Development of a State-of-the-Art Dry Low NOx Gas Turbine Combustor for IGCC with CCS

The successful development of the coal-based integrated gasification combined cycle (IGCC) with carbon capture and storage (CCS) requires gas turbines capable of achieving dry low nitrogen oxide (NOx) combustion of hydrogen-rich syngas fuels for low emissions and high plant efficiency. This chapter describes the development of a “multi-cluster combustor” as a state-of-the-art dry low NOx combustor for hydrogen-rich syngas fuels. The combustor consists of multiple clusters of pairs of one fuel nozzle and one air hole that are installed coaxially. The essence of the design concept is the integration of two key technologies: rapid mixing of fuel and air for low NOx and flame lifting for flashback-resistant combustion. The combustor has been developed in three steps: burner development, combustor development, and feasibility demonstration for practical plants. The combustor was tested with a practical syngas fuel in a multi-can combustor configuration in an IGCC pilot plant in the final step. The combustor achieved the dry low NOx combustion of the syngas fuel in the pilot plant and the test results demonstrated the feasibility for achieving dry low NOx combustion of the syngas fuel in practical plants

Drell-Yan Production of Z' in the Three-Site Higgsless Model at the LHC

In the Higgsless models, there are extra gauge bosons which keep the perturbative unitarity of a longitudinally polarized gauge boson. The three-site Higgsless model is a minimal Higgsless model and contains three extra gauge bosons, $W^{\prime \pm}$ and Z'. In this paper, we report the discovery potential of the Z' gauge boson via Drell-Yan production with Z'(mass=380, 500, 600 GeV) $\rightarrow WW \rightarrow \ell\nu qq$ ($\ell=e$, $\mu$) at the LHC ($\sqrt{s}$=14 TeV).Comment: 7 pages, 5 figures included. References revise

Adverse effect profile of trichlormethiazide: a retrospective observational study

<p>Abstract</p> <p>Background</p> <p>Trichlormethiazide, a thiazide diuretic, was introduced in 1960 and remains one of the most frequently used diuretics for treating hypertension in Japan. While numerous clinical trials have indicated important side effects of thiazides, e.g., adverse effects on electrolytes and uric acid, very few data exist on serum electrolyte levels in patients with trichlormethiazide treatment. We performed a retrospective cohort study to assess the adverse effects of trichlormethiazide, focusing on serum electrolyte and uric acid levels.</p> <p>Methods</p> <p>We used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between Nov 1, 2004 and July 31, 2010, to identify cohorts of new trichlormethiazide users (n = 99 for 1 mg, n = 61 for 2 mg daily dosage) and an equal number of non-users (control). We used propensity-score matching to adjust for differences between users and control for each dosage, and compared serum chemical data including serum sodium, potassium, uric acid, creatinine and urea nitrogen. The mean exposure of trichlormethiazide of 1 mg and 2 mg users was 58 days and 64 days, respectively.</p> <p>Results</p> <p>The mean age was 66 years, and 55% of trichlormethiazide users of the 1 mg dose were female. In trichlormethiazide users of the 2 mg dose, the mean age was 68 years, and 43% of users were female. There were no statistically significant differences in all covariates (age, sex, comorbid diseases, past drugs, and current antihypertensive drugs) between trichlormethiazide users and controls for both doses. In trichlormethiazide users of the 2 mg dose, the reduction of serum potassium level and the elevation of serum uric acid level were significant compared with control, whereas changes of mean serum sodium, creatinine and urea nitrogen levels were not significant. In trichlormethiazide users of the 1 mg dose, all tests showed no statistically significant change from baseline to during the exposure period in comparison with control.</p> <p>Conclusions</p> <p>Our study showed adverse effects of decreased serum potassium and increased serum uric acid with trichlormethiazide treatment, and suggested that a lower dose of trichlormethiazide may minimize these adverse effects. These findings support the current trend in hypertension therapeutics to shift towards lower doses of thiazides.</p

Effect of candesartan monotherapy on lipid metabolism in patients with hypertension: a retrospective longitudinal survey using data from electronic medical records

<p>Abstract</p> <p>Background</p> <p>Studies focusing on the add-on effects of angiotensin II type 1 receptor blockers (ARBs) other than their antihypertensive effect are receiving attention. However, the effects of prolonged administration of ARBs on lipid metabolism in clinical cases are unclear. Our aims were to survey the changes in plasma lipid profile in patients with hypertension over a one-year period, and to examine the correlations between these values and the time after the start of ARB monotherapy with candesartan.</p> <p>Methods</p> <p>We carried out candesartan monotherapy in patients with mild to moderate hypertension and examined the longitudinal changes in plasma lipid profile. Data from 405 patients for triglyceride (TG), 440 for total cholesterol (TC), 313 for high density lipoprotein cholesterol (HDL-C) and 304 for low density lipoprotein cholesterol (LDL-C) were obtained from the electronic medical records (EMRs) in the Clinical Data Warehouse (CDW) of Nihon University School of Medicine (NUSM). The inverse probability of treatment weighting (IPTW) method (calculated from the inverse of the propensity score) was used to balance the covariates and reduce bias in each treatment duration. Linear mixed effects models were used to analyse the relationship between these longitudinal data of blood examinations and covariates of patient sex, age, diagnosis of diabetes mellitus (DM) and duration of candesartan monotherapy.</p> <p>Results</p> <p>Plasma HDL-C level was associated with sex, duration of treatment, and interaction of sex and treatment duration, but not with age or diagnosis of DM. HDL-C level was significantly decreased during the 6~9 months period (p = 0.0218) compared with baseline. TG and TC levels were associated with sex, but not with age, diagnosis of DM or treatment duration. LDL-C level was not associated with any covariate. Analysis of the subjects divided by sex revealed a decrease in HDL-C in female subjects (during the 6~9 months period: p = 0.0054), but not in male subjects.</p> <p>Conclusions</p> <p>Our study revealed that administration of candesartan slightly decreased HDL-C in female subjects. However, TG, TC and LDL-C levels were not influenced by candesartan monotherapy. Candesartan may be safely used for patients with hypertension with respect to lipid metabolism, because the effect of candesartan on lipids may be small.</p

A Review of Oxidative Stress and Urinary Dysfunction Caused by Bladder Outlet Obstruction and Treatments Using Antioxidants

Urinary dysfunction is a common pathological condition that can significantly decrease the quality of life.Bladder outlet obstruction (BOO) is a major cause of urinary dysfunction, and various lower urinary tract diseases including benign prostatic hyperplasia and urethral stricture disease cause BOO. According to the results of a variety of animal experiments on partial BOO (PBOO), there is a general agreement that ischemic conditions and repeated ischemia/reperfusion of the bladder are closely associated with BOO-induced bladder damage, and that increased oxidative stress by ischemia/reperfusion plays a crucial role in the pathological mechanisms underlying urinary dysfunction. Changes in biomarkers of oxidative stress in PBOO animal models support this association between oxidative stress and urinary dysfunction. Oxidative stress is defined as an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidants. Therefore, organizing the knowledge on the state of oxidative stress, changes in biomarkers, and biological roles of antioxidants in systemic and bladder tissues is essential to understand the detailed pathological characteristics of the urinary dysfunction caused by PBOO. Furthermore, information on drugs and supplements that have antioxidant effects is important for defining treatment strategies for urinary dysfunction with PBOO. In this review, we paid special attention to the following three issues; (1) changes in oxidative stress, including its biomarkers, (2) antioxidant status, and (3) previous reports on treatment strategies involving agents with antioxidative activity for urinary dysfunction caused by BOO. In particular, we provide systematic information on the detailed mechanisms underlying the antioxidative effects of agents used to treat PBOO. In addition, we show present research issues and research limitations, as well as suggest possible future antioxidant treatment strategies for patients with PBOO

Development Of Fuel-Flexible Gas Turbine Combustor

LectureGrowing global energy demands are motivating the gas turbine industry to seek fuel-flexible gas turbines capable of burning a wide variety of fuels as a means of increasing energy supply stability and security. These fuel-flexible gas turbines require diluent-free (“dry”), low nitrogen oxide (NOx) and flashback-resistant combustors for various fuels in order to achieve low NOx emissions and high plant efficiency for low carbon dioxide (CO2) emissions. This paper describes the development of a state-of-the-art dry low-NOx and flashback-resistant combustor for fuel-flexible gas turbines. This advanced combustor consists of multiple fuel nozzles and multiple air holes. One fuel nozzle and one air hole are installed coaxially to give one key element, and a cluster of key elements constitutes one burner, which forms one flame. Multiple cluster burners constitute a can combustor, and several can combustors are installed on a gas turbine. In this paper, the burner is called a “cluster burner,” and the combustor is called a “multi-cluster combustor.” The essence of the burner concept is the integration of two key technologies: low-NOx combustion due to the enhancement of fuel-air mixing; and flashback-resistant combustion due to short premixing sections, air-stream-surrounded fuel jets and lifted flames. The development approach of the multi-cluster combustor consists of three steps: burner development; combustor development; and feasibility demonstration for practical plants. The first step optimizes burner configurations by fundamental research at atmospheric pressure. The second step optimizes combustor configurations by single-can combustor testing at medium to high pressures. The third step demonstrates the feasibility of the combustor by field testing with real gas turbines. This paper describes the development work in each step of the multi-cluster combustor developed particularly for hydrogen content syngas fuels in a coal-based integrated gasification combined cycle (IGCC), and the field test in an IGCC pilot plant demonstrates the feasibility of the combustor for practical plants. This paper also describes applications of this combustion technology to expand fuel flexibility