Pesticides removal performance by low‐pressure reverse osmosis membranes

Pressure driven techniques (viz. reverse osmosis and nanofiltration) have the potentiality to remove the pesticides from water. The observations revealed that pesticides removal mostly depends upon the molecular weight (size exclusion) and hydrophobicity (log P) of the pesticides. Interfacial polymerization of m‐phenylene diamine (MPD) and trimesoyl chloride (TMC) on the polysulfone membranes impart the salt rejection property in it. It is shown that with the greater salt rejection property, the performance removal of pesticides also is in increasing trend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3575–3579, 2006     

Rheological Properties of Certain Processed Rice Products

Two popular rice products, namely expanded rice and flaked rice, are prepared from parboiled rice. As about 90% dry weight of milled rice is starch, the behaviour of rice and its products reflects largely the behaviour of its starch. The above precooked rice products which undergo a high degree of thermal and/or mechanical treatment during processing have a high degree of gelatinization and display therefore properties like those of pregelatinized starch. Both expanded rice and flaked rice have high water binding capacity and cold-swelling properties. Under suitable moisture conditions they undergo retrogradation and show reduced hydration and viscosity. Normal steam-parboild rice shows much lower viscosity because of a comparatively low degree of starch gelatinization during processing and its subsequent retrogradation. Rheologically the cold slurry of these products indicates a thixotropic system demonstrating time dependent thinning. Further, a dependence on slurry concentration and degree of processing and a yield value behind a certain concentration were also apparent. The cold swelling properties of flaked rice and expanded rice show potential use of their flour as a possible subsitute for pregelatinized starch in food and other industries.     

Offshore manufacturing contract design based on transfer price considering green tax: a bilevel programming approach

The problem of designing offshore manufacturing contract resulting in optimal transfer price is troubling multinational companies over the past few years. This paper proposes designing offshore manufacturing contracts based on the transfer price in the form of bilevel programming problems after considering green tax. In these contract designs, a firm in a developed country sells a single product in its market. The same product is simultaneously being manufactured by another firm in a developing country with lower manufacturing cost. After anticipating the consumer demand, the seller places an order, based on which the manufacturer manufactures the ordered quantity, and offers a transfer price which in turn maximises its net profit after paying green tax to its government. While setting the transfer price, the manufacturer considers the manufacturing cost, the export duty payable to its government and the cost of shipping the product to the developed country. After buying the product from the manufacturer at the transfer price, the seller then sets the retail price which maximises its net profit after paying the import duty to its government; the retail price, however, must not be more than the maximum retail price applicable to the market. Thus, offshore manufacturing contract results in optimal after-tax profits for both the firms. An experimental study has been carried out to discuss the practical aspects of the results developed, where a US firm is offshoring its manufacturing activity to a Chinese firm in order to draw maximum profit.     

Optimizing microstructure for toughness: the model problem of peeling

We consider the problem of peeling an adhesive thin film from a substrate that has a non-uniform distribution of adhesive. When the length scale of the non-uniformity is small compared to the overall dimensions of the film being peeled, it is possible to describe the overall peeling behavior with an effective adhesive strength. In this paper, we seek to find the distributions of adhesive strength at the microscale that optimize various aspects of the effective adhesive strength at the macroscale. We do so using both analytic bounds and topology optimization. We formulate the problem of peeling as a free boundary problem, and the effective strength as a maximum principle over the trajectory. For topology optimization, we replace the maximum with an integral norm, and use an adjoint method for the sensitivity. The problem of peeling may be viewed as a model problem in fracture mechanics where the crack (peel) front is confined to a plane, and thus our analysis as a first step toward studying the more general problem of optimizing microstructure for toughness.     

Postgrowth heat-treatment effects in high-purity liquid-phase-epitaxial In0.53Ga0.47As

Heat treatment at 670°C for 20 min has been performed on high-purity In0.53Ga0.47As/InP: Fe layers grown by different melt-baking schemes. Layers with higher purity (?77 K ? 55000 cm2/Vs) exhibit increased resistivity and the presence of a deep level after the heat treatment. It is possible that the deep level, apparently 0.56 eV above the valence band, results from Fe outdiffusion from the substrate.     

Using channel state dependent packet scheduling to improve TCPthroughput over wireless LANs

In recent years, a variety of mobile computers equipped with wireless communication devices have become popular. These computers use applications and protocols, originally developed for wired desktop hosts, to communicate over wireless channels. Unlike wired networks, packets transmitted on wireless channels are often subject to burst errors which cause back to back packet losses. In this paper we study the effect of burst packet errors and error recovery mechanisms employed in wireless MAC protocols on the performance of transport protocols such as TCP. Most wireless LAN link layer protocols recover from packet losses by retransmitting lost segments. When the wireless channel is in a burst error state, most retransmission attempts fail, thereby causing poor utilization of the wireless channel. Furthermore, in the event of multiple sessions sharing a wireless link, FIFO packet scheduling can cause the HOL blocking effect, resulting in unfair sharing of the bandwidth. This observation leads to a new class of packet dispatching methods which explicitly take wireless channel characteristics into consideration in making packet dispatching decisions. We compare a variety of channel state dependent packet (CSDP) scheduling methods with a view towards enhancing the performance of transport layer sessions. Our results indicate that by employing a CSDP scheduler at the wireless LAN device driver level, significant improvement in channel utilization can be achieved in typical wireless LAN configurations. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genomic organization of the human TIMP-1 gene. Investigation of a causative role in the pathogenesis of X-linked retinitis pigmentosa 2

PURPOSE: To evaluate the role of TIMP-1 in inherited retinal degeneration. METHODS: The genomic structure of the TIMP-1 gene was established and male patients with x-linked retinitis pigmentosa 2 from five families were screened for sequence alterations by direct sequencing in all exons, exon-intron boundaries, and the 5' upstream region of the gene. RESULTS: TIMP-1 appears to be expressed in the retina at low levels and consists of six exons spanning a genomic region of approximately 4.5 kb on Xp11.23. No disease-specific sequence alterations were identified. A site substitution in exon 5 was observed in samples from control subjects and patients, but it did not alter the amino acid sequence of the protein product. CONCLUSIONS: The results of this study exclude mutations in the TIMP-1 coding sequence, splice sites, and the 5' upstream region as a cause of retinal degeneration in x-linked retinitis pigmentosa 2. However, an as yet unidentified regulatory element that lies outside these intervals may be implicated. The role of this tightly regulated protein in the normal functioning of the retina has yet to be determined.