scholarly journals Barrier Longevity of NaCl-Laden Soil against Subterranean Termites in an Earth Embankment

2021 ◽  
Vol 13 (23) ◽  
pp. 13360
Author(s):  
Ying Li ◽  
Dong-Zi Pan
Keyword(s):  
Control Method ◽  
Salt Transport ◽  
Subterranean Termite ◽  
Richards Equation ◽  
Subterranean Termites ◽  
Environmentally Sustainable ◽  
Nacl Concentration ◽  
Field Efficacy ◽  
Earth Embankment ◽  
Good Potential

Subterranean termite-induced damage to earth embankments in agricultural systems occurs globally. NaCl-laden soil barriers (NLSBs) are an environmentally sustainable termite control method, and have exhibited good potential in preventing termite-related tunneling damage in Zhejiang Province, China. The persistence of the NaCl concentration in NLSBs is a key characteristic for the long-term prevention of subterranean termite infestations. This study is a scientific attempt to estimate the field efficacy and barrier longevity of NLSBs in reservoir embankments based on the Richards equation and the convection–dispersion equation using HYDRUS (2D/3D). The observed and simulated NaCl concentrations at the end of a 1915-day simulation were compared. The results indicated that the proposed model performed well and can effectively characterize the water flow and salt transport in NLSBs. The salt desalination rate of the NLSB in the upstream slope was higher than that in the downstream slope, both of which were significantly higher than that at the embankment axis. Regardless of the type of embankment (homogeneous or core-wall), the barrier longevity of NaCl-laden soil against subterranean termites can reach 50 years with an optimized NaCl/soil ratio in different parts of the embankment.

scholarly journals A Simulation of Salt Transport in NaCl-Laden Soil Barrier to Control Subterranean Termites in an Earth Embankment

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1204
Author(s):  
Ying Li ◽  
Dong-Zi Pan
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Hydraulic Conductivity ◽  
Rainfall Infiltration ◽  
Salt Transport ◽  
Subterranean Termite ◽  
Water Level Fluctuations ◽  
Subterranean Termites ◽  
Promising Alternative ◽  
Earth Embankment

Subterranean termite activity can increase the hydraulic conductivity and water infiltration of filling soil, and therefore affects the stability of an earth embankment and subsequent safety. As a physical barrier for sustainable termite management, NaCl-laden soil barrier (NLSB) is a promising alternative for subterranean termite control in earth embankments. This novel technology can prevent tunneling and penetration of subterranean termites into the interior of an embankment and has been widely employed for more than 20 years in Zhejiang Province, China. The efficacy and longevity of NLSB depend on the long-term presence of NaCl concentration in soil barriers. The aim of this study is to develop an understanding of water flow and salt transport in NLSB based on the two-dimensional Richards’ equation and convection dispersion equation using the HYDRUS software package. Conceptual and numerical models of NLSB are modeled using scenario analysis according to water level fluctuations, saturated hydraulic conductivity, and rainfall infiltration conditions. Furthermore, the center and spread variance of a solute mass over a 100-year period are quantified using moment analysis. As flood frequency, saturated hydraulic conductivity, and rainfall infiltration flux increase, salt desalination in NLSB significantly increases. When the rainfall infiltration flux is 1% of the annual average rainfall, the total amount of salt transport and leaching can increase by 55%. Moreover, these results facilitate better long-term sustainable management of existing sites and optimal design of future NLSBs.

scholarly journals Color change and termite resistance of fast-growing tropical woods treated with kesambi (Schleichera oleosa) smoke

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Yusuf Sudo Hadi ◽  
Muh Yusram Massijaya ◽  
Dodi Nandika ◽  
Wa Ode Muliastuty Arsyad ◽  
Imam Busyra Abdillah ◽  
...  
Keyword(s):  
Color Change ◽  
Acacia Mangium ◽  
Chemical Compounds ◽  
Subterranean Termite ◽  
Subterranean Termites ◽  
Schleichera Oleosa ◽  
Termite Attack ◽  
Wood Resistance ◽  
Tropical Woods ◽  
Anthocephalus Cadamba

Abstract Smoke treatment can be used to enhance wood resistance to subterranean termite attack. In this study, kesambi (Schleichera oleosa) wood was pyrolyzed to produce charcoal. The smoke produced as a by-product of pyrolysis was used to treat sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), mangium (Acacia mangium), and pine (Pinus merkusii) wood samples for 1, 2, or 3 weeks. Following the smoke treatment, the wood specimens were exposed to subterranean termites (Coptotermes curvignathus Holmgren) according to the Indonesian standard 7207-2014 in a laboratory. The color change caused by smoke treatment was observed, and chemical analysis of smoke was also done. The results showed that chemical compounds of kesambi smoke predominantly consisted of acetic acid, phenol, ketones, amines, and benzene. The color of smoked wood became darker, less yellow, and a little redder, while a longer smoking period produced a darker color which was more resistant to termite attack. Smoke treatment enhanced the resistance of wood to subterranean termite attack, and the resistance levels were not significantly different based on the duration of the smoke treatment.

Relative sodium-to-chloride permeability in the proximal convoluted tubule

1978 ◽  
Vol 235 (6) ◽  
pp. F592-F604 ◽  
Author(s):  
C. A. Berry ◽  
F. C. Rector
Keyword(s):  
Ion Selectivity ◽  
Paracellular Pathway ◽  
Salt Transport ◽  
Chloride Permeability ◽  
Nacl Concentration ◽  
Active Salt ◽  
Junctional Complexes ◽  
Series Of Experiments ◽  
Dilution Potential

Electrophysiological techniques were used in isolated perfused proximal convoluted tubules (PCT) to examine the effect of changes in bath protein concentration on paracellular properties and of active salt transport on relative sodium-to-chloride permeability (PNa/PCl). Control transepithelial potential difference (PD) and NaCl dilution potentials were determined in tubules perfused and bathed with an ultrafiltrate-like solution. PNa/PCl was calculated from the NaCl dilution potential. In the first series of experiments PD and PNa/PCl were redetermined in the same PCT following three experimental maneuvers known to inhibit active salt transport. Addition of 10(-5) M ouabain to the bath, removal of luminal glucose and alanine, and removal of luminal glucose, alanine, bicarbonate, and acetate reduced PD but did not alter the NaCl dilution potential, and therefore PNa/PCl was constant. Constant PNa/PCl in these experiments suggests a) that lowering bath NaCl concentration does not change transcellular current flow, b) that PNa/PCl reflects the ion selectivity of the paracellular pathway, and c) that the ion selectivity of the paracellular pathway is independent of active salt transport. In the second set of experiments PD and PNA/PCl were redetermined following addition of protein to the bath. Neither PD nor PNa/PCl was altered. Analyses of these data argue against modulation of paracellular permeability by bath protein in the in vitro rabbit PCT and suggest that the ion selectivity of the paracellular pathway is determined predominantly by junctional complexes rather than lateral intercellular spaces.

Termite Behavior: Measuring the Postanoxic Consumption Rates of Landscape Mulches by Eastern Subterranean Termites

2013 ◽  
Vol 75 (1) ◽  
pp. 41-45
Author(s):  
D. Parks Collins
Keyword(s):  
United States ◽  
Reticulitermes Flavipes ◽  
Statistical Test ◽  
Subterranean Termite ◽  
Subterranean Termites ◽  
Eastern United States ◽  
Different Types ◽  
Consumption Rates ◽  
Petri Dishes ◽  
Eastern Subterranean Termite

Populations of the Eastern subterranean termite, Reticulitermes flavipes, are widespread throughout most of the eastern United States. Subterranean termites have the ability to survive flooding conditions by lowering their metabolism. This lesson investigates the connection between the ability of termites to lower their metabolism to survive floods and their feeding behavior. Using an incubator, Petri dishes, and different types of mulch, termite consumption can be measured and compared. These results can be analyzed with a simple statistical test to look for significance.

scholarly journals Set-point Control of Mobile Robot with Obstacle Detection and Avoidance Using Navigation Function - Experimental Verification

2016 ◽  
Vol 85 (3-4) ◽  
pp. 539-552 ◽  
Author(s):  
Wojciech Kowalczyk ◽  
Mateusz Przybyla ◽  
Krzysztof Kozlowski
Keyword(s):  
Mobile Robot ◽  
Experimental Verification ◽  
Control Method ◽  
Laser Scanner ◽  
Obstacle Detection ◽  
Navigation Function ◽  
Mobile Robot Control ◽  
Good Potential ◽  
Point Control ◽  
Robot Position

AbstractThis paper presents the results of an experimental verification of mobile robot control algorithm including obstacle detection and avoidance. The controller is based on the navigation potential function that was proposed in work (Urakubo, Nonlinear Dyn. 81(3), 1475–1487 2015). Conducted experiments considered the task of reaching and stabilization of robot in point. The navigation potential agregates information of robot position and orientation but also the repelling potentials of obstacles. The obstacle detection is performed solely with the use of laser scanner. The experiments show that the method can easily handle environments with one or two obstacles even if they instantly hide or show-up due to the scanner range limits. The experiments also indicate that the utilized control method has a good potential for being used in parallel parking task.

scholarly journals Native Subterranean Termites: Reticulitermes flavipes (Kollar), Reticulitermes virginicus (Banks), Reticulitermes hageni Banks (Insecta: Isoptera: Rhinotermitidae)

EDIS ◽  
1969 ◽  
Vol 2004 (5) ◽  
Author(s):  
Nan-Yao Su ◽  
Rudolf H. Scheffrahn ◽  
Brian Cabrera
Keyword(s):  
North America ◽  
Reticulitermes Flavipes ◽  
Subterranean Termite ◽  
Subterranean Termites ◽  
Eastern Region ◽  
Pest Species ◽  
University Of Florida ◽  
Reticulitermes Virginicus ◽  
Eastern Subterranean Termite ◽  
Reticulitermes Hageni

Most pest species of subterranean termites in North America belong to the endemic genus Reticulitermes. Reticulitermes species are found in every state in the continental United States except Alaska, but are most common in the warm and humid southeastern region. The eastern subterranean termite, R. flavipes is the most widely distributed and is found in the entire eastern region of North America as far north as Ontario, Canada, and south to Key Largo, Florida. Its counterpart, the western subterranean termite, R. hesperus Banks, is found along the entire Pacific Coast ranging from southern California to British Columbia. Reticulitermes tibialis occurs in the inter-mountain region of the West. In addition to R. flavipes, two other Reticulitermes occur in Florida, R. virginicus, and R. hageni. This document is EENY-212, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: May 2001. EENY-212/IN369: Native Subterranean Termites: Reticulitermes flavipes (Kollar), Reticulitermes virginicus (Banks), Reticulitermes hageni Banks (Insecta: Isoptera: Rhinotermitidae) (ufl.edu)

scholarly journals Cassava flour separation using inverse cyclone

2007 ◽  
Vol 11 (5) ◽  
pp. 515-520
Author(s):  
Carlos A. Herrera ◽  
Miguel E. Rosillo ◽  
Alberto García
Keyword(s):  
Developing Countries ◽  
Cassava Starch ◽  
Recovery Efficiency ◽  
Solid Concentration ◽  
Waste Waters ◽  
Gas Velocity ◽  
Cassava Flour ◽  
Environmentally Sustainable ◽  
Good Potential ◽  
Flour Production

In developing countries cassava starch is produced mostly rurally using artisan methods through wet-way processes that consume as much as 37 m³ of water per processed ton. In comparison, the little industrial production consumes 5 m³ of water per processed ton. These waste waters, highly contaminated, are usually discharged in to the rivers without any treatment. With the aim of industrializing the cassava flour production, CIAT and CLAYUCA are developing an alternative dry technology, environmentally sustainable, to produce enriched flour as a starch substitute. The intention is to separate the starch enriched flour (< 44 mum) from the fiber rich coarse flour (> 44 mum). The use of an inversely operated cyclone (related to the conventional operation) showed good potential in terms of efficiency and economy. In this paper we propose pressure drop (deltap), fines (< 44 mum) recovery efficiency (eta), and fines recovery quality (q), as main functional parameters to characterize the apparatus. Results show that deltap, eta, and q only depend on gas velocity (v g) and on the feed solid concentration (c). The h and q magnitudes, approximately 60 and 80% respectively, demonstrate the effectiveness of this technique. Potential improvements merit further exploration.

Active Friction Control Based on Electrorheological Effect

2009 ◽  
Vol 79-82 ◽  
pp. 171-174
Author(s):  
Ji Le Jiang ◽  
Yu Tian ◽  
Yong Gang Meng
Keyword(s):  
Friction Coefficient ◽  
Control Method ◽  
Industrial Applications ◽  
Structure Design ◽  
Friction Control ◽  
Electrorheological Effect ◽  
Active Friction ◽  
Good Potential ◽  
Preliminary Study ◽  
Er Fluids

A preliminary study of active friction control method based on electrorheological (ER) effect is experimentally investigated. The friction coefficient can be changed from 0.07 to 0.9 continuously with the applied voltage in the range of 0 to 2000 V. Results show that by using proper ER fluids and structure design, active friction control based on ER effect has good potential in real industrial applications.

Robust Variable Structure Control for Compound Active-Clamp Three-Phase PFC Converter with Soft Switch

2012 ◽  
Vol 433-440 ◽  
pp. 610-616
Author(s):  
Xin Guo ◽  
Hai Peng Ren
Keyword(s):  
High Efficiency ◽  
Control Method ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Simulation Method ◽  
Soft Switch ◽  
Structure Control ◽  
Three Phase ◽  
Parameter Perturbations ◽  
Good Potential

Compound active clamping three-phase Boost PFC converter with soft-switch has a good potential application because of its high power factor, high efficiency and simple structure. The mathematical model of this converter is analyzed. A variable structure control method with the robustness item is proposed for the control of this converter, in order to overcome the shortcoming of the existing method, when the converter parameters changes. The time-varying boundary layer is used to smooth the control discontinuity. Simulation is performed using PSIM and MATLAB hybrid simulation method. The results indicate that the proposed method possesses not only better transient and steady state performance under the nominal parameters, but also better robustness under the parameter perturbations, compared with the traditional PI control and the former variable structure control without the robustness item.

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