtain a high yield performance in a shorter period of time, but depending on the use of anabolics in animal feed, anabolic residues that may occur in meat and meat products would present the risks to the human health. The present study was undertaken to detect and quantify the levels of trenbolone residues (a potent synthetic analog of testosterone) in the market meat in Iran. Cattle meat samples were collected from the markets in Tehran. A total of 120 samples of cattle meat were analyzed for level of trenbolone by Enzyme-Linked Immunosorbant Assay method. The average experimental values of trenbolone in cattle meat were 3.76±5.26ng/kg. This value gave no evidence for the illegal use of hormones in Tehran, but these results do not exclude the possibility of misuse of these potentially harmful chemicals in future. There is, therefore, need to routinely monitor these chemicals as a food quality and health control measure

Determination of Total Antioxidant Capacity of Green Teas by the Ferric Reducing/Antioxidant Power Assay

Green tea is one of the important sources of bioactive compounds which have been used in folk medicinefor many centuries. This study aimed to compare in vitro antioxidant power of different types of green tea (Camellia sinensis   ). Antioxidant activity of methanolic (50%) extracts of five green tea samples wasinvestigated according to Ferric reducing ability power method. Total phenolic contents were analyzedusing a spectrophotometric technique, based on the Folin-ciocalteau reagent, and calculated as gallic acidequivalents per gram dry weight. Total flavonoid and antocyanidin were also investigated according toaluminum chloride and vanillin colorimetric assay respectively. Total antioxidant activity varied from0.554±0.042 in Avicen green tea sample to 3.082 ± 0.150 mmoL FeII /g in Chinas green tea and totalphenolic content ranged from the 0.030±0.001 in Avicen green tea sample to 0.196±0.012 g gallic acidper gram dry weight in Ahmad green tea. A linear positive relationship existed between the antioxidantactivity, total phenolic, flavonoid and antocyanidin content of the tested green tea samples. Green teasamples possess relatively high antioxidant activity due to contribution of phenolic compounds. Thepresent study showed that green tea samples which are more frequently consumed in Iran are strongradical scavengers and can be considered as good sources of natural antioxidants for medicinal andcommercial uses