Novel Suspension Mechanisms For A Three Wheeled Mobile Robot Traversing Uneven Terrains Without Slip

A wheeled mobile robot (WMR) will move on uneven terrain without slip if the length of the axle connecting two wheels can change or for a fixed length axle the wheels are allowed to tilt in a lateral direction. In this work, we consider a three-wheeled mobile robot with torus shaped wheels capable of lateral tilting. Due to the requirement of lateral tilting a two degree of freedom (DOF) suspension, one for maintaining contact with terrain and one for lateral tilting, is assumed to connect the wheels to the WMR body. Six concepts of two DOF suspension mechanisms are proposed. A WMR with these suspension mechanisms are modeled and two kinds of simulations, namely, direct kinematic analysis and inverse kinematic analysis are performed on several uneven terrains with and without suspension. Slip velocity, the path followed and the lateral tilt angle are estimated as a function of time. The force-angle stability measure is used to check the tip-over instability of the WMR on uneven terrain. It is shown that without the two DOF suspensions and with the wheels not allowed to tilt laterally, the WMR is not capable of traversing uneven terrains without large slip. When the wheels are allowed to tilt laterally with a two DOF suspension, the wheeled mobile robot slips very little. Based on least slip and less deviation from desired path, it is shown that the two best possible suspension mechanisms are the SFTA suspension and D4Bar suspension. Two prototype of three-wheeled mobile robot with these suspensions are fabricated using some components from a readily available commercial kit and with especially designed and manufactured wheels with the two degrees of freedom suspension. Simulations on an uneven terrain verify that the three-wheeled mobile robot can traverse uneven terrains with very little slip for three representative paths, namely a straight line, a circular arc and a path representing a lane change. Experiments with the two prototypes on physically constructed uneven terrain, very similar to the one used for simulation, confirm that the slip is significantly reduced with the two degree of freedom suspensions. The path of the centre of mass of the WMRs, projected on uneven surface, and the error from the desired path is presented for all the three representative paths. The simulation and experimental results clearly show that the three wheeled mobile robot with the novel two DOF suspension mechanisms can traverse uneven terrain with low slip

Analgesic Activity of Some 1,2,4-Triazole Heterocycles Clubbed with Pyrazole, Tetrazole, Isoxazole and Pyrimidine

Purpose: In the present study in vivo analgesic activity of some previously synthesized 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine ring have been evaluated. Methods: Acetic acid induced writhing method and Hot plate method has been described to study analgesic activity of some 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine as a pharmacological active lead. Results: Thirty six different derivatives containing 1,2,4-triazole ring were subjected to study their in vivo analgesic activity. Chloro, nitro and methoxy, hydroxy and bromo substituted derivatives showed excellent analgesic activity and dimethylamino, furan and phenyl substituted derivatives showed moderate analgesic activity in both of the methods. Compounds IIIa, IIId, IIIf, IIIi, IIIj, IVa, IVb, IVd, IVf, IVh, IVj IV3a and IIj were found to be superior analgesic agents after screening by Acetic acid induced writhing method. Compounds IIIb, IIId, IIIf, IIIh, IIIj, IVa, IVb, IVd, IVf, IVh, IVi, IV3c, IV3e and IIj were showed analgesic potential after screening of Hot plate method. Conclusion: All tested compounds containing 1,2,4-triazole were found to be promising analgesic agents, for this activity pyrazole, tetrazole, isoxazole and pyrimidine leads might be supported

3D continuum phonon model for group-IV 2D materials

A general three-dimensional continuum model of phonons in two-dimensional materials is developed. Our first-principles derivation includes full consideration of the lattice anisotropy and flexural modes perpendicular to the layers and can thus be applied to any two-dimensional material. In this paper, we use the model to not only compare the phonon spectra among the group-IV materials but also to study whether these phonons differ from those of a compound material such as molybdenum disulfide. The origin of quadratic modes is clarified. Mode coupling for both graphene and silicene is obtained, contrary to previous works. Our model allows us to predict the existence of confined optical phonon modes for the group-IV materials but not for molybdenum disulfide. A comparison of the long-wavelength modes to density-functional results is included

Quantification of Tylosin Antibiotics in Cattle Waste

Antibiotics are used as prophylactic agents to promote growth and for treating infections in animals. However, the irrational use of antibiotics in livestock management is a significant cause of the development of antibioticresistant genes in the environment. Each year 2 million people suffer from the infections caused by bacteria which are resistant to antibiotics and 23,000 of these people are estimated to die because of antibiotic resistance. New drugs are continually coming into the market but are at the risk of developing resistance. Thus, there is a need for the development of analytical methods which can be used to monitor these antibiotic concentrations in environmental samples. This research is focused on developing and validating a Solid Phase Extraction (SPE) procedure and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying tylosin antibiotic in cattle waste. Tylosin was extracted from cattle waste samples using Strata polymeric weak cation cartridges by adding a sodium-EDTA buffer solution and methanol. Chemical analysis of the extracted tylosin was performed using a Varian 212-LC HPLC and Agilent 500 Ion Trap mass spectrometric detector. The concentrations of tylosin in study group animals were compared with respect to the date of sampling and cattle body weight with a control group and results are presented

Wi-Fi Finger-Printing Based Indoor Localization Using Nano-Scale Unmanned Aerial Vehicles

Explosive growth in the number of mobile devices like smartphones, tablets, and smartwatches has escalated the demand for localization-based services, spurring development of numerous indoor localization techniques. Especially, widespread deployment of wireless LANs prompted ever increasing interests in WiFi-based indoor localization mechanisms. However, a critical shortcoming of such localization schemes is the intensive time and labor requirements for collecting and building the WiFi fingerprinting database, especially when the system needs to cover a large space. In this thesis, we propose to automate the WiFi fingerprint survey process using a group of nano-scale unmanned aerial vehicles (NAVs). The proposed system significantly reduces the efforts for collecting WiFi fingerprints. Furthermore, since these NAVs explore a 3D space, the WiFi fingerprints of a 3D space can be obtained increasing the localization accuracy. The proposed system is implemented on a commercially available miniature open-source quadcopter platform by integrating a contemporary WiFi - fingerprint - based localization system. Experimental results demonstrate that the localization error is about 2m, which exhibits only about 20cm of accuracy degradation compared with the manual WiFi fingerprint survey methods

Estimating the Carbon Fluxes using the CASA Model in the Southern United States

A minute change in human body temperature can get one collapsed permanently. If this is the case with human body, one might wonder what would be the case with Earth. The result is the greenhouse. The main function of the greenhouse gases (GHG’s) is to tap energy from the sun and prevent the heat energy escaping to space, thus sustaining life on earth. Because of increased human activity, industrialization, and deforestation, the concentration of the GHG’s in the atmosphere has increased, resulting in a temperature rise. Considering the effects of temperature rise, caused by the GHG’s, one should know the ways to minimize them. In order to do this, an estimation of the amount of GHG’s is important. The CASA model is one such model that estimate the GHG’s and also the amount of carbon in the atmosphere by estimating the Net Ecosystem Productivity (NEP) and Net Primary Productivity (NPP)

A PROSPECTIVE STUDY ANALYSIS OF LIMB LENGTH DISCREPANCY FOLLOWING TOTAL HIP ARTHROPLASTY

Objective: The present study was designed and implemented to assess the incidence and occurrence of LLD in post-hip arthroplasty and also to evaluate the causes of limb length discrepancy both intra- and post-operative period to manage total hip arthroplasty effectively. Methods: It is a prospective study involving 52 patients underwent for THA and conducted in the Department of Orthopedics, Tertiary Care Hospital, Visakhapatnam, India from the period of January 2013 to December 2019. The study used Southern approach or “Moore” approach. All the patients are assessed for limb length discrepancy immediately after the surgery and followed at 6 weeks, 3 months, and after 6 years. Results: Three patients had significant limb length discrepancy among the 52 patients (5.77%) while the remaining had no significant discrepancies in all X-rays which assess the radiological discrepancies in length. The study yields a satisfactory result as very few patients reported LLD during follow-up period and outcomes such as pain alleviation, walking capacity, limping, and patient satisfaction were insignificantly influenced by leg lengthening (p≤0.05). Conclusion: A combination of pre-operative templating, intra-operative marking and usage of intra-operative image intensifier and an understanding of anatomy, biomechanics of hip, and implant design would reduce the error of limb length discrepancy

IDENTITY AND CLEANUP OF AUTHORIZATION SESSION WORK IN A SOFTWARE-DEFINED ACCESS ENABLED INTERNET OF THINGS NETWORK

Techniques are described herein for making identity work when inline tagging is not supported. This may apply to an Internet of Things (IoT) network connected to a Software Defined Access (SDA) edge

LIFE CYCLE OF THE BLUE TIGER BUTTERFLY TIRUMALA LIMNIACE (LEPIDOPTERA: RHOPALOCERA: DANAIDAE)

Tirumala limniace the blue tiger butterfly from India was studied in the environs of Eastern Ghats. It lays eggs singly on Wattakaka volubilis and this butterfly was seasonal in its distribution. The life cycle from egg to adult emergence is relatively shortest and spanning over 21-28 days. Besides, the population index of Tirumala limniace on same host plant leaves was discussed

LIFE CYCLE OF THE LARGE SALMON ARAB BUTTERFLY COLOTIS FAUSTA (LEPIDOPTERA: RHOPALOCERA: PIERIDAE

The life cycle of the large salmon arab Colotis fausta from Eastern ghats of India was investigated. The population index of eggs, larvae and pupae on the host plant Cadaba fruiticosa was recorded. The number of broods yearly was estimated i.e., from 10-12. Life cycle from egg to adult emergence was spanning over 19- 26 days