Pseudomyxoma peritonei in association with primary malignant tumor of the ovary and colon

Pseudomyxoma peritonei (PMP) is a rare entity that is characterised by abundant intraperitoneal mucinous and gelatinous material associated with an intraperitoneal adenocarcinoma. We report the case of a patient who presented with PMP associated with a ruptured well-differentiated mucinous adenocarcinoma of the ovary and an infiltrating moderately-differentiated mucinous adenocarcinoma of the sigmoid. Diagnosis was made by ultrasonography and CT. Due to the presence of 2 mucinous tumors with different histological grade the most likely pathogenesis was that of multifocal metaplasia. The ovarian and colonic mucinous tumors were independent primary neoplasms and PMP probably was the result of rupture of one of these tumors with peritoneal seeding of viable mucus secreting tumor cells. Aggressive surgical debulking in addition to left hemicolectomy and radical hysterectomy were performed.     

The effects of fatty acids on the particle size distribution of the Portland cement

The cement has to be ground fine enough and have the optimum particle size distribution (PSD) to meet the requirements such as strength properties and setting times in current standards. As it takes quite a long time to determine especially the late strength, grinding has to be based on the cement fineness and the PSD. In this study, the effects of fatty acids were investigated on the PSD of Portland cement. Experimental results showed that the fineness of the cement was decreased for that replaced with 0.025 wt.% lauric acid (LA), myristic acid (MA) and sunflower oil acid (SO), then increased for the other additions. The fineness measurements revealed that the cement grains aggregated for an amount of 0.025 % (w) during the grinding. Also, when the PSD of the ground cement is examined, the relationship between the saturated and the unsaturated components is evident that milling the cement clinker together with 0.1% (w) LA and 0.1 wt. % MA gave the finer cement from that with 0.1 wt.% SO.     

Performance comparison of a single and multiband power amplifiers using IHP 0.25 μm SIGe HBT technology

In this work, a single‐band power amplifier (PA) with a fixed‐frequency/band output matching network and multiband PA with a switch‐tuned output matching network is designed, using IHP (Innovations for High Performance), 0.25 μm‐SiGe HBT process. The behavior of the amplifiers has been optimized for 2.4 GHz (WLAN), 3.6 GHz (UWB‐WiMAX), and 5.4 GHz (WLAN) frequency bands for a higher 1‐dB compression point and efficiency. Multiband characteristics of the amplifier were obtained by using a MOS‐based switching network. Two MOS switches were used for tuning the band of the output matching network. Postlayout simulations of the multiband‐PA provided the following performance parameters: 1‐dB compression point of 25.2 dBm, gain value of 36 dB, efficiency value of 12.8% operation and maximum output power of 26.8 dBm for the 2.4 GHz WLAN band, 1‐dB compression point of 25.5 dBm, gain value of 32 dB, efficiency value of 13.3% and maximum output power of 26.6 dBm for the 3.6 GHz UWB‐WiMAX band and 1‐dB compression point of 24.8 dBm, gain value of 23 dB, efficiency value of 12.5% and maximum output power of 26.3 dBm for the 5.4 GHz WLAN band. For the fixed‐band, at 3.6 GHz, the postlayout simulations resulted the following parameters: 1‐dB compression point of 25.5 dBm, gain value of 32 dB, efficiency value of 18% and maximum output power value of 26.8 dBm. Measurement results of the single‐band PA provided the following performance parameters: 1‐dB compression point of 20.5 dBm, gain value of 23 dB and efficiency value of 7% operation for the 2.4 GHz band; 1‐dB compression point of 25.5 dBm, gain value of 31.5 dB and efficiency value of 17.5% for the 3.6 GHz band; 1‐dB compression point of 22.4 dBm, gain value of 24.4 dB and efficiency value of 9.5% for the 5.4 GHz band. Measurement results show that using multistage topologies and implementing each parasitic as part of the matching network component has provided a wider‐band operation with higher output power levels, above 25 dBm, with SiGe:C process. These results proved that the PA, with switching/tunable output matching network, provides compatible performance parameters, when compared with the fixed‐band PA. The ability of being capable of operation in different frequency bands with compatible performance parameters, when compared with fixed‐band PA, multiband PA can be realized with additional less parasitics, area, and cost advantages. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.     

Direct descent curvature optimal control with a modification algorithm and its application to nonlinear process

This paper presents a direct descent second order or direct descent curvature algorithm with some modifications for the optimal control computations. This algorithm is compared with Hamiltonian methods in the literature. The proposed algorithm has generated numerically robust solutions with respect to conjugate points. The weighting matrix updating scheme was developed to improve the second-order optimal control algorithm, tested the performance of the algorithm, and shown on the benchmark and industrial process. The time-varying optimal feedback (TVOFB) gains are also generated along the trajectory as byproducts. If the trajectory deviates from the optimal trajectory for any reason (i.e., changing of system parameters, step disturbance into the plant, changing of initial conditions), it is held on the optimal trajectory by means of the optimal feedback. Simulations have been given for controlling the Van der Pol and bioreactor system, which are nonlinear benchmark systems.     

Association of relative nocturnal hypertension and autonomic neuropathy in insulin-dependent diabetic children

Twenty-four hour BP and heart rate measurements were carried out in fourteen newly diagnosed-, and in twenty-eight diabetics with 5-13 years of duration; and in eight healthy control children. Mean arterial BP rose at night in five-, fell slightly (less than 10%) in five- and fall markedly (more than 10%) in eighteen diabetics with longer duration of the disease. The diurnal-nocturnal difference of mean arterial pressure was significantly lower in the groups with nocturnal BP rise and slight nocturnal BP fall, compared to the control group (< 0.001; p < 0.01, respectively). The diurnal-nocturnal differences of heart rates were significantly lower in diabetics with relative "nocturnal hypertension" compared to the control group (p < 0.05). The presence of subclinical signs of diabetic autonomic neuropathy was significantly higher in patients with nocturnal BP rise and slight nocturnal BP fall compared to patients with marked nocturnal BP fall and newly diagnosed diabetics (chi squared p = 0.02 and p = 0.01, respectively). In conclusion, the prevalence of autonomic symptoms in diabetic children could be related to change in diurnal/nocturnal arterial BP, however longitudinal studies of ABPM are needed to define, whether patients with abnormal BP profiles are candidates for the development of diabetic vascular disease.     

A compact implantable RFID tag antenna dedicated to wireless health care

Implantable tag antennas are an integral component of contemporary pervasive patient monitoring setups envisioned to reduce the medical errors and improve the quality of health care facilities. These tags, embedded into the human body, transmit critical patient information to the external equipment via a wireless communication link. This research article presents an implantable compact folded dipole antenna of size 10 mm × 15 mm × 2 mm, designed to operate in the industrial‐scientific‐medical band (2.4‐2.48GHz). A three‐layered phantom representing the human arm is used to evaluate the subcutaneous antenna performance. The tag antenna embedded in the middle of the fat layer offers a maximum gain of ?16.3 dBi. The tag antenna performance as a function of implant position and phantom dimensions is analyzed. Link budget calculations show that with the achieved antenna gain the link power exceeds the required power by 38.37 dBm, and hence wireless communication is viable.     

Modelling spatial distributions of moisture and quality during drying of granular baker's yeast

A distributed parameter model was developed to predict the drying behaviour of granular baker's yeast by setting up material and heat balances at the particle level. Temperature and moisture gradients were calculated for cylindrical and spherical granules. The performance of the model with two granule sizes was compared with experimental measurements. The model was initially used for non‐shrinking granules but later modified to take shrinkage into account. The reduction in granule size during the course of drying was estimated and good correspondence with experimental measurements was obtained. In addition to temperature and moisture gradients, the product quality was predicted during drying and compared to experimental results. The accuracy of the model was better than the lumped parameter model.     

Molecular Modelling of Pentapeptide and Tetrapeptide Sequences of C-Hordein

The contribution of the three dimensional structures of one pentapeptide (PQQPY) and two common tetrapeptide sequences (QPQQ and QPFP; in one letter code) to the conformation of C-hordein are investigated using the recently developed multicanonical simulation procedure. Ramachandran plots were prepared and analysed to predict the relative occurrence probabilities of β-turn and γ-turn structures. Structural predictions of PQQPY and QPQQ sequences indicated the presence of considerable level of β-turns and high level of γ-turns. It was possible to distinguish different types of β-turns and their occurrence probabilities. Structural predictions of QPFP sequence indicated that occurrence probabilities of different types of β-turns were negligable as F is placed in second or third positions of the turn.     

Analytical prediction of pressure loss through a sudden-expansion in two-phase pneumatic conveying lines

Estimation of separation or minor pressure losses for pipe fittings of a pneumatic conveying system at design stage is critical as much as determination of frictional pressure losses through it. The flow in many pneumatic conveying systems is a two-phase flow; it is so complex and difficult to be investigated by experimental techniques. The static pressure recovery and the minor loss coefficient through an axis-symmetric, circular cross-section, sudden-expansion fitting of a horizontal pneumatic conveying line with air–solid particle flow are analytically studied. The theoretical models proposed in the literature are scarce, and do not confirm the experimental studies. The well-known homogeneous and separated flow models proposed in the literature are initially applied to the case by means of mass and momentum conservation laws. The predictions of both the models on the pressure recovery were compared with the experimental and the numerical data in the literature and a bad agreement was observed between them; therefore, a new original analytical model is proposed by the present study. The new model is called as the slip flow model, which takes into account the slip velocity between gas and solid phases evaluated by coupling the well-known separated flow model with the empirical slip ratio predictions in the literature. The predictions of the proposed slip flow model on both the pressure recovery and minor loss coefficient are found in good agreement with the corresponding data in the literature.     

Vertical rock cutting rig (VRCR) suggested for performance prediction of roadheaders

This study demonstrates the roadheader performance prediction ability of previously developed vertical rock cutting rig (VRCR). Conical pick cutting tests were conducted on selected rock samples in both relieved and unrelieved cutting modes to determine the relationships between dependent and independent parameters in rock cutting and to investigate the optimum cutting condition. It was seen that relationships among dependent and independent variables match up with previous studies. Furthermore, two roadheader sites were visited, rock samples were collected and cutting rates of roadheaders were recorded. Rock cutting tests on these samples showed that performance prediction with VRCR is a plausible option.