Advanced Faraday cage measurements of charge, short-circuit current and open-circuit voltage

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004."Spetember 2004."Includes bibliographical references.(cont.) above atmospheric pressure caused both positive current and negative current pulses with the negative pulse larger than the positive pulse. A pressure decrease of more than 10psi below atmospheric pressure also caused both positive current and negative current pulses with the positive current larger than the negative current pulse. Experiments showed that the negative current was generated by the galvanic action between the two dissimilar metals in the triaxial connector connecting the center electrode of the electrode chamber with the electrometer, as water condensed. Positive current could have been produced by the evaporation of moisture from the center electrode of the electrode chamber. Dew point analysis is performed to show that for water to condense on metallic surfaces, it is not necessary to reach the dew point. The calculated dew point temperature is lower than the temperature at which the water condenses upon the electrode surfaces. In the liquid and solid dielectric experiments, we use a patented Faraday cage which is composed of two identical in-line hollow, gold-plated Faraday cup electrodes that enclose the samples which move between them during each measurement under computer control. We conducted charge measurements using various electrometers to rule out the possibility of false instrument readings due to input offset voltage and other experimental effects. One wire mesh style of Faraday cage connected with an electrometer was also used to measure the charge. The liquid dielectrics are distilled water, tap water, Sargasso Sea water ...This thesis is devoted to Faraday cage measurements of air, liquid, and solid dielectrics. Experiments use pressurized air with fixed Faraday cage electrodes, and a moving sample of liquid and solid dielectrics between two Faraday cup electrodes. Extensive experiments were conducted to understand the source of the unpredictable net measured charge. In the air experiment, the Faraday cage consists of a hollow, cylindrical, gold-plated brass electrode mounted within a gold-plated brass hermetic chamber that connects with earth ground. Measurements of transient current at various temperatures and humidity during transient air pressure change are presented. The flow of electrode current is shown not to be due to capacitance and input offset voltage changes, since the calculated value is on the order of 10⁻¹⁶ Amperes which is much less than the measured currents of order 10⁻¹³ Amperes. By controlling the internal relative humidity of air in the Faraday cage, and from the measurements of current using dry nitrogen, we confirm that the absence of moisture causes no current to flow. Amplitude of the measured current is found to be dependent upon the internal relative humidity. Repeatedly, polarity reversals were observed to occur, in part due to galvanic action between dissimilar metals as water condensed upon the insulating surface between them. At a low temperature with a small pressure change, only one pulse of current was observed to occur but, with a pressure change of more than l0psi, two opposite polarity pulses of current were shown to occur almost simultaneously. A small pressure increase only caused a pulse of negative current, and a small pressure decrease only caused a pulse of positive current. A pressure increase of more than l0psiby M. Shahrooz Amin.S.M

Mites of the genus Antennoseius Berlese (Acari: Mesostigmata: Ascidae) from Iran

Abstract: Three species of mites in the subgenus Antennoseius (Antennoseius) Berlese, 1916 associated with ground beetles (Coleoptera, Carabidae) are reported for the first time from Iran: A. (A.) longisetus Eidelberg, A. (A.) sabulicola Bregetova and A. (A.) sharonovi Eidelberg. These species and A. (A.) masoviae Sellnick, are diagnosed in detail. Idiosomal poroidotaxy and adenotaxy for the subgenus are illustrated. A. (A.) vysotskajae Sklyar is considered as junior synonym of A. (A.) sharonovi. A key to Iranian species of the genus is presented

Influence of microstructural variations on morphology and separation properties of polybutadiene-based polyurethanes

Polybutadiene-based polyurethanes with different cis/trans/1, 2-vinyl microstructure contents are synthesized. The phase morphology and physical properties of the polymers are investigated using spectroscopic analysis (FTIR and Raman), differential scanning calorimetry (DSC), X-ray scattering (WAXD and SAXS) and atomic force microscopy (AFM). In addition, their gas transport properties are determined for different gases at 4 bar and 25 °C. Thermodynamic incompatibility and steric hindrance of pendant groups are the dominant factors affecting the morphology and properties of the PUs. FTIR spectra, DSC, and SAXS analysis reveal a higher extent of phase mixing in high vinyl-content PUs. Moreover, the SAXS analysis and AFM phase images indicate smaller microdomains by increasing the vinyl content. Smaller permeable soft domains as well as the lower phase separation of the PUs with higher vinyl content create more tortuous pathways for gas molecules and deteriorate the gas permeability of the membranes

Evaluation of Fuzzy Logic Subsets Effects on Maximum Power Point Tracking for Photovoltaic System

Photovoltaic system (PV) has nonlinear characteristics which are affected by changing the climate conditions and, in these characteristics, there is an operating point in which the maximum available power of PV is obtained. Fuzzy logic controller (FLC) is the artificial intelligent based maximum power point tracking (MPPT) method for obtaining the maximum power point (MPP). In this method, defining the logical rule and specific range of membership function has the significant effect on achieving the best and desirable results. This paper presents a detailed comparative survey of five general and main fuzzy logic subsets used for FLC technique in DC-DC boost converter. These rules and specific range of membership functions are implemented in the same system and the best fuzzy subset is obtained from the simulation results carried out in MATLAB. The proposed subset is able to track the maximum power point in minimum time with small oscillations and the highest system efficiency (95.7%). This investigation provides valuable results for all users who want to implement the reliable fuzzy logic subset for their works

Acquired craniomeningocele in an infant with craniosynostosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Craniosynostosis can affect the skull in various ways. The most common forms are abnormal skull shape and beaten copper pattern, while Lückenschädel (or lacunar skull) is one of the least common forms.</p> <p>Case presentation</p> <p>We report the case of a 3-month-old Caucasian boy with multiple suture craniosynostosis and with acquired craniomeningocele presenting as a bulging mass in the lateral occipital area.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first report of a patient with multiple suture craniosynostosis and acquired craniomeningocele.</p

Cocaine-induced renal infarction: report of a case and review of the literature

BACKGROUND: Cocaine abuse has been known to have detrimental effects on the cardiovascular system. Its toxicity has been associated with myocardial ischemia, cerebrovascular accidents and mesenteric ischemia. The pathophysiology of cocaine-related renal injury is multifactorial and involves renal hemodynamic changes, alterations in glomerular matrix synthesis, degradation and oxidative stress, and possibly induction of renal atherogenesis. Renal infarction as a result of cocaine exposure, however, is rarely reported in the literature. CASE PRESENTATION: A 48 year-old male presented with a four-day history of severe right flank pain following cocaine use. On presentation, he was tachycardic, febrile and had severe right costovertebral angle tenderness. He had significant proteinuria, leukocytosis and elevated serum creatinine and lactate dehydrogenase. Radiographic imaging studies as well as other screening tests for thromboembolic events, hypercoagulability states, collagen vascular diseases and lipid disorders were suggestive of Cocaine-Induced Renal Infarction (CIRI) by exclusion. CONCLUSION: In a patient with a history of cocaine abuse presenting with fevers and flank pain suggestive of urinary tract infection or nephrolithiasis, cocaine-induced renal infarction must be considered in the differential diagnosis. In this article, we discuss the prior reported cases of CIRI and thoroughly review the literature available on this disorder. This is important for several reasons. First, it will allow us to discuss and elaborate on the mechanism of renal injury caused by cocaine. In addition, this review will demonstrate the importance of considering the diagnosis of CIRI in a patient with documented cocaine use and an atypical presentation of acute renal injury. Finally, we will emphasize the need for a consensus on optimal treatment of this disease, for which therapy is not yet standardized

Crohn's Disease and Early Exposure to Domestic Refrigeration

Environmental risk factors playing a causative role in Crohn's Disease (CD) remain largely unknown. Recently, it has been suggested that refrigerated food could be involved in disease development. We thus conducted a pilot case control study to explore the association of CD with the exposure to domestic refrigeration in childhood.Using a standard questionnaire we interviewed 199 CD cases and 207 age-matched patients with irritable bowel syndrome (IBS) as controls. Cases and controls were followed by the same gastroenterologists of tertiary referral clinics in Tehran, Iran. The questionnaire focused on the date of the first acquisition of home refrigerator and freezer. Data were analysed by a multivariate logistic model. The current age was in average 34 years in CD cases and the percentage of females in the case and control groups were respectively 48.3% and 63.7%. Patients were exposed earlier than controls to the refrigerator (X2 = 9.9, df = 3, P = 0.04) and refrigerator exposure at birth was found to be a risk factor for CD (OR = 2.08 (95% CI: 1.01-4.29), P = 0.05). Comparable results were obtained looking for the exposure to freezer at home. Finally, among the other recorded items reflecting the hygiene and comfort at home, we also found personal television, car and washing machine associated with CD.This study supports the opinion that CD is associated with exposure to domestic refrigeration, among other household factors, during childhood

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Retrofit of existing reinforced concrete bridges with fiber reinforced polymer composites

"December 2001."; Includes bibliographical references (p. 52-53).; Final report.; Sponsored by Ohio Dept. of Transportation in cooperation with the U.S. Department of Transportation, Federal Highway Administration under state job no.; Harvested from the web on 3/20/06Four 76-year old T reinforced concrete beams were retrofitted with four different systems employing carbon fiber polymer reinforced (CFRP) composites to examine the success of FRP systems to strengthen aged members with substantial deterioration. The beams were removed from FAI-37-2899 and FAI-37-2915. The systems used in this project were (a) external post-tensioning system with CFRP rods, (b) bonded CFRP plates, (c) bonded CFRP fabrics, and (d) bonded CFRP plates with mechanical anchors at the ends of the plates. The experimental data were augmented with analytical results to better understand the observed behavior, particularly when visual data or the measured data were insufficient.Four 76-year old T reinforced concrete beams were retrofitted with four different systems employing carbon fiber polymer reinforced (CFRP) composites to examine the success of FRP systems to strengthen aged members with substantial deterioration. The beams were removed from FAI-37-2899 and FAI-37-2915. The systems used in this project were (a) external post-tensioning system with CFRP rods, (b) bonded CFRP plates, (c) bonded CFRP fabrics, and (d) bonded CFRP plates with mechanical anchors at the ends of the plates. The experimental data were augmented with analytical results to better understand the observed behavior, particularly when visual data or the measured data were insufficient