IRANIAN JOURNAL OF LABORATORY KNOWLEDGE
Year:2022 | Volume:9 | Issue:4 (36)|Papers Count:7

Severe acute respiratory syndrome coronavirus 2, is the cause of the new Coronavirus 2019 disease, which has caused a severe pandemic that is unprecedented 21st century. The virus has triggered at least seven mutations in the last two years, leading to either an increase in pathogenicity or transmission. Including, Alpha, Beta, Gamma, Eta, Delta, Lambda, and the recent emergence of Omicron variants. Indicating, we have a long way to deal with the complete eradication of this disease. Several scientific evidence show that respiratory droplets and aerosols are the most common route for coronavirus transmission. Using face masks by all people is generally recommended as a simple and inexpensive solution to cut this outbreak as the virus can be transmitted by asymptomatic patient. Many governments and public health organizations around the world have promoted the use of face masks in public places and have made them mandatory, especially in situations where social distancing is not possible; However, the effectiveness of face mask remains a challenge. This paper considers the challenges from three viewpoints: the quality standards of different face masks and the basis of their filtration mechanisms, the quantitative methods available to determine mask integrity and efficiency in particle filtration, and finally disinfection methods for disposable masks that make possible their reuse.

Emerging Infectious Diseases Affecting Farmed Shrimp in farming countries. High-risk activities such as transporting broodstock, larvae and food from contaminated areas and upsetting the environment balance have been cited as causes of the emergence and spread of shrimp diseases. Having disease management programs in clean countries is very important in preventing the occurrence of these pathogens as well as timely diagnosis of the disease and proper treatment and prevention of its spread. Various methods have been reported for the diagnosis of diseases, including molecular methods, in situ hybridization method, dot blot hybridization, ELISA and pathobiology method.

One of the cultural rationales is the bone remains (animal or human) found by archaeologists at historical sites. Identifying and preserving them is very important to determine the identity and authenticity of an ethnic group, and identifying and recognizing their genetic characteristics is a key step in this direction. DNA from archaeological and paleontological remains makes it possible to go back in time and study the genetic relationships of extinct organisms with their contemporary families. This offers a new perspective on the evolution of organisms and their DNA sequences. Archaeological remains of ancient DNA should be examined in such a way that the results can be spoken with confidence [5]; The challenge now is to facilitate these processes so that they can be extracted from molecular biology laboratories and placed in the archaeological environment and in the hands of archaeologists. The study of ancient bones and skeletons is called ancient DNA, which is used in various fields, including zoology, botany, forensics, and anthropology and genealogy. This article will talk about the issues as well as what part of the cell is used in more detail. study of ancient DNA, given that the DNA of the nucleus has been destroyed and can not be extracted; Therefore, mitochondrial DNA is studied on a specific region.

Geotechnical and Strength parameters such as uniaxial compressive strength (UCS), modulus of deformation, cohesion and internal friction angle are the most important parameters for practical design as well as numerical modeling in rock mass. UCS as an index parameter is very important. This parameter can be estimated using direct and laboratory methods, which in many cases are expensive and time consuming. So far, various experimental models have been proposed to estimate rock compressive strength using different parameters, mainly for rocks in a particular area and there are many uncertainties for its use in other areas. Artificial neural network is a powerful tool used to create predictive models and studies have shown the superiority of this technique over classical statistical methods. The purpose of this paper is to estimate UCS of limestone rocks using elastic modulus, effective porosity, specific gravity, Poisson's ratio. In this paper, two models of multilayer neural network (MLP) and fuzzy logic adaptive system (ANFIS) are used to model UCS. Based on the results, both constructed networks have acceptable performance for estimating rock compressive strength and selecting the most accurate network based on the quantity and quality of the statistical population used. In this paper, the designed neural network performs somewhat better than the fuzzy logic network.

An estimation of the uncertainty of the determination is required as a part of method validation. The determination of the vicat softening temperature is affected by a large number of uncertainty sources originating from the different steps of the laboratory procedures applied and equipment of the measuring device. Many factors determine the accuracy and reliability of tests and / or calibrations performed on the device. in the present paper, for order to evaluate the validity and reliability of the results, the parameters of the test and machine uncertainties were studied. The apparatus consisting, heating equipment, indenting tip, weights, penetration-measuring device and temperature-measuring device were studied periodically with refrence equipment. The Uncertainty of components was calculated with uncertainty from resulting reproducibility. The maximum contribution uncertainty was related to reproducibility with 98. 989%, and the lowest value were related to weight and penetration measurement gauge with 0. 00028% and 0. 006%, respectively. The value of extended uncertainty at 95% confidence level with coverage coefficient K = 2 was as 0. 84 calculated.

Today, the study of surface properties has become widely used in industry and research, so many technologies are used to observe and study surface properties in a wide range of measurements (from millimeters to nanometers. One of the most important items in the study of surface properties is surface roughness. Surface roughness is a one of property of the material surface texture that is identified by comparing of its topography with an ideal smooth surface. A rough surface contains roughness, peaks, and Valleys that are very close to each other. There are several methods for measuring surface roughness that can be divided into contact and non-contact techniques. In the contact method, which is the basis of profillometrs stylus and scanning probe microscopes, the surface roughness is measured by moving a probe along the surface. Interferometry techniques and confocal microscopes are also common examples of non-contact roughness measuring devices. Of course, the type of surface and its physical properties also have a significant impact on choosing the right tool. In this article, some of common methods in roughness measuring and their principles are investigated and these techniques compared with the atomic force microscopy method.