Nesting preferences of the green sea turtle (Chelonia mydas L.) and the hawksbill sea turtle (Eretmochelys imbricata L.) in the SW of Mahe Island in the Seychelles

Data concerning 212 turtles emerging on the southwest beaches of Mahe Island in the Seychelles were collected in 2017 and 2018. These data were used to model the probability of eggs being laid in relation to several variables. The probability of successful laying after emergence was highest on certain beaches and in areas of short vegetation, between open sand and trees. We found successful laying was related to the physical properties of the soil, indicating that survivability of embryos and hatchlings is higher in certain areas. The turtles appeared to choose zones where soil had low salinity, good drainage but ability to retain water, and absence of spring tides and extreme temperatures.

Respons tanaman tebu (Saccharum officinarum L.) terhadap aplikasi konsorsium biostimulan di tiga tipologi lahan

The consortium biostimulant combines several types of biostimulant applied holistically, such as phytohormones to induce physiological processes, humic acid to improve nutrition intake and land fertility, and biofertilizer arbuscular mycorrhizal fungi to improve abiotic stress tolerance. The objectives of this research were to analyze the effect of application consortium biostimulant on the growth and productivity of Bululawang sugarcane variety planted in three land typologies, i.e. irrigated heavy soil with good drainage (BPL), irrigated heavy soil with poor drainage (BPJ), and rainfed light soil with good drainage (RHL). The research was conducted on plant cane (PC) sugarcane areal in Lumajang Regency, East Java, from July 2019 to September 2020. The treatment plot area was 1 ha for each land typologies, and the observation were conducted on 10 m plant row with ten times replications. Each treatment was replicated ten times. The results showed that the application of consortium biostimulant could induce faster growth of sugarcane shoots and better roots at one month after planting (MAP). Stalk height and diameter showed significantly different values between treatment and control at the plant age 6 to 12 MAP. In addition, the sugarcane stalk weight per meter row also increases by 13.72 – 28.57%. The growth performance of sugarcane on a commercial scale increased, also sugarcane productivity increased by 11.08 – 20.36%. The potential sugar yield increased by 15.05% in BPL land typology, 4.9% in BPJ land typology, and 9.7% in RHL land typology. The difference in land typologies affected the effectiveness of the consortium biostimulant application in increasing sugarcane productivity.

Temporal and Local Heterogeneities of Water Table Depth under Different Agricultural Water Management Conditions

Integrated water management has become a priority for cropping systems where subirrigation is possible. Compared to conventional sprinkler irrigation, the controlling water table can lead to a substantial increase in yield and water use efficiency with less pumping energy requirements. Knowing the spatiotemporal distribution of water table depth (WTD) and soil properties should help perform intelligent, integrated water management. Observation wells were installed in cranberry fields with different water management systems: Bottom, with good drainage and controlled WTD management; Surface, with good drainage and sprinkler irrigation management; Natural, without drainage, or with imperfectly drained and conventional sprinkler irrigation. During the 2017–2020 growing seasons, WTD was monitored on an hourly basis, while precipitation was measured at each site. Multi-frequential periodogram analysis revealed a dominant periodic component of 40 days each year in WTD fluctuations for the Bottom and Surface systems; for the Natural system, periodicity was heterogeneous and ranged from 2 to 6 weeks. Temporal cross correlations with precipitation show that for almost all the sites, there is a 3 to 9 h lag before WTD rises; one exception is a subirrigation site. These results indicate that automatic water table management based on continuously updated knowledge could contribute to integrated water management systems, by using precipitation-based models to predict WTD.

The history of the forming and the features of the soil, lithological and geomorphological structure of the Jizzakh steppe as the basais for its natural zoning

The paper provides initial materials characterizing the complicated history of formation, natural soils and lithological-geomorphological conditions of the Jizzakh steppe before the beginning of reclamation development. It is shown that on the basis of soil-lithological and geomorphological zoning, the Jizzakh steppe is divided into a number of natural regions belonging to different levels (altitude levels) of the piedmont plain. In total, 22 districts have been identified within the Jizzakh steppe, including the foothill margins. On the piedmont plain itself, the regions are combined into two high-altitude levels: the upper step and the lower step or blanket zone. These two levels differ sharply in terms of drainage conditions and soil salinity. The upper level, covering the upper and middle parts of the alluvial fan, the high interconal Zaamin-Sanzar plain and the Lomakino plateau, is characterized by a weak manifestation of salinity due to relatively good drainage, except for the sloping depressions of the Lomakino plateau. In contrast to the upper level, the lower level, located in the blanket zone of the piedmont plain, is characterized by active natural salinization because of the poor drainage. The saline sediments of the Zaamin cone delta are characterized by the greatest thickness. To a lesser extent, the rocks of the Sanzar cone delta, which are drained by deep gullies, are salinized. The Khavast sloping plain is characterized by a strongly saline upper two-meter layer, with salt and gypsum content decreasing with depth. Thus, it is shown that high salinity and gypsum bearing rocks, as well as high groundwater salinity of the cone delta zone are the source of modern salt accumulation in soils of foothill Golodnostepskaya plain, as well as in soils of the cone delta zone of Djizak steppe.

Den characteristics and ecological significance of Marmota himalayana on the Qinghai-Tibet Plateau

Dens are places for cavernicolous animals to hibernate, reproduce, and avoid predators and harsh weather conditions, and thus they have a vital impact on their survival. M. himalayana is the main large cavernicolous rodent on the Qinghai-Tibet Plateau. The analysis of den traits and their ecological functions can reveal mechanisms by which marmots have adapted to their environment, which is important for further understanding the ecological significance of this species. From July to August 2019 (warm season), we used unmanned aerial vehicles to fly at low altitudes and slow speeds to locate 131 marmot burrows (45 on shaded slopes, 51 on sunny slopes, and 35 on flat areas) in the northeastern Qinghai-Tibet Plateau. We then measured the physical characteristics (den density, entrance size, first tunnel length, volume, orientation and plant characteristics near the den entrance) of these dens on site. The physical parameters of the M. himalayana dens showed that they function to protect the marmots from natural enemies and bad weather, provide good drainage, and maintain a stable microclimate around the entrance. This is a result of the marmot’s adaptation to the harsh environment (cold and humidity) of the Qinghai-Tibet Plateau.

Studying the Effects of Roads Geometry and Design Parameters on the Pavement Drainage System

Background: Water floods have a considerable impact on roads sustainability by creating roads cracks, breaking down and holes, and failure for some other parts. The existence of good drainage system serviced the road and draining the water resulted from rain floods is crucial. These significant influences can be classified as positive or negative, low, moderate, or high. Aim and Objectives: This paper discusses the water floods and rainfall effects on roads and highways in Jordan as well as the drainage system on road sustainability and performance. The main aim of this paper is to investigate and analyse water as rainfall or floods affecting roads and highways in Jordan. The importance of this study is represented by studying and analysing the effects of rainfall and water floods on road construction and sustainability in Jordan after the latest high rain sizes of this winter and water floods, which affect the roads and highways in a good percentage. The other importance of the study is represented in offering solutions to problems caused by the environmental effects, specially floods and high rainfall rates. Methodology: all data and information about status of Jordanian roads during winter and floods are collected from real cases of about 40 main and semi-main roads in Jordan. Results and Conclusions: A good drainage system and repair operations and maintenance generally have a positive impact on road sustainability and survival age. The effects of slopes of the road and surface of the asphalt, rainfall intensity, and water flow velocity on drainage length and drainage time and water depth are discussed here. Doi: 10.28991/cej-2021-03091636 Full Text: PDF

Recent studies on railway-track substructure at TTCI

Railway-track substructure is the foundation of the railway-track infrastructure and consists of four major components: ballast, sub-ballast, subgrade and drainage. Safety and performance of the track infrastructure, to a large degree, depends on the performance of the track substructure. Adequate support from the track substructure is the most critical element needed for good track performance. When properly constructed and maintained, the ballasted track is the most cost-effective track structure for railway operations, especially for heavy-haul freight operations. Good track-substructure support is characterized by good drainage and strong resistance of the ballast, sub-ballast and subgrade layers to excessive deformation and failures under repeated dynamic wheel loads. As the track substructure plays such important roles, research concerning track substructure has been broad and extensive around the world, with many universities and research institutes conducting various studies and investigations. This paper provides an overview of the recent research conducted at Transportation Technology Center, Inc. (TTCI), a subsidiary of the Association of American Railroads (AAR), in the following areas: ballast mud pumping and its effects on track performance, remediation of subgrade mud pumping, remediation of ballast pockets, ground-penetrating radar (GPR) for inspecting track substructure, and development of software tools with focus on track-substructure functions and management.

Effect of Stabilization on Failure Susceptibility of Oshogbo-Iwo Road in South-Western Nigeria

The research evaluated the failure susceptibility of biopolymers (Guar Gum, Xanthan Gum, Bentonite) and polyvinyl acetate (PVAc) stabilized soil samples from three failed locations along Oshogbo – Iwo Road’s using the TDRAMS mathematical model formulated by Aderinola et al., (2015). The stabilizers were added to the soils in concentrations of (0.25-2) % Biopolymers, (1-3) % Bentonite and 2% PVAc. The samples were classified according to AASHTO as A-5 (slty-sand) and ML group (inorganic silts, sfine sands with low plasticity) based on USCS classification system. Geotechnical tests carried out on both natural untreated and treated samples showed that the natural soil samples gave OMC values of between (11.7-14.97) %, MDD (1644-1453.6) Kg/m3, and soaked CBR (2-6) %. 1% Guar gum, 1 % Xanthan gum, 3% Bentonite and 2% Poly vinyl Acetate were deduced to be optimal mixes for improved strength. However, Guar gum was observed to be the best stabilizer. With the TDRAMS model, 1% Guar gum reduced the failure susceptibility indices of the road by 11.02 % (i.e. from 127 to 113). However, for maximum benefits to be achieved from the stabilization, other factors like provision of good drainage facilities, adequate road sections etc. must be provided. This will help in improving the strength of the subgrade soils and overall durability of the road.

Environmental Management Strategy In Schools: A Case Study At SMA Negeri 1 Bekasi, West Java

This paper aims to find out about school environmental management strategies in West Java secondary schools. To guide the study, three research questions were formulated. This is achieved by administering a structured questionnaire in a random sample school of 100 students. The findings show regular lawn cleaning, school complex sweeping and painting, landscaping and flower planting, good drainage and garbage disposal are strategies adopted for managing school environments. While the lack of gardeners to keep the school complex clean, erosion, students and teachers are not responsive to environmental problems, difficulties in instilling students' environmental values due to different care of homes, lack of funds for procurement of work tools/equipment and challenges of waste disposal are some of the challenges. Identified in the management of the school environment. For a better and better school environment for good academic practice, school environmental management team, plans for drainage and waste disposal, consideration of school locations for new schools, janitorial work, terminal orientation programs, development of curricula on environmental management, inspections and school competitions and awards are recommended

Engineering Properties Of Ceramsite Proppant And Its Application On Hydraulic Fracture For A Coalbed Methane Well

Ceramsite is a porous engineering material with some basic mineral constituents, and has advantages of low density, high sphericity and high flow conductivity. It should be a good attempt to be adopted in hydraulic fracture, but related researches are really weak. In this paper, laboratory experiments are conducted on ceramsite, coated ceramsite and other typical proppants, which indicates that the coated ceramsite is the best proppant. Then, a coalbed methane well located in the soft coal area in Qinshui basin of China is selected as the research object, numerical simulations and statistic analyses are both conducted to obtain the granularity proportion and parameter optimization by using coated ceramsite. Some findings are achieved. Numerical simulation indicates that the granularity proportion for coated ceramsites of 40/60, 16/40 and 12/20 mesh should choose 1:6:2, which can receive a biggest proppant concentration and strongest flow conductivity. Construction parameters are all optimized for a best fracture performance. Micro seismic monitoring indicates that the actual fracture performance matches well with the simulated result. Drainage performance comparisons reveal that coated ceramsite is suitable for soft coal areas, and can achieve good drainage performances.