Perspectives for biogas generation from manure on the farms in the Leningrad Region of the Russian Federation

Received: January 27th, 2021 ; Accepted: March 28th, 2021 ; Published: April 8th, 2021 ; Correspondence: [email protected] interest in biogas in the Leningrad Region is consistently growing. Biogas can replace fossil fuels in different applications and reduce greenhouse gas emissions. The study aimed to demonstrate the perspectives for its generation from livestock waste and further farm application. The farm energy audits identified the pattern of fuel and energy consumption. Computational and statistical methods were applied to estimate the biogas generation. First, the study considered a cattle farm with 1,800 head and manure output of 43,300 t year-1 . According to calculations, the farm can fully meet its own needs for electricity or motor fuel by converting the manure into biogas. Meanwhile, the fuel use of biogas can reduce pollutant emissions by almost 30% against conventional fuel. Secondly, the study estimated the biogas production potential from the farm organic waste in the whole Leningrad Region with the total cattle stock of 165,000 head, pig stock of 184,000 head, and poultry stock of 29,180,000 head, producing about 8 million t year-1 of animal/poultry manure. According to calculations, the livestock waste processing will yield up to 500 million m3 of biogas. This is enough to fully cover the energy inputs of the farms in this region. However, the payback period for biogas plants is above eight years. The positive aspects of biogas application are introducing biogas in the farm energy balance as an energy resource; reducing the hazardous emissions owing to the improved processing of organic farm waste; obtaining high-quality fertilisers to consequently increase crop yields

Rheo-PIV Investigation of Fracture and Self-Healing in a Triblock Copolymer Gel

Physically associating polymer gels have shown the ability to heal after failure, making them promising candidates for various medical applications or consumer products. However, the processes by which these materials self-heal is not well-understood. This study seeks to explain the self-healing behavior of the triblock copolymer poly(methyl methacrylate)-poly(n-butyl acrylate)-poly(methyl methacrylate), or PMMA-PnBA-PMMA, by probing the material’s post-fracture behavior with rheometry and particle image velocimetry (PIV). The self-healing behavior was studied by deforming each gel in shear until failure multiple times with “recovery” periods in-between. PIV was used to verify the occurrence of each fracture in both time and space. Stress relaxation experiments were also performed on the gels to give greater context to the results of the investigation into fracture recovery. Using these data, it was possible to determine the activation energy required for the network chain dissociation and re-association that transpires during the deformation and self-healing of the gel. Stress relaxation experiments yielded an activation energy of 359 kJ/mole for chain dissociation, while fracture-recovery experiments produced an activation energy of 439 kJ/mole for chain re-association. Building upon these insights could lead to a better understanding of the microscopic mechanisms that govern the behavior of intrinsic self-healing materials so that they can be used to their full potential

Characterization of Superabsorbent Polymers in Aluminum Solutions

Over the past few decades, super absorbent polymers (SAPs) have been the topic of research projects all around the world due to their incredible ability to absorb water. They have applications in everything from disposable diapers to high performance concrete. In concrete, aqueous cations permeate the polymer network, reducing swelling and altering properties. One of these ions, aluminum, alters SAP properties by creating a stiff outer shell and greatly reducing absorbency, but these effects have not been well characterized. One method of characterizing the effects of aluminum on SAP hydrogels was performing gravimetric swelling tests to determine equilibrium water capacity at different aluminum ion concentrations. Compressive strength was also determined for swollen particles using a rheometer to perform compression tests. Results from this testing show that low concentration solutions take several hours to permeate the polymer network and reduce swelling capacity, while high concentration solutions are able to limit swelling immediately. The compressive strength of the gel was increased greatly in polymers containing mostly poly(acrylic acid), while SAPs containing more poly(acrylamide) did not have their strength as greatly influenced by the aluminum ions. These results help elucidate the negative effects that may be caused by multivalent cations in concrete. Further research will include studying the interactions of aluminum ions with polymer strands using polymer brushes on a quartz crystal microbalance. This will hopefully reveal the mechanism and kinetics of salt absorption in polymer networks

Characterization of Suspension Polymerized Polyacrylamide and Poly(sodium acrylate-acrylamide) Copolymer and their Size Influence on the Properties of Concrete

Shrinkage leading to cracking and mechanical instability is a major problem for concrete due to the loss of water during the curing process. However, through the addition of Superabsorbent Polymer (SAP) hydrogels, shrinkage can be prevented, increasing the strength of concrete. Characterization of suspension polymerized polyacrylamide (PAM) poly(sodium acrylate-polyacrylamide) (PANa-PAM) copolymer microsphere sizes, morphology and swelling behavior was conducted before adding them to concrete. Size was determined using microscopy paired with ImageJ analysis. Coulter Counter size characterization was also used to determine the particle size distribution. Swelling behavior was determined using the tea bag method as well as size analysis before and after hydration. After characterization, concrete containing various sizes of SAP microspheres will be tested for shrinkage and mechanical strength. These tests will allow us to discover the optimal size of SAP microspheres in concrete to increase its mechanical properties as well as control shrinkage. We will also investigate if the shape of particles has an impact on the final properties of the concrete. The results of this study will contribute to the growing knowledge of applying SAPs in concrete and will give a better understanding on how the size and shape of SAP hydrogels influence the properties of concrete. Using this knowledge, concrete can be made to perform better resulting in more mechanically sound structures

Customized television: Standards compliant advanced digital television

This correspondence describes a European Union supported collaborative project called CustomTV based on the premise that future TV sets will provide all sorts of multimedia information and interactivity, as well as manage all such services according to each user’s or group of user’s preferences/profiles. We have demonstrated the potential of recent standards (MPEG-4 and MPEG-7) to implement such a scenario by building the following services: an advanced EPG, Weather Forecasting, and Stock Exchange/Flight Information

Assessing the Elastic Moduli of Pavement Marking Tapes using the Tape Drape Test

Temporary pavement marking (TPM) tape adhesion with roadway surfaces is critical for tape performance. The two main TPM performance issues both stem from the adhesive strength. Weak adhesion results in premature detachment and excessive adhesion requires extensive removal processes that often leave ghost markings, both of which can cause dangerous confusion in road construction zones. Tape adhesion is directly related to the elastic modulus (E) role= presentation \u3e(E) of TPM tapes. Thus, accurate characterization of E role= presentation \u3eE before tape installation is essential to fully understand and predict the adhesion performance and ultimately the durability of TPMs. To determine the most appropriate E role= presentation \u3eE characterization technique for three different commercial TPM tape brands, two commonly used techniques—tensile and three-point bend testing—were compared with a less common technique, the Peirce cantilever testing or “Tape Drape Test” (ASTM D1388-18). The Tape Drape Test was the only method that accurately characterized E role= presentation \u3eE of tapes with raised surface features. Measured E role= presentation \u3eE values from tensile and three-point bend testing showed significant variation caused by the structural features of the tapes. The Tape Drape Test, which can be implemented quickly in the field before tape installation with little equipment, effectively characterized E role= presentation \u3eE for all the tapes to inform tape adhesion performances and installation procedures

Efficient long-pulse fully-loaded CTF3 linac operation

An efficient RF to beam energy transfer in the accelerating structures of the drive beam is one of the key points of the Compact Linear Collider (CLIC) RF power source. For this, the structures are fully beam-loaded, i.e. the accelerating gradient is nearly zero at the downstream end of each structure. In this way, about 96 % of the RF energy can be transferred to the beam. To demonstrate this mode of operation, 1.5 ..s long beam pulses are accelerated in six fully loaded structures in the CLIC Test Facility (CTF3) Linac. The final beam energy is compared to the input RF power of the structures, proving the efficient energy transfer

RP-LC and HPTLC Methods for the Determination of Olmesartan Medoxomil and Hydrochlorothiazide in Combined Tablet Dosage Forms

Two new, rapid, precise, accurate and specific chromatographic methods were described for the simultaneous determination of olmesartan medoxomil and hydrochlorothiazide in combined tablet dosage forms. The first method was based on reversed phase liquid chromatography using an Eurosphere 100 RP C18 column (250 × 4.6 mm ID, 5 μm). The mobile phase was methanol–0.05% o-phosphoric acid (60:40 v/v) at a flow rate of 1.0 mL min−1. Commercially available tablets and laboratory mixtures containing both drugs were assayed and detected using a UV detector at 270 nm. The second method involved silica gel 60 F254 high performance thin layer chromatography and densitometric detection at 254 nm using acetonitrile–ethyl acetate–glacial acid (7:3:0.4 v/v/v) as the mobile phase. Calibration curves ranged between 200–600 and 125–375 ng spot−1 for olmesartan and hydrochlorothiazide, respectively