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Este trabalho apresenta o desenvolvimento e a avaliação de um sistema de tratamento de águas residuárias de suinocultura constituído de decantador e seguido de reator anaeróbio de manta de lodo (reator UASB), em escala real. O reator UASB foi construído de alvenaria e concreto armado. Coletaram-se amostras do esgoto bruto e do efluente do decantador e reator UASB, e se monitoraram os seguintes parâmetros: temperatura, pH, alcalinidade, ácidos voláteis totais (AVT), sólidos suspensos totais (SST), sólidos suspensos voláteis (SSV), demanda bioquímica de oxigênio (DBO) e demanda química de oxigênio (DQO), de acordo com os métodos estabelecidos pelo Standard Methods (APHA, 1998). Os resultados médios de remoção total de DQO e de DBO foram de 93 e 92%, respectivamente. As concentrações médias de DQO, DBO e SST no efluente final foram de 0,8, 1,8 e 0,8 g L-1, respectivamente. A carga orgânica volumétrica (COV) aplicada no reator UASB variou de 1,1 a 17,5 kg DQO m-3 d-1. O sistema decantador-reator UASB apresenta-se como alternativa promissora para o tratamento de águas residuárias de suinocultura.This research presents the development and evaluation of a system for treatment of swine wastewaters constituted by slat settler, followed by upflow anaerobic sludge blanket (UASB) reactor, at full scale. The UASB reactor was completely made of masonry and reinforced concrete. The evaluation of the treatment system was carried out through samples collected in the influent and effluent from the settler and UASB reactor. The following parameters were analyzed: temperature, pH, alkalinity, total volatile acids (VFA), suspended solids (TSS), volatile suspended solids (VSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), according to the methods established by the Standard Methods (APHA, 1998). The mean results of COD and BOD removal were 93 and 92%, respectively. The mean concentrations of COD, BOD and TSS in the final effluent were 790, 1818 and 854 g L-1, respectively. The volumetric organic load (VOL) in the UASB reactor ranged from 1.1 to 17.5 kg COD m-3 d-1. The system slat settler-UASB reactor showed itself to be a promising alternative for the treatment of swine wastewaters.

We propose an algorithm for the cost-effective evaluation of structured sparse matrix-vector multiplications on massively parallel SIMD computers with distributed memory. Under the assumption that a large percentage of the nonzero entries of the matrix is concentrated on almost full diagonals, a specific data transport problem arises, for which we derive an equivalent graph theoretical formulation. We find an optimal solution of this communication problem in terms of a minimum-cost spanning tree. We demonstrate the efficiency of our matrix-vector multiplication on a MasPar MP-1 with 16,384 processors.

CdS quantum dots under weak confinement conditions embedded in a polyvinyl alcohol (PVA) polymer film have been studied in the presence of an external electrical field at different densities of photoexcited carriers. Applying an external electric field strength of 5 × 104 V/cm, the observed absorption change δα/α in this material is ≈ 7%. At high laser excitation the electric field separates the laser excited carriers and the change in absorption is attributed to a compensation of the many-particle interaction by the external electrical field. A restoring of the oscillator strength is observed and explained by screening effects of the polarization fields in the interface region due to the photogenerated electron-hole pairs.

The paper deals with the determination of the settling velocity of phosphorus in lakes and reservoirs. The main approaches to estimate the phosphorus loss in aquatic ecosystems are presented. A case study of a lake situated in Berlin, Germany is discussed. The results show that in aerated lakes the values of the settling velocity of phosphorus can be much higher than currently assumed in the literature.

We have studied the linear absorption and the photoluminescence of quantum-confined structures in a polyvinylalcohol matrix doped with CdS. We could observe a coexistence between rather spherical and rod-like growth phases. The different stages of the growth process have been identified by HRTEM measurements.

Objective To compare pulsed-field gel electrophoresis (PFGE) typing and O:K-serotyping of Klebsiella in two different epidemiological settings. Methods One hundred and four bacteremia isolates without known epidemiological relation and 47 isolates from an outbreak in a neonatal intensive care unit (NICU) were K-typed by countercurrent immunoelectrophoresis (CCIE), O-typed by an inhibition enzyme-linked immunosorbent assay method, and typed by pulsed-field gel electrophoresis (PFGE) using the restriction enzyme XbaI. Results Typing data for the 104 bacteremia isolates were compared with regard to typability, number of types, maximum number of isolates per type, and the Discriminative Index (DI). O-typing combined with K-typing (DI 0.98) as O:K-serotyping (DI 0.99) gave a very discriminative typing system, whereas O-typing alone was not very discriminative (DI 0.76). PFGE (DI 1.00) was a more discriminative typing method than O:K-serotyping, as it could subdivide 13/22 O:K-serotypes into smaller groups. Isolates with the same PFGE-type had the same O:K-serotype, indicating that isolates with different O- and/or K-types could be expected to be of different PFGE-types. Typing of the 47 isolates from the outbreak in the NICU showed that 38 isolates belonged to a single clone, and that during an epidemic limited in time and space, differences in the electrophoretic patterns of up to five bands between a parental pattern type and a subtype may be found in the PFGE profiles. Conclusions Both O:K-serotyping and PFGE typing are highly discriminative typing methods. PFGE is the most discriminative method and is excellent for typing outbreaks with few isolates. If large numbers of isolates are to be typed, a more convenient strategy might be first to K- or O:K-serotype isolates followed by PFGE typing of possible identical isolates. Since K- or O:K-serotyping is a definitive typing method, while PFGE typing is a comparative one, PFGE cannot, for the time being, replace O:K-serotyping for surveillance purposes.

Studies on the relaxation process of coherently excited polarizations associated with excited states are interesting to reveal the mechanisms of dephasing in quantum confined semiconductor systems. In two-dimensional systems like quantum wells (QW) or superlattices (SL), the most important mechanisms considered are the scattering of the excited electron-hole pairs with phonons (LO-phonons or confined acoustic phonons), with interface potential fluctuations or localized states or, at higher excitation densities, the scattering by carrier-carrier interaction. In QD’s, at present, the relative contribution of these mechanisms to the dephasing process is an open question and one is trying to identify the different dephasing processes from the experiment. To determine ultrafast relaxation times in the range below 100 fs, various nonlinear spectroscopic methods in the frequency domain have been applied, like hole-burning spectroscopy [1–3] or coherent transient spectroscopy using broadband incoherent light [4,5]. In the present paper the method of nondegenerate four-wave mixing (NDFWM) has been used to derive the dephasing time T 2. The samples investigated are CdS and CdS0.7Se0.3 quantum dots in glass with radii 2 to 3 times larger than the Bohr radius. The large sizes were chosen to minimize the interface influence and by this to investigate the electron-hole pair states before trapping. The minor importance of trap states have been deduced from the dominance of a sharp band-edge related luminescence for these large dot sizes [6]. The dephasing times determined are consistent with results from differential absorption spectroscopy [7,8] at comparable excitation densities. As a new phenomenon we discuss the influence of carrier-carrier scattering in the weak confinement range and determine the dephasing time of this process by increasing gradually the excitation intensity.

When brucite, Mg(OH)2, is carefully heated in vacuum beyond the dehydration temperature (250–270°C) the (001) x-ray intensity decreases rapidly but does not vanish. The (100) reflection persists up to 480°C. The lattice contracts by 0.2% in c -direction. The thermal expansion in a -direction slows down. This indicates the formation of a nearly anhydrous high defect MgO which retains the brucite structure: Mg(OH ) 2−x O x 2 □ x 2 with x→2 (□ unoccupied anion site). This relict structure collapses progressively to the cubic MgO.

A patient with Cronkhite-Canada syndrome had multiple juvenile colonic polyps with hyperplastic, adenomatous, and mixed villous and adenomatous changes. A Dukes B mucus-secreting adenocarcinoma of the cecum was also present. Currently considered a benign disease, the Cronkhite-Canada syndrome may be a premalignant disorder, as our patient's course suggests. We review the literature in this regard.

Intramural diverticulosis of the esophagus is a rare disease of unknown etiology with a characteristic esophagogram consisting of small flask-like diverticula. This paper presents the ninth patient with this disease. There has been confusion about the etiology of the disease and its relation to monilial esophagitis, and this differential diagnosis is discussed. Although the etiology remains speculative, we conclude that intramural diverticulosis of the esophagus may develop in a normal esophagus and that it is not caused byMonilia.

A case of adenocarcinoma of the stomach spreading to the esophagus is described. It was well seen on computerized tomography and appeared more ominous than the esophagram. The latter illustrated an appearance simulating narrowing secondary to peptic esophagitis; the former demonstrated a relatively large encompassing mass. The definitive diagnosis was made during endoscopy and confirmed by biopsy. Although computerized tomography is not considered the method of choice for establishing an abnormality in this organ, it can occasionally help. It can usually show the total extent of the tumor better. Additional cases are presented.

A review about the linear-, nonlinear-, and electro-optic properties of CdS nanocrystals embedded in films of polyvinyl- alcohol (PVA) are given. The preparation of CdS crystals using a polymer matrix is shown to be an alternative method to produce 3D-quantum confined structures, instead of, e.g., the usual growth in glasses. To characterize the optical properties, degenerate four-wave mixing and absorption-saturation experiments have been carried out. Additionally, the electric field-induced absorption change has been measured at different laser excitation intensities. Comparing different glass matrizes with the polymer, the nonlinear-optical experiments show a considerable decrease in the bleaching efficiency with increasing trap density. This behaviour can be explained by an additional term introduced into the two-level system representing the properties of the interface. The probability of localisation, capture, and transfer of carriers into the surrounding matrix rises with increasing density of traps in the interface region. This is in agreement with a theoretical model describing the probability to find an excited electron-hole pair near the interface.1 The measurements of degenerate four-wave mixing show an astonishing result if comparing the values of nonlinear susceptibility χ(3)- For the PVA-film the susceptibility is about twice the value of χ(3) reported for the experiments carried out at CdS-doped in glasses.

A case of herpes gastritis is presented. This complication is being described more frequently in the gastrointestinal tract and can be best diagnosed by endoscopic appearance and examination of brush specimens by cytology.

THE INGESTION of lye, either as a suicidal measure or accidentally, leads to multiple problems. Lye (sodium hydroxide) is highly destructive and may lead to perforation of the esophagus by liquefaction necrosis.1Hypovolemic shock and bacterial invasion are other immediate dangers of lye ingestion. Additional well-known complications are stricture formation, pulmonary insufficiency as the result of repeated aspirations, and perforation of the esophagus or stomach as a result of endoscopic examination. Necrosis of the tissues may extend through the entire esophageal wall, producing periesophagitis, pleurisy, pericarditis, mediastinitis, and bronchoesophageal fistula.2Chemical gastritis, peritonitis, pulmonary edema, and laryngeal obstructions are other possible complications. Cardona and Daly3reported duodenal ulcerations and strictures as a result of lye ingestion. The effects of alkali ingestion are seen primarily in the upper gastrointestinal tract.4In our patient, lye ingestion led to perforations of the small intestine and colon. To our knowledge