Determination of orifice diameter for horizontal pipelines in layers for composing windrows via variation of pressure losses

Compressed air plays an important role in forced aeration composting systems; the lateral outlet orifices on the main pipeline must be properly sized to maintain a pressure drop of less than 5% at the output of each orifice. Organic matter (OM) was aerated at a rate of 0.557 m³ air·d^-1·kg^-1, as determined by dry weight (DW), and the internal temperature and humidity of the windrows were monitored. The calculated variation of the pressure loss for the pipelines in the experimental windrow was between 1.53% and 2.56% at a maximum internal temperature of 70.8°C, unlike the conventional windrow, which reached a maximum temperature of 47.1°C. In both systems, the humidity was greater than 50%. The cost per metre for commercial scale implementation is equivalent to US$21.22, considering the use of alternative materials with the necessary mechanical and thermal resistance values.     

The surgical treatment of thoracolumbar metastases

Intrathecal implants of adrenal chromaffin cells are known to release analgesic substances such as catecholamines and opioid peptides. In the present study, bovine chromaffin cells were encapsulated in a permselective polymer membrane which protects the cells from the host immune system and allows grafting of xenogeneic cells without immunosuppression. The effects of such implants were evaluated on the pain behavior resulting from a chronic constrictive injury (CCI) of the rat sciatic nerve. Sprague-Dawley rats with a unilateral lesion were implanted in the lumbar subarachnoid space and tested for mechanical/thermal allodynia and hyperalgesia. A significant reduction in pain was observed after mechanical non-nociceptive stimulation in animals implanted with chromaffin cells. Furthermore, these animals showed decreased signs of spontaneous pain. However, response to thermal non-noxious stimuli or to painful mechanical stimuli was not significantly decreased. Abundant clusters of viable chromaffin cells intensely labeled with the anti-tyrosine hydroxylase antibodies were observed in the retrieved implants. These results establish the analgesic efficacy of intrathecal encapsulated chromaffin cells in a chronic pain model of nerve injury. Immunoprotected allo- or xenogeneic chromaffin cells acting as 'mini pumps' continuously delivering neuroactive substances could be a useful therapy for patients suffering from neuropathic pain.     

Hydatidosis/echinococcosis in General Acha, La Pampa Province, Argentina

Hydatidosis situation in the General Acha area (La Pampa Province) is described herein. The work comprises a retrospective compilacion of new hydatidosis human cases, the findings in seroepidemiological surveys with enzyme immuno assay (EIA) for hydatidosis in human population, and investigation on dog Echinococcus granulosus infection prevalence carried out on the basis of arecoline bromhydrate application. Sixteen human cases were detected during 1994 (incidence rate: 26.7/100,000), founding a serological prevalence of 1.3%. Studies on dog echinococosis have shown a prevalence rate of 2.3%. The epidemiological situation of hydatidosis is analyzed by comparison with values from other endemic areas. These results suggest the necessity of completing surveys in the whole provincial territory, and the implementation of educational and sanitary measures aimed to controlling this zoonosis.     

Then an angel came

The metabolic affects of anapriline, captopril, and clophelin were studied in the blood and liver homogenates ex vivo and in vitro in experiments on intact rats and rats with alloxan diabetes. Anapriline lowered the blood lactate content in rats with diabetes and intact rats, reduced the level of glycemia in animals with marked hyperglycemia. Captopril increased the blood insulin and lactate content in rats with diabetes and the content of pyruvate in vivo. The results of the study show that the use of clophelin and anaprilin in the treatment of patients with diabetes mellitus is most rational.     

The Acoustic Characterization of Broom Fibers

Natural materials are becoming a valid alternative to traditional synthetic ones for sound absorption applications. In this paper, the acoustic properties of broom fibers are reported and discussed. Broom plants grow up on hills and mountains and are common in many Mediterranean countries. The materials were cut and shredded to prepare several samples. Test specimens made of broom pieces with a diameter from 1.5 mm to 4 mm were prepared. The normal sound absorption for samples with a thickness of 60 mm, 80 mm and 120 mm was then measured. Results are particularly promising especially above 500 Hz, as the samples consistently reported a normal sound absorption above 0.5. The increase in the sample thickness allowed to obtain higher sound absorption at lower frequencies, as generally expected for porous materials. The main limit of the investigated samples was the appearance of sound absorption resonances. These were more evident for the samples composed of pieces with larger diameter, and may be attributed to the loose nature of the tested samples.     

Analytical model to estimate performances of autonomous vehicle storage and retrieval systems for product totes

In today's competitive scenario of increasingly faster deliveries and smaller order sizes, material-handling providers are progressively developing new solutions. A recent, automated material-handling technology for unit load storage and retrieval consists of an autonomous vehicle storage and retrieval system (AVS/RS). The present paper presents an analytical model to estimate the performances (the transaction cycle time and waiting times) of AVS/RS for product tote movement. The model is based on an open queuing network approach. The model effectiveness in performance estimation is validated through simulation.     

Simulations of flow-like landslides invading urban areas: a cellular automata approach with SCIDDICA

Different methodologies are used for modelling flow-like landslides. A common critical point concerns the flooding into town areas, which cannot be assimilated straight to a morphology, especially, when the urban tissue is very irregular with narrow streets and odd setting of buildings, so that discretization processes of approximating numerical methods have to be carefully examined in their limits. A semi-empirical approach by the computational paradigm of cellular automata is here considered with SCIDDICA, a competitive (related to PDE approach) cellular automata model for 3-dimensions simulation of flow-like landslides. This paper presents innovations to the transition function of SCIDDICA-SS2, which manage opportunely building data in the cells corresponding to the urban tissue. The novelties of the transition function need a theorem, here demonstrated which regards the Algorithm of Minimization of Differences in the new context of inhomogeneous cells. This progress permits to simulate the complete evolution of landslides, from the detachment area to its exhaustion almost on the same precision level. This is an advantage for hazard and risk analyses in threatened zones. Improved SCIDDICA-SS2 was applied successfully to all the well-known 2009 debris flows of Giampilieri Superiore (Sicily) also in comparison with simulation results of the previous versions.     

Investigating the demand propagation in EOQ supply networks using a probabilistic model

In this paper, we introduce a new demand probabilistic approach, named M.DPA.eoq (Montanari Demand Probabilistic Approach in economic order quantity [EOQ] scenario), for predicting the demand seen by an upper tier echelon (e.g. a distribution centre) of a supply network, serving several lower tier echelons operating according to an EOQ reorder policy. The M.DPA.eoq is based on an analytic approach, by which we derive the distribution of the demand seen by the upper tier echelon of the supply network. The approach has been designed to be very simple, so as to gain in pedagogical value. The simplicity and ease of application of this approach are confirmed by the possibility of exploiting general purpose software, such as Microsoft Excel^TM, to implement and validate it. Moreover, the M.DPA.eoq has potential to be directly exploited by practitioners, such as supply network managers, to estimate the distribution of the demand the upper tier echelon will face under a defined network structure. Students and researchers could also benefit from such a model, given its ease of understanding and usage. With the purpose of showing its potential usefulness in real cases, we discuss two practical implications of the M.DPA.eoq, referring to the use of its results for: (1) computing the bullwhip effect of the network; and (2) analysing the impact of each retail store on the variance of the demand seen by the upper tier echelon.     

Nanocellulose Reinforced Chitosan Composite Films as Affected by Nanofiller Loading and Plasticizer Content

ABSTRACT: Chitosan is a biopolymer obtained by N-deacetylation of chitin, produced from shellfish waste, which may be employed to elaborate edible films or coatings to enhance shelf life of food products. This study was conducted to evaluate the effect of different concentrations of nanofiller (cellulose nanofibers, CNF) and plasticizer (glycerol) on tensile properties (tensile strength—TS, elongation at break—EB, and Young's modulus—YM), water vapor permeability (WVP), and glass transition temperature (T_g) of chitosan edible films, and to establish a formulation to optimize their properties. The experiment was conducted according to a central composite design, with 2 variables: CNF (0 to 20 g/100 g) and glycerol (0 to 30 g/100 g) concentrations in the film (on a dry basis), which was produced by the so-called casting technique. Most responses (except by EB) were favored by high CNF concentrations and low glycerol contents. The optimization was based on maximizing TS, YM, and T_g, and decreasing WVP, while maintaining a minimum acceptable EB of 10%. The optimum conditions were defined as: glycerol concentration, 18 g/100 g; and CNF concentration, 15 g/100 g. AFM imaging of films suggested good dispersion of the CNF and good CNF-matrix interactions, which explains the good performance of the nanocomposite films. Practical Application: Chitosan is a biodegradable polymer which may be used to elaborate edible films or coatings to enhance shelf life of foods. This study demonstrates how cellulose nanofibers (CNF) can improve the mechanical and water vapor barrier properties of chitosan films. A nanocomposite film with 15% CNF and plasticized with 18% glycerol was comparable to some synthetic polymers in terms of strength and stiffness, but with poorer elongation and water vapor barrier, indicating that they can be used for applications that do not require high flexibility and/or water vapor barrier. The more important advantage of such films when compared to synthetic polymer films is their environmentally friendly properties.