Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input ...

Purdue University

Use of the radial artery as a conduit for coronary artery surgery has increased dramatically. It has been assumed that blood flow to the forearm will not be compromised by its removal.

Harvest of the radial artery for coronary artery surgery preserves maximal blood flow of the forearm.

In the present study, catalytic wet oxidation (CWO) was investigated for the destruction of organic pollutants in the thermally pretreated effluent from a pulp and paper mill under moderate temperature and pressure conditions. The thermal pretreatment studies were conducted at atmospheric pressure and 368K using copper sulfate as a catalyst. The thermal pretreatment reduced COD by about 61%. The filtrate of the thermal pretreatment step was used at pH 8.0 for CWO at 383-443K temperature and a total pressure of 0.85MPa for 4h. Catalysts used for the reaction include copper sulfate, 5% CuO/95% activated carbon, 60% CuO/40% MnO(2), and 60% CuO/40% CeO(2). Maximum COD reduction was found to be 89% during CWO step using 5% CuO/95% activated carbon with a catalyst loading of 8gl(-1) at 443K and 0.85MPa total pressure. Overall COD reduction for the pretreatment and the CWO was found to be 96%. Besides this, 60% CuO/40% CeO(2) catalyst also exhibited the similar activity as that of obtained with 5% CuO/95% activated carbon catalyst at 423K temperature and 0.85MPa total pressure. The pH of the solution during the experimental runs decreases initially due to the formation of carboxylic acid and then increases due to the decomposition of acids.

Catalytic wet oxidation of the pretreated synthetic pulp and paper mill effluent under moderate conditions.

This paper presents a model using fuzzy synthetic evaluation to estimate the methane generation rate constant, k, for landfills. Four major parameters, precipitation, temperature, waste composition and landfill depth were used as inputs to the model. Whereas, these parameters are known to impact the methane generation, mathematical relationships between them and the methane generation rate constant required to estimate methane generation in landfills, are not known. In addition, the spatial variations of k within a landfill combined with the necessity of site-specific information to estimate its value, makes k one of the most elusive parameters in the accurate prediction of methane generation within a landfill. In this paper, a fuzzy technique was used to develop a model to predict the methane generation rate constant. The model was calibrated and verified using k values from 42 locations. Data from 10 sites were used to calibrate the model and the rest were used to verify it. The model predictions are reasonably accurate. A sensitivity analysis was also conducted to investigate the effect of uncertainty in the input parameters on the generation rate constant.

A model to estimate the methane generation rate constant in sanitary landfills using fuzzy synthetic evaluation.

European Union (EU) member states are adopting the mechanical-biological treatment (MBT) of municipal solid waste (MSW) to comply with EU Landfill Directive (LD) targets on landfill diversion. We review the policy framework for MSW-derived solid recovered fuel (SRF), composed of paper, plastic, and textiles, in the energy-intensive industries. A comparatively high calorific value (15-18 MJ/ kg) fuel, SRF has the potential to partially replace fossil fuel in energy-intensive industries, alongside MSW in dedicated combustion facilities. Attempts by the European standards organization (CEN) to classify fuel properties consider net calorific value (CV) and chlorine and mercury content. However, the particle size, moisture content, and fuel composition also require attention and future studies must address these parameters. We critically review the implications of using SRF as a co-fuel in thermal processes. A thermodynamic analysis provides insight into the technical and environmental feasibility of co-combusting SRF in coal-fired power plants and cement kilns. Results indicate the use of SRF as co-fuel can reduce global warming and acidification potential significantly. This policy analysis is of value to waste managers, policy specialists, regulators, and the waste management research community.

Wastes as co-fuels: the policy framework for solid recovered fuel (SRF) in Europe, with UK implications.

Wet-air oxidation of diluted black liquor (chemical oxygen demand [COD] approximately 3250 to 14 500 mg/L) was performed at mild operating conditions (temperature = 388 to 423 K and total pressure = 0.6 MPa) in the presence of heterogeneous 60% copper oxide (CuO)/ 40% cerium oxide (CeO2) catalyst. Maximum COD reduction of 77.3% was obtained at 423 K at pH 3.0, which was marginally higher than that obtained at 413 K temperature (77.1%). In the acidic environment (pH < or = 3), most of the COD was removed in the form of settleable solids during the transient heating of the wastewater from room temperature to the desired one. The solid residue obtained after the reaction has a heating value of 20.1 MJ/kg, which is comparable with that of Indian coal. Thermal degradation kinetic determination suggested that thermal characteristics of the solid residue are well represented by a power law model with Agarwal and Sivasubramanian approximation (Safi et al., 2004).

Catalytic oxidative treatment of diluted black liquor at mild conditions using copper oxide/cerium oxide catalyst.

The effectiveness of coagulation (using aluminium-based chemicals and ferrous sulfate) and acid precipitation (using H(2)SO(4)) processes for the pre-treatment of diluted black liquor obtained from a pulp and paper mill is reported. Commercial alum was found to be the most economical among all the aluminium and ferrous salts used as a coagulant. A maximum removal of chemical oxygen demand (COD) (ca. 63%) and colour reduction (ca. 90%) from the wastewater (COD = 7000 mg l(-1)) at pH 5.0 was obtained with alum. During the acid precipitation process, at pH < 5.0, significant COD reductions (up to 64%) were observed. Solid residue obtained from the alum treatment at a temperature of 95 degrees C showed much better (3 times) settling rate than that for the residue obtained after treatment with the same coagulant at a temperature of 25 degrees C. The settling curves had three parts, namely, hindered, transition and compression zones. Tory plots were used to determine the critical height of suspension-supernatant interface that is used in the design of a clarifier-thickener unit. High heating values and large biomass fraction of the solid residues can encourage the fuel users to use this waste derived sludge as a potential renewable energy source.

Effectiveness of coagulation and acid precipitation processes for the pre-treatment of diluted black liquor.

The complex manifestations of chronic multiple sclerosis (MS)are due in part to widespread axonal abnormalities that affect lesional and nonlesional areas in the central nervous system. We describe an association between microglial activation and axon/oligodendrocyte pathology at nodal and paranodal domains in normal-appearing white matter (NAWM) of MS cases and in experimental autoimmune encephalomyelitis (EAE). The extent of paranodal axoglial (neurofascin-155(+)/Caspr1(+)) disruption correlated with local microglial inflammation and axonal injury (expression of nonphosphorylated neurofilaments) in MS NAWM. These changes were independent of demyelinating lesions and did not correlate with the density of infiltrating lymphocytes. Similar axoglial alterations were seen in the subcortical white matter of Parkinson disease cases and in preclinical EAE, at a time point when there is microglial activation before the infiltration of immune cells. Disruption of the axoglial unit in adjuvant-immunized animals was reversible and coincided with the resolution of microglial inflammation; paranodal damage and microglial inflammation persisted in chronic EAE. Axoglial integrity could be preserved by the administration of minocycline, which inhibited microglial activation, in actively immunized animals. These data indicate that, in MS NAWM, permanent disruption to axoglial domains in an environment of microglial inflammation is an early indicator of axonal injury that likely affects nerve conduction and may contribute to physiologic dysfunction.

Activated microglia mediate axoglial disruption that contributes to axonal injury in multiple sclerosis.

Eosinophilic mucin rhinosinusitis is an inflammatory pathological condition of the nose and paranasal sinuses. It is rare, occurs in immunocompetent patients and is characterised by peripheral eosinophilia and extensive bilateral sinus disease. To the best of our knowledge, visual loss with this condition has not been previously reported.

Visual loss secondary to eosinophilic mucin rhinosinusitis in a woman: a case report.

Left ventricular myxoma are quite rare and have not been reported in children. We report a left ventricular myxoma arising from interventricular septum in a 12-year-old girl who presented with history of single episode of syncope while playing in school. General examination of the child did not reveal any abnormality except a grade II/VI systolic murmur in left parasternal area. Transthoracic echocardiography revealed a round pedunculated mass (18 × 30 mm) in left ventricle arising from middle of interventricular septum with a pedicle measuring 4 mm at its base. The tumour was projecting through aortic valve in systole. Syncope in this case was probably due to obstruction of left ventricular outflow tract by myxoma leading to a decrease in cardiac output. Complete excision of myxoma was done through transmitral approach.

Left ventricular myxoma in a child: a case report.

Pulmonary artery aneurysm presenting with dissection and hemopericardium is extremely rare, and we came across one such case in our center. The patient was a 22-year-old man who presented with dyspnoea, tachypnoea, and pallor. On evaluation, he was found to have a leaking pulmonary artery aneurysm with dissection and hemopericardium, and a patent ductus arteriosus. He underwent pericardiocentesis followed by successful closure of the ductus, aneurysmectomy, and reconstruction of the pulmonary artery.

Pulmonary artery aneurysm with dissection and hemopericardium.

To devise a simple, cheap and effective improvised method of treating deep sternal wound infections (DSWI) by negative pressure obviating high cost of patented systems.

Use of improvised vaccum assisted suction drainage for cases of deep sternal wound infection.

Acute macular neuroretinopathy (AMNR) is a rare disorder characterised by acute onset of unilateral or bilateral visual impairment associated with reddish-brown wedge-shaped outer macular lesions. It is more frequently reported in young females and though the pathophysiology remains unclear, factors reported in association with its onset include post-viral illness and vasoconstrictor use. We report a case of AMNR in an 18-year old female patient presenting with a 2-day history of acute painless blurring of central vision bilaterally, following 1 month of preceding flu-like illness. For 1 week prior to presentation, the patient had taken large doses of oral preparations containing phenylephrine hydrochloride. In addition to demonstrating characteristic optical coherence tomography findings seen in AMNR, we illustrate some rarely seen acute ophthalmoscopic features. Based on associations from this case, we add further insight into the pathophysiology of this condition which remains poorly understood.

Anurag Garg

Birck Nanotechnology Center and the Department of Electrical and Computer Engineering

Purdue University

Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

Anurag Garg

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Birck Nanotechnology Center and the Department of Electrical and Computer Engineering

Purdue University

Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

Birck Nanotechnology Center and the Department of Electrical and Computer Engineering