Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

There are many overlaps between sustainability concepts so they are sometimes used interchangeably. This study was aimed to provide a deep analysis of the sustainability concepts in the circular supply chain (CSC) field and to identify research gaps and paths for future research. We conducted a search using keywords including “sustainability” combined with at least one of the keywords sustainable supply chain, green supply chain, circular supply chain, and closed-loop supply chain in the Google Scholar, ScienceDirect, and Emerald as well as the Web of Science. Mind Map Software was used to identify the gaps in the use of the CSC. The comparative investigation of the different concepts of sustainability showed that the CSC encompasses all concepts of sustainability and has a comprehensive concept that goes beyond all concepts of sustainability.

Carbon bonds are a management tool that is being implemented globally to reduce CO2 emissions into the environment, through forest, soil and water conservation protocols. It forms a main part of the commitments made in the Kyoto Protocol to reduce global warming. For its part, the state of Quintana Roo is a pioneer in the incursion of carbon bonds at the micro-basin level, and where sustainable tourism is consolidated as a preponderant activity catapulted by the spill over effect of the Mayan Train Megaproject, however; the lack or inadequate environmental planning could produce deleterious effects. In this sense, they have been allocated by assembly agreement in 2019 (35 thousand Ha) of tropical forest as ANP. With the technical support of specialists (UTCalakmul), the total biomass, carbon storage and fixation in PF and SAF were estimated as a mitigation indicator according to IPCC. Total height and DBH of trees with DBH≥10 cm and D30 in the case of timber trees were measured. BA was estimated using allometric methods and with biomass expansion factors. The average fixation rate was 5.9 t C/ha/year and the FPs stored up to 70 t C/ha. The participation of the ejido in caring for the forest, soil and water in collaboration with NGOs led to the issuance of the bonds as of August 15, 2021. The results obtained demonstrate the importance of these mechanisms for the promotion of soil, water and forest conservation in Quintana. Roo. And that the integral participation in community projects by academics, NGOs and community members is viable and feasible.

Pastes of sugarcane bagasse ash (SCBA) and calcium aluminate cement (CAC) were activated with sodium silicate solutions, varying the SCBA content (80-95 wt.%), the SiO2/Na2O ratio (8-14 wt.% respect to the weight of SCBA), and the curing temperature (20 and 40 ºC or 100 and 200 ºC). 28 days-compressive strength between 5-20 MPa were obtained. The results are close to the reported in the literature for pastes of SCBA/metakaolin. Overall, it was observed that the compressive strength decreased with the increase in the curing temperature from 100 to 200 ºC. The gain in the compressive strength was attributed to the formation of a dense matrix of amorphous reaction products such as C-S-H, N-A-S-H, C-A-S-H, or silica gel. Our results stress the feasibility to use higher contents of sugarcane bagasse ash to obtain alkali-activated cement with compressive strengths up to 20 MPa. Further work is currently underway to identify the effect of some variables on the compressive strength of composites.

The Trichoderma spp genus represents a very important group of organisms in modern agriculture because they inhibit the growth of phytopathogenic fungi. However, it has been published that its ecological behavior varies depending on the geographical region where it comes from. In this study, the ability of 17 native Trichoderma spp isolates to inhibit the in vitro growth of three Fusarium spp isolates was evaluated. For the isolation of the fungi, the serial dilution technique and the growth medium Papa Dextrose Agar (PDA) were used, later the antagonism against three isolates of Fusarium spp was evaluated by means of the dual culture technique. The three Fusarium spp isolates were molecularly identified as belonging to two F. equiseti isolates and one identified as Fusarium spp. The percentage of Radial Growth Inhibition (PICR) was determined; obtaining the following results T. harzianum, T. asperellum and T. virens presented the percentages of PICR with 81.57%, 79.62% and 78.62% respectively, surpassing the rest of the isolates. The isolates T. harzianum, T. asperellum and T. virens must be evaluated under greenhouse and field conditions to define effectiveness and establish applicability.

The combination of different qualities of leather waste with different polymers and the resulting mechanical properties are potentially important for obtaining new materials. In this study, experiments combining leather chip residue, vinnapas ®400 resin and distilled water produced a new composite material with interesting mechanical properties. In the elaboration, the pH of the leather chip, chip size, resin temperature, softening temperature, pressure and the pressing time exerted on the reconstituted leather plate were controlled. Using fractional factorial design, the influence of the selected independent variables was determined: chip size, chip/resin ratio, percentage of water, resin temperature, pressure and pressing time on the mechanical properties of the composite material. The experimental results showed that there was a main effect of the Chip/Resin ratio variable at its minimum value on the maximum traction effort, reaching a value of 2,657 MPa. Additionally, in the mechanical creep test, it was found that the composite material called reconstituted leather shows a viscoelastic behavior, which resembles the behavior of tanned leather.

In the present study, a bibliometric analysis was carried out on the species Dermochelys coriacea in the Scopus database for the last ten years. Two inquiry analyzes were used (co-authorship and co-presence), from the VOSviewer version 1.6.17 software. The items Dermochelys coriacea, and Mexico were used to search for relevant publications. A total of 7 articles were found during the period 2010 - 2021, in each year there was at least one publication. The author who published the most on this species is García-Grajales (N=2) (Universidad del Mar) and the state that recorded the most articles on the species is Oaxaca (N=4). The topics of Ecology and Microbiology have been the most addressed and a total of 52 authors with articles on D. coriacea in Mexico were registered. The keywords provided by the authors of the articles were a total of 66, three of which reached the threshold. The words that appeared most frequently were: Dermochelys coriacea, leatherback and morphology.

According to the Federal State Statistics Service regarding respiratory diseases in Krasnoyarsk Krai, the increase in this indicator was 6% over the five years, and the increase in oncologic diseases was 4% over the same period. Polluted air is one of the leading causes of the increased incidence. The paper aims to find ways to clean indoor air using ion-electronic technology and bring the microclimate parameters to optimal values in cold and warm seasons. Experimental and theoretical studies substantiated the possibility of developing a device capable of creating and maintaining an air environment in closed premises, close in terms of indicators to the healthy air of ecologically clean regions. The device can have different performance and can be used in domestic, industrial, and public premises. Depending on the mode of operation and purpose, this device can be both stationary and mobile. Fine dust cannot be removed from the room even if the air exchange rate is increased by 200 and 400 times. It has been experimentally proven that ion-electronic technology and volatile matter of woody plants remove dust to achieve a clean room. This concept formed the basis for developing a device using nanotechnology combined with the volatile matter of woody plants. The dependences of the influence of artificial ionization of air and volatile matter of woody plants on reducing the amount of fine dust and pathogenic microflora are theoretically substantiated. The air purified in this way maintains immunity and reduces the incidence of respiratory diseases, which has been proven experimentally based on a prototype of the developed device.

The paper aims to compare the CO2, CO, CH, and O2 concentrations in the exhaust gases of Cummins KTA 50 diesel engines of BelAZ 75131 mining dump trucks equipped with an onboard cryogenic fuel system and running on diesel and gas-diesel fuel at coal mines of Kuzbass (Russia). The research novelty lies in determining ecological efficiency when using liquefied natural gas (methane) as a motor fuel for heavy-duty mining dump trucks. In the near future, the use of this type of motor fuel will minimize the anthropogenic impact on the environment by reducing harmful emissions and provoking the environmental safety of the region where a large amount of mining equipment is used in coal mining enterprises. The demand for mining dump trucks, their operating conditions, and the world experience in converting mining equipment to liquefied natural gas (methane) were briefly analyzed. The use of alternative fuel sources for heavy-duty mining trucks is a promising way to reduce harmful emissions into the atmosphere. This paper presents a research technique. The data on the study of the CO2, CO, and CH groups and O2 concentrations in the exhaust gases of Cummins KTA 50 diesel engines of BelAZ 75131 mining dump trucks hauling rock mass are presented. The obtained data on the CO2, CO, and CH groups and O2 concentrations during diesel and gas-diesel operation of empty and laden BelAZ 75131 mining dump trucks when going uphill and downhill were substantiated. The results of calculating the average weighted emissions of the CO2, CO, and CH groups in the exhaust gases of Cummins KTA 50 diesel engines were presented.

Improving the efficiency of technological tillage methods is primarily associated with developing existing tools and creating new types of working tools for tillage machines. Tillage efficiency improvement depends on the correct choice of the most energy-efficient working tools belonging to the same class of the technological process. This research aims to develop scientific baselines for choosing energy-efficient working tools of different structural designs based on the criteria of power consumption and quality of shallow tillage. The object of this research includes working tools for shallow and deep tillage. The research subject is the changes in the criteria chosen to evaluate the working tools’ efficiency. We involved mathematical modeling based on laws of science observed during tillage, carried out experiments and analyses, and summarised the experimental findings. The scientific novelty of this research justifies the criteria for evaluating the efficiency and quality of working tools used for shallow and deep tillage. The research relies on graphical and empirical dependencies describing the trends in efficiency evaluation criteria for tillage working tools with various operation speed modes. We discovered that to evaluate the efficiency and choose the most energy-efficient tillage working tool, one should use a system of criteria: specific tractive resistance of the active frontal area, terra-dynamic resistance coefficient, and the primary tillage quality parameters. The probability of compliance of the mean values of calculated and experimental findings (0.51–0.87) confirms the adequacy of proposed mathematical models describing changes in specific tractive resistance per unit of active frontal area and terra-dynamic resistance coefficient of tillage working tools. According to the research, when a more energy-efficient tillage working tool is chosen, the working tools under comparison belong to the same class of working tools based on the technological process principle and functioning conditions. Discovered trends in the changes in the efficiency evaluation criteria and the choice of energy-efficient tillage working tools for shallow and deep tillage are represented by empirical dependencies applicable in specific ranges of motion speed under certain functioning conditions. Consequently, we emphasized that further studies should justify the upper and the lower borders of the tillage working tools and terra-dynamic resistance coefficient in accordance with the agrotechnical quality indicators of tillage.

This study aims to justify the possibility of expanding the energy and economic efficiency of a district heating [DH] system. The case study territory is a remote area of the Omsk region (Russia); the method is electric heating. To address this issue, we (1) considered the potential of modernizing these DH systems, (2) analyzed available options, (3) designed the main and auxiliary heat generation equipment, and (4) committed a feasibility study. The design heat consumption was 0.24 MW. To achieve this goal, we suggested two heat pumps; their capacity was 280 kW, and the investment required to install two heat pumps of 150 kW was 2.6 billion rubles. The total capital cost was 4.0 billion rubles. The annual effect after the heat pumps were installed was 0.7 billion rubles. The payback period was 5.6 years; to decrease it, one should install multiple heat pumps on the consumer side. The reason is to avoid heat distribution losses. Replacing traditional DH plants with electric boilers is feasible only if the cost of heat is 6,600 rubles per MWh or above. This cost has already been achieved for several DH plants. Ground source heat pumps are viable at lower prices, approximately 4,100 rubles per MWh. This option is especially helpful in remote areas of the Omsk region where the billing tariff is already high. When modernizing the heat supply infrastructure of the northern areas of the Omsk region, one can increase annual electricity consumption by 6%, decrease tariffs, and become more ecologically friendly at the same time.