Rubber tapping

Abstract: Natural rubber is widely used in human life because of its excellent quality. At present, manual tapping is still the main way to obtain natural rubber. There is a sore need for intelligent tapping devices in the tapping industry, and the autonomous navigation technique is of great importance to make rubber-tapping devices intelligent. To realize the autonomous navigation of the intelligent rubber-tapping platform and to collect information on a rubber forest, the sparse point cloud data of tree trunks are extracted by the low-cost LiDAR and a gyroscope through the clustering method. The point cloud is fitted into circles by the Gauss–Newton method to obtain the center point of each tree. Then, these center points are threaded through the Least Squares method to obtain the straight line, which is regarded as the navigation path of the robot in this forest. Moreover, the Extended Kalman Filter (EKF) algorithm is adopted to obtain the robot’s position. In a forest with different row spacings and plant spacings, the heading error and lateral error of this robot are analyzed and a Fuzzy Controller is applied for the following activities: walking along one row with a fixed lateral distance, stopping at fixed points, turning from one row into another, and collecting information on plant spacing, row spacing, and trees’ diameters. Then, according to the collected information, each tree’s position is calculated, and the geometric feature map is constructed. In a forest with different row spacings and plant spacings, three repeated tests have been carried out at an initial speed of 0.3 m/s. The results show that the Root Mean Square (RMS) lateral errors are less than 10.32 cm, which shows that the proposed navigation method provides great path tracking. The fixed-point stopping range of the robot can meet the requirements for automatic rubber tapping of the mechanical arm, and the average stopping error is 12.08 cm. In the geometric feature map constructed by collecting information, the RMS radius errors are less than 0.66 cm, and the RMS plant spacing errors are less than 11.31 cm. These results show that the method for collecting information and constructing a map recursively in the process of navigation proposed in the paper provides a solution for forest information collection. The method provides a low-cost, real-time, and stable solution for forest navigation of automatic rubber tapping equipment, and the collected information not only assists the automatic tapping equipment to plan the tapping path, but also provides a basis for the informationization and precise management of a rubber plantation.

Abstract: Natural rubber latex allergy was identified as an increasingly significant health care problem in the late 1980s. Though the incidence of latex allergy has decreased in the United States over the last several years, 150,000 to 1 million healthcare workers and over 15 million people worldwide still suffer from latex allergy. Natural rubber is obtained from the Hevea brasiliensis tree, a tree of the family Euphorbiacieae and also known as the “rubber tree.” Through a process called “rubber tapping,” latex is collected from the milky sap of this tree and is derived of 33% rubber, cis-1,4polyisoprene, 2% resin, 65% water, and proteins. Crude latex is collected in ammoniated solution to prevent microbial growth. It contains an array of cellular proteins, lipids, and amino acids, which are the allergens that induce sensitization. In manufacturing rubber, many chemicals may be added to latex such as thiurams in the vulcanization process, stabilizers, and antioxidants. Vulcanization is the chemical process by which the physical properties of natural or synthetic rubber are improved by heating rubber with sulfur. Since rubber deteriorates with aging by oxidation, antioxidants are incorporated in the final rubber products to prevent the polymer chain from degrading. Current antioxidants include thiocarbamates, diphenylamines, dihydroquinolines, and phenylenediamine, all of which are potential contact allergens. The prevalence of latex allergy is dependent on the population studied and ranges from 3% to 64%. Latex sensitization in the general population varies from 5.4% to 7.6%. Repeated contact with or prolonged exposure to latex containing products may result in adverse latex reactions. Patients with spina bifida or urogenital abnormalities are a particular subpopulation at risk with a prevalence 460% due to multiple surgeries early in life, resulting in frequent exposure to latex. Approximately 10–20% of healthcare workers are sensitized to latex. Exposure to rubber gloves is a frequent cause of occupational latex allergy, but contact with other types of latex containing

Abstract: The Extractive Reserve System is championed as a win–win model of sustainable development in which rubber tappers serve to protect the forest while improving economic growth and resident well-being. Recently, reserves are being questioned in terms of their environmental sustainability, as many rubber tappers increasingly turn to market agriculture in times of economic duress and instability. This study explores land-use/land-cover change in six rubber estates within the Chico Mendes Extractive Reserve, using both remote sensing analysis and household surveys, and addresses the differences in deforestation by livelihood trajectories. A remote sensing analysis between 1986 and 2003 shows that some communities are close to surpassing the allowable limits of deforestation. Rubber tapping plays a less important role in livelihood strategies, as welfare is linked to non-extractive activities. Households pursue diverse livelihood activities including extractivism, small-scale market cultivation, animal rearing, ...