Analysis of the payback period of a modernized pump unit with induction electric motors of advanced energy efficiency classes

Aim. The comparative analysis of energy consumption, electricity costs during lifetime cycle and payback period of a pump unit with 90 kW 2-pole induction motors, belonging to various energy efficiency classes, feeding directly from power grid. Methods. The examined operating modes aligned with a typical operating cycle of a pump unit with approximately constant flow rate of 75-110 % of the rated flow. The calculations were based on the pump and induction motors nameplate data, which, in their turn, were based on the manufacturers’ experimental data. Results. The calculations of energy consumption, electricity costs and payback periods of a pump unit with 90 kW 2-pole induction motors, feeding directly from power grid have been performed in the article. The application of induction motors belonging to IE2, IE3 and IE4 energy efficiency classes has been discussed. Practical value. It has been demonstrated, than in case of replacement of an induction motor of energy efficiency class IE2 due to planned retrofit, payback period for an IE4 induction motor is 2.18 years, energy savings within a calculated 20-year operating period are 268MW·h, which makes €41110 in money terms. Under the same conditions, the replacement of an induction motor of energy efficiency class IE2 with an induction motor of energy efficiency class IE3 will allow to save 88 MW·h within a calculated operating period, which, expressed in monetary terms, is €13500 and the payback period is 5.11 years. Thus, the article proves that despite a higher initial price, the choice of an induction motor of energy efficiency class IE4 tends to be more economically advantageous

Анализ срока окупаемости модернизированной насосной установки при использовании асинхронных двигателей повышенных классов энергоэффективности

Aim. The comparative analysis of energy consumption, electricity costs during lifetime cycle and payback period of a pump unit with 90 kW 2-pole induction motors, belonging to various energy efficiency classes, feeding directly from power grid. Methods. The examined operating modes aligned with a typical operating cycle of a pump unit with approximately constant flow rate of 75-110 % of the rated flow. The calculations were based on the pump and induction motors nameplate data, which, in their turn, were based on the manufacturers’ experimental data. Results. The calculations of energy consumption, electricity costs and payback periods of a pump unit with 90 kW 2-pole induction motors, feeding directly from power grid have been performed in the article. The application of induction motors belonging to IE2, IE3 and IE4 energy efficiency classes has been discussed. Practical value. It has been demonstrated, than in case of replacement of an induction motor of energy efficiency class IE2 due to planned retrofit, payback period for an IE4 induction motor is 2.18 years, energy savings within a calculated 20-year operating period are 268MW·h, which makes €41110 in money terms. Under the same conditions, the replacement of an induction motor of energy efficiency class IE2 with an induction motor of energy efficiency class IE3 will allow to save 88 MW·h within a calculated operating period, which, expressed in monetary terms, is €13500 and the payback period is 5.11 years. Thus, the article proves that despite a higher initial price, the choice of an induction motor of energy efficiency class IE4 tends to be more economically advantageous.Цель. Сравнительный анализ расчетов энергопотребления, затрат на электроэнергию в течение жизненного цикла и сроков окупаемости насосной установки с 2-полюсными асинхронными электродвигателями мощностью 90 кВт различных классов энергоэффективности, питающимися напрямую от электрической сети. Методика Рассматриваемые режимы работы соответствовали типовому циклу работы, характерному для насосных установок с приблизительно постоянным расходом 75-110 % от номинального. Расчет основывался на паспортных данных насоса и электродвигателей, которые в свою очередь основаны на экспериментальных данных производителей. Результат В статье произведен расчеты энергопотребления, затрат на электроэнергию и сроков окупаемости насосной установки с 2-полюсными асинхронными электродвигателями мощностью 90 кВт, питающимися напрямую от электрической сети. Рассмотрено применение электродвигателей с классами энергоэффективности IE2, IE3 и IE4. Практическое значение. Показано, что в случае замены электродвигателя класса энергоэффективности IE2 в связи с плановой модернизацией электродвигателем класса энергоэффективности IE4 срок окупаемости для электродвигателя класса энергоэффективности IE4 составляет 2,18 года, экономия электроэнергии в течение расчетного 20-летнего срока эксплуатации составляет 268 МВт·ч, что в денежном выражении составляет 41110 €. При тех же условиях замена электродвигателя класса энергоэффективности IE2 на электродвигатель класса энергоэффективности IE3 позволит достичь экономии электроэнергии в течение расчетного срока эксплуатации 88 МВт·ч, что составляет в денежном выражении 13500 €, и срока окупаемости 5,11 года. Таким образом, в статье показано, что, несмотря на более высокую начальную стоимость, выбор электродвигателя класса энергоэффективности IE4 более выгоден с экономической точки зрения

Observation of inverse Compton emission from a long γ-ray burst.

Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs

Adsorption of Polyadenylic acid on graphene oxide: experiments and computer modeling

In this work, we study the adsorption of poly(rA) on graphene oxide (GO) using AFM and UV absorption spectroscopies. A transformation of the homopolynucleotide structure on the GO surface is observed. It is found that an energetically favorable conformation of poly(rA) on GO is achieved after a considerable amount of time (days). It is revealed that GO can induce formation of self-structures of single-stranded poly(rA) including a duplex at pH 7. The phenomenon is analyzed by polymer melting measurements and observed by AFM. Details of the noncovalent interaction of poly(rA) with graphene are also investigated using molecular dynamics simulations. The adsorption of (rA)10 oligonucleotide on graphene is compared with the graphene adsorption of (rC)10. DFT calculations are used to determine equilibrium structures and the corresponding interaction energies of the adenine-GO complexes with different numbers of the oxygen-containing groups. The IR intensities and vibrational frequencies of free and adsorbed adenines on the GO surface are calculated. The obtained spectral transformations are caused by the interaction of adenine with GO

Development of a manual extruder for liposome homogenization

Medications using liposomes are of great interest in pharmaceuticals. They increase the therapeutic index of the drug by enclosing the medicinal substance inside a biocompatible lipid envelope, which releases the solution only in the required area. Such drugs have already shown their effectiveness in the treatment of diseases related to oncology, dermatology, neurology, surgery, etc. To use liposomes for these purposes, it is necessary that their size be in the range from 50 to 200 nm. There are several ways to create vesicles of this size, but mostly they use either ultrasound exposure to a liposome solution or extrusion. The extrusion method is a method that allows to obtain the most homogeneous solution from liposomal particles. For extrusion, a special device – an extruder is required. It is a system that passes a liposomal solution under pressure through a filter with a certain pore size. In this paper, the process of liposome extrusion, types of liposomal extruders are considered and their pros and cons are evaluated, a model of a manual extruder capable of homogenizing up to 20 ml of solution was also developed. Different materials were considered and used for the construction of this device. The inspection of the extruder showed its operability and showed the advantages of using extrusion compared to the ultrasound exposure method

Binding of Polycitydylic Acid to Graphene Oxide: Spectroscopic Study and Computer Modeling

Hybridization of nucleic acids with graphene nanomaterials is of great interest due to its potential application in genosensing and nanomedicine. In this work we study the interaction between polyribocytidylic acid (poly(rC)) and graphene oxide (GO). The study involves comparing the UV absorption spectra of the free polymer and the polymer bonded to graphene oxide and analyzing the vibrational structure of the systems and their components using FTIR spectroscopy. Spectral shifts of the electronic and vibrational bands of the poly(rC) and changes of their thermostability due to the adsorption on GO are observed. Molecular dynamics simulation of the adsorption process of the r(C)10 and r(C)30 oligomers on graphene demonstrates their disordering due to the π-π stacking of cytosine on graphene and shows that the longer oligomer adsorbs slower. The binding energies of a single cytosine stacked with graphene in water and in vacuum were determined. The calculated IR lines of the stacked cytosine with graphene are red shifted by up to 20 cm-1 compared to free cytosine. A strong decrease of the intensities of the cytosine vibrations in the 1800-1400 cm-1 range resulting from the interaction with graphene is revealed in the spectra. When cytosine is adsorbed to graphene oxide, their complex is additionally stabilized by H-bonding. It leads to an increase of the red shifting of the cytosine lines