Beachrock Formation Mechanism Using Multiproxy Experimental Data from Natural and Artificial Beachrocks: Insights for a Potential Soft Engineering Method

Beachrocks are a window to the past environmental, geological, sedimentological and morphological conditions that were dominant in the coastal zone during their formation. Furthermore, beachrocks have the ability to reduce coastal erosion impact on sandy beaches. This study focuses on the beachrock formation mechanism through the comparison of cement characteristics, mineral chemistry and sedimentology of beachrock occurrences from two different geological and geographical localities: Diolkos, Corinth, Greece and Sumuide, Okinawa, Japan. In addition, in order to investigate a potential soft engineering method to protect coasts from erosion, artificial beachrock samples were created in vitro using sand samples and ureolytic bacteria from both areas under accelerating conditions. For Okinawa artificial beachrock experiments, the bacteria Pararhodobacter sp. was used, and for Diolkos, it was the bacteria Micrococcus yunnainensis sp. For the natural beachrocks, a multi-analytical approach was accomplished with the use of microscopic investigation, a scanning electron microscope, energy-dispersive X-ray spectroscopy, X-ray diffraction and X-ray fluorescence. Correlations were made between natural and artificial beachrocks. Results have shown that Diolkos beachrock was formed in the upper part of the intertidal zone, consisting of detrital material originating from the local bedrock, while Sumuide beachrock formed in the low intertidal–upper subtidal zone, consisting of coral sand and foraminifera fragments. For the artificial beachrocks, three samples were created using the microbial-induced carbonate precipitation (MICP) method, one from Diolkos (Corinth, Greece) and two from Sumuide (Okinawa, Japan). Diolkos artificial beachrock was better consolidated in comparison to Sumuide. Our investigation has shown that bacterial density was the key factor for the creation of the artificial beachrocks, while the samples’ granulometry played a secondary role in the process. The laboratory artificial beachrocks show encouraging results for a new soft engineering method to encounter beach erosion while keeping an ecofriendly character by saving energy, material resources and gas emissions. Artificial beachrocks can share the same properties of a natural beachrock and can contribute positively to marine biodiversity as a natural rocky habitat.

Interface Engineering Improves the Performance of Green Perovskite Light-emitting Diodes

To realize high-performance perovskite light-emitting diodes (PeLEDs), the underlying charge transport layer plays a vital role in charge injection and perovskite growth. Herein, a rational interface engineering method has been...

Engineering Method for Calculating the Temperature on the Inner Surface of the Outer Corner of a Building

Постановка задачи. Температура на внутренней поверхности наружного угла всегда меньше, чем по глади наружной стены, что при низких температурах наружного воздуха может приводить к образованию конденсата на внутренней поверхности стены. В связи с этим актуальным является проблема разработки инженерного метода расчета температуры в наружном углу для исключения возможности конденсатообразования на внутренней поверхности угла на стадии проектирования стеновых конструкций. Результаты. Для решения этой задачи на основе решения уравнения теплового баланса, учета амплитуды колебания температуры воздуха в помещении и теплопоглощения внутренних поверхностей стен, междуэтажных перекрытий (поверхности потолка и пола), перегородок, окон получена формула для вычисления температуры на внутренней поверхности наружного угла. Также в ходе исследования проведены натурные испытания стеновой конструкции с наружным углом и получены значения температур на внутренней и наружной поверхностях. Выводы. Сопоставление результатов расчетов по разработанной методике и экспериментальных данных показало, что значения температур на внутренней поверхности наружного угла практически совпадают. Это дает основание использовать предложенный инженерный метод расчета температуры на внутренней поверхности угла наружной стены при проектировании ограждающих конструкций зданий для создания благоприятных комфортных и санитарно-гигиенических условий в помещении. Statement of the problem. The temperature on the inner surface of the outer corner is always lower than on the inner surface of the outer wall. This temperature difference might lead to the formation of condensation on the inner surface of the wall at low outdoor temperatures. Therefore the problem of developing an engineering method for calculating the temperature in the outer corner to exclude the possibility of condensation on the inner surface in the design process of the outer wall structures is extremely relevant. Results. To address this problem, based on solving the heat balance equation, taking into account the amplitude of air temperature fluctuations in the room and heat absorption of the inner surfaces of walls, intermediate bottoms (ceiling and floor surfaces), parting walls, a formula was obtained to calculate the temperature on the inner surface of the outer corner. Also, through the course of the study, natural tests of the wall structure with an outer corner were carried out and the temperatures on the inner and outer surfaces were obtained. Conclusions. Comparison of the calculation results using the developed engineering calculation method and experimental data showed that the temperatures on the inner surface of the outer corner almost coincided. This makes it possible to use the suggested engineering method for calculating the temperature on the inner surface of the outer wall corner in the design of enclosing structures to exclude condensation.

Destruction of polymer insulation and threshold amplitudes of current pulses of different temporal shapes for electric wires and cables in the low- and high-current circuits of pulse power engineering, electrical engineering and electronic devices

Goal. Development of engineering method for settlement of threshold amplitudes Impk of single-pulse current ip(t) of different temporal shapes for electric wires and cables with polyethylene (PET), polyvinylchloride (PVC) and rubber (R) half-length insulation, used in modern pulsed power engineering, electrical engineering and electronics in their low- and high-current circuits. Methodology. Basis of the theoretical and applied electrical engineering, electrical power engineering, electrophysics bases of technique of high-voltage and large pulsed currents, bases of low- and high-current electronics, measuring technique, electromagnetic compatibility and standardization. Results. Development of engineering method is executed on close calculation determination of threshold amplitudes Impk of single-pulse axial-flow current ip(t) of different temporal shapes for electric wires and cables with copper (aluminum) current-carrying parts and PET, PVC and R half-length insulation, used in the ow- and high-current circuits of pulsed electrical power engineering, electrical engineering and electronics. Electrothermal resistibility of half-length insulation of the examined cable and wire products (CWP), proper maximum to the possible temperatures of heating of current-carrying and insulating parts of the probed wires and cables and shutting out the offensive of the phenomenon destruction in the indicated insulation of CWP, was fixed based on this method. Calculation analytical correlations are obtained for finding in probed CWP of threshold numeral values of Impk amplitudes of pulses of current ip(t), time-varying both on aperiodic dependence of type τf/τp with duration of their front τf and duration of their pulses τp and by law of exponential attenuation sinewave. It is shown that at Imp>Impk destruction of their half-length insulation, resulting in the decline of service life of CWP, will come from the thermal overheat of current-carrying parts of the examined electric wires and cables. The examples of practical application of the offered method are resulted upon settlement for a radiofrequency coaxial cable RC 50-4-11 with middle sizes is easily soiled with continuous PET insulation of threshold amplitudes of Impk of standard aperiodic pulses of current ip(t) from nano-, micro- and millisecond temporal ranges of shape of τf/τp=5 ns/200 ns, τf/τp=10 μs/350 μs and τf/τp=7 ms/160 ms. It is shown that with the proper growth of parameter τp>>τf for flow on a continuous copper tendon and split copper shell of radiofrequency coaxial cable RC 50-4-11 with middle sizes is easily soiled indicated homopolar pulses of current ip(t) substantial diminishing of their threshold amplitudes of Impk (with 531,2 кА for the nanosecond pulse of current of type 5 ns/200 ns to 1.84 кА for the millisecond impulse of current of type of 7 ms/160 ms takes place). Originality. An engineering method is first developed for close settlement of threshold numeral values of Impk amplitudes of single-pulse axial-flow current ip(t) of arbitrary peak-temporal parameters for electric wires and cables with copper (aluminum) current-carrying parts and PET, PVC and R half-length insulation. Practical value. Application in electrical engineering practice of the offered engineering method for determination of threshold amplitudes Impk of the indicated pulses of axial-flow current ip(t) for the probed electric wires and cables will allow considerably to increase service life of examined CWP.

ENGINEERING METHOD FOR CALCULATING THE TEMPERATURE ON THE INNER SURFACE OF THE OUTER CORNER OF A BUILDING

Statement of the problem. The temperature on the inner surface of the outer corner is always lower than on the inner surface of the outer wall. This temperature difference might lead to the formation of condensation on the inner surface of the wall at low outdoor temperatures. Therefore the problem of developing an engineering method for calculating the temperature in the outer corner to exclude the possibility of condensation on the inner surface in the design process of the outer wall structures is extremely relevant. Results. To address this problem, based on solving the heat balance equation, taking into account the amplitude of air temperature fluctuations in the room and heat absorption of the inner surfaces of walls, intermediate bottoms (ceiling and floor surfaces), parting walls, a formula was obtained to calculate the temperature on the inner surface of the outer corner. Also, during the study, natural tests of the wall structure with an outer corner were carried out and the temperatures on the inner and outer surfaces were obtained.Conclusions. Comparison of the calculation results using the developed engineering calculation method and experimental data showed that the temperatures on the inner surface of the outer corner almost coincided. This makes it possible to use the suggested engineering method for calculating the temperature on the inner surface of the outer wall corner in the design of enclosing structures to exclude the appearance of condensation.

Reliability of Certain Class of Transportation Networks

The reliabilityof a special class of technical objects - tree-like transportation networks is considered. It is argued that the indicators traditionally used to assess reliability in relation to such objects are not very informative and are ambiguously interpreted from a physical point of view. As a quantitative measure, an indicator of operational reliability is proposed and an engineering method for its calculation has been developed. It uses the features of the object, is based on an analogue of the Y-shaped structure-forming fragment of the network and is reduced to a repeating step-by-step computational procedure, when at each step the results of the calculation are obtained at the previous stage and used as initial data. Relationships are derived that allow extending this approach to the case when at the junction point of network elements not two, but, in general, n elements are combined. The advantages of the introduced indicator of the operational reliability of tree-like transportation networks are discussed and the ways of its further generalization and use are outlined

Packaging Design Model Of Talang Salted Fish Processing Industry Using Value Engineering Method

One of the products that need attention, especially related to packaging, is the Talang Salted Fish product, which has been selling Talang Salted Fish without using packaging. So that this study aims to design the packaging of talang salted fish to add selling value which can later be an attraction for consumers to buy it. The method used is value engineering and the analytical hierarchy process (AHP). The value engineering method is applied to increase the value, performance, and cost of packaging design consisting of brand criteria, net weight measurement, product identity, attractiveness, color suitability, typography, and font size. The Analytical Hierarchy Process method is applied at the analysis stage to help determine the priority criteria in accordance with the wishes of consumers. The results showed that the alternative design with the highest performance value was alternative 1 (A-B-D-E), namely the design with packaging materials made of transparent plastic, the colors used were bright, the packaging was rectangular and all capital letters were used. This selected alternative design has a value of 0.039. This value is obtained from the performance of 38.9 and the cost of Rp. 1000 per pack.

New Methodology for Calculating the Impact of High Free Gas Content in the Flow on ESP Characteristics for the West Siberia Fields

One of the most common complications in the operation of wells with electric submersible pumps (ESP) is the presence of free gas in the produced well product. The work considers a model of ESP operation taking into account a large share of free gas in the flow obtained on the basis of bench tests and its applicability for analyzing the operation of real producing wells equipped with ESPs. Tests of ESP5-50 (118 radial stages) with model gas-liquid mixtures in a wide range of inlet gas volume-flow rate (0-60%), inlet pressure (0.6-2.1 MPa), shaft speed (2400-3600 rpm) with simultaneous pressure measurement along the pump length and direct measuring of power at the shaft by means of motor weights were performed at the oilfield development and operation department. Mathematical model is obtained by means of regression analysis of experimentally received characteristics of ESPs on gas liquid mixtures; a simple engineering method of calculating the degradation of ESPs characteristics by flow, head and power is suggested. The experience of building similar models described in the literature was taken into account. Experimental studies and creation of a mathematical model of ESP were carried out during Kirill Goridko's PhD thesis. As a result of the research we obtained the degradation dependencies of the pump's delivery and the head of ESP while pumping mixtures of different foam capacity, which simulate the pump operation in low and high watercut wells. The patterns of delivery and head coefficients depending on the zone (left, optimum, right) of ESP characteristic are revealed. The degradation of ESP power during pumping gas liquid mixture is clarified, which allows to calculate more accurately the specific energy consumption of well products lifting. The developed method of recalculation of the pressure and power characteristics of ESPs is implemented in the form of calculation modules designed for engineering calculations in oil production. The proposed tool has been tested on the data of the Western Siberia fields while analyzing the operation of wells with high gas content in the produced product. Calculation modules have been made publicly available. A new simple engineering method was developed to account for the degradation of the pressure and flow and power characteristics of ESPs for low- and medium-rate wells based on a large number of benchmark studies. Оbtained degradation dependences are programmed in the form of calculation modules, which allows to analyze the operation of a large number of wells on the basis of their technological mode, as well as to propose optimization measures to change the ESP operation at a higher level.

Automated Feature Engineering Method in the Problem of Forecasting Energy Consumption

The automated feature engineering method in the problem of forecasting energy consumption is considered. The algorithm of the method and the scheme of the forecasting model construction are stated. The proposed approach was tested on data about electricity consumption in Russian regions. The results of the computational experiments carried out using the described method demonstrate an increase in the efficiency of the developed forecasting model and improvement of accuracy.