A new approach to active vibration isolation for microgravity space experiments

A new method was developed to design an active vibration isolation system for microgravity space experiments. This method yields the required controller transfer functions for a specified transmissibility ratio. Hence, it is a straightforward task to guarantee that the desired vibration isolation performance is achieved at each frequency. The theory for such a controller design was presented by considering a single degree of freedom system. In addition, the magnitude of the input required by the new method has been found to be less than that used by a standard phase lead/lag compensator

Robust and real-time control of magnetic bearings for space engines

Currently, NASA Lewis Research Center is developing magnetic bearings for Space Shuttle Main Engine (SSME) turbopumps. The control algorithms which have been used are based on either the proportional-intergral-derivative control (PID) approach or the linear quadratic (LQ) state space approach. These approaches lead to an acceptable performance only when the system model is accurately known, which is seldom true in practice. For example, the rotor eccentricity, which is a major source of vibration at high speeds, cannot be predicted accurately. Furthermore, the dynamics of a rotor shaft, which must be treated as a flexible system to model the elastic rotor shaft, is infinite dimensional in theory and the controller can only be developed on the basis of a finite number of modes. Therefore, the development of the control system is further complicated by the possibility of closed loop system instability because of residual or uncontrolled modes, the so called spillover problem. Consequently, novel control algorithms for magnetic bearings are being developed to be robust to inevitable parametric uncertainties, external disturbances, spillover phenomenon and noise. Also, as pointed out earlier, magnetic bearings must exhibit good performance at a speed over 30,000 rpm. This implies that the sampling period available for the design of a digital control system has to be of the order of 0.5 milli-seconds. Therefore, feedback coefficients and other required controller parameters have to be computed off-line so that the on-line computational burden is extremely small. The development of the robust and real-time control algorithms is based on the sliding mode control theory. In this method, a dynamic system is made to move along a manifold of sliding hyperplanes to the origin of the state space. The number of sliding hyperplanes equals that of actuators. The sliding mode controller has two parts; linear state feedback and nonlinear terms. The nonlinear terms guarantee that the systems would reach the intersection of all sliding hyperplanes and remain on it when bounds on the errors in the system parameters and external disturbances are known. The linear part of the control drives the system to the origin of state space. Another important feature is that the controller parameter can be computed off-line. Consequently, on-line computational burden is small

Human health risk analysis from disinfection by-products (DBPs) in drinking and bathing water of some Indian cities

BACKGROUND: Human health risk assessment from exposure to disinfection by-products (DBPs) during drinking and bathing water vary from country to country as per life expectancy, body mass index, water consumption pattern and individual concentration of DBPs component, etc. METHODS: Present study considered average direct water intake per person for adult males and females as 4 & 3 L/day, respectively as per Indian literature for risk evaluation from another component of pollutant. While other important factor like average life expectancy, body weight & body surface area for male and female were considered 64 & 67 years, 51.9 & 45.4 Kg and 1.54 & 1.38 m(2) respectively as per Indian Council of Medical Research and WHO report. The corresponding lifetime cancer risk of the formed THMs to human beings was estimated by the USEPA and IRIS method as per Indian population. RESULTS: The total cancer risk reached 8.99 E-04 and 8.92 E-04 for males and females, respectively, the highest risk from THMs seems to be from the inhalation route followed by ingestion and dermal contacts. CONCLUSIONS: The multipath way evaluations of lifetime cancer risks for THMs exposure through ingestion, dermal absorption, and inhalation exposure were examined at the highest degree of danger. Results reveals that water containing THMs of the selected water treatment plant of the eastern part of India was unsafe in terms of risk evaluation through inhalation and ingestion, while dermal route of risk was found very close to permissible limit of USEPA. Sensitivity analysis shows that every input parameter is sole responsible for total risk potential, whereas exposure duration playing important role for estimation of total risk

Mistuning Analyses of a Bladed Disk: Pole-Zero and Modal Approaches

ABSTRACT This paper examines the fundamental aspects of amplitude amplification due to mistuning in a bladed disk. Both pole-zero and modal approaches are used to understand the effects of changes in mode shapes and the natural frequencies on the minimum and maximum values of peak amplitudes among all blades over all excitation frequencies. The nature of variation of this peak amplitude is studied, and algorithms are discussed to determine the statistics of the peak amplitude, maximum and minimum values of the peak amplitude, and corresponding mistuning patterns

REAL-TIME NETWORK EVENT CORRELATION BASED ON DEPENDENCY GRAPH FOR NETWORK ISSUE ROOT CAUSING

Techniques are described for a graph based approach to co-relate events in a network. The root cause of any network failure may be determined in real time

A Mitogen-activated Protein Kinase cascade module, MKK3-MPK6 and MYC2, is involved in blue light-mediated seedling development in Arabidopsis

Mitogen-activated protein kinase (MAPK) pathways are involved in several signal transduction processes in eukaryotes. Light signal transduction pathways have been extensively studied in plants; however, the connection between MAPK and light signaling pathways is currently unknown. Here, we show that MKK3-MPK6 is activated by blue light in a MYC2-dependent manner. MPK6 physically interacts with and phosphorylates a basic helix-loop-helix transcription factor, MYC2, and is phosphorylated by a MAPK kinase, MKK3. Furthermore, MYC2 binds to the MPK6 promoter and regulates its expression in a feedback regulatory mechanism in blue light signaling. We present mutational and physiological studies that illustrate the function of the MKK3-MPK6-MYC2 module in Arabidopsis thaliana seedling development and provide a revised mechanistic view of photomorphogenesis

Eosinophilia as Initial Presentation of Occult Malignancy

Eosinophilia is not an uncommon finding on a routine complete blood count (CBC) during a primary care visit. The differential diagnosis is varied including allergic/atopic disease, drug reaction, infection, inflammatory conditions, and malignancy. An 80-year-old male was incidentally found to have leukocytosis on routine labs. White blood cell (WBC) was 27.5 K/ul with eosinophilia 4.3 K/ul (normal range 0-0.6 Kul) and Hemoglobin/Platelet counts were normal. Patient was asymptomatic. Denied history of medication change or allergy. Chest X-Ray (CXR) followed by Computed tomography (CT) showed 5 cm pulmonary mass with mediastinal lymphadenopathy. Patient developed progressively enlarging left neck mass, hoarseness, weight loss and decreased appetite in the next 3 weeks. WBC increased steeply to 65 K/ul with eosinophil count - 18.5 K/ul. CT neck revealed a large heterogeneous mass of the thyroid extending to the trachea, esophagus, and mediastinum. Patient decided not to proceed with further diagnostic workup and management given his age and comorbidities. Eosinophilia can be asymptomatic or present with nonspecific symptoms like cough, fatigue, skin rash or neuropathy. Eosinophilia work up starts with a comprehensive history detailing travel history, exposure to well water/spring water, analysis of past medical history to include asthma, atopy and especially medication history. Physical exam with attention to atopy/eczema and skin rash is vital. Work up may include a CBC, peripheral blood smear, stool test (for ova and parasite), IgE/tryptase levels and evaluation for occult malignancy (CXR is an ideal first step). Further testing with Bone marrow biopsy and CT scans is a consideration if a clear diagnosis is not achieved. Life-threatening complications of untreated hyper-eosinophilia include thromboembolism, endomyocardial fibrosis, cognitive disturbances, and respiratory failure. Incidence of eosinophilia is 1% in malignant tumors. Malignancy encompasses hematological cancers (acute leukemia, chronic myeloid leukemia, systemic mastocytosis, lymphoid neoplasms) and solid tumors (lung, thyroid, breast and gastrointestinal tract cancers). Eosinophilia suggests advanced disease in solid tumors and portends poor prognosis. Paraneoplastic eosinophilia has been reported in thyroid cancer (sclerosing muco-epidermoid) and lung cancer (squamous and adenocarcinoma). Pathophysiology of eosinophilia in solid tumors is related to bone marrow stimulation through cytokines (interleukin-5, granulocyte-macrophage colony-stimulating factor, and interleukin-2). Primary eosinophilia responds to steroids and hydroxyurea. Treating the underlying malignancy is the cornerstone of paraneoplastic eosinophilia management. We present a case of extreme progressive eosinophilia secondary to a malignancy which would be of interest to the primary care clinician

Pelletisation Behavior of Fluxed Iron Ore Pellets of Varying Basicities Made with Waste Fines

The present study deals with the utilization of fines generated from comminution process (crushing, grinding and screening) of the Run of Mines into value added products i.e. fluxed iron ore pellets. The study comprises to understand the physical and mechanical behavior of five distinguished chemical compositions of green and dried iron ore pellets with respect to a typical Mini Blast furnace (MBF) burden data and furnace operating parameter. The maximum basicity of pellets was calculated 2.37 to make slag neutral when blast furnace runs at 100% high ash coke (avg. ash content= 29%). The crushing strength and drop number of various green pellets were measured. Green Crushing Strength was decreased with increasing lime fines. The addition of lime fines as a burnt lime, which has acicular structure creates less plasticity and brittle like fracture occurred. Due to formation of hard CaCO3 layer on the surface, after increasing lime contain crushing strength was increased in the air and oven dry pellets with respect to acid pellet (0% lime fines addition). [How to cite this article: Sarkar, A., Mandal, A.K., and Sinha, O.P. (2013) Pelletisation Behavior of Fluxed Iron Ore Pellets of Varying Basicities Made with Waste Fines. International Journal of Science and Engineering, 5(2),9-14. Doi: 10.12777/ijse.5.2.9-14

Second Interim Technical Report for Advanced Research in Range Image Interpretation for Automated Mail Handling

This is the report on range image interpretation of singulated irregular parcels. The overall approach to this problem was to find the most general and generic method that will interpret the data yet is computationally economical. We have observed that the large majority of objects that are classified as Irregular Parcels are convex or can be modeled as such plus some deformation. Hence the primitive model that we have chosen, is the superquadric plus deformations such as tapering and bending along the major axis. The superquadric model is an analytic representation of volume for which cross-sections are a class of curves varying between rectangular to elliptical (of course, circular and square shapes are included). As a side product of this representation we obtain naturally the position, orientation and the scale of the object. The principle of recognition is a fitting procedure which changes the parameters so as to minimize the difference between the data and the volume of the model. We believe that this approach is more general than any previously model based approach including CAD/CAM systems. In comparison to the Generalized Cylinder model proposed by Binford [3] and continued with his students [13], our model has the advantages that: a) It does not require any preprocessing, that is the fitting is performed on raw 3-D data points. b) The interpretation is performed in coarse to fine fashion, or from global to local

Phyto-chemical Standardization of Herbal Formulation (PMM3) for Blood Sugar Attenuating Actions in Streptozotocin induced Rats

The present study was intended to prepare herbal formulation, PMM3 using purified and modified parts of five common Indian herbs like, Trigonella foenum-graccum, Tinospora cordifolia, Scoparia dulcis, Adhatoda vasica and Cassia occidental. PMM3 was standardized using physico-chemical, phytochemical, UV-VIS spectral, HPTLC, AAS and GC methods. The phenolics and flavonoids contents were assessed. Anti-hyperglycaemic activities of PMM3 was evaluated on Streptozotocin induced (50mg/kg, i.v) diabetic rats. PMM3 (50-150 mg/kg, p.o) exhibited best potentiality in reducing blood glucose within 14 days treatment in comparison with Diabecon® (Himalaya, India) at the same dose. The preset observation identified formulation PMM3 for anti-hyperglycaemic effect