Development of low power non-thermal plasma jet and optimization of operational parameters for treating dyes and emerging contaminants

Non-thermal plasma has emerged as an effective treatment system against the latest class of highly recalcitrant and toxic environmental pollutants termed emerging contaminants (ECs). In the present work, a detailed experimental study is carried out to evaluate the efficacy of a non-thermal plasma jet with two dyes, Rd. B and Met. Blue, as model contaminants. The plasma jet provided a complete dye decoloration in 30 min with an applied voltage of 6.5 kV_p−p. ·OH, having the highest oxidation potential, acts as the main reactive species, which with direct action on contaminants also acts indirectly by getting converted into H2O2 and O3. Further, the effect of critical operational parameters viz, sample pH, applied voltage (4.5‒6.5 kV_p−p), conductivity (5‒20 mS cm⁻¹), and sample distance on plasma treatment efficacy was also examined. Out of all the assessed parameters, the applied voltage and sample conductivity was found to be the most significant operating parameters. A high voltage and low conductivity favored the dye decoloration, while the pH effect was not that significant. To understand the influence of plasma discharge gas on treatment efficacy, all the experiments are conducted with argon and helium gases under the fixed geometrical configuration. Both the gases provided a similar dye decoloration efficiency. The DBD plasma system with complete dye removal also rendered maximum mineralization of 73% for Rd. B, and 60% for Met. Blue. Finally, the system's efficiency against the actual ECs (four pharmaceutical compounds, viz, metformin, atenolol, acetaminophen, and ranitidine) and microbial contaminant (E. coli) was also tested. The system showed effectivity in the complete removal of targeted pharmaceuticals and a log2.5 E. coli reduction. The present systematic characterization of dye degradation could be of interest to large communities working towards commercializing plasma treatment systems.     

Expert systems in industrial engineering

An expert system can be denned as ‘a tool which has the capability to understand problem specific knowledge and use the domain knowledge intelligently to suggest alternate paths of action’. This paper presents a structured framework for the development of an expert system. The five major aspects of expert system development are: Problem definition; knowledge acquisition, representation and coordination; inference mechanism; implementation; and learning. These aspects are illustrated through the help pf a modular robot configuration prototype expert system. Several industrial engineering applications in the areas of process planning, facilities planning, and maintenance and fault diagnosis are discussed and a comparative analysis of the different systems is presented.     

MODIFICATIONS IN THE DESIGN OF GAS INDUCING IMPELLER

The new process called Adsorptive Distillation is extended by allowing solids loading per stage to vary. The optimization problem is to uncover the unique solids profile which produces the minimum total solids needed for a prescribed separation. Two types of optimum designs are studied: (i) uniform loadings within sections but unequal sectional loadings, and (ii) unequal solids loadings in every stage of the cascade. In both cases, unique optimum profiles and feed stage locations are uncovered. The optimization problems posed above lead to 15% and 22% reductions, respectively, in total solids relative to the idealized case of uniform loadings throughout the cascade. Furthermore, the profiles uncovered for the second problem show solids loading to be always maximum at the feed stage diminishing to minimum loadings at the ends of the cascade. This smooth variation in stage capacity (diamond profile) leads to a condition of zero reflux.     

Message Filters for Object-oriented Systems

In the conventional object model, encapsulated objects interact by messages that result in method invocations on the destination object. A message is delivered directly at the destination object. As a result of the direct deliveries, the message control code performing intermediate message manipulations cannot be abstracted out separately from the message processing code in the destination object without sacrificing the transparency of the intermediate message control. We propose the filtered delivery model of message passing for object-oriented languages to provide the separation of message control from message processing in a transparent manner. An interclass relationship, called a filter relationship, is introduced. As a consequence, a filter object can intercept and manipulate messages sent to another object called its client via filter member functions. A filter member function in a filter object can intercept a particular member function invocation on its client object. The filtered delivery model supports both upward and downward filtering mechanisms, facilitating interception of an upward message and its return message value. Filter objects can be plugged or unplugged at runtime. Binding of filter member functions to corresponding member functions in the client is selective and dynamic. The filtered delivery model is developed for the C++ object-oriented language; its applications are described and implementation is discussed. © 1997 John Wiley & Sons, Ltd.     

EVALUATION OF NUTRITIONAL QUALITY AND FOOD SAFETY OF SEAWEEDS OF INDIA

Indian seaweed species Enteromorpha linza, Enteromorpha prolifera, Ulva fasciata, Caulerpa taxifolia and Sargassum johnstonii from natural and cultivated populations were evaluated for food safety and nutritional quality. Among the above seaweeds , Enteromorpha prolifera showed the highest caloric value and protein content, while these values were lowest in Sargassum johnstonii species of natural habitat. The lipid content was maximum in cultivated seaweeds of E. linza and U. fasciata species. Crude fiber varied within a narrow range in all the seaweeds analyzed. Protein efficiency ratio (PER) studies conducted with E. linza and U. fasciata showed low PER values compared to control rats fed on casein as source of protein. Acute oral feeding of seaweeds E. linza, U. fasciata, C. taxifolia and S. johnstonii and subacute oral feeding of E. linza for 12 weeks did not produce any toxic effects on male and female rats .     

ANTIOXIDANTS IN ONION (ALLIUM CEPA L) CULTIVARS GROWN IN INDIA

Health benefits of phenolics are prompting vegetable breeders to identify cultivars with enhanced functional properties. Ten onion cultivars grown under North Indian conditions were evaluated for their total phenolics, flavonoids, quercetin and total antioxidant activity for two consecutive years. Total phenolics, flavonoids and antioxidant activity exhibited significant variation ( P <  0.05) among cultivars. Red cultivars, namely Sel-383, N-53, Pusa red and Sel-402, constituted a high phenolic group, with a mean content higher than 100 mg/100 g gallic acid equivalents. Mean flavonoid content was highest in cultivars, Pusa red, Sel-402, H-44 and N-53 ( > 40 mg/100 g). White cultivars namely, Pusa white flat, Pusa white round and Early grano, consistently showed low phenolics, flavonoids and total antioxidant activity. Total antioxidant activity as determined by ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC) was highest in cultivars Sel-383, N-53, Pusa red and Sel-126. Over both consecutive years, phenolics correlated positively with total antioxidant activity ( R ²  =  0.95 FRAP and R ²  =  0.87 CUPRAC). Over all red cultivars, Sel-383 and Pusa red are promising cultivars for incorporation in existing breeding programs for the production of onions with high antioxidant content.

PRACTICAL APPLICATIONS

Onion, being a major constituent of Indian diet, is a potential source of phenolics and flavonoids. Selection of the phenolic-rich cultivars, preferably the red ones with high antioxidant activity, can deliver a variety of health benefits. The breeders can use total phenolics and flavonoids as parameters to develop varieties with increased levels of target antioxidants.     

Surface texture modification of spin-coated SiO2 xerogel thin films by TMCS silylation

The SiO₂ xerogel thin films were deposited successfully by sol?Cgel technique via the acid-catalyzed hydrolysis and condensation of tetraethylorthosilicate (TEOS) with ethanol as a solvent. Further, the deposited thin films were treated wet chemically by trimethylchlorosilane (TMCS) and hexane solution with 10% and 15% volume ratio to remove the hydroxyl groups from the surface of deposited SiO₂ thin films. These as deposited and surface-modified films were characterized by ellipsometer, Fourier transform infrared (FTIR) spectrometer and contact angle meter. The presence of 2900 and 850?cm^?1 peaks of CH₃ vibrations in FTIR spectra of surface-modified films confirms the hydrphobisation of SiO₂ surface. The maximum contact angle of 108·7° was observed for the surface-modified film at 10% TMCS.     

Two-Phase Heat Spreaders Utilizing Microfabricated Boiling Enhancement Structures

Results from various enhancement techniques to improve the performance of a recently developed two-phase heat spreader are reported. The spreader has a central evaporator section, with an integrated condenser along the edges. A micro-fabricated three-dimensional enhancement structure is employed to improve the heat transfer performance of the spreader. This study considers the performance of several liquid coolants to be used with the device and evaluates the effect of initial pressures on the thermal performance of the spreader plate. Liquids with lower boiling points were found to result in lower wall temperatures of the spreader plate due to earlier onset of boiling. Studies also showed an improvement in heat transfer performance with increase in stack height of the enhancement structures used in the evaporator section.     

Methodologies for rapid and effective response to requests for quotation (RFQs)

The ability to respond quickly and effectively to requests for quotation (RFQs) from customers can be a significant source of competitive advantage to manufacturing companies. This paper presents a new paradigm for processing RFQs and describes methodologies for rapid and accurate estimation of manufacturing cost for modified standard products and custom-made products. Insights gained through industry collaboration on the development of rapid cost estimation systems are also discussed. The work presented in this paper complements ongoing efforts by government and industry to establish the infrastructure and enabling technologies for electronic commerce, and can therefore contribute to significant gains in supply chain agility.     

电源用电容器的选择

电容器是实现电源的宽范围电压和电流组合的最关键的无源元件之一。尽管每种电容器都能储存电能，但对于特定的应用来说，电介质技术在电容器的选择中起着重要的作用。电容器在电源中最重要的应用是在存储能量、浪涌电压保护、EMI抑制和控制电路等方面。我们可以通过图1了解到针对不同的应用领域，这些电介质技术彼此竞争或互为补充的关系。储能储能型电容器通过整流器收集电荷，并将存储的能量通过变换器引线传送至电源的输出端。电压额定值为40～450Vdc、电容值在220～150 000μF之间的铝电解电容器（如EPCOS公司的B43504或B43505）…