In Situ Performance Testing of Deteriorating Water Tanks for Durability Assessment

Reports of failure of existing concrete structures due to a lack of durability, rather than a deficiency in structural strength, has made concrete technologists, engineers, and researchers focus research on the parameters influencing durability performance with respect to time. Systematic performance monitoring, with respect to chosen durability parameters of existing concrete structures, will decide the direction of future research in this area. Inferences based on laboratory simulations and testing need to be confirmed by in situ field measurements and studies. In situ condition rating and performance monitoring surveys have been conducted by many researchers, scientists, and professional associations, and reported in literature. Inferences of few such studies are summarized and discussed. Deterioration of concrete structures constructed in recent times is observed at relatively faster rates, and has been mainly attributed to cracking. Cracking is associated with the use of faster-hydrating portland cements with increased fineness and the tricalcium silicate (C3S) content to support the high speed of modern construction. In the present research, a case study of deteriorated water tank structures situated in the semitropical region of India is presented. Some selected parameters—such as concrete cover, carbonation depth, chloride concentration, compressive strength, etc. which influence long term durability of structures—have been measured.     

Action and reason in the theory of Āyurveda

The paper explores the relation between reason and action as it emerges from the texts of āyurveda. Life or Ayus (commonly understood as life-span) is primary subject matter of Ayurveda. Life is a locus of experience, action and disposition. Experiences and actions are differentially determined by dispositions that characterize the organism; otherwise all living organisms will be identical. Ayus of each living being is uniquely individual and remains constant between birth and death. In this journey, upkeep of ayus is the purpose of āyurveda or science of life. Ayurveda is a science of experienced matter as well as of experienced body. The living body is critically dependent on the influx of matter for its upkeep. āyurveda offers a conceptual system to reason about balance and imbalances of the system and the causal role of the material flux through the system. This sensate matter is causally open and makes room for definite causal role for the individual and the effective insertion of the felt-purpose of action. Some of the strengths of Ayurveda are brought forth in the paper such as (a) reasoning out the compatibility between the bodily processes and the selection of the natural products for diet and drug, (b) role for heuristics in medical diagnosis, which takes into cognizance the particularity of each living body and the teleology evident in the very act of diagnostic reasoning. The paper shows that āyurvedic theory is built on experiential datum whereas scientific medical theory is built on experience-independent datum. āyurveda explores causal efficacy of ‘secondary qualities’ whereas scientific medicine explores causal efficacy of ‘primary qualities’. The actionable experiential reasoning is at the foundations of āyurveda whereas modern medical science is ab initio saddled with difficult ‘hiatus theoreticus’ between theory and practice. For Ayurveda it is experience of qualities that discloses behavior of matter. The types of qualities that appear in experience have a special significance for theorizing about the actions of matter with the help of qualities. The paper explores the relation between experience of qualities and the method of science. It shows how efficacy of medical practice is based on the foundational stance of experiential realism in theory. To bring the point home, the paper borrows Aristotalian concepts to show how the relation between phantasm and phronesis is honored in the very theory of āyurveda.     

Finite-difference time-domain analysis and experimental examinationof the performance of a coupled-cavity MQW laser/active waveguide at1.54 μm

The performance characteristics of a coupled cavity InGaAsP-InP MQW laser/active waveguide made by one-step epitaxy and well-controlled reactive ion etching (RIE) have been theoretically analyzed and experimentally determined. A theoretical model based on a finite-difference time-domain (FDTD) technique was used to simulate the propagation of an optical wave launched in the coupled system and determine the reflectivity of the facets created by RIE. The calculated effective reflectivity of the coupling region consisting of two facets and an air gap is between 0.45 and 0.55, which is in good agreement with the experimentally measured value of 0.5. The reflectivity of a single etched mirror derived from this value is estimated to be 0.3. A 120-μm-long monolithically integrated active waveguide when biased as a modulator and excited by the laser shows a maximum extinction ratio of 8 dB and a modulation bandwidth ⩾14 GHz at a dc bias of -0.5 V with a bias swing of 2 V     

Sub-quarter micron silicon integrated circuits and single wafer processing

This paper describes the role of single wafer processing in the development of sub-quarter micron silicon integrated circuits (ICs). The issues related to device processing, choice of materials, performance, reliability, and manufacturing are covered. Single wafer processing based rapid photothermal processing (dominant photons with wavelength less than about 800 nm) is an ideal answer to almost all the thermal processing requirements of current and future Si ICs. For process integration, a new model for process optimization based on minimization of thermal stress is proposed. For breaking the sub-100 nm manufacturing barriers, high throughput lithography based on direct writing is a proposed solution.     

ERCP and CT findings of ectopic drainage of the common bile duct into the duodenal bulb

OBJECTIVE: The purpose of this study was to evaluate ERCP and CT findings of ectopic drainage of the common bile duct into the duodenal bulb. CONCLUSION: Although rare, the diagnosis of ectopic drainage of the common bile duct into the duodenal bulb is important to prevent inadvertent damage during biliary tract or gastric surgery and to clarify the cause of chronic peptic ulcers.     

Use of the polymerase chain reaction in the diagnosis of leprosy

A case is described in which a pericardial branch of a nongrafted left internal mammary artery communicated directly with the distal left anterior descending artery, following saphenous vein bypass grafting. This type of collateralization following coronary artery bypass surgery seems to be very rare, and perhaps could protect the myocardium from severe ischemia.     

Acromioclavicular joint cyst and rotator cuff tear

The role of a depressor factor, atrial natriuretic peptide, in the development of arterial hypertension in adolescents with pubertal hypothalamic syndrome was studied in 52 patients and 13 healthy males aged 13-24 years. The duration of disease was 2-11 years. Radioimmunological methods were used to measure plasma atrial natriuretic peptide, plasma renin activity, and serum aldosterone. Patients with borderline arterial hypertension were found to have a significant reduction in their atrial natriuretic peptide levels, and this correlated directly with the renin-aldosterone system, demonstrating insufficiency of the depressor system in patients with pubertal hypothalamic syndrome and the involvement of atrial natriuretic peptide in the development of arterial hypertension, along with disturbances in the functional relationship between atrial natriuretic peptide and the renin-aldosterone system.     

Serum amyloid P component scintigraphy and turnover studies for diagnosis and quantitative monitoring of AA amyloidosis in juvenile rheumatoid arthritis

OBJECTIVE: To evaluate aspects of the natural history of AA amyloidosis complicating juvenile rheumatoid arthritis (JRA), and its response to therapy with chlorambucil. METHODS: Scintigraphy and 7-day turnover studies were performed in JRA patients with histologically proven (n = 35) or clinically suspected (n = 30) AA amyloidosis, following intravenous injection of 123I and 125I-labeled serum amyloid P component (SAP). Prospective monitoring studies were performed over 2-3 years in 20 patients with amyloidosis. All but 2 amyloidosis patients were treated with chlorambucil. RESULTS: Positive scanning results were obtained in all patients in whom imaging was performed within 12 years of positive biopsy findings of amyloid and in 5 patients with clinically suspected amyloidosis. Negative scanning results with normal SAP metabolism, indicating regression of amyloid, were obtained in 4 patients whose amyloidosis had been in full clinical remission for more than 12 years. Prospective monitoring studies in patients whose JRA-associated inflammatory activity was in remission demonstrated regression of amyloid in 8 patients and no substantial changes in 8 others; however, in 4 further patients with active inflammation, there was accumulation of amyloid. There was a very poor correlation between the amount of amyloid present at a particular site and the resultant organ dysfunction. CONCLUSION: Radiolabeled SAP scintigraphy and turnover studies are useful complementary tools in the diagnosis, screening, and quantitative monitoring of type AA amyloidosis in JRA. The amyloid deposits may progress and/or regress at different rates in different anatomic sites over short periods.