Big Arm Research Articles

Design and Test of Seed–Fertilizer Replenishment Device for Wheat Seeder

In view of existing problems, such as the seed and fertilizer supply link for wheat seeders still relying on manual installation and the lack of practical application equipment, a seed–fertilizer replenishment device based on the three-degree-of-freedom mechanical arm and screw conveying principle is designed using the seed box installation and supply as the operation scenario to replace the manual installation process. Combined with the requirements of the seed box replenishment operation, the key parameters of the replenishment robot arm and the screw conveyor auger are determined. Then, the kinematic model of the replenishment robot arm is established based on the modified D-H method, forward and inverse kinematics calculations are performed, and the workspace is analyzed using the Monte Carlo method. Based on this, the robotic arm task path is designed, the fifth-degree polynomial interpolation method is used to complete the trajectory planning, and MATLAB R2016a software is used to simulate the motion trajectories of each joint, verifying the feasibility of the trajectory planning solution. Finally, a prototype is trial-produced and quadratic regression orthogonal testing and response surface analyses are conducted to obtain the optimal working parameters of the replenishment device. The verification test shows that when the angular velocity of the lumbar joint of the replenishment device is 4°/s, the speed of screw conveyor is 90 r/min, and the angle of the big arm is 12°, the conveying loss rate is 3.98%, and the conveying efficiency is 0.833 kg/s. The relative errors with the theoretical optimal values are 4.2% and 2.4%, respectively, both less than 5%. The supply trajectory is reasonable, and the robot arm runs smoothly. This study can provide reference for the design of seed–fertilizer replenishment device for wheat seeders.

Simulation-Based Reliability Design Optimization Method for Industrial Robot Structural Design

Robots are main elements in Industry 4.0. Research on the design optimization of robots has a great significance in manufacturing industries. There inevitably exist various uncertainties in robot design that have an important influence on the reliability of robots. At present, the design optimization of robots considering the uncertainties is mainly focused on joints design and trajectory optimization. However, for the structural design of robots, deterministic design optimization still plays a leading role. In this paper, a simulation-based reliability design optimization method is proposed to improve the reliability of robots’ structural design. In the proposed method, the Latin hypercube sampling (LHS), computer simulation, response surface method (RSM) and SORA (Sequential Optimization and Reliability Assessment) algorithm are integrated to complete the structural design of the robot. Firstly, samples of the uncertainty design variables were obtained by LHS, and then, the reliability performance constraint functions were firstly constructed through the RSM in which the joint simulation of MTLAB and ANSYS was adopted. Afterwards, the reliability design optimization model was established on the basis of the probabilistic reliability theory. At last, the SORA algorithm was employed to realize the optimization. The design optimization problems of the big arm and the small arm of a 6 Kg industrial robot were considered to verify the proposed method. The results showed that the weights of the big arm and the small arm were, respectively, reduced by 7.73% and 25.70% compared with those of the original design, and the design was more effective in ensuring the reliability requirements compared with the deterministic optimization. Moreover, the results also demonstrated that the proposed method has a better computational efficiency compared with the reliability design optimization of the double-loop method.

HeterBot: A heterogeneous mobile manipulation robot for versatile operation

AbstractThis study presents the overall architecture of HeterBot, a heterogeneous mobile manipulation robot developed in our lab, which is designed for versatile operation in hazardous environments. The most significant feature of HeterBot is the heterogeneous design created by adopting the idea of ‘big arm + small arm’ and ‘big car + mini car’. This combination has the advantage of functional complementation, which achieves performance promotion in both locomotion and manipulation capabilities, making HeterBot distinguished from other mobile manipulation robots. Besides, multiple novel technologies are integrated into HeterBot to expand its versatility and ease of use, including Virtual Robot Experimentation Platform‐based teleoperation, reconfigurable end effectors, laser‐aided grasping, and manipulation with customised tools. Experimental results validate the effectiveness of HeterBot in various locomotion and manipulation tasks. HeterBot displays huge potential in future applications, such as searching and rescue.

枣树修剪机机械臂的设计与运动学分析

The development of mechanization has greatly liberated the labour force, promoted socialized mass production, and created infinite social wealth. Its influence is significant and far-reaching, and agricultural production has undergone revolutionary changes. Aiming at the problems of poor working environment, high labour intensity and low working efficiency of manual pruning, a mechanical arm of branch pruning machine was designed, which realized the three-dimensional layered cylindrical pruning of individual tree. In this paper, a five-degree-of-freedom trimmer manipulator is designed, which is mainly composed of base, big arm, small arm, wrist and finger blade. The motion equation of the mechanism is established by using the Denavit–Hartenberg parameter (D-H parameter) method, and the corresponding motion curve is fitted by using MATLAB software. The components of the trimmer arm are designed virtually by using 3D modeling software, and assembled into a complete trimmer arm. The assembly drawing is imported into the simulation analysis software ADAMS for kinematics simulation. The results show that the speed-time pattern has obvious positive and negative changes at 3s, which proves that this stage is the hand cutting stage of jujube pruning; The acceleration time graph is gentle in the whole movement, and the curve approaches to a straight line, which proves that the movement of the mechanical arm of the jujube pruning machine is stable in the pruning process. Through the analysis of the simulation curve, it provides a theoretical basis for the research of the mechanical arm of the trimmer.

Automatic Turning Manipulator for Cake Production Line

In the production process of baking food processing enterprises, cakes, biscuits and other products made by steaming are generally installed in the baking tray and baked in the oven. The temperature of the baking tray is above 100 degrees Celsius when leaving the oven. The high temperature environment is not conducive to the protection of workers. It needs to be left to cool and then be transported, so the production efficiency is low. In order to solve this problem, a method of replacing the manual handling of the baking tray and removing the baked cake product with a turning robot is proposed. At the same time, two methods for improving the design of the cake production line are given, and the structure and use of the two products of the single-column turning manipulator and the articulated turning manipulator are introduced. The single-column turning manipulator consists of a base, a single-column rotating mechanism, a lifting mechanism, a swing arm, a pneumatic gripping mechanism, etc. A frame-type pneumatic gripping mechanism is adopted, and driven by the turning motor, and can realize the turning of the baking tray. The articulated turning manipulator consists of a base, a waist, a big arm, a small arm, a wrist, and a hand actuator. The hand adopts a rotatable square shaft end structure with an electromagnetic device, transforming the cake baking tray to increase the square groove meshed with it, so as to realize the flipping action of the cake baking tray.

Computer Simulation Design of Joint Manipulator for Handling Pipeline

The joint manipulator is a transmission device suitable for operation close to the body, which can realize multiple degrees of freedom and move flexibly. In this paper, through the transmission analysis of the big arm, the small arm, the wrist and the other parts of the manipulator, a kind of joint manipulator used in the transportation pipeline is proposed, and a three-degree-of-freedom wrist transmission mechanism is designed. On this basis, the structure of the wrist transmission parts is analyzed and designed, and the mechanical analysis and strength check of the gear connecting shaft of the wrist part are carried out.

Chromosome measurements of wild roses of Iran

The genus Rosa is made up of four subgenera, of which the subgenus Rosa (= Eurosa) contains about 95% of all species, and is subdivided into 10 sections. In Iran, there are 15 rose species. In the present investigation, chromosome characteristics of 14 Iranian rose species were studied: Rosa persica, Rosa hemisphaerica, Rosa foetida, Rosa pimpinellifolia, Rosa beggeriana, Rosa boissieri, Rosa iberica, Rosa orientalis, Rosa elimatica, Rosa canina, Rosa pulverulenta, Rosa villosa, Rosa moschata and Rosa × damascena. Chromosome characteristics were measured using image analyzer MicroMeasure 3.3. Genome size and ploidy level of the roses were determined using a flow cytometer. The results of the flow cytometry analysis revealed that the genome size of diploid species was from 0.83 to 1.21 pg, and their genome size by karyotyping measurements was between 46.36 and 56.63 μm. In tetraploids, the genome size was between 1.91 and 2.29 pg and between 86.55 and 106.31 μm by flow cytometry and karyotype analysis, respectively. In the pentaploid species, genome sizes were 2.69 to 3.09 pg and 90.35 to 140.96 μm calculated by flow cytometry and karyotyping analysis, respectively. In hexaploid rose, flow cytometry and karyotyping analysis showed that the genome sizes were 3.54 pg and 147.84 μm, respectively. R. moschata (2n=2x=14) had the longest total chromosome length of the monoploid set (28.32 μm) and average length of one chromosome (4.04 μm). R. orientalis (2n=5x=35) had the longest average length of the small arm (1.76 μm) and big arm (2.28 μm). The maximum average ratio of length of big arm to the length of small arm (1.39) was in R. × damascena (2n=4x=28). The results of this study could be used in future rose breeding and in taxonomic and evolutionary studies of Iranian rose species.

Design and performance analysis of an industrial robot arm for robotic drilling process

PurposeThe purpose of this paper is to present a robotic arm that can offer better stiffness than traditional industrial robots for improving the quality of holes in robotic drilling process.Design/methodology/approachThe paper introduces a five-degree of freedom (DOF) robot, which consists of a waist, a big arm, a small arm and a wrist. The robotic wrist is composed of two DOFs of pitching and tilting. A parallelogram frame is used for robotic arms, and the arm is driven by a linear electric cylinder in the diagonal direction. Double screw nuts with preload are used in the ball screw to remove the reverse backlash. In addition, dual-motor drive is applied for each DOF in the waist and the wrist to apply anti-backlash control method for eliminating gear backlash.FindingsThe proposed robotic arm has the potential for improving robot stiffness because of its truss structure. The robot can offer better stiffness than industrial robots, which is beneficial to improve the quality of robotic drilling holes.Originality/valueThis paper includes the design of a five-DOF robot for robotic drilling tasks, and the stiffness modeling of the robot is presented and verified by the experiment. The robotic system can be used instead of traditional industrial robots for improving the hole quality to a certain extent.

The Package Deal

The Package Deal Emma Duffy-Comparone (bio) You know he has a kid, but right now it's whatever. Right now it—the Kid—is a safe distance from you, far, far away on the remote island called Dad's Just a Rebound. It is early days. If the Boyfriend has the Kid, which is half the week, you don't even talk on the phone until the Kid is asleep. The Kid doesn't know you exist, in this context or any other, and truth be told, you don't ask that much about him, either, but you're not a total asshole. You know enough to look pleasant and interested when he talks about him. You learn he plays Little League, which is nice. You learn he gets pancakes on Sundays, also nice. You learn the two of them slouch around in beanbags all weekend, playing video games. "All weekend?" "Well, not all weekend." "Are they violent?" "Violent? No! No. Clowning." "Clowning with guns?" "Just silly boy stuff. Father-son bonding." "Oh," you say. "That's nice." ________ You have no intention of ever meeting the Kid, so logically you should not be dating the guy in the first place. At the very least, you should wrap this thing up. But it's hard to find the right time when he holds you in his arms and fucks you like that, standing up, no wall. Or when he lays you down, spreads your legs, and takes an hour not touching you at all, just looking at you carefully, telling you how fucking small you are, and how pink, and how beautiful you smell. Or when he puts you in his bed and reads aloud The Wind in the Willows, his big arm resting gently on your chest, his elbow near your collarbone, his fingers just beneath the edge of your underpants, until you're falling asleep, until you're falling in love with him. ________ You tell yourself, "Kid, schmid." You tell your friends, who ask why you're doing what you're doing, "It's not a big deal." You tell your mother, who grips your biceps and whispers with soupy eyes that entering a child's life is a very, very big deal, "I know, Mom, Jesus!" ________ On your first date, the three of you get ice cream and walk the jetty, the ocean [End Page 54] swirling against the rocks, cowlicked and pale. You feel anxious and strung out, your tongue thick as a futon, although you've pulled it together somewhat with lipstick and Xanax and long glass earrings. The Kid stumbles ahead, his feet bigger than he's used to, his windbreaker billowing because he refuses to zip up. Besides the bad bowl job from Supercuts and the teeth, which are bucked and khaki-colored, he is objectively good looking, which means so is his mother. "Careful!" he yells to you, pointing dramatically to each rock he's just vetted. "That one moves a little!" He has been showing off his knowledge of sports stats, eager to stump his father. "Cy Young career wins?" he shrieks into the wind. "Three-hundred-forty-one?" the Boyfriend shouts, discreetly hooking his thumb inside the waistband of your jeans, whispering in your ear that later, when the Kid goes to bed, he's going to get you naked, lay you facedown across his lap, and make you come for his— "No!" "God, I don't—hey," he says to you, pulling his hand away. He mouths the right answer in your ear then says to you loudly, "You don't know, do you?" "Geez," you say, pretending to think. You are so turned on you can barely breathe. "I'm feeling like it's—I'm probably wrong." "Guess!" the Kid yells. You feign doubt, defeat. "Five-hundred eleven?" The Kid whips around, his lips licked so big and red he looks like your great Aunt Lois. "How did you do that?" "Hey, buddy," you say. "Come here." When he does, you grab the hood and pull it over the Kid's head. "I know hoods are crappy," you say. "But having no...

How to exploit high performance computing in population-based metaheuristics for solving association rule mining problem

The application of population-based metaheuristics approaches to the association rules mining problem is explored in this paper. The combination of GPU and cluster-based parallel computing techniques is investigated for the purpose of accelerating the process of extracting the correlations between items in sizeable data instances. We propose four parallel-based approaches that benefit from the cluster intensive computing in the generation process and the massively GPU threading. This is by evaluating the association rules in parallel on GPU. To validate the proposed approaches, the most used population-based metaheuristics (GA, PSO, and BSO) have been executed on a cluster of GPUs to solve benchmarks of large and big ARM instances. We used Intel Xeon 64bit quad-core processor E5520 coupled to an Nvidia Tesla C2075 GPU device. The results show that the BSO outperforms GA and PSO. They also show that the proposed solution outperforms the HPC-based ARM approaches when exploring Webdocs instance (the largest instance existing on the web). To our knowledge, this is the first work that explores the combination of GPU and cluster-based parallel computing with the population-based metaheuristics in association rule mining.

Features of the protection of the intellectual property related to the military-industrial complex of Russia

An integral part of today’s cross-border civil and trade relations is cooperation and trade in the military-industrial complex. One of the key problems for the countries selling production of the military-industrial complex is the protection of the intellectual property rights in the field of defence industry. Russia, being one of the biggest arms exporters in the world, has accumulated an interesting experience of legal regulation of this problem. This article focuses on aspects of intellectual property protection in the sphere of military-industrial complex.

Anthropometric measurements of HIV-infected children aged one to five years in a tertiary hospital in Lagos Nigeria

Objectives: To determine the association between HIV infection and anthropometric measures (weight, height, midupper arm circumference and head circumference) of children aged one to five years. Method: A cross sectional descriptive study using structured questionnaire and measurement of weight, height, head and midupper arm circumference of 846 infected children and matched controls. Results: The mean weights of the controls were significantly higher than those of the infected children at all age groups (p<0.005) while, the controls were significantly taller than the infected children after 49months (p=0.019). The controls had bigger arm than the infected (p=<0.029) while the head circumference was also significantly higher in the controls (p=<0.033) with the difference being more in the children aged less than 3 years. Conclusion: HIV infection has a profound association with growth being earliest on the head size, followed by weight and then height. Keywords: HIV, children, weight, height, MUAC, head circumference

Modal Analysis of Scraper Chain Industrial Robot System

This paper researched dynamic characteristics of 5-DOF scraper chain handling robot by finite element modal analysis. Firstly established the whole three-dimensional model with Solidworks, secondly, transferred it into the ANSYS finite element analysis software to analyze dynamic characteristics in two fixed work positions when it was grasping a scraper chain and carrying a scraper chain on a rail line. It was found the weak component which vibrated heavily was the big arm from the analysis of the top 5 order vibration mode. Then studied modal analysis of the big arm to obtain the its inherent frequency and vibration mode. Finally put forward some suggestions about the design of the handling robot and improved its dynamic characteristics which is meaningful to increase its stability and reliability.

Optimization of the Hinge Point Position of Luffing Mechanism in Reach Stacker for Container

The luffing mechanism of reach stacker is the core of big arm lifting mechanism. The hinge point position in it influences directly the comprehensive performances. The mathematical model of three hinge points was established through the force analysis of luffing mechanism, which aims to reduce the maximum force of hydro-cylinder and decrease the oil pressure of hydraulic system. A hierarchical ordering method was utilized to optimize the multi-objective problem. The optimization calculation was presented by using the genetic algorithm in Matlab. Experimental results indicate that the optimization enhance the comprehensive performance of reach stacker. And this also provides important foundation to the parameters design of luffing mechanism.

Killing the Documentarian: Richard Wright and Documentary Modernity

As Bigger Thomas sits wedged uncomfortably between the young, would-be radicals Jan and Mary, Mary touches Bigger's arm and gestures the tall, apartment buildings of Chicago's South Side, telling him, You know, Bigger . . . I've long wanted go into these houses . . . and ]ustsee how your people live.1 To anyone familiar with the history of documentary photography, it's hard not read this scene early in Richard Wright's Native Son (1940) as a pointed satire of the documentary aesthetic. Mary's comment that she wants how your people live carries with it strong connotations of Jacob Riis's seminal How the Other Half Lives (1890), emphasizing the documentary's power of sight interpret, interpellate-and invade-the dark and seemingly unknowable lives of the poor and marginal. Likewise, that her statement is made as Mary imposes an unwanted, or at least highly transgressive, intimacy between she and Bigger further suggests the ways in which the documentary impulse is one of crossing barriers and borders-an impulse that often works reinscribe as much as overcome the privilege on which the borders are founded. As a figure of the documentarian, Mary Dalton fits this role all too tragically: a wealthy progressive who believes that if she is allowed to the conditions in which poor African Americans live, this uniquely visual regime of knowing will transform her and lead her political action. This emphasis on sight, underscored by Wright's italics, as the crucial precursor progressive change is, as critics have argued, the ontology of the political documentary. That Jan and Mary have essentially kidnapped their black subject of knowledge and that their act of vision on the South Side produces race/ism rather than resolves it could easily be taken as Wright's final statement on the 1930s radical documentary.For all of Wright's pointed satire, it's equally important note that less than a year after the publication of Native Son, Wright edits a selection of documentary photographs that do exactly what Mary expresses she wants do: go into tall, apartment buildings and justsee how Wright's people live. As Native Son murders its own white documentarian, then we must ask what the relationship is between Mary's misguided, ultimately desire see and even touch how the Other lives and Wright's own documentary impulse do just that in 12 Million Blac Voices (1941). I would argue that 12 Million Blac Voices-Richard Wright's documentary photo-montage of the Great Migration-is not merely the nonfiction companion Native Son as it was advertised, but rather the culmination of Wright's own contradictory and dialectical concerns with the politics of black representation. In killing the documentarian-the white chronicler of black life-Wright does not abandon the public sphere dominated by a white gaze. As documentary photography has been a significant means by which the West has constructed and codified modern ideas of race, Wright's critique of the mode and his insistence on its constructed nature call into question the very possibility of a visible regime of knowing. Yet, the documentary is also the form perhaps most associated with the political and representational projects of modernity. As Paula Rabinowitz notes, documentary photography is also the medium that can translate the into the future and redeem, in a Benjaminian fashion, the wreckage of history.2 Thus, for Wright, the documentary image stands at just that nexus of historical trauma and liberation that ends 12 Million Blac Voices, the past living in the present and the new procession and new tide of revolutionary progress.3 Like Wright's own contradictory statements on modernity, at once based on the deadly web of slavery and higher human consciousness, photography for Wright becomes an expression of a racial past, as well as a liberatory future.4 For Wright, the documentary image's dialectical mode-containing technologies of both liberation and domination-is thus Wright's precise claim on African American modernity. …

Design and Simulation of Space Deformable-Contact-Surface-Based End Effector

It is common to use space arm for maintaining and assembling. The major technology problems to solve first are the deformability, the soft and tightening contact with the target. Use ER as the contactor of end effector which is learned from the space station end effector can overcome many problems, as the poor location precision and uncontainable attitude which is bring by the big space arm. The design of multi-DOF Deformable-Contact-Surface-Based shape adaptive end effector is introduced in this text. The simulation result by Matlab software proves the design not only can tight connect the target, but also can suppress vibration and meet the precise demand of location, precise force control and deformability. It can meet the multi-mission in the future.

Structural Design of the Robot Arm for Massage Based on the Chain Drive

With the development of robot technology, massage robot has attracted fully attention, and the study about robot arm has been a growing interest in the area of massage robot. This article has put forward a new massage robot arm, which uses the chain as the main transfer mode by the requirements of the overall design massage of the robot arm. The design of big arm, shoulder joint, forearm, elbow joint and wrist are introduced. Based on the design requirements, we made some improvements with sprockets, ensuring transmission conditions and meeting the massage requirements. And finite element analysis for the designed arm, results show that the structure design can meet the requirements.

Geology of Los Angeles, California, United States of America

Geology of Los Angeles, California, United States of America

Sinkholes and Subsidence: Karst and Cavernous Rocks in Engineering and Construction: (Tony Waltham, Fred Bell, and Martin Culshaw)

Book Review| January 01, 2007 Sinkholes and Subsidence: Karst and Cavernous Rocks in Engineering and Construction(Tony Waltham, Fred Bell, and Martin Culshaw) Allen W. Hatheway Allen W. Hatheway 11003 LaBella Lane, Big Arm, MT 59910 Search for other works by this author on: GSW Google Scholar Environmental & Engineering Geoscience (2007) 13 (1): 83–84. https://doi.org/10.2113/gseegeosci.13.1.83 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Allen W. Hatheway; Sinkholes and Subsidence: Karst and Cavernous Rocks in Engineering and Construction(Tony Waltham, Fred Bell, and Martin Culshaw). Environmental & Engineering Geoscience 2007;; 13 (1): 83–84. doi: https://doi.org/10.2113/gseegeosci.13.1.83 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Of the many geotechnical hazards broadly represented as geologic constraints, the net result of long-term dissolution of carbonate rock has perhaps the greatest range of possible combinations related to cause and effect. The authors proclaim that this is a book aimed at the needs of civil engineers, but engineering geologists will find considerable value in its contents for predicting the potential for collapse and subsidence and in specifying the parameters necessary for their mitigation and remediation. Broadly speaking, those of us who work in this demanding field of application can prepare only by becoming able to characterize the ground by... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Limb swelling with hypereosinophilia

In July, 2005, a 28-year-old white man was referred to our unit with a 3-month history of recurrent painful asymmetrical swelling and induration of the limbs (fi gure, A). His history was otherwise unremarkable. On physical examination, the skin was too taut to pinch. The rest of the examination was normal, and there was no pruritus. 8 months previously he had spent 6 weeks travelling in several African countries. Blood test results showed hypereosinophilia (4·69×10/L). Liver function tests were normal, and C-reactive protein was below 8 mg/L. Rheumatoid factor was negative, and total complement, C3 and C4 concentrations, and anti-DNA antibody titres were normal. Stool examination for ova and larvae was negative. No microfi lariae were detected in peripheral blood. The serum antifi larial titre was 1 in 200 by direct immunofl uorescence (normal: less than 1 in 200), and electrosyneresis was negative. Serological tests for schistosoma, toxocara, distomatosis, and trichina were negative. Hepatic ultrasonography was normal. MRI of the aff ected limb showed increased signal intensity within the superfi cial and deep fascia (fi gure, B). We made a presumptive diagnosis of onchocerciasis with limb swelling, and treated our patient with ivermectin (8 mg), after which the swelling rapidly subsided. Two further doses were followed by the disappearance of hypereosinophilia after 6 months of follow-up. Tests for antifi larial antibodies by direct immunofl uorescence became positive (1 in 800) after 4 weeks, and one arc appeared on electrosyneresis. When last seen, in May, 2006, the patient had no further symptoms. Onchocerciasis is a fi larial disease caused by the nematode Onchocerca volvulus. It is transmitted by small blackfl ies of the genus Simulium, which breed in fastfl owing water. The infection is endemic throughout tropical Africa, parts of central and south America, and parts of the Arabian peninsula. Onchocerciasis can be acquired during short visits to highly endemic foci, especially in forested areas. The incubation period ranges from 5 to 20 months. The typical clinical signs of onchocerciasis in endemic populations include intense pruritus, subcutaneous nodules, papular dermatitis, and disfi guring depigmentation (leopard skin). Onchocerciasis is a common cause of visual impairment (river blindness). Peripheral eosinophilia is present in all cases. The diagnosis is based on clinical fi ndings. Diff erent clinical manifestations have been observed in expatriates and travellers, in whom onchocerciasis rarely leads to irreversible skin or eye damage. The infection may remain asymptomatic or lead to a simple erythematous rash, with maculopapular lesions on the trunk or legs and, in some cases, pruritus. Travellers returning from endemic areas with onchocerciasis may present with signs of eosinophilic fasciitis, which is characterised by swelling of the limbs, severe eosinophilia, and fascia infi ltration. Although limb swelling is uncommon, French authors fi rst coined the terms “equatorial arm” and “gros bras camerounais” (Cameroonian big arm). The diagnosis of onchocer chiasis is diffi cult in mildly or recently infected individuals. Microfi lariae are few in number and tend not to be present in peripheral blood. In addition, serological tests have poor sensitivity. In one study, the specifi c skin snips test was positive in only 53% of 31 reported cases. Negative parasitological and serological tests for O volvulus contribute little to the diff erential diagnosis. The presence of recurrent limb swelling and eosinophilia, combined with a history of travel to endemic areas, should alert the clinician to the possibility of onchocerciasis. Ivermectin is eff ective in onchocerciasis but is best combined with doxycycline to avoid possible recolonisation of the skin once the adult worms resume production of micro fi lariae.