Electrical Characterization of Conductive Concrete Containing Graphite Powder

Electrically conductive concrete has various potential non-structural functions such as self-sensing, de-icing, and electromagnetic shielding. Since conductive concrete is a composite containing moisture and discrete conductive additives, its electrical properties are very complex. Understanding these properties is the fundamental requirement for developing its non-structural applications. In this research, graphite powder is used as a conductive additive with varying percentages (0% to 30%) by cement paste volume. Both AC impedance analysis and DC measurement are performed in both wet and dry conditions. The results show that the resistivity measured by DC are not consistent because of polarization before/during the measurement. On the other hand, the AC measurements yield consistent results. The resistivity of concrete is lower in wet conditions than in dry conditions. The AC impedance spectroscopy shows that conductive concrete behaves like a circuit made of resistor and capacitor, and the capacitance causes polarization. Various impedance circuits were tested, and the best equivalent circuits for the conductive concrete in dry and wet conditions were proposed based on the simulation results

Process involved in designing of an intelligent additional track mechanism tracked vehicle for swamp peat terrain

Different types of off road vehicles are widely used in agriculture, oil industry, mining and military operations but none of them can effectively operate over the swamp peat terrain because of its low bearing capacity of 7kN/m 2. Segmented rubber tracked vehicle and intelligent air-cushion system tracked vehicle were developed in Malaysia for swamp peat terrain.16kN/m2 of ground pressure was exerted by using the segmented rubber tracked vehicle during field operation therefore could not be operated efficiently. The air-cushion tracked vehicle increased the floatation capacity but at the same time increased the frictional effects therefore the tracks of the vehicle easily slipped out from the traction wheels during operation. Addressing these issues an intelligent additional track mechanism for tracked vehicle has been designed to improve the mobility over swamp peat terrain where the additional track would be increased the ground surface area and reduced the vehicle ground pressure. This paper presents the process involved in designing the intelligent additional track mechanism tracked vehicle for transportation of agricultural and industrial goods on the swamp peat terrain with bearing capacity of 7kN/m2. The mechanical design comprises of track vehicle frame with track mechanism. Additional track mechanism with Fuzzy expert system. The design parameters are optimized using developed mathematical model based on the dynamics and kinematics behavior of the vehicle. In order to increase the vehicle contact surface area and reduce the surface contact pressure the additional track mechanism is designed in such way that it can be folded and unfolded from its position by using the ball-screw scissor lift mechanism. While, Fuzzy expert system is used to control the movement of the lift mechanism based on 70mm critical sinkage of vehicle detected from a set of sensors. The completed to vehicle system would be used for off-road applications as required

Variability in lipid profile in patients with acute myocardial infarction from two tertiary care hospitals in Pakistan

Objective: To investigate changes in total cholesterol, high density lipoprotein (HDL)-cholesterol, low density lipoprotein (LDL)-cholesterol and triglycerides in serum of Pakistani patients with AMI due to age, gender, body mass index (BMI), diabetes, hypertension, and smoking, and also find out the prevalence of hypercholesterolemia, hypertriglyceridemia, low HDL-cholesterol and isolated low-HDL cholesterol in them.Patients and Methods: Serum samples from 451 consecutive AMI patients (250 from National Institute of Cardiovascular Diseases, Karachi and 201 from Armed Forces Institute of Cardiology, Rawalpindi) were analyzed for total cholesterol, HDL-cholesterol and triglycerides using kit methods. LDL-cholesterol was determined using the Friedewald formula.Results: Mean serum concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides in AMI patients were found to be 181 +/- 50 mg/dl, 35.7 +/- 11.3 mg/dl, 110 +/- 47 mg/dl and 177 +/- 127 mg/dl, respectively. Mean levels of total cholesterol and HDL-cholesterol were not significantly affected by age, gender, BMI, diabetes mellitus, hypertension and smoking. Mean LDL-cholesterol concentration, however, was found to be significantly increased in diabetes mellitus (p=0.047), while age, gender, BMI, hypertension and smoking had no significant effect on the levels of this lipoprotein. Mean levels of triglycerides were significantly decreased in older patients (\u3e50 years) compared to younger (\u3c50 \u3eyears) ones (p=0.019). Gender, BMI, diabetes mellitus, hypertension and smoking, however, had no effect on triglyceride levels The frequencies of hypercholesterolemia, hypertriglyceridemia, low HDL-cholesterol and isolated low-HDL-cholesterol were found to be 30.6%, 30.1%, 48.6% and 34.1%, respectively.Conclusion: High prevalence of hypertriglyceridemia and low HDL-cholesterol (which constitute a component of metabolic syndrome) in Pakistani AMI patients is suggestive that these two lipid abnormalities could be playing a major role in the development of atherosclerosis in Pakistani population

Using the Sharp Operator for edge detection and nonlinear diffusion

In this paper we investigate the use of the sharp function known from functional analysis in image processing. The sharp function gives a measure of the variations of a function and can be used as an edge detector. We extend the classical notion of the sharp function for measuring anisotropic behaviour and give a fast anisotropic edge detection variant inspired by the sharp function. We show that these edge detection results are useful to steer isotropic and anisotropic nonlinear diffusion filters for image enhancement

Smartphone-Based Prenatal Education for Parents with Preterm Birth Risk Factors

Objective To develop an educational mobile application (app) for expectant parents diagnosed with risk factors for premature birth. Methods Parent and medical advisory panels delineated the vision for the app. The app helps prepare for preterm birth. For pilot testing, obstetricians offered the app between 18–22 weeks gestational age to English speaking parents with risk factors for preterm birth. After 4 weeks of use, each participant completed a questionnaire. The software tracked topics accessed and duration of use. Results For pilot testing, 31 participants were recruited and 28 completed the questionnaire. After app utilization, participants reported heightened awareness of preterm birth (93%), more discussion of pregnancy or prematurity issues with partner (86%), increased questions at clinic visits (43%), and increased anxiety (21%). Participants reported receiving more prematurity information from the app than from their healthcare providers. The 15 participants for whom tracking data was available accessed the app for an average of 8 h. Conclusion Parents with increased risk for preterm birth may benefit from this mobile app educational program. Practice implications If the pregnancy results in preterm birth hospitalization, parents would have built a foundation of knowledge to make informed medical care choices

Supersymmetric hydrodynamics from the AdS/CFT correspondence

We compute holographically the dispersion relation for a hydrodynamic mode of fluctuation (the phonino) of the density of supersymmetry current in N = 4 SYM at strong coupling. The mode appears as a pole at low frequency and momentum in the correlator of supercurrents. It has a wave-like propagation, and we find its speed and coefficient of attenuation.Comment: 17 page