An interpolative bandpass converter on a 1.2-μm BiCMOSanalog/digital array

The architecture and performance of an interpolative bandpass A/D converter (ADC) and digital quadrature demodulator dedicated for digital narrowband transmission systems, like the cellular radio mobile receiver, are presented. A prototype version has been implemented on a 1.2-μm/7-GHz BiCMOS analog/digital array. A bandpass signal centered at 6.5 MHz with 200-kHz bandwidth is demodulated and converted with a 55-dB signal-to-noise ratio giving 9-b performance     

Beschleunigung der Kalkauflösung bei den Stahlerzeugungsverfahren

Bildung einer den Kalk umschließenden Dicalciumsilicathülle in Abhängigkeit vom Eisenoxidgehalt der Schlacke. Auflösungsvorgang von synthetischen, gesinterten Kalk-Flußmittel-Mischungen in LD-Schlacken unter betriebsnahen Bedingungen. Bestimmung der Erweichungs- und Fließtemperaturen. Untersuchungen des Gefüges. Verhalten der gesinterten Proben gegen Feuchtigkeit und in flüssiger Schlacke in Abhängigkeit vom Flußmittelanteil der Proben. Folgerungen aus der Anwendung von teilverschlacktem Kalk.     

ENPRO Data Integration: Extending DEXPI Towards the Asset Lifecycle

Chemical plants are engineered to yield high output, while also complying to regulations. In initial R&D phases, experts gather large amounts of information to ensure an optimal design. Here, the influence of the optimization of the process on planning and operation of the plant is important. However, during operation of the facility, little of the information required for R&D work is available in electronic and interoperable form. It is described how this challenge can be overcome by a systematic data integration approach using international standards, centered around the DEXPI working group.     

Organische LEDs

Certain polymers are able to generate luminescence when being applied to an electric field. Basically, this effect allows to manufacture luminous flat displays on a low cost basis. However, most processes involved are still in a development stage. High vacuum evaporation is applied for the conductive layers and is also used to deposit the low molecular organic material. Co‐evaporation, fine tuning of evaporation sources and prevention of cross‐contamination are basic demands on process equipment. Materials involved are sensitive to Oxygen and water vapour. Therefore they need to be handled by load lock transfer systems or under inert gas. Integrating vacuum deposition systems into inert gas glove boxes is a state‐of‐the‐art solution.     

Sicherheit im Chemieapparatebau mit Borosilicatglas

Safety in chemical equipment construction with borosilicate glass. Thanks in particular to its universal corrosion resistance borosilicate glass has acquired a firm place among the materials of construction for pipework, equipment, and plant in chemical engineering. Pertinent technical rules containing all necessary material data and regulations are available for design and planning. Observation of these regulations and adherance to appropriate designs ensure a high degree of safety in operation of glass installations in the rough conditions of a chemical plant.     

Effects of intensive blood-pressure lowering and low-dose aspirin in patients with hypertension: principal results of the Hypertension Optimal Treatment (HOT) randomised trial. HOT Study Group

BACKGROUND: Despite treatment, there is often a higher incidence of cardiovascular complications in patients with hypertension than in normotensive individuals. Inadequate reduction of their blood pressure is a likely cause, but the optimum target blood pressure is not known. The impact of acetylsalicylic acid (aspirin) has never been investigated in patients with hypertension. We aimed to assess the optimum target diastolic blood pressure and the potential benefit of a low dose of acetylsalicylic acid in the treatment of hypertension. METHODS: 18790 patients, from 26 countries, aged 50-80 years (mean 61.5 years) with hypertension and diastolic blood pressure between 100 mm Hg and 115 mm Hg (mean 105 mm Hg) were randomly assigned a target diastolic blood pressure. 6264 patients were allocated to the target pressure < or =90 mm Hg, 6264 to < or =85 mm Hg, and 6262 to < or =80 mm Hg. Felodipine was given as baseline therapy with the addition of other agents, according to a five-step regimen. In addition, 9399 patients were randomly assigned 75 mg/day acetylsalicylic acid (Bamycor, Astra) and 9391 patients were assigned placebo. FINDINGS: Diastolic blood pressure was reduced by 20.3 mm Hg, 22.3 mm Hg, and 24.3 mm Hg, in the < or =90 mm Hg, < or =85 mm Hg, and < or =80 mm Hg target groups, respectively. The lowest incidence of major cardiovascular events occurred at a mean achieved diastolic blood pressure of 82.6 mm Hg; the lowest risk of cardiovascular mortality occurred at 86.5 mm Hg. Further reduction below these blood pressures was safe. In patients with diabetes mellitus there was a 51% reduction in major cardiovascular events in target group < or =80 mm Hg compared with target group < or =90 mm Hg (p for trend=0.005). Acetylsalicylic acid reduced major cardiovascular events by 15% (p=0.03) and all myocardial infarction by 36% (p=0.002), with no effect on stroke. There were seven fatal bleeds in the acetylsalicylic acid group and eight in the placebo group, and 129 versus 70 non-fatal major bleeds in the two groups, respectively (p<0.001). INTERPRETATION: Intensive lowering of blood pressure in patients with hypertension was associated with a low rate of cardiovascular events. The HOT Study shows the benefits of lowering the diastolic blood pressure down to 82.6 mm Hg. Acetylsalicylic acid significantly reduced major cardiovascular events with the greatest benefit seen in all myocardial infarction. There was no effect on the incidence of stroke or fatal bleeds, but non-fatal major bleeds were twice as common.     

Decomposition and oxidation of pyrite

An assessment of the mechanisms and kinetics of pyrite transformation in inert and oxygen-containing atmospheres at elevated temperatures has been performed based on a literature review. In inert atmospheres, the transformation of pyrite proceeds through a multi-step process in the sequence of pyrite→pyrrhotite→troilite→iron. The whole process is determined by the temperature and the total sulfur gas pressure in the system. Under equilibrium conditions, the composition of the resulting pyrrhotite from pyrite decomposition is determined by the temperature.     

Characteristics of 9194 patients with left ventricular hypertrophy: the LIFE study. Losartan Intervention For Endpoint Reduction in Hypertension

-Losartan was the first available orally administered selective antagonist of the angiotensin II type 1 receptor developed for the treatment of hypertension. The Losartan Intervention For Endpoint (LIFE) Reduction in Hypertension Study is a double-blind, prospective, parallel group study designed to compare the effects of losartan with those of the beta-blocker atenolol on the reduction of cardiovascular morbidity and mortality. Patients with essential hypertension, aged between 55 and 80 years, and ECG-documented left ventricular hypertrophy (LVH) were included. Altogether, 9223 patients in Scandinavia, the United Kingdom, and the United States were randomized from June 1995 through April 1997, and 9194 remain after exclusion of a study center at which irregularities were discovered. This population of hypertensives (mean systolic/diastolic blood pressure, 174.4/97.8 mm Hg) with LVH comprises women (54.1%) and men, mostly retired from active work (mean age, 66.9 years), with a high prevalence of overweight (mean body mass index, 28.0 kg/m2), diabetes mellitus (12.3%), lipid disorders (18.0%), and symptoms or signs of coronary heart disease (15.1%). There were fewer current smokers (<17%) than in the general population, and approximately 7% were nonwhite. Almost 30% of participants had been untreated for at least 6 months when screened for the study. Only 1557 persons who entered the placebo run-in period of 14 days were excluded, predominantly because of sitting blood pressures above or below the predetermined range of 160-200/95-115 mm Hg and ECG-LVH criteria not met. By application of simple 12-lead ECG criteria for LVH (Cornell voltage QRS duration product formula plus Sokolow-Lyon voltage read by a core laboratory), hypertensive patients with LVH with an average 5-year coronary heart disease risk of 22.3% according to the Framingham score were identified. This population is now being treated (goal, <140/90 mm Hg) in adherence with the protocol for at least 4 years after final enrollment (ie, through April 2001) and until at least 1040 patients suffer myocardial infarction, stroke, or cardiovascular death.