bluuebunny/crossref_metadata_2025 huggingface dataset:
Connectivity model of archipelagic areas: a case study of Kepulauan Riau
Authors: Achmadi T , Nur H I , Banjarnahor F N , Kuik S , Ardhi E W , Permana C B S , Riduwan M
Published: February 2021

Marine transportation plays a vital role in the development of Kepulauan Riau as an archipelagic province. The GRDP 2017 of Kepulauan Riau shows that Batam city contributed the most to the figures, which amounted to 64%, followed by other cities outside Batam at 8.54%, and other districts are only under 10%. This condition might be caused by the lack of connectivity and network accessibility between those areas. The growth of passengers and general cargo in Kepulauan Riau was predicted to increase in the next few years, so there must be an improvement in marine services. This study aims to determine the conditions of connectivity for marine transportation in Kepulauan Riau using a degree connectivity matrix and a model for calculating the unit costs. The region with the highest passenger connectivity value is Tanjungpinang (0.83), while general cargo is Tanjungpinang and Batam (0.83). The effect of increasing connectivity to existing conditions and the results of an analysis of services between regions that have the smallest unit cost difference is Karimun-Bintan (IDR 6,881/ton or USD 0.48/ton), and the most significant difference is Natuna-Lingga (IDR 1,568,442/ton or USD 110.26). In terms of time, the slightest difference is Batam-Natuna (3 hours), and the most significant difference is Bintan-Lingga (1,001 hours).
Experimental study on heave damping due to the heave plate addition on the SPAR keel
Authors: Murdjito  , Ali B , Ardhianutama F , Djatmiko E B , Syahroni N , Mulyadi Y , Riyanto R D , Prastianto R W , Handayanu  , Rochani I
Published: February 2021

Recent years have shown the increasing number of SPAR offshore floating platforms built and delivered worldwide. This eventually is strongly related to the generic potential of such platforms, in term of economy and performance aspects, especially for the operation in deep water. For operation in harsh sea environment previous SPAR investigations suggested the addition of heave plate on its keel to enhance the heave motion quality. This paper reports an experimental study conducted on SPAR model, scaled 1: 125 from the full size, installed with a heave plate sized 1.3 of hull diameter. Results of the study demonstrate the additional of heave plate may reduce the heave reaction force due to wave excitation approximately 35% in comparison with that without heave plate. This in turn leads to the decreasing of heave response by as much as 54%. Evaluations suggest the reductions in heave reaction force and response are induced by the escalation of heave damping in the order of 49% generated by the heave plate. The experimental results are well verified by the outcomes of computations based on analytical method and strip theory.
L1 adaptive controller for unmanned surface vehicle type monohull LSS01 autopilot system and guidance design
Authors: Maruf A , Kadir R E A , Gamayanti N , Santoso A , Bilfaqih Y , Sahal M , Hidayat Z
Published: February 2021

The control technology grows rapidly at present, especially in the field of autonomous vehicles. This research presents the application of an L1 adaptive controller to an autopilot system and guidance design for an Unmanned Surface Vehicle (USV). The purpose of the L1 adaptive controller deals with how the adaptive control technology solve the problems related to the performance, robustness, and the time adaptability in the issues of uncertainty conditions. The dynamic behaviors of the USV are modeled with 3 degrees of freedom movement in the planar field, where disturbances are applied onto the system. The parameter values of the vessel will be inserted into the state space dynamic equation. The transient response behavior of the system will be analyzed to show the vessel’s movement through the desired waypoints. The L1 adaptive controller method has a fast adaptation rate without losing robustness, which provides better stability using Lyapunov analysis and abilities to dampening the high-frequency as the disturbance by adding Low Pass Filter (LPF) on the control law architecture. Besides this, the L1 adaptive control is relatively simple and easy for industrial implementation. The results show the effectiveness of the L1 adaptive controller when applied to the USV guidance system.
Unbalance load analysis on closed bus electrical system under ship dynamic positioning scenario
Authors: Sarwito S , Semin  , Zaman M B , Soedibyo  , Fawaiz I
Published: February 2021

Dynamic Positioning (DP) operation on offshore auxiliary vessels emerges as a challenge in need of ensured high-powered bow thruster stability. DP operation is widely adopted under an open electrical system (open bus). Open bus-configured DP usually has low electricity disturbance. However, open bus-configured DP is always attributed to its low efficiency. Our study revealed that DP ships using closed bus configuration are prone to the unbalance three-phase electric load problem. Unbalanced load, which always results in the unbalance three-phase voltage problem, can affect the performance of the motor or another electrical component. Our simulation successfully showed the effect of unbalance load on the ship’s electric stability. By using commonly electric ship configuration as simulation testing, the ship grid configuration with the power supply of two generator thruster and one diesel generator with the 2-bow thruster and a static load can indicate unbalanced load on AHTS vessels with variations up to 75%. By minimizing the variation of percentages of the bow thruster operating point and other loads, minimum allowable three-phase deviation of the unbalance, which indicated by the three-phase voltage operating point could be met. The simulation study was done using MATLAB as a tool.
Operational limitation of Indonesian traditional wooden boat in the framework of second generation intact stability criteria
Authors: Paroka D , Muhammad A H , Rahman S , Azis M A
Published: February 2021

Recently, the International Maritime Organization (IMO) developed the second generation intact stability criteria for all possible capsizing scenario in seaways with performance based approach. This paper presents application of the criteria to investgate operational limitation of an Indonesian traditional woooden boat for dead ship condition. The hydrodynamic characteristics of the ship are determined by model experiment except the effective wave slope coefficient is calculated using the simplified Froude-Krylov assumption of roll exciting moment and the formula of weather criterion. The wave characteristics are described by JONSWAP spectrum based on the wave statistic of Flores sea and the gusty wind is calculated by Davenport spectrum. The results show that the Indonesian traditional wooden boat comply with the criteria when the downflooding angle is larger than 25.0 degrees. The vulnerability criteria level 1 and the vulnerability criteria level 2 of the criteria are not consistent when the effective wave slope coefficient is calculated using the formula of weather criterion but it is consistent when the simplified Froude-Krylov assumption is used. The inconsistency could appear due to the geometry characteristics of Indonesian traditional wooden boats which are different from the geometry characteristics of ships used to develop the weather criterion as the level 1 of vulnerability criteria.
Search and rescue station location selection and conceptual design: a case study of western region of Indonesia
Authors: Hadi F , Nur H I , Maharani N K P , Permana C B S , Buana I G N S , Ardhi E W
Published: February 2021

The existence of marine Search and Rescue Units (SRU) to support the search and rescue operations currently are not supported by sufficient infrastructures and facilities. The infrastructures and facilities operated by the National Search and Rescue Agency (NSARA) have not been able to cover all working areas. One example is the location of NSARA dock facilities which is in remote area and has a narrow access channel causes duration to get to the area of accident is quite long. In that condition, the coordination among the SAR vessels and crew cannot perform efficiently and effectively. On the other hand, the National SAR Agency regulation No. 14, the year 2015, describes the necessary infrastructures and facilities that must be provided to support the implementation of marine SAR operations. This paper uses Western Region of Indonesia as a case study aiming to determine the optimum location and conceptual design of SAR station. Set Covering Problem method used to determine SAR station location and SAR vessels required, whereas conceptual design of the infrastructures is established based on data of routes and location selected. From the set covering model, we found 10 locations of SAR station, namely Aceh, South Kalimantan, Bengkulu, South Sumatra Bangka Belitung, Riau, West Kalimantan, Central Java, Riau Islands, and Yogyakarta. There is a total of 20 units of ships deploy with the total operation cost of IDR 263 billion/year (USD 18.5 million/year). The minimum dimensions of the berth have a length of 15 m and a width 5 m, while the gangway has a length of 163 m and a width of 5 m. The total cost of SAR station is IDR 8 billion/year (USD 562,390/year).
Exploring Architectural Style of Gianyar and Creating Building Material Innovations
Authors: Wirawibawa Ida Bagus Gede , Dewa Gede Agung Diasana Putra I
Published: February 2021

Traditional architectural styles are essential for presenting local identity, so that it is necessary to recognize and explore local architectural identities in an attempt to maintain traditional architectural styles as one of the richness of local culture. Generally, the traditional Balinese architecture, particularly the Gianyar architectural style, is still used by Balinese. The design’s application is also attributable to the Balinese local government legislation about using traditional Balinese architectural style in a building. However, the style’s design process is an architectural challenge for building actors and people willing to realize that the construction processes usually need more time and costly. Because of this situation, it is considered essential to producing a building material that gives a traditional impression through the efficient use of resources and funds. By introducing a phased approach, this research starts with an analysis of the Gianyar architecture, which is used as a guide in designing traditional-style materials used by the broader communities.
Heating Treatment of Air in Combustion Chamber For The Use of Mixture Ethanol and Gasoline Fuel
Authors: Ikhsani A A , Kustanto M N , Fachri B A
Published: February 2021

This research was conducted to improve the engine performance with ethanol and gasoline mixture, because from fuel mixture with high concentrate causes value of flash point and heat evaporation fuels becomes higher. To overcome these, the air that entrance in combustion chamber heated up to 26°C, 30°C, 40°C and 50°C, the fuel used are E0, E30 and E50 on 2000 to 8000 rotation. The result of research shows E0 fuel highest torque on 30°C with a value 8,98 Nm had 0,22% increase, E30 fuel highest torque on 50°C with a value 9,5 Nm had 1,05% increase and E50 fuel highest torque on 50°C with a value 7,77 Nm had 0,64% increase. On E0 power is 5,96 kW on 30°C had 0,33% increase, the highest power of E30 is 6,29 kW on 50°C had 1,9% increase and the highest power of E50 on 50°C with a value 4,49 kW had 0,89% increase. For the highest consumption is 2000 rotation, for E0 fuel on 50°C with a value 1,43Kg / Hp.Hour, E30 with a value 1,48 Kg/Hp.Hour on 26°C and E50 with a value 2,03 Kg/Hp.Hour on 26°C, this result shows that air heating treatment can improve the engine performance.
Risk Allocation Model For Cisumdawu Toll Road Projects
Authors: Setiawan D , Milyardi R , Ing T L , Rizkiana C
Published: February 2021

In the Cisumdawu Toll Road project there are some complex problems, including the first tunnel structure in Indonesia that functions as a toll road. This complex construction project is currently experiencing delays which creates risks for project delays. In this study the aim is to identify risks and create an optimal risk allocation model between the project owner and the contractor. The allocation of risk between project owner and contractor in a contract plays an important role for the success of the project. It should be based on a proper assessment of the involved risks and choosing the party best able to manage them. This research was obtained about risks that can be impacted by the project in each phase. The scope of non-excusable factors often is considered a contractor’s fault which results in project construction. Based on the results of descriptive test of the 5 main risks include the most important risk in the Cisumdawu Toll Road Construction Phase II (STA 9+750 – STA 27+100) is soil work. The results show that the soil work risk should bear by the contractors by lump sum fixed price contract.
Physical Stability Test Sunscreen Gel Extracts Blackberry Fruit (rubus fruticosus l.)
Authors: Gunarti N , Aisyah I , Lia F
Published: February 2021

Blackberry (Rubus sp.) fruit contains high levels of anthocyanins and other phenolic compounds, mainly flavonols and ellagitannins, which contribute to its high antioxidant capacity and other biological activities. Sunscreen preparations are cosmetic preparations that are used as protection to reduce the impact of sun exposure, whose formulations contain active ingredients to absorb or reduce sunlight, especially in areas exposed to ultraviolet rays and infrared waves. One of the potential natural ingredients for sunscreen is blackberry fruit (Rubus sp.). Contains flavonoid compounds that can prevent the harmful effects of UV rays. This study aims to determine the stability of the blackberry fruit extract sunscreen gel formula for 90 days of storage to determine the SPF value test results of blackberry fruit extract using UV-Visible. The research design is an experimental research conducted in a laboratory. The sample used in this study was Blackberry which was made into thick extract by maceration method. Furthermore, the thick extract obtained was made into a sunscreen gel and then tested for physical stability and the calculation of the SPF value. The sunscreen potency test is determined based on the method of calculating the percent erythema transmission value (%Te) and the percent transmission pigmentation (%Tp) as well as the Sun Protection Factor (SPF) value. On testing the SPF the average value on the test day 0, day 7, day 15, day 21, day 30, day 60, day 90, respectively 28,03±0,77; 28,28±0,16; 28,46±0,41; 28,66±0,59; 28,85±0,33; 29,04±0,11; 29.24±0,27. Percent of erythema (% Te) testing over 90 days was included in the total block category. Percent pigmentation (% Tp) testing for 90 days was included in the total block category and the SPF test for 90 days was included in the category ultra.
Formulation and Antibacterial Activity Test of Foot Spray with Beluntas Leaf Ethanol Extract (Pluchea Indica L.)
Authors: Farhamzah  , Herli A , Mursal I L P
Published: February 2021

Foot odor is one of the things that is quite disruptive to appearance, the 2014 American Podiatric Medical Association studied a significant increase in the prevalence of foot odor in the community. One of the causes of foot odor is the presence of bacteria, especially the bacteria Bacillus Subtilis. This study used the ethanol extract of beluntas leaf (Pluchea Indica L.) as the active ingredient because the ethanol extract of beluntas leaf has been widely used and proven to have antibacterial activity besides the ethanol extract of beluntas leaf has a high enough compatibility to be used as a cosmetic product, including spray preparations. The spray form was chosen because of its easy and pleasant use. This study aims to make a foot odor control product in the form of a spray with 3 concentrations of beluntas leaf ethanol extract, 0.5%, 1.0% and 1.5% to study the antibacterial activity using the well diffusion method. The results showed that the ethanol extract of beluntas leaf can be formulated into foot spray preparation with the results of the organoleptic examination of the three formulas are clear liquid, and yellow slightly green color. The pH of the preparation is in the range 5.10 -5.92. In formula 3 (F3) with a concentration of 1.5% beluntas leaf ethanol extract, it has a strong bacterial inhibition zone with an average inhibition zone diameter of 12.5 mm.
Chemical Characteristics of Motaf Sweet bread with Addition of Temulawak Starch
Authors: Sandri D , Lestari E
Published: February 2021

Bread is one of the processed foods from wheat which is widely consumed by the wider community which is used as a source of carbohydrates other than rice and noodles. In some countries, bread made from wheat flour is a staple food. Along with the development of the food industry made from wheat flour, the need for wheat flour is also increasing. So it is necessary to do efforts to find food sources other than wheat flour. In Indonesia, there are talipuk seeds which have the potential to be developed into a future source of carbohydrates and temulawak which contains quite a lot of starch. This study aims to analyze the chemical characteristics ofsweet bread modified talipuk flour (motaf)with the addition of temulawak starch. This research was conducted using a completely randomized design method (CRD) which consisted of 5 treatments consisting of the ratio of wheat flour, motaf, and temulawak starch flour. The sweet bread of these 5 treatments was tested for moisture content, ash content, protein, fat, carbohydrate and crude fiber analysis. The data were analyzed using the effectiveness test. The results showed that the best treatment produced on sweet bread made from the addition of modified talipuk flour (motaf) and temulawak starch was treated with the addition of 0.01 g of temulawak starch flour. The resulting sweet bread has 19.96% moisture content, 1.01% ash content, 8.65% protein content, 13.62% fat content, 56.76% carbohydrate content, 35.19% fiber content and the value of effectiveness results. the highest is 0.39.
Web-based Design of Financial Apps: Case of Kosan 54
Authors: Sari D , Pradana M , Nugraha D W , Oktafani F
Published: February 2021

Financial Management is the process of financial planning in budgeting, auditing, management, control, deposit funds that are held for effective and efficient financial decisions.. As the existing financial management processes in boarding house number 54 (Kosan 54) is still manual, it is prone to mistakes during the recording and making their own bills and financial statements, along with the process of bill payment by the boarding members. Therefore, a system that can perform data processing in an integrated and well computerized system using a WEB-based system is urgently needed. The designed system is a WEB-based Financial Management Application. To build the application, a software such as MySQL database is needed, as well as using the PHP programming language. This finance management application then will be of great help in the planning of appropriate financial income and expenses incurred.
Decision Making Analysis for Free Internet Quota Assistance Online Learning during the Covid-19 Pandemic
Authors: Budiman E , Hairah U
Published: February 2021

One of the Indonesian government’s efforts to reduce the impact of the crisis due to the Covid-19 pandemic is through the distribution of social assistance through the distribution of free internet data for students to support online learning during the implementation of government policies regarding large-scale social restrictions. This social assistance involves 350 students as an alternative as a target for decision making. In an effort to support this policy, this study offers a multi-criteria decision-making analysis approach using the Moora and Vikor methods. The results of this study present the optimal performance of the accuracy, precision and error rate of the two methods.
The future has arrived, are we ready for EV?
Authors: Bose Probhas , Mandal Dipak Kumar
Published: February 2021

With the invention of petroleum in 1859, R & D of internal combustion (IC) engine powered vehicle commenced and the first gasoline powered automobiles hit the market of Germany in 1876. Two major problems are associated with petroleum powered automobiles; these are chemical and noise pollution. These are causing tremendous damage to the nature and its habitat. Also the petroleum reserve is fast depleting. Hence all the eyes were focused towards non-petroleum bases automobile. Automobile with alternate fuels, engine with improved efficiency were tried but keeping the health of our planet in mind, maximum thrust of research is aim to run the automobile using green energy. Solar energy, the most popular green energy, found suitable in light transport like rickshaw and three wheelers because of low energy density. EV may be the solution of future transportation system. It offers zero emission and reduces noise pollution. Cost of purchase of EV is more, though its less running cost. The technology, especially the energy storing technology is yet to be matured. Overall cost of EV will come down within affordability with the technology. EV will be popular over conventional vehicle and it appears to be the viable solution in near future.
Flattening analysis of plastically graded cylindrical contact under plane stress condition
Authors: Jana Tamonash , Mitra Anirban , Sahoo Prasanta
Published: February 2021

The present work deals with finite element based flattening analysis of a functionally graded cylindrical contact against a rigid flat surface under plane stress condition. The yield strength of the semi-cylinder is varied radially according to an exponential function. The contact between the semi-cylinder and the rigid flat is considered to be perfect-slip type in nature. To reduce the computational time, a 2D quarter circle is used to model the cylinder and rigid flat surface is modelled using a straight line. The effect of the gradation parameter on contact behaviours e.g. contact area, contact force, contact pressure etc. of the semi-cylinder are presented and discussed.
EXPERIMENTAL INVESTIGATION ON A DOWNDRAFT BIOMASS GASIFIER USING TREE WASTE AND SAWDUST PELLET
Authors: Dutta A. , Das Sampad Kumar , Roy P. C.
Published: February 2021

In this article, investigation and analysis of an experiment for downdraft biomass gasification has been conducted using two different feed stocks namely tree waste and sawdust pellet at different equivalence ratio. The different gas yield due to gasification mainly hydrogen, carbon monoxide, methane, carbon dioxide and nitrogen have been observed by the use of online gas analyser. The equivalence ratio of air has been varied from 0.3 to 0.4 for both of the biomass feedstock. On the basis of producer gas yield, the LHV of producer gas have also been calculated for different equivalence ratio and for both of the biomass. After that the LHV has been compared between the two biomass feedstock for equivalence ratios of 0.3, 0.33 and 0.4. The trend of LHV on the basis of different equivalence ratio has been examined and plotted.
Experimental analysis of small scale water cooler equipped with TTHC heat exchanger
Authors: Kumar Rajesh , Gaurav Kumar , Chandra Prakash
Published: February 2021

In the present work, experiments were conducted to recover waste heat from water cooler condenser. A Tube in Tube Helical Coil (TTHC) heat exchanger was made from cu pipe of 4.47 mm outer diameter of inner tube and 8.30 mm inner diameter of outer tube replaced the water cooler condenser to recover the waste heat. A new empirical correlation was suggested to predict the annulus Nusselt number for laminar flow of water with Reynolds number ranging from 1500 to 3900 and Prandtl number approx 1.6. The results reveal that the annulus Nusselt number varies with volume flow rate through annulus of helical tube significantly in laminar flow region. The small scale water cooler equipped with TTHC heat exchanger recovered maximum 371.5 W heat by cooling water.
Thermal Model Development of a Biomass Regenerated Desiccant Supported Greenhouse Cooling for Orchid Cultivation
Authors: Mandal Chandan , Ganguly A.
Published: February 2021

In this paper, a novel scheme of biomass regenerated desiccant supported greenhouse cooling with distributed fan-pad evaporative system has been proposed. The system aims to provide suitable thermal condition inside the greenhouse for cultivation of high value flowers like varieties of Orchid which require a temperature between 21 °C to 26 °C and humidity from 50 to 70% for the sub-tropical climate prvailing in the plains of India. In the proposed system two stage desiccant based cooling is used to obtain a low humidity ratio. A biomass based heating system is coupled for regeneration of the desiccant. Thermal modeling of desiccant wheel and greenhouse are done to estimate air temperature inside the greenhouse. A comparative study has been made based on estimated greenhouse air temperature with the results of the reference model available in the literature. From the performance analysis of the proposed system, it is revealed that the maximum temperature of the greenhouse air can be restricted within 25 °C and 25.8 °C for a hot and humid day prevailing in the month of July and September respectively. However the system can maintain a lower temperature of 19 °C during the morning time which is more conducive for target plantation (Orchid) in the given region.
RANS studies of hydrogen-enrichment premixed turbulent flames
Authors: Muppala Siva PR , Vasudevan Sooraj Paleli M
Published: February 2021

In this study, we show numerical predictions of the Zimont and Peter’s turbulent flame speed models for low-swirl Methane/Air/Hydrogen flames [1]. These models are contained as default options within the ANSYS Fluent Premixed reaction model. Two distinct simulation tasks as part of the present study are – non-reacting and reacting flows, for with three different methane mixtures in compositions added with – 0, 40 and 60% hydrogen. The results show that the RANS approach provides a reasonable prediction of the cold flow conditions, whilst the reacting flow conditions, good agreement is reached up to 40% enrichment, except near the recirculation region,.
Energy harvesting applications using 3D-printed coreless generator
Authors: Herawan Safarudin Gazali , Syahputra Said Abi , Tokit Ernie Mat , Sa’at Fatimah Al-Zahra Mohd , Rosli Mohamad Afzanizam Mohd
Published: February 2021

3D-printed coreless generator has been presented for energy harvesting applications using permanent magnet as source of external magnetic field in the rotor. The phototype of proposed coreless generator is built using 3D-printer with Black Polylactic Acid (PLA) as a filament for stator housing, rotor and other parts. The major parts of the proposed coreless generator are the stator, which has four coils of winding copper wire and the rotor with eight permanent magnets which are arranging N and S magnet poles alternately. This research is conducted to determine how much power can be generated from the proposed 3D-printed permanent magnet generator. The prototype permanent magnet generator is tested with rotational speed and load condition. The experimental results have been shown that the coreless generator can generate the electrical energy up to 5 W at 6000 rpm.
Comparison of BLOCPLAN and CORELAP algorithm for Material Handling Improvement at M Bakery
Authors: Lufika Raihan Dara , Sentia Prima Denny , Maulana Irfan
Published: February 2021

It is essential to have a suitable and effective layout design on a production floor. M Bakery is one of the bread industries that has been established since 2010. The core problem in the case study object is the far distance of the material handling movement. One solution to this problem is to improve the layout of facilities in the production area. The study will compare two different algorithms which are BLOCPLAN and CORELAP and choose the best one between these algorithms. The total movement moment of the current layout is 379,932 meters/year and OMH is IDR 1,215,712/year. The results of the BLOCPLAN based layout are the total movement moment of 263,767 meters/year, OMH of IDR 1,054,201/year, and an efficiency rate of 30.57%. While the results of the CORELAP based layout are the total movement moment of 418,710 meters/year, OMH of IDR 1,477,648/year, and an efficiency rate of -10.21%. From the comparison of the result of the two algorithms, the chosen proposed layout design is the BLOCPLAN based layout which has the highest efficiency rate of 30.57%.
RETRACTED: Mechanical and Acoustical Properties of Short Oil Palm Frond Fibre Reinforced Polyester Composites
Authors: Sabri  , Fuadi Zahrul , Kurniawan Rudi , Rizal Samsul
Published: February 2021

This paper presents the determination of tensile, flexural, and acoustical properties of short oil palm frond (OPF) fibre reinforced polyester composites and issues that have to be controlled in order to improve those properties. Three composite samples were fabricated using fibre content of 5%, 10% and 15% (by mass fraction) each. The tensile strength and elastic modulus of the composites were determined by tensile test conforming to the ASTM D638 standard and the flexural strength was measured by the three-point bending test method in accordance to ASTM D790 standard whereas the acoustical properties were determined by transfer function method conforming to the ISO 10534-2 standard. It is showed that the OPF-polyester composites possess greater tensile strength and flexural strength at lower fibre content while the elastic modulus registered increment with higher fibre loadings. Reduction in tensile and flexural strengths at higher fibre content is caused by poor stress transfer mechanism as the combined effect of inadequate fibre/matrix interface adhesion and stress concentration spots. Fibre agglomeration, which causes hindrance to the polyester macromolecule chain mobility, is accounted for the increment in stiffness properties as the amount of fibre is increased. From the measurement of the acoustical properties shows that the sound absorption coefficient is a function of incidence frequency. The normal incidence sound absorption coefficients for different frequencies tend to increase with increasing frequency operation. There is an excellent agreement between the absorption coefficient and the input frequency.
Review and comparative analysis of computational algorithms for modeling the dynamics of elastically supported structural systems
Authors: Skalko Yu I , Gridnev S Yu
Published: February 2021

The work is devoted to the comparative analysis of computational algorithms for modeling the dynamics of elastically supported structural systems with intermediate and limiting supports in the presence of point forces applied to the superstructure. The considered algorithms are based on the model formulation in the form of a system of partial differential equations for generalized functions. This approach avoids the need to subordinate the basic functions to the boundary conditions and include the presence of sources of the forces, applied at a certain point, in the model.
Buckling of compressed rods taking into account their own weight under different boundary conditions
Authors: Chepurnenko A S , Yazyev S B , Vysokovskiy D.A , Verzhbovskiy G B
Published: February 2021

The article is devoted to the problem of calculating the stability of compressed rods taking into account their own weight. The fourth order resolving differential equation with respect to dimensionless deflection was obtained. A technique for the numerical solution of the resulting equation is proposed using finite differences method. As a result, the problem was reduced to a generalized eigenvalue problem. Comparison with the solution of other authors is given.
Updating the architectural heritage of the Krasnodar Territory, in the context of its preservation and restoration
Authors: Subbotin O S
Published: February 2021

The priority for the preservation and restoration of objects of architectural heritage, which are an important historical and cultural potential of the Kuban is indicated. It was noted that this potential has actual effectiveness and allows it to be realized in the strategic development of the region. The expediency of applying the preservation mechanism for the objects of architectural heritage for the investors and non-budgetary organizations wishing to rent premises in these objects is recommended. An assessment of the economic significance of this mechanism implementation is given. The necessary measures are identified, in the context of “smart space” to carry out appropriate work to create the historical environment comfort, in terms of the innovative technologies‘ application.
Strength and deformation of bending normal sections made of concrete frame structure
Authors: Mailyan D R , Nesvetaev G V , Koryanova Yu I , Lesniak E V
Published: February 2021

Concrete of the frame structure, obtained by the separate concreting technology by immersing a coarse aggregate in a low-viscosity mortar component due to increased concentration of coarse aggregate, have a number of advantages in comparison with the traditional concretes of vibration compaction.
Analytical optimization of the dispersion-reinforced fine-grained concrete composition
Authors: Zhukov A D , Bessonov I V , Bekele A D , E A Zinoveva E A
Published: February 2021

The article presents the results of studying the problem of the concrete scrap accumulation and disposal. It is noted that after the implementation of comprehensive programs, including the renovation and modernization of the housing stock, a significant amount of concrete scrap has already been accumulated, and its amount will only increase. The results of scientific research on the compositions development of composite binder and fine-grained dispersed reinforced concrete based on this binder are presented. The purpose of the research described in the article was to develop the elements of a methodology for selecting the dispersed reinforced composite material composition based on finely ground waste of concrete scrap, mineral binder, thin basalt fiber and superplasticizers. The goal was solved using the methodology of technological processes system analysis and, in particular, mathematical planning, processing the experimental results and applying the analytical optimization method. It is noted that fine grinding of mineral components and the use of fibers with a diameter of 0.1 … 6 microns allows not only to modify the concrete structure with an increase in strength characteristics, but also changes the chemical and physicochemical processes‘ nature on the contact surfaces of the mineral matrix and fiber, as well as the same binder and finely ground reactive mineral particles with the formation of microsystems qualified as nanostructures.
Calculation of a beam with external reinforcement. Contact layer model
Authors: Tsybin N Yu , Andreev V I , Turusov R A
Published: February 2021

The article is devoted to the stress-strain state study of the beam, with external reinforcement in the tensile zone. The classical Euler-Bernoulli hypotheses are used for the beam. The interaction of the beam with the reinforcement layer is carried out using the contact layer. In order to simplify the previously obtained solution, the flexural stiffness of the reinforcement layer is not taken into account. As a result, the solution of the resolving equations system for this model has been obtained. It is shown that the obtained solution allows satisfying all boundary conditions, including the equality to zero of the shear stresses at the corner points. The influence of various mechanical and geometric parameters on the stress-strain state of the beam, the reinforcement layer and the contact layer is analyzed. The influence of the introduced simplifications on the solution results is analyzed.
A non-standard mark‘s center recognition correctness by a 3D laser scanner
Authors: Gura D A , Shevchenko G G , Dyakova N A , Pshidatok S K
Published: February 2021

Terrestrial laser scanners have sophisticated specialized software that makes it possible to measure three-dimensional coordinates of a huge number of points in a short period by registering vertical and horizontal angles. To determine the spatial position of the scanner and the coverage of the area of interest on one scan, special marks are placed around the scanner. These marks are used for further high-precision scan matching. The problem of the process of recognizing the center of black and white marks during field shooting, as separate from the scanning process itself, is a separate task, which has not been sufficiently studied. The purpose of the experiment is to establish the correctness dependence of the mark center recognition on its various characteristics. The technique is the experimental component and theoretical analysis of the obtained material. The experiment was carried out under the same conditions, so that the influence of the distance from the device to the mark, a change in the angle between the laser beam and the mark plane could not affect the recognition correctness of the mark center. In the course of the experiment, 8 marks were prepared with a non-standard view and size, as well as one standard black and white mark, to check the reliability of the data obtained (diameter 74.1 mm, two opposite sectors are black, and the other two are white). This experiment showed that the process of recognizing the mark center depends on the combination of the following characteristics: mark geometry, mark color, the opposite sectors of the mark.
Geodesic provision for cadastral works: development prospects
Authors: Gura D A , Nedyakina A P
Published: February 2021

The article analyzes the geodesic provision development when performing a cadastral survey. It has been established that improvement will be manifested in the use of modern geodetic technologies - three-dimensional laser scanning. The analysis of literary sources showed that there is a significant number of scientific works on the use of laser scanning for obtaining cadastral data and creating a three-dimensional cadaster. Methods for performing cadastral surveys, criteria for choosing a measuring instrument, methods for assessing the accuracy of coordinates, algorithms for processing the scan data, building models have been developed. However, the issues of further use of three-dimensional information for the cadastral documentation preparation are practically not covered, while the cadastral documentation is the basis for introducing the information into the real estate cadaster. The article presents the results of performing the ground-based laser scanning of a linear object. Additional information that can be introduced to the real estate cadaster in connection with the use of three-dimensional technology - height, technical condition of a linear object has been established. The sections of the technical plan and the changes made to them have been given. In addition, it was revealed that when using three-dimensional data in the preparation of technical plans, it would be inevitable to develop the software that can create boundary, technical plans based on three-dimensional data.
Opportunities for the drinking water resources‘ export-oriented commercialization as a potential element of the economic framework in mountainous areas
Authors: Kalov R O , Kiloev D D , Elmurzaev R S
Published: February 2021

The predicted reserves of fresh groundwater in the Kabardino-Balkarian Republic (KBR) reach 7200 thousand m3/day, which is 31.2% of similar resources in the North Caucasus Federal District, ranking first in the region. In terms of mineralization in general, groundwater in the KBR belongs to the class of “fresh groundwater” in terms of chemical composition they are classified as “drinking” in terms of total hardness - to “moderately hard water”. Water does not contain significant concentrations of heavy metals and inorganic nitrogen compounds. However, the use of the indicated potential is limited only to the creation of local lines for bottling water with a small capacity, mainly focused on the republican and regional markets of Russia. The purpose of this study is to substantiate the hypothesis about the sufficient resources‘ availability of hydrogeological materials suitable for industrial production and bottling as ecologically clean drinking water. Within the framework of the designated goal, the following tasks were solved: - search for mountain landscapes, in the first approximation localizing the balance reserves of fresh groundwater; - environmental monitoring of the sites previously designated as favorable for the drinking water extraction; - the productive aquifers‘ assessment nature and the conditions of their natural protection from pollution; - identification of natural components that maintain the balance of groundwater and factors of its change over time; - establishing the specifics of groundwater discharge and the dynamics of regime-forming processes in the vertical zoning conditions in the study area.
Rating assessment of an urbanized area for insurance purposes
Authors: Zaalishvili V B
Published: February 2021

A rating assessment of the engineering-geological and geomorphological features of the territory has been carried out in the work. An area of 5 km x 4 km was allocated on the territory of Tbilisi. The area was divided into the squares with the size 100x100m. The minimum size of the plots was determined by the maps scale 1: 10,000. On the basis of these maps, each plot was assigned a rating according to the appropriate factor (soil type, layer thickness, groundwater level, relief, hazardous geological processes - landslide, avalanche, rockfall). Each factor was assigned a corresponding rating index (0-4). The best sites had the lowest index. Final maps of individual site ratings were compiled for various factors (soil type, thickness, etc.). On their basis, a summary rating map has been drawn up. All maps were made in GIS technology. The paper shows that the influence of these conditions can be significant in the absence of seismic impact. The results of the work can serve as a basis for assessments of any level, including for assessing seismic risk, as well as for insurance of buildings and structures located in the relevant territories.
Management of organizational and technological design in construction based on information modeling (BIM-technologies)
Authors: Gushchina Yu V , Nikolaev Yu N , Chernikov A A
Published: February 2021

The article discusses the modern application aspects of information modeling technologies for buildings and structures (BIM-technologies) in the construction projects’ management. The introduction of information modeling technologies into the investment and construction project management process will allow not only using automated tools for performing various types of analysis and verification, visual planning and optimization of the construction process, but also provide regulated access to the object data to all interested parties in a single information environment.
The microstructure and mechanical properties of Mg-Gd-Y-Zn-Zr system and Mg-Gd-Y-Zr system alloys by RUE deformation
Authors: Jia Leichen , Yu Jianmin , Xu Wenlong , Wu Guoqin , Xia Qing , Zhang Zhimin
Published: February 2021

This study investigates the effects of long-period stacking order (LPSO) phases on the dynamic recrystallization (DRX) process. By comparing Mg-Gd-Y-Zn-Zr (GWZ) alloy and Mg-Gd-Y-Zr (GW) alloy deformed by 4 passes of Isothermal Reciprocating Upsetting-Extrusion (RUE), the initial alloy grain sizes are 113.4 μm and 88.2 μm, respectively, after 4 passes, the grain size becomes 3.5 μm and 4.8 μm, and the grain refinement of GWZ is greater. After 1 pass, the DRX volume fraction of GWZ alloy is 83% and 15%, which is related to the LPSO phases contained in the GWZ alloy. The texture strength of the GWZ alloy ranges from 8.5 of 1 pass to 2.2 of 4 passes, while the GW alloy is from 5.9 of 1 pass to 2.8 of 4 passes, mainly due to the DRX grain volume fraction. The tensile test results at room temperature (RT) showed that the ultimate tensile strength (UTS) and tensile yield strength (TYS) of GWZ alloy are higher than that of GW alloy, and the elongation is lower than that of GW alloy.
Large area deposition of Janus MoS2x
Se2(x−1) on paper as a multifunctional electromechanical sensor for versatile physiological signal monitoring
Authors: Bokka Naveen , Ganeshan Sankalp Koduvayur , Sahatiya Parikshit
Published: February 2021

The recent advancements in smart materials, processing techniques, and sensing technology have pervasive to the development of the modern era of flexible electronic systems. Flexible pressure and strain sensors with multi-functional sensing capabilities have gained significant interest as they have potential applications in human motion detection, physiological signal monitoring, flexible robotics, electronic skin, and smart displays. Hence this puts forward a higher requirement to develop highly sensitive, low cost and high-performance electromechanical sensors. Herein, we demonstrate the fabrication of solution-processed MoSSe/paper-based flexible Pressure and strain sensor with PDMS encapsulation using facile hydrothermal and vacuum filtration method with merits of low cost, large-area deposition, high scalability, and superior sensing performance. The fabricated device exhibited a very high sensitivity of 108.09 kPa−1 and a gauge factor of 27.57 with good reproducibility, stability, and resilience for 1200 bending cycles which indicates the robustness of the device. The enhanced sensing efficiency can be accounted for the excellent piezoelectric property and the pressure, strain-induced bandgap modulation observed in Janus MoSSe which arises due to the loss of symmetry in the crystal lattice. The sensors were utilized for real-time applications for the detection of various human physiological signals by integrating them into body parts, breath sensing, handwriting recognition, unknown shape detection, and pressure mapping. This successful demonstration of high performance, low cost, and large area deposited paper-based pressure and strain sensors, opens up new opportunities for far-reaching applications in health care, security, smart systems, and robotics.