Development and performance characterization of a new standard mercury manometer

A new standard mercury manometer has been developed to calibrate low vacuum gauges in the range from atmospheric pressure to 1 mbar. It consists of a cistern that is a small stainless steel container used as mercury reservoir and also as the first Hg column connected to a long glass tube used as the second Hg column. Manometer scale covers the difference in Hg heights in two columns up to the length equivalent to 1000 mbars. This is a novel low cost manometer with simple design, compact fabrication, better accuracy, easy operation, low vibration, and thermal stability. In order to evaluate the performance of the equipment, its generated pressures are compared with those of secondary standard, i.e., calibrated capacitance diaphragm gauge, giving the average correction factor 0.998. Different uncertainties of the generated pressures are discussed in detail along with the evaluation of correction factors. The relative uncertainty in the higher pressure side is found to be in the range of 10(-4) which is within the limit (approximately 10(-4)).     

Intelligent building energy management system using rule sets

The current study presents an intelligent decision support model using rule sets based on a typical building energy management system. In addition, the model's impact on the energy consumption and indoor quality of a typical office building in Greece is presented. The model can control how the building operational data deviates from the settings as well as carry out diagnosis of internal conditions and optimize building's energy operation. In this context, the integrated “decision support model” can contribute to the management of the daily energy operations of a typical building, related to the energy consumption, by incorporating the following requirements in the best possible way: (a) the guarantee of the desirable levels of living quality in all building's rooms and (b) the necessity for energy savings.     

Optimization of Composite Material System and Lay-up to Achieve Minimum Weight Pressure Vessel

The use of composite pressure vessels particularly in the aerospace industry is escalating rapidly because of their superiority in directional strength and colossal weight advantage. The present work elucidates the procedure to optimize the lay-up for composite pressure vessel using finite element analysis and calculate the relative weight saving compared with the reference metallic pressure vessel. The determination of proper fiber orientation and laminate thickness is very important to decrease manufacturing difficulties and increase structural efficiency. In the present work different lay-up sequences for laminates including, cross-ply [0 _m /90 _n ] _s , angle-ply [±θ] _ns , [90/±θ] _ns and [0/±θ] _ns , are analyzed. The lay-up sequence, orientation and laminate thickness (number of layers) are optimized for three candidate composite materials S-glass/epoxy, Kevlar/epoxy and Carbon/epoxy. Finite element analysis of composite pressure vessel is performed by using commercial finite element code ANSYS and utilizing the capabilities of ANSYS Parametric Design Language and Design Optimization module to automate the process of optimization. For verification, a code is developed in MATLAB based on classical lamination theory; incorporating Tsai–Wu failure criterion for first-ply failure (FPF). The results of the MATLAB code shows its effectiveness in theoretical prediction of first-ply failure strengths of laminated composite pressure vessels and close agreement with the FEA results. The optimization results shows that for all the composite material systems considered, the angle-ply [±θ] _ns is the optimum lay-up. For given fixed ply thickness the total thickness of laminate is obtained resulting in factor of safety slightly higher than two. Both Carbon/epoxy and Kevlar/Epoxy resulted in approximately same laminate thickness and considerable percentage of weight saving, but S-glass/epoxy resulted in weight increment.     

Scanning electrochemical microscopy. 57. SECM tip voltammetry at different substrate potentials under quasi-steady-state and steady-state conditions

We discuss SECM tip voltammetry, where a UME tip is held above a conductive substrate within about a tip radius and a tip voltammogram is recorded as its potential is slowly scanned while the substrate is held at a fixed potential. When the potential of the substrate is changed, the series of steady-state tip voltammograms provide information about the reactants and products. When the potential of the substrate, ES, is set so that the reaction at the substrate is opposite to that at the tip (the usual SECM conditions), a total positive feedback (tpf) tip voltammogram is recorded. When the substrate potential is set to values where the reaction at the substrate is the same as that occurring on the tip, the tip is shielded from the species in the bulk solution. Depending upon the substrate potential, this can cause total shielding (ts) or a voltammogram that is the result of partial feedback/partial shielding (pf-ps). The result is a series of tip voltammograms that are characterized by tpf, pf-ps, or ts, depending upon ES. Experimental tip voltammograms resulting from the reversible reduction of TCNQ and oxidation of ferrocene in MeCN are reported. These are compared with those from simulations and approximate equations developed to describe the features of the tip voltammograms generated under tpf, ts, or pf-ps conditions. The effect of the diffusion coefficient ratio on the ability of the UME tip to reach a true steady state is also addressed and possible applications, e.g., obtaining information about the reversibility of an electrochemical reaction, the product of an electrochemical reaction, the stability of that product, or the diffusion coefficients of the electroactive species, are discussed.     

Sustainable reference methodology for energy end-use efficiency data in the EU

One of the most important goals of the European energy policy involves the implementation of energy-efficiency measures in large scale so as to promote sustainable development in the European Union (EU) level. The multidimensional character of energy end-use efficiency (EEE) necessitates the collection of a number of related data, apart from the performance and system parameters data, such as socio-economic (e.g., employment, turnover) and Research and Development (R&D) expenditures. Moreover, improved co-ordination of EEE programmes and policies of the community and the member states so as a unified acceptable system to be developed for the monitoring of the EEE data with respect to the existing targets is of significant importance. Even though data-gathering efforts have been implemented, a lot of fragmented data and deduced findings are currently available, which sometimes lack consistency and verification. In this context, the main aim of the paper is to present a sustainable reference methodology for validating EEE data in EU, through the review of existing approaches and methods, defining of most relevant inconsistencies and gaps and provision of recommendations for improvements in EEE data aggregation and statistical interpretation, taking into consideration the related analysis of statisticians, energy technology experts and energy socio-economists.     

Chemokine-Cytokine Networks in the Head and Neck Tumor Microenvironment

Head and neck squamous cell carcinomas (HNSCCs) are aggressive diseases with a dismal patient prognosis. Despite significant advances in treatment modalities, the five-year survival rate in patients with HNSCC has improved marginally and therefore warrants a comprehensive understanding of the HNSCC biology. Alterations in the cellular and non-cellular components of the HNSCC tumor micro-environment (TME) play a critical role in regulating many hallmarks of cancer development including evasion of apoptosis, activation of invasion, metastasis, angiogenesis, response to therapy, immune escape mechanisms, deregulation of energetics, and therefore the development of an overall aggressive HNSCC phenotype. Cytokines and chemokines are small secretory proteins produced by neoplastic or stromal cells, controlling complex and dynamic cell–cell interactions in the TME to regulate many cancer hallmarks. This review summarizes the current understanding of the complex cytokine/chemokine networks in the HNSCC TME, their role in activating diverse signaling pathways and promoting tumor progression, metastasis, and therapeutic resistance development.     

New Integral Antiwindup Scheme for PI Motor Speed Control

Windup refers to the phenomenon where a control system operates in a nonlinear region when the controller's output exceeds the input limits of the plant being controlled. Windup can lead to performance degradation in terms of overshoot, settling time and even system stability. Many anti‐windup strategies involve switching and manipulating the integral control component in various ways when saturation occurs aiming to bring control back into the linear region. For better insight into windup, the proportional–integral (PI) plane is now used as a means to explain the phenomenon in terms of the controller's signals. A PI controller with a built‐in closed‐loop integral controller that has a reference set based on the input command and external torque is proposed. The performance for this proposed method is compared against existing conditional integration, tracking back calculation and integral state prediction schemes on second and third order systems using MATLAB/SIMULINK simulations of an induction motor and a DC motor respectively. The proposed controller showed promising potential with its ability to eliminate overshoot in both no load and full load conditions due to the decoupling of its parameters from its response and has the shortest settling time when compared against existing schemes, even in the presence of noise.     

Isolation of a cell surface component of Helicobacter pylori that binds H type 2, Lewis(a), and Lewis(b) antigens

BACKGROUND & AIMS: Individuals of blood group O and nonsecretors of ABO blood group antigens are more susceptible to peptic ulcers. The aim of this study was to determine if blood group antigens associated with group O or secretor status are epithelial cell receptors for Helicobacter pylori. METHODS: Bacterial binding and binding of monoclonal antibodies to H type 2, Lewis(a), and Lewis(b) to Kato III, buccal epithelial, and gastric mucosal cells were shown by flow cytometry. Bacterial outer membrane proteins eluted from H type 2, Lewis(a), or Lewis(b) were shown by polyacrylamide gel electrophoresis. RESULTS: Kato III and human epithelial cells bound each monoclonal antibody; O cells bound more anti-H type 2 (P < 0.05). Binding indices for H. pylori correlated with those for anti-H type 2 (P < 0.005) and anti-Lewis(b) (P < 0.001) but not anti-Lewis(a). A 61-kilodalton protein was eluted from H type 2, Lewis(a), or Lewis(b). CONCLUSIONS: Our results indicate that H type 2 is an important receptor for the 61-kilodalton bacterial adhesin, partly explaining increased susceptibility of individuals of blood group O to ulcers. Lewis(b) binds H. pylori more efficiently than Lewis(a). If these interactions occur in vivo, lack of Lewis(b) in mucosal fluids of nonsecretors may contribute to colonization by H. pylori.