Developmental qualitative and quantitative aspects of the subependymal layer from the caudato-pallial angel of the rat lateral ventricles

We have studied by both qualitative and quantitative methods the subependymal cells in the caudato-pallial angle (CPA) of the lateral ventricle from 1, 2, 6 and 18 month-old rats. We have chosen the CPA, among other zones, because it is an easily delimited glial proliferative zone. The qualitative analysis was carried out using both Klüver-Barrera and Luxol-Fast-Blue stains. The quantitative study was carried out by a semiautomatized image analysis system. Three types of subependymal nuclei were classified by Klüver-Barrera stain, according to the following parameters: staining intensity, morphology and size. Each of the three type groups was found at different frequency depending of rat age. Luxol-Fast-Blue stained mitotic images in metaphase or anaphase: n = 38 in the 1 month, n = 49 in 2 months, n = 12 in the 6 months, and n = 5 in the 18 month-old rats. The quantitative analysis (length, areas and volume of CPA) were in agreement with the above data, showing a more subependymal activity in the 2 month-old animals than in the 1, 6 and 18 month-old rats.     

Synergistic CO2‐Sieving from Polymer with Intrinsic Microporosity Masking Nanoporous Single‐Layer Graphene

High‐flux nanoporous single‐layer graphene membranes are highly promising for energy‐efficient gas separation. Herein, in the context of carbon capture, a remarkable enhancement in the CO₂ selectivity is demonstrated by uniquely masking nanoporous single‐layer graphene with polymer with intrinsic microporosity (PIM‐1). In the process, a major bottleneck of the state‐of‐the‐art pore‐incorporation techniques in graphene has been overcome, where in addition to the molecular sieving nanopores, larger nonselective nanopores are also incorporated, which so far, has restricted the realization of CO₂‐sieving from graphene membranes. Overall, much higher CO₂/N₂ selectivity (33) is achieved from the composite film than that from the standalone nanoporous graphene (NG) (10) and the PIM‐1 membranes (15), crossing the selectivity target (20) for postcombustion carbon capture. The selectivity enhancement is explained by an analytical gas transport model for NG, which shows that the transport of the stronger‐adsorbing CO₂ is dominated by the adsorbed phase transport pathway whereas the transport of N₂ benefits significantly from the direct gas‐phase transport pathway. Further, slow positron annihilation Doppler broadening spectroscopy reveals that the interactions with graphene reduce the free volume of interfacial PIM‐1 chains which is expected to contribute to the selectivity. Overall, this approach brings graphene membrane a step closer to industrial deployment.     

A biased‐randomized metaheuristic for the capacitated location routing problem

The location routing problem (LRP) involves the three key decision levels in supply chain design, that is, strategic, tactical, and operational levels. It deals with the simultaneous decisions of (a) locating facilities (e.g., depots or warehouses), (b) assigning customers to facilities, and (c) defining routes of vehicles departing from and finishing at each facility to serve the associated customers’ demands. In this paper, a two‐phase metaheuristic procedure is proposed to deal with the capacitated version of the LRP (CLRP). Here, decisions must be made taking into account limited capacities of both facilities and vehicles. In the first phase (selection of promising solutions), we determine the depots to be opened, perform a fast allocation of customers to open depots, and generate a complete CLRP solution using a fast routing heuristic. This phase is executed several times in order to keep the most promising solutions. In the second phase (solution refinement), for each of the selected solutions we apply a perturbation procedure to the customer allocation followed by a more intensive routing heuristic. Computational experiments are carried out using well‐known instances from the literature. Results show that our approach is quite competitive since it offers average gaps below 0.4% with respect to the best‐known solutions (BKSs) for all tested sets in short computational times.     

Scanning Electron Microscopy Study of Starch Granule Degradation in Chick-pea Cotyledons

The embryonic axis plays an important role in the processes of starch degradation. Before germination starts, the starch granules of chickpea cotyledons have an almost smooth surface. As germination progresses, membrane-like material is deposited on the granules from the adaxial to the abaxial face of the cotyledon. At 10 days after the start of germination, the starch granules disappear, giving rise to numerous polyhaedral starch bodies. When excised cotyledons are cultured, a pronounced temporal delay occurs in these events.     

Estimate of aflatoxin M1 exposure in milk and occurrence in Brazil

The presence of aflatoxin M₁ (AFM₁) was investigated in 125 samples of powdered milk, pasteurized milk and ultra high treated (UHT) milk in the city of São Paulo, and estimates of AFM₁ intake were assessed. The samples were analysed using an immunoaffinity column for cleanup and a HPLC-FLD for determining AFM₁. The quantification limit was 10 ng/kg. AFM₁ was found in 119 (95.2%) at levels ranging from 10 to 200 ng/kg with mean concentration of 31 ng/kg. The average daily intake estimated for AFM₁ was 1 ng/kg bw per day for children and 0.188 ng/kg bw per day for adults.     

Stress in copper ion-exchanged glass waveguides

This paper obtains stress profiles of copper ion-exchanged glass waveguides from the analysis of transverse electric (TE) and transverse magnetic (TM) modes which was measured by means of the prism-coupling technique. The reconstruction of stress profiles have been realized from an interpolation of the obtained data of effective refractive indexes. We found that the stress profiles decrease with the depth, in agreement with the behaviour of refractive index profiles. We also discuss the theory of the swelling of the glassy network, and we used an approximated model to fit our data of swelling versus diffusion time. The swelling measurements were done by means of a microinterferometrical technique     

Corrective maintenance through dynamic work allocation and pre-emption: case study and application

This case study develops an innovative management and scheduling system for corrective maintenance of machines in a manufacturing facility. The study also involves a comparative evaluation of the proposed and the existing systems under a spectrum of operating conditions. A comprehensive simulation is used to evaluate system performances under a variety of settings which include reliability, service level, and cost consequences. The analysis is based on a full factorial experimental design. In summary, the developed self-regulating management system which involves dynamic work allocation and pre-emption is shown to yield higher machine availability and higher mechanic utilisation even with fewer mechanics. The study also finds that the new system is more streamlined, agile, and robust although it is subject to more-constrained machine reliability and mechanic service time environments. Further, a major reduction of current manpower can still achieve at least 95% machine availability, illustrating the cost effectiveness and efficacy of the developed system. This rule-based corrective maintenance system can be operated in uncertain environments on a real-time basis without additional reformatting costs and provides a competitive measure to deal with managerial issues such as low retention rate for skilled mechanics, highly uneven training levels and pay scales. The financial consequences and gains in strategic advantage with respect to the facility's operational structure are promising after implementation. Moreover, the system developed in this case study represents a meaningful starting point for a more vigorous theoretical research on the bucket brigade system to different functions in industrial and operations management.     

Thermally-stimulated current and dielectric loss measurement ofpolypropylene and Teflon-FEP films immersed in diarylethane

Some properties of oil/PP (biaxially stretched polypropylene) and oil/FEP (Teflon FEP) composite insulators have been investigated with TSC (thermally stimulated current) techniques. The oil/PP system showed three TSC peaks originating from carriers captured in the swollen surface region of the PP. The TSC spectra depended strongly on the polarity of the poling voltage and on the impregnating temperature. Their analysis yielded information on the carrier traps existing near the PP surface in the oil/PP interface region. On the other hand, the TSC spectrum of the oil/FEP system has a small impregnating temperature dependence and a small effect of the poling voltage polarity. The difference in TSC between oil/PP and oil/FEP systems is closely related to the difference in the oil-polymer interaction. The TSC is a useful method for investigating carrier traps in the surface region and their change due to the oil-polymer interaction. To investigate further the relation between the carrier traps and tanδ, collecting bias TSC was measured on a specimen to which an ac voltage was applied. The results indicate that the decrease in tanδ during the ac voltage application depends on the amount of trapped carriers near the polymer's surface or, the decrease in carriers in the oil     

Characterization of different sugarcane bagasse ashes generated for preparation and application as green products in civil construction

Clean Technologies and Environmental Policy - The characterization and manipulation of solid residues according to their types can enable different ways of efficient and specialized applications in...