Towards a benchmarking model for winery wastewater treatment and disposal.

We propose a benchmarking model for winery wastewater treatment systems and use it to quantitatively compare the performance of Chilean wine-making operations. The benchmarking model integrates three components: the influent characteristics, the wastewater treatment alternatives, and the location constraints. Four performance levels may be defined when plotting the available data of the wine production versus the ratio of wastewater to wine, for the French, US, and Chilean industries. Knowing where a certain system lies in this diagram helps to quantify the gap between the current and a target performance, and to set performance goals for planned expansions. The analysis of construction and operating costs of treatment systems currently in operation in Chile shows that similar compliance levels can be achieved at remarkably different costs. A steep decrease in the unitary cost is observed as wastewater flow increases; yet, the treatment alternative for achieving that cost may change. Further selection is obtained when location constraints are considered, including stringent discharge standards and proximity to urban settlements. The application of this simple benchmark model to three Chilean winery facilities shows how it produces meaningful quantitative and qualitative results. However, there is still ample room to improve this benchmarking model by considering additional complexity, including technical detail in the treatment options and costs related to technology conversion.     

Effect of the heating rate on crystallization behavior of mechanically alloyed amorphous alloy

The mechanical alloying is the most convenient method to produce Mg–Ni alloys. In this study, the effect of ball-to-powder weight ratios and the mechanical alloying time on amorphization of Mg₅₀Ni₅₀ alloy and its thermal stabilities were investigated. Mg₅₀Ni₅₀ alloy has been produced by using Spex 8000 D mixer/mill with different ball-to-powder weight ratios (5:1, 10:1, 20:1). Amorphization times by XRD analysis are found to be 60 h for 5:1 ball-to-powder weight ratio, 10 h for 10:1 ball-to-powder weight ratio and 5 h for 20:1 ball-to-powder weight ratio. The thermal stabilities of amorphous Mg₅₀Ni₅₀ alloys, obtained by different ball-to-powder weight ratios, have been determined and the effect of heating rates on the crystallization temperatures have also been investigated by DSC. The heating rates employed were 5, 10, 15, 20 °C/min. During the first crystallization reaction, the amorphous and Mg₂Ni intermetallic phases occurred. DSC studies show that increase in heating rates increased the crystallization temperatures for all samples. The apparent activation energies were determined by means of the Kissinger method.     

Status of solar desalination in India

The work was motivated by the increasing awareness of the need for enhancing water supplies schemes in arid lands featuring an appropriate technology for solar energy use in the desalination field in India. The fresh water crisis is already evident in many parts of India, varying in scale and intensity at different times of the year. India's rapidly rising population and changing lifestyles also increases the need for fresh water. Fresh water is increasingly taking centre stage on the economic and political agenda, as more and more disputes between and within states, districts, regions, and even at the community level arises. The conventional desalination technologies like multi stage flash, multiple effect, vapor compression, iron exchange, reverse osmosis, electro dialysis are expensive for the production of small amount of fresh water, also use of conventional energy sources has a negative impact on the environment. Solar distillation represents a most attractive and simple technique among other distillation processes, and it is especially suited to small-scale units at locations where solar energy is considerable. India, being a tropical country is blessed with plenty of sunshine. The average daily solar radiation varies between 4 and 7 kWh per square meter for different parts of the country. There are on an average 250–300 clear sunny days in a year, thus it receives about 5000 trillion kWh of solar energy in a year. In spite of the limitations of being a dilute source and intermittent in nature, solar energy has the potential for meeting and supplementing various energy requirements. Solar energy systems being modular in nature could be installed in any capacity as per the requirement. This paper consists of an overall review and technical assessments of various passive and active solar distillation developments in India. This review also recommended some research areas in this field leading to high efficiency are highlighted.     

Coexpression of major histocompatibility complex class I and LMP1 in Epstein-Barr virus-positive Hodgkin's lymphoma in a pediatric age group

The Epstein-Barr virus (EBV)-encoded latent membrane proteins (LMP1 and LMP2) are consistently expressed by malignant Hodgkin Reed-Sternberg (HRS) cells of EBV-associated Hodgkin's disease (HD). The EBV LMP1 has been implicated in tumorogenesis. Cytotoxic T lymphocyte (CTL) responses to both of these proteins have been shown in the blood of EBV-seropositive individuals, and in HD, the apparent failure of the CTL response to eliminate HRS cells expressing LMP1 in vivo has given rise to the suggestion that HD may be characterized by the presence of defects in antigen CTL-presentation or in CTL dysfunction. This study examined 28 cases seen at the Regional Children's Hospital Arturo Grullón in Santiago, the Dominican Republic, by immunohistochemistry. High level of expression of major histocompatibility complex (MHC) class I molecules in HRS cells of EBV-associated HD was recorded. These results suggest that deregulation of MHC class I molecules does not account for the apparent ability of EBV to infect HRS cells and to evade CTL protection. Therefore, the result from our work and similar studies will help to determine whether, or which, immunotherapy should be used in positive and negative cases of HD related to EBV.     

Antibacterial activity of lactose-binding lectins from <i>Bufo arenarum</i> skin

Amphibians respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretion. Most humoral defense proteins are synthetized in the skin. In this study we isolated two β-galactoside-binding lectins with molecular weights of 50 and 56 KDa from the skin of Bufo arenarum. These lectins have significant hemagglutination activity against trypsinized rabbit erythrocytes, which was inhibited by galactose-containing saccharides. They are water-soluble and independent of the presence of calcium. The antimicrobial analysis for each lectin was performed. At µmolar concentration lectins show strong bacteriostatic activity against Gram negative bacteria (Escherichia coli K12 4100 and wild strains of Escherichia coli and Proteus morganii) and Gram positive bacteria (Enterococcus faecalis). The antibacterial activity of these lectins may provide an effective defense against invading microbes in the amphibian Bufo arenarum.     

On the feasibility of re-stimulation of shale wells

As a result of advances in horizontal completions and multi-stage hydraulic fracturing, the U.S. has been able to economically develop several decades of worth of natural gas. However, a considerable concern has risen on the economic viability of shale gas development for reasons associated with the fast production declines as well as recent down-turns of natural gas prices besides rises in the costs of new technologies. Therefore, an economic analysis is required to investigate the profitability of the refracturing treatment of unconventional gas resources. Net present value of cash flows and internal rate of return are calculated for a range of gas prices considering 20 years of natural gas production from a typical unconventional shale gas reservoir. A systematic comparison is then accomplished for three scenarios: (1) re-fracturing versus no refracturing, (2) combination of re-fracturing and drilling new wells, and (3) time-dependent re-fracturing treatment. Further, this paper incorporates the cost of re-fracturing treatment, the cost of drilling a new horizontal well, the water treatment cost, as well as the current and future price of natural gas in the model. The findings of this work would help the future re-stimulation development plans of the emerging unconventional shale gas plays.     

A Review of Thermal Conductivity Models for Nanofluids

Nanofluids, as new heat transfer fluids, are at the center of attention of researchers, while their measured thermal conductivities are more than for conventional heat transfer fluids. Unfortunately, conventional theoretical and empirical models cannot explain the enhancement of the thermal conductivity of nanofluids. Therefore, it is important to understand the fundamental mechanisms as well as the important parameters that influence the heat transfer in nanofluids. Nanofluids’ thermal conductivity enhancement consists of four major mechanisms: Brownian motion of the nanoparticle, nanolayer, clustering, and the nature of heat transport in the nanoparticles. Important factors that affect the thermal conductivity modeling of nanofluids are particle volume fraction, temperature, particles size, pH, and the size and property of nanolayer. In this paper, each mechanism is explained and proposed models are critically reviewed. It is concluded that there is a lack of a reliable hybrid model that includes all mechanisms and influenced parameters for thermal conductivity of nanofluids. Furthermore, more work needs to be conducted on the nature of heat transfer in nanofluids. A reliable database and experimental data are also needed on the properties of nanoparticles.     

Mathematical modeling of an inclined solar water distillation system

An inclined solar water distillation (ISWD) system, which generates distilled water (i.e., condensate) and hot water at the same time, was modeled and simulated. In the parametric studies, the effects of feed water mass flow rate and solar intensity on the system parameters were investigated. Finally, the system was simulated using actual deviations of solar intensity and environment temperature during a typical summer day in North Cyprus. The system can generate 3.5–5.4 kg (per m² absorber plate area) distilled water during a day (i.e., 7 am till 7 pm). The temperature of the produced hot water reached as high as 60°C, and the average water temperature was about 40°C, which is good enough for domestic use, depending on the type of feed water. The simulation results are in good agreement with the experimental results.     

Overlapping decompositions and expansions of Petri nets

Overlapping decompositions and expansions are considered to design decentralized controllers for discrete-event systems (DESs) modeled by Petri nets. The inclusion principle for Petri nets is first defined. It is shown that properties like boundedness, reversibility, and liveness (with a mild additional condition) carry over from the including net to the included net. Moreover, a new property called obstruction, is introduced for the including net, and it is shown that if obstruction does not occur in the including net, then deadlock does not occur in the included net. An expansion procedure, which guarantees inclusion for an overlappingly decomposed Petri net, is then introduced