IONIZED CALCIUM IN ACIDOSIS: DIFFERENTIAL EFFECT OF HYPERCAPNIC AND LACTIC ACIDOSIS

The effects of various forms of acidosis on ionized calcium concentrations were investigated in vivo in rabbits and in vitro in human plasma. Calculation of least square regression equations of ionized calcium (mM) on pH yielded the following regression coefficients in human plasma: hypercapnic acidosis —0.53±0.07; hydrochloric acidosis —0.65±0.06; lactic acidosis —0.27±0.05. These findings in human plasma are roughly paralleled by those in rabbits. From stability constants it was calculated that the formation of Ca-lactate complexes accounts for the difference between lactic and hydrochloric acidosis. It is concluded that differences in the behaviour of ionized calcium between hypercapnic and lactic acidosis might contribute to the known differences in cardiovascular effect

A dimension conjecture for q-analogues of multiple zeta values

We study a class of q-analogues of multiple zeta values given by certain formal q-series with rational coefficients. After introducing a notion of weight and depth for these q-analogues of multiple zeta values we present dimension conjectures for the spaces of their weight- and depth-graded parts, which have a similar shape as the conjectures of Zagier and Broadhurst-Kreimer for multiple zeta values

NESTMOD: The NetMod-NEST Interface

NESTMOD is a combined analytical modeling and simulation tool, based on the existing tools NetMod and NEST. It provides both transient and steady-state response statistics from models of interconnected local area networks that can execute at any level of detail desired. This gives users the potential to model both networks of extremely large scope (hundreds of thousands of nodes), and to look at great detail for any combination of the ISO layers. This paper describes the interface implementation, and presents an example to illustrate the potential power of the tool.http://deepblue.lib.umich.edu/bitstream/2027.42/107970/1/citi-tr-91-7.pd

Photovoltaic -Battery System to Power Fan-Controlled Rice Husk Gasifier Cooking Stove

More than three billion people use wood, dung, coal and other traditional fuels for cooking inside their homes. Inefficient wood stoves are responsible for indoor air pollution, respiratory related diseases and deaths but also accelerated deforestation due to excessive fuel consumption. A promising stove is the open-source, fan-controlled, top-lit updraft, autothermal Belonio gasifier. The need of electricity to power the fan proves to be an obstacle for low-income families without access to electricity. The aim of this study therefore was to develop an economical, environmentally friendly, emission-free solution to power the Belonio stove fan. Consequently, a PV-battery system was designed inclusive of charge controller and inverter. The overall efficiency of the PV-battery, battery-inverter, and inverter-fan in the system was found to be 43.8 %. Fan speed had a great effect on inverter efficiency requiring either additional electricity consumers such as lighting or mobile phone charger or the use of a DC fan in which case the inverter can be omitted. However, economically viable fan speed controllers for DC fans must be developed. The daily cost of cooking for an average 5 family household was estimated to be RM 0.40 which can be further reduced with mass production of the stand-alone PV powered Belonio gasifier system

Investigation of the performance of an optimised MicroCAT, a GEM and their combination by simulations and current measurements

A MicroCAT (Micro Compteur A Trous) structure which is used for avalanche charge multiplication in gas filled radiation detectors has been optimised with respect to maximum electron transparency and minimum ion feedback. We report on the charge transfer behaviour and the achievable gas gain of this device. A three-dimensional electron and ion transfer simulation is compared to results derived from electric current measurements. Similarly, we present studies of the charge transfer behaviour of a GEM (Gas Electron Multiplier) by current measurements and simulations. Finally, we investigate the combination of the MicroCAT and the GEM by measurements with respect to the performance at different voltage settings, gas mixtures and gas pressures.Comment: 26 pages, 32 figure

Casimir Effect in the Presence of Minimal Lengths

It is expected that the implementation of minimal length in quantum models leads to a consequent lowering of Planck's scale. In this paper, using the quantum model with minimal length of Kempf et al \cite{kempf0}, we examine the effect of the minimal length on the Casimir force between parallel plates.Comment: 10 pages, 2 figure

Studies of aging and HV break down problems during development and operation of MSGC and GEM detectors for the Inner Tracking System of HERA-B

The results of five years of development of the inner tracking system of the HERA-B experiment and first experience from the data taking period of the year 2000 are reported. The system contains 184 chambers, covering a sensitive area of about 20 * 20 cm2 each. The detector is based on microstrip gas counters (MSGCs) with diamond like coated (DLC) glass wafers and gas electron multipliers (GEMs). The main problems in the development phase were gas discharges in intense hadron beams and aging in a high radiation dose environment. The observation of gas discharges which damage the electrode structure of the MSGC led to the addition of the GEM as a first amplification step. Spurious sparking at the GEM cannot be avoided completely. It does not affect the GEM itself but can produce secondary damage of the MSGC if the electric field between the GEM and the MSGC is above a threshold depending on operation conditions. We observed that aging does not only depend on the dose but also on the spot size of the irradiated area. Ar-DME mixtures had to be abandoned whereas a mixture of 70% Ar and 30% CO2 showed no serious aging effects up to about 40 mC/cm deposited charge on the anodes. X-ray measurements indicate that the DLC of the MSGC is deteriorated by the gas amplification process. As a consequence, long term gain variations are expected. The Inner Tracker has successfully participated in the data taking at HERA-B during summer 2000.Comment: 29 pages, 22 figure