Sliding mode controller design based on fuzzy inference fornonlinear systems [power systems]

Sliding-mode control can deal with nonlinearities of control systems and is robust. However, it has drawbacks, such as high control gain effect and control chattering. A method of nonlinear feedback control that introduces fuzzy interference into sliding-mode control, to treat nonlinearities and reduce chattering is proposed. The stability of the system is discussed using fuzzy stability theory based on Lyapunov's direct method. The method is applied numerically to the stabilizing control of an electric power system, and is shown to give good results     

Oxidation behavior of Ni2Al-0.1B containing 2Cr

Ni ₃ Al-0.1B containing 2% Cr was subjected to a thermal cycling oxidation test in pure flowing oxygen at atmospheric pressure at temperatures cycled between 400 and 1300 K. Scales formed on the alloy spalled repeatedly after several tens of cycles, resulting in a considerable mass loss of mass of the specimen. The isothermal oxidation behavior of the alloy was also studied at temperatures of 1300, 1400, and 1500 K in the same oxidizing atmosphere. Characteristic breakaway oxidation caused by extensive scale blistering was observed at 1300 and 1400 K after a protective period of about 50 ksec, whereas the oxidation at 1500 K followed a parabolic law without any significant blistering. Particularly at 1300 K, the alloy grain boundaries provided favorable sites for blistering. The influence of Cr may be explained by the modification of mechanical property of the scale.     

Sevoflurane inhalation reduced bronchospasm after extubation

A 73-year-old female was scheduled for left upper lobectomy. She had no history of asthma or chronic obstructive pulmonary disease. During the operation, respiratory sound was clear. As spontaneous breathing was regular and stable after the reversal of neuromuscular blockade, an endotracheal tube was extubated. But soon after the extubation, wheezing and gasping respiration occurred and she complained of dyspnea. Therefore, we administered aminophylline and steroid intravenously, and the patient's lungs were ventilated manually with 100% oxygen. But after 10 minutes, there was no improvement in symptoms, and sevoflurane inhalation was started immediately. Inspiratory sevoflurane concentration was 4% at first, and was decreased to 2%. About 20 minutes after starting sevoflurane inhalation, wheezing was reduced. Sevoflurane may be useful in the treatment of bronchospasm after extubation.     

Clinicopathological characteristics of gastric cancer in the elderly

The clinicopathological features of 380 elderly patients 70 years of age or older with gastric cancer were reviewed retrospectively from hospital records between 1969 and 1993. They were then compared with 1134 middle-aged patients between 40 and 69 years. The elderly constituted 18.4% of all gastric cancer patients 20 years ago but now comprise 24.4% of all patients in the most recent decade, despite the overall decrease in the rate of gastric cancer. The distinguishing histological features of gastric cancer in the elderly were an intestinal type of cancer, expansive tumour growth and synchronous multiplicity of the lesions. Elderly patients had a similar rate of tumour extension but had poorer survival as compared with the middle-aged patients. Post-operative death within 30 days after surgery was also higher in the elderly than in the middle-aged patients.     

Specific hybrid liposomes composed of phosphatidylcholine and polyoxyethylenealkyl ether with markedly enhanced inhibitory effects on the growth of tumor cells in vitro

The hybrid liposomes (90mol% DMPC/10mol% C12(EO)8 and 90mol% DMPC/10mol% C12(EO)12) have a highly inhibitory action against the growth of tumor cells. The uniform and stable structure of the hybrid liposomes was revealed on the basis of electron microscopy and dynamic light scattering measurements.     

Diphtheria toxin binds to the epidermal growth factor (EGF)-like domain of human heparin-binding EGF-like growth factor/diphtheria toxin receptor and inhibits specifically its mitogenic activity

The membrane anchored form of human heparin-binding epidermal growth factor-like growth factor (HB-EGF) acts as the diphtheria toxin (DT) receptor. Transfection of human HB-EGF cDNA into mouse LC cells, L cells stably expressing DRAP27, conferred sensitivity to DT, but transfection of mouse HB-EGF cDNA did not. To define the essential regions of HB-EGF that serve as the functional DT receptor, we examined the sensitivity to DT and DT binding of cells expressing several human/mouse HB-EGF chimeras. It was found that DT binds to the EGF-like domain of the human HB-EGF. However, mouse HB-EGF does not serve as a functional DT receptor due to non-conserved amino acid substitutions in this domain. In addition, CRM197, a non-toxic mutant of DT, inhibited strongly the mitogenic activity of the secreted form of human HB-EGF, but not of mouse HB-EGF and other EGF receptor-binding growth factors. These results confirmed further that DT interacts with the EGF-like domain of HB-EGF and that this interaction is specific for human HB-EGF.     

Immunohistochemical study of MT-MMP tissue status in gastric carcinoma and correlation with survival analyzed by univariate and multivariate analysis

Matrix metalloproteinase (MMP) expression is associated with advanced-stage cancer and contributes to tumor progression, invasion, and metastasis. Membrane type matrix metalloproteinase (MT-MMP) has a potential transmembrane domain at the C terminus and activates pro-MMP-2, which is mainly produced from interstitial fibroblasts. Its expression on the membrane of invasive tumor cells results in the pericellular space degradation at cell-matrix contact sites and renders cancer cells more invasive at the migration front. To elucidate the relationship between MT-MMP expression and metastasis and prognosis in gastric cancer patients, MT-MMP expression was analyzed immunohistochemically in 127 primary tumors and results were correlated with several prognostic parameters and patient's survival. MT-MMP immunoreactivity was stained on the cell membrane of cancer cells and fibroblasts in the invasion front. MT-MMP was detected in 72 tumors (57%) (MT-MMP-positive). MT-MMP expression was closely associated with macroscopically invasive type, nodal involvement, lymphatic invasion, vessel invasion, and peritoneal dissemination. Patients with MT-MMP-positive tumor had a significantly worse prognosis than those with MT-MMP-negative tumor (p<0.001). Multivariate analysis showed MT-MMP overexpression as an independent prognostic factor in gastric cancer patients. Immunohistochemical analysis for MT-MMP may be an indicator of metastatic potential or the prognosis of gastric cancer patients.     

Production of macrocyclic ellagitannin oligomers by Oenothera laciniata callus cultures

Melanocyte-stimulating hormone (MSH) has been reported to enhance the experimental metastatic behaviour of melanoma cells in the mouse model. alpha-MSH production and MSH receptor (melanocortin 1 receptor gene) expression have been detected in cultured normal human melanocytes and metastasized melanomas. The exact role of MSH in the metastatic behaviour of human melanoma cells is, however, not yet known. To clarify a possible role of proopiomelanocortin (POMC)-derived peptides, including alpha-MSH, in melanoma development and progression, we analysed immunohistochemically the localization of alpha-MSH adrenocorticotrophic hormone (ACTH) and beta-endorphin in various kinds of benign pigmented naevocytic lesions and malignant melanomas. Three of 21 samples of common and dysplastic naevi showed detectable alpha-MSH staining in naevus cells, and five and six of 15 samples were weakly positive for ACTH and beta-endorphin staining, respectively. In melanoma samples, 24 of 45, 23 of 39 and 30 of 42 samples showed positive staining with alpha-MSH, ACTH and beta-endorphin antibodies, respectively. Furthermore, staining for all three antibodies was noted to be more intense and diffuse in samples of nodular melanoma, vertically growing acral lentiginous melanoma and superficial spreading melanoma as well as metastatic lesions compared with those of naevi. Although it is yet to be determined whether or not this strong staining for POMC-derived peptides in advanced melanoma cells indicates a role of autocrine or paracrine regulation, our results suggest a possible involvement of POMC gene products in melanoma progression.     

Long-term experiences of 3.5 mgd Roga-spiral RO installation

The 800,000 GPD Reverse Osmosis Plant was put on stream in late 1971 at the Kashima Steel Works of Sumitomo Metal Industries Ltd., Japan and it has been expanded up to the capacity of 3.5 MGD, the world's largest RO Plant now under commercial operation.

Development of the most appropriate pretreatment process and application of specially determined indexes to evaluate the pretreated RO feed water-quality have greatly contributed to maintain the membrane performance at satisfactory level and to prolong or lengthen the membrane life-time. During these four and half years since its installation, operation results show the plant availability of 98%, the module replacement of 5–6% per year and the flux decline slope of -0.02 with better salt rejection than the guaranteed level.

Kurita Water Industries Ltd. has installed many RO plants since 1971, aggregating to approx. 12 MGD in total capacity. Informations are also reported herein regarding other two bigger installations, 1.4 MGD and 2.5 MGD in capacity respectively.