Dual Soil Decontamination Procedures

Pollutants actually existing in various types of soil, ranging from rural, agricultural soils to urban or factory soils, belong to a wide range of chemical compounds, both organic and inorganic. The modern decontamination methods were each specifically designed for a particular pollutant. Reagents and procedure conditions targeted only one particular contaminant, more rarely several pollutants, all usually belonging to the same family (e.g., several heavy metals or polychloro-p-dibenzodioxins and polychloro-p-dibenzofurans). Most reviews on the subject presented soil decontamination processes under the same auspices: specific process with specific reagent for a specific pollutant. Unfortunately, soils are often cross-contaminated with various types of pollutants, which make the decontamination procedure much more complicated: indeed, for each contaminant, a certain procedure must be carried out. This transforms the whole decontamination process in a multi-step procedure, enhancing the costs. Therefore, any method that could realize a simultaneous decontamination for at least two different types of pollutants would be extremely advantageous. In the recent years, such methods made an interesting appearance in the environmental science and engineering literature. We wish to review these dual decontamination methodologies that deal simultaneously with at least one organic and one inorganic contaminant in the same soil matrix

Decompositions of matrices by using commutators

We will use commutators to provide decompositions of $3\times 3$ matrices as sums whose terms satisfy some polynomial identities, and we apply them to bounded linear operators and endomorphisms of free modules of infinite rank. In particular it is proved that every bounded operator of an infinite dimensional complex Hilbert space is a sum of four automorphisms of order $3$ and that every simple ring that is obtained as a quotient of the endomorphism ring of an infinitely dimensional vector space modulo its maximal ideal is a sum of three nilpotent subrings

Mechanistic Considerations on the Hydrodechlorination Process of Polychloroarenes

Defunctionalization of organochlorines through reductive dechlorination (also known as hydrodechlorination—replacement of chlorine atoms by hydrogen—is one of the main methodologies used in the detoxification of these harmful compounds. Most of the published papers on this particular matter focused on specific reagents, reaction conditions, and mainly result efficiency. Some of the authors were also concerned with reaction pathways (e.g., the order in which chlorine atoms were removed from a polychlorinated aromatic substrate—polychlorinated biphenyls, PCBs; polychlorinated dibenzo-p-dioxins, PCDDs; or polychlorinated dibenzofurans, PCDFs). However, the papers that dealt with the investigation of reaction mechanism were rather scarce. This chapter presents the advances made by researchers in understanding, from a mechanistic point of view, the hydrodechlorination process, along with our own assumptions. In doing so, it would be easier to predict the behavior of such compounds in a specific environment, showing more clearly the scope and limitations of each process, depending on the reaction conditions and reagents

STUDIES AND RESEARCHES ON DESIGNING AND CONSTRUCTING A MECHANICAL MACHINE FOR MEAT TENDERIZATION WITH PNEUMATIC ACTION AND POSSIBILITIES FOR AUTOMATION

Within meat processing technology the tenderization operation is important in the rapid maturation technique. Among tenderization methods, the least studied, yet with full ecological, biological and economical advantages is the mechanical tenderization. In this paper is presented an experimental model of machine of our own conception for the optimization of the tenderization process of the meat used for preparing traditionally products. Beside this the present paper presents the adequate system of pneumatic action and the automation elements of the working parameters which were made as our own conception for construction a machine for meat tenderization. Within the elaborated pneumatic scheme of driving there are identified the elements that can be electrically driven and the basis established scheme includes the programmable controller of the process. This allows the presenting of the organization schemes for every phase within the working process of machine and, finally, the cyclic scheme of function in order to establish the specific solutions for different meat types

A survey on the security protocols employed by mobile messaging applications

Recently, there has been an increase in the popularity of messaging applications that use end-to-end encryption. Among them were Telegram (in October 2021 it has 550 million active users), Signal (in January 2022 it has over 50 million downloads in the Google Play Store), WhatsApp (according to Statista, in 2021 it has over 2 billion active users), Wire (until January 2022 it has been downloaded for over 1 million times on Android devices). Two distinct protocols underlying these applications are noted: MTProto (developed in Russia by Nikolai Durov) and Signal (developed in the US by Moxie Marlinspike). This paper presents the two protocols and examines from the point of view of the primitive cryptographic security used and how the authenticated encryption, key derivation and asynchronous messaging are performed

Conductance model for single-crystalline/compact metal oxide gas-sensing layers in the nondegenerate limit: Example of epitaxial SnO2(101)

Semiconducting metal oxide (SMOX)-based gas sensors are indispensable for safety and health applications, for example, explosive, toxic gas alarms, controls for intake into car cabins, and monitor for industrial processes. In the past, the sensor community has been studying polycrystalline materials as sensors where the porous and random microstructure of the SMOX does not allow a separation of the phenomena involved in the sensing process. This led to conduction models that can model and predict the behavior of the overall response, but they were not capable of giving fundamental information regarding the basic mechanisms taking place. The study of epitaxial layers is a definite improvement, allowing clarifying the different aspects and contributions of the sensing mechanisms. A detailed analytical model of the transduction function for n-A nd p-type single-crystalline/compact metal oxide gas sensors was developed that directly relates the conductance of the sample with changes in the surface electrostatic potential. Combined dc resistance and work function measurements were used in a compact SnO2(101) layer in operando conditions that allowed us to check the validity of our model in the region where Boltzmann approximation holds to determine the surface and bulk properties of the material.Fil: Simion, Cristian Eugen. Institut de Physique Des Matériaux, Bucarest-magurele; RumaniaFil: Schipani, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Papadogianni, Alexandra. Paul Drude Institut Fur Festkorperelektronik; AlemaniaFil: Stanoiu, Adelina. Institut de Physique Des Matériaux, Bucarest-magurele; RumaniaFil: Budde, Melanie. Paul Drude Institut Fur Festkorperelektronik; AlemaniaFil: Oprea, Alexandru. Universität Tübingen; AlemaniaFil: Weimar, Udo. Universität Tübingen; AlemaniaFil: Bierwagen, Oliver. Paul Drude Institut Fur Festkorperelektronik; AlemaniaFil: Barsan, Nicolae. Universität Tübingen; Alemani

TOR - Didactic pluggable transport

Considering that access to information is one of the most important aspects of modern society, the actions of certain governments or internet providers to control or, even worse, deny access for their citizens/users to selected data sources has lead to the implementation of new communication protocols. TOR is such a protocol, in which the path between the original source and destination is randomly generated using a network of globally connected routers and, by doing so, the client is not identified as actually accessing the resource. However, if the ISP knows that the first hop is part of TOR or if it can identify the contents of the exchanged packages as being TOR packages, by using advanced detection algorithms, it can still perform it’s denial policies. These types of detection are circumvented by the usage of bridges (TOR routers which aren’t publicly known) and pluggable transports (content changing protocols, in order to pass through as innocent-looking traffic). The development of a didactic pluggable transport in a simulated TOR network is the main purpose of this paper, in order to investigate the current state of the art of TOR development and analysis