An efficient algorithm for optimal generation mix taking into account fuzziness of decision making and planning parameters

This paper presents an efficient computational algorithm for selecting the optimal generation mix under uncertain circumstances. Subjective, experiential or linguistic uncertainties are selected from among various uncertainties, i.e., we treat fuzziness in generation expansion planning. The fuzziness can be divided into: (1) the fuzziness of decision making; and (2) the fuzziness of some planning parameters, such as load growth, fuel price, and so on. Both classes of fuzziness are integrated into a fuzzy decision based on fuzzy sets theory, and then the optimal generation mix can be determined by the Fuzzy Dynamic Programming (FDP) technique. The proposed method, which is based on the dynamic programming technique, is extended by using the Bellman-Zadeh maximizing decision. In the method, each generation technology and generation capacity are selected as a stage and state, respectively. The proposed method can easily accommodate not only the fuzziness but also many constraints of generation expansion planning, such as integer solutions of unit capacities, condition of existing units, and so on. Furthermore, the arbitrary shape of membership function can be used. The effectiveness and feasibility of the proposed method are demonstrated on a typical power system model.     

Surgery for thoracic empyema concurrent with rupture of lung abscesses in a child

The authors report surgical treatment for thoracic empyema concurrent with rupture of lung abscesses and completely collapsed lung in a child. Right middle lobectomy for ruptured abscess, debridement and closure with interrupted sutures for another abscess in the lower lobe, and decortication were performed. Positive-pressure ventilation was needed to prevent reexpansion pulmonary edema because of long-term collapsed lobes. The patient is doing well with no recurrent empyema or thoracic deformity at 3 years postoperation.     

Traumatic intracranial foreign body embolization--case report

A 27-year-old male presented with intracranial embolization due to accidental penetration of his neck by an iron fragment at work. Cerebral angiography revealed foreign body embolization of the left middle cerebral artery. The foreign body was successfully removed via craniotomy and arteriotomy. The extended period from onset to surgical treatment prevented acute hemodynamic reconstruction. However, he had good collateral circulation and was discharged with mild hemiparesis and moderate motor aphasia. The possibility of intracranial embolization should be considered in patients presenting with penetrating injury of the neck.     

Measurement of the tensile strength of a powder bed by a swing method measuring instrument

The measurement of the tensile strength of a powder bed has been carried out by means of the swing method measuring instrument, which has been developed by the authors. The effects on the void fraction and the moisture content have been investigated.From the stress—displacement curves obtained directly with this instrument, the work required for the tensile breakage of the powder bed was calculated.The most interesting problem is the application of the measurement of tensile stress to the design of powder treatment processes.The floodability of fine powders has been discussed empirically but theoretical bases are not sufficient for the evaluation of the potential floodability.The following dimensionless number, namely the ratio of the cohesive force to the gravity force on a single particle,

was found to give a good correlation with the empirical floodability index evaluated by Carr's method.     

Activity tests of various catalysts for hydrocracking of coal by means of high pressure differential thermal analysis

The activities of fourteen kinds of catalysts for the hydrocracking of Taiheiyo coal were examined by a high pressure differential thermal analytical method. Exothermic peaks appeared at low temperatures (420–430°C) when MoO₃TiO₂, NiY zeolite and CoY zeolite were used as catalysts, indicating that these catalysts are highly active compared with other catalysts including MoO₃CoOAl₂O₃. The qualitative analysis of gas and liquid products revealed that MoO₃TiO₂ and CoY are good catalysts for the liquefaction reaction. The hydrogenation ability of the catalyst is concluded to be more important than its acidic property.     

Plasma centrifuge for separation of metal elements and isotopes

Centrifugal separation of elements has been explored in rapidly rotating metal plasmas. The plasma is produced and driven into rotation by cross-field, vacuum discharge in a coaxial plasma gun. A large separation factor is measured in Cu/Zn plasmas. In particular, a hollow density profile which improves the separative power is found to be established in the plasma column.