Monitoring process variation using modified EWMA

A new control chart, namely, modified exponentially weighted moving average (EWMA) control chart, for monitoring the process variance is introduced in this work by following the recommendations of Khan et al.¹⁵ The proposed control chart deduces the existing charts to be its special cases. The necessary coefficients, which are required for the construction of modified EWMA chart, are determined for various choices of sample sizes and smoothing constants. The performance of the proposed modified EWMA is evaluated in terms of its run length (RL) characteristics such as average RL and standard deviation of RL. The efficiency of the modified EWMA chart is investigated and compared with some existing control charts. The comparison reveals the superiority of proposal as compared with other control charts in terms of early detection of shift in process variation. The application of the proposal is also demonstrated using a real-life dataset.     

Underground energy storage utilizing concrete building foundation: Experimental and numerical approach

Space heating and cooling represent 63% of total building energy demand. In the present study, the concept of concrete foundation piles was used as an underground storage medium. This system requires no additional drilling costs or space, unlike conventional boreholes. A laboratory-scaled experiment facility was designed to experimentally investigate the thermal response of a concrete pile during the charging and discharging processes. The amount of energy stored and released during each process was evaluated. A flow rate parametric study was also conducted to explore the effect of the laminar and turbulent flow behavior. In order to complement the experimental study, an extensive CFD model was developed and compared with the experimental data. There was good agreement between the numerical and experimental results for each process at different flow rates. The results revealed that increasing the flow rate increases not only the heat rejection and extraction but also the storage efficiency.     

Experimental measurements and numerical computation of nanofluid and microencapsulated phase change material in porous material

The electronic industry is increasingly investigating different approaches for the cooling of electronic equipment. The use of bulk phase change materials is also a promising approach for energy storage. The introduction of microencapsulated phase change materials combined with nanofluids can be beneficial. The combined use of a nanofluid and a metallic porous material can be used to mitigate problems resulting from small thermal conductivity. This study investigated a ternary mixture of water with a nanofluid and a microencapsulated phase change material in a porous medium. The model was previously validated with experimental data using a 0.5%vol concentration nanofluid in water. The results revealed that heat storage capability can be achieved as long as the microencapsulated phase change materials, which consists of encapsulated eicosane, is at a concentration of 20%. Because the melting temperature of microencapsulated phase change materials is approximately 36^°C , energy storage at a low flow rate and heat flux is recommended.     

Effect of Pickings on Germination Percentage and Fiber Quality Traits in Gossypium Hirsutum L

The present investigations were designed to determine the impact of picking dates on seed germination, 100 seed weight and various fiber parameters. Two genotypes FH-113 and FH-114 were evaluated under early and normal sowing. Nine and six pickings were taken under early and normal conditions, respectively. The results revealed significant variation in both the years for fiber traits but for seed germination, the results were non-significant and for seed weight remained significant under both sowing times, respectively. For picking time the estimates were significant under both sowing times thus exhibiting the major role of picking time in this experiment. For germination percentage, the results were variable for both the genotypes. For genotype FH-113, germination remained above 60% during 1st pick and for 5th, 6^th, and 7th pick, the germination rates were higher and nearing almost 70%. For 2nd genotype, the germination remained below 50% from pick-1 to pick-4 and above 50% in pick 5 and 8 but for all other pickings the values remained in the range 45–50%. Under normal sowing both genotypes exhibited germination percentage near 60% at 1st pick but for 2nd and 3rd pick, the germination rate remained between 45% and 50%. Regarding correlation studies among the studied traits germination % had positive and highly significant correlation with 100 seed weight under both sowing times. Fiber fineness and strength had strong and highly significant correlation with fiber maturity under both conditions. The results from this study revealed that pickings during favorable conditions produce better quality and germination.     

Multicomponent transport studies of crude oils and asphaltenes in DSC program

Crude oils have matured during ages in reservoirs under obvious non-equilibrium conditions. The resulting stratification and phases present can be predicted only with non-equilibrium thermodynamics tools. Possibly, convection is present and enforced by the Soret effect. These parameters are the focus of the MAP DSC (Diffusion and Soret Coefficients) multicomponent studies. Theoretical and ground based studies are completed by measurements performed in the SCCO experiments (Soret Coefficients of Crude Oils), of the DSC experiment on SODI facility (Beginning 2008). The problem is presented here in a simplified manner using Maxwell-Stéfan formalism, and is applied to some situations occurring in reservoirs and in the GATE experiment proposed for the study of growth conditions of asphaltenes.     

Near‐optimal online routing in opportunistic networks

In opportunistic networks, nodes communicate intermittently based on store‐carry‐forward paradigm while exploiting node mobility. The challenge is to determine the ideal nodes to deliver the messages since there is no end‐to‐end connectivity. The nodes might make this decision based on the data sensed from the network. This technique is not ideal in scenarios where the speed of changes in the network topology is greater than the speed at which the nodes can collect info on the network, which might, in turn, be restricted due to usage constraints and uncertainty of knowledge about future contacts. To tackle the problems raised by the non‐deterministic environments, in this paper, a stochastic optimization model and corresponding algorithm are developed to find the optimal routes by considering the short and long‐term impact of choices, ie, the next hop. Herein, we first propose a stochastic model to resolve the routing problem by identifying the shortest path. In the second step, we show that the optimal solution of the proposed model can be determined in polynomial time. An online algorithm is then proposed and analyzed. The algorithm is O( lognρ ) competitive considering the number of nodes and their associated energy. This model can take advantage of the unexpected meets to make the routing more elastic in a short time of contact and with less of a burden on the buffer. The simulation results, against the prominent algorithms, demonstrate significant improvement of the proposed approach in delivery and average delay ratio.     

Quality enhancement of video on demand implementation in peer-to-peer networks by optimum chunk length in the BitTorrent

BitTorrent in efficiency content distribution is a major concern efficiency among the researchers of this field with respect to streaming video on demand (VoD) production. BitTorrent is not appropriate for real-time applications; therefore, in order to apply it in VoD it should go through the necessary changes. Most of the available studies have greatly focused on changes in methods regarding chunk and peer selections method regarding BitTorrent, which proposed methods have improved the quality of VoD to a certain degree, while, the effect of chunk size on quality of video has been of less concern among them. Noting the fact that the buffer is used on VoD, the specified time for filling the buffer would allow for appropriate management of the chunk’s length. The Bit error rate and the time overhead of the operating algorithm parameters, somehow effect the chunk size. Because of bit error rate, the probability of correctly received chunks with great length is much less, that is, offering shorter pieces, while these pieces would lead to formation of more pieces in a buffer. The results indicate that a specific amount of time is required for obtaining the buffer’s content, and it must be dividable into more chunks. Running algorithms for each chunk generate a greater overhead which would result in of the QoS reduction. This overhead would make the bigger pieces perform better. As for the opposite impacts of these two parameters on the chunk size, in this article the optimal length of the chunks is found by considering both the effective characteristic. This optimal length is an established balance between the correctly received chunks’ rate and the greater rate of the buffer context obtained in a specified time.     

Chemical modification and structural rearrangements of polyketone‐based polymer membrane

Alternating polyketones constitute a very interesting class of polymers, which can be modified for the preparation of functional polymers. The chemical modification of polyketone using 1,2‐diaminopropane was used to prepare a conductive membrane. This paper is focused on the synthesis and structural rearrangements of polyamine for preparing anion‐exchange membranes by the solvent casting technique. According to the Paal‐Knorr mechanism, 1,4‐dicarbonyl of polyketone reacts with 1,2‐diaminopropane to form a pyrrole ring along the polyketone backbone. In addition, the so‐modified polyamines can undergo structural rearrangements to form N‐substituted pyrrole crosslinked with dihydropyridine units. The conversion degree and the N content are quite low. The pathway reactions have been proposed on the basis of ¹H‐NMR, ultraviolet–visible, and Fourier transform infrared results. Scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction techniques were used to study the morphological, thermal, and structural characteristics of the modified polyketone, as well as the correspondoing membrane. The experimental results indicated that the membrane is a potential candidate for energy conversion technology. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45485.     

Packaging handling evaluation methods in the grocery retail industry

The grocery retail industry, with its large product volumes, low margins and fierce competition, is constantly seeking efficiency improvements in its supply chain. The grocery retail industry uses an immense amount of packaging and is directly affected by packaging logistics activities. There is, therefore, a potential for efficiency improvements in the grocery retail supply chain through the integration and development of new systems of packaging and logistics. Packaging handling is identified as one of the main activities that has a strong impact on the overall logistical cost of a grocery chain. This research article investigates packaging handling evaluation methods and discusses how these are employed to benefit the industry. Case studies, involving six major companies from the Swedish grocery retail industry, have been used to evaluate packaging and logistics activities. This work, together with a literature review, was used to identify the need for evaluative methods and the present availability of such methods. The results indicated a lack of sufficient and usable packaging handling evaluation methods in today's grocery and packaging industry especially from a logistical point of view. The paper also highlights the lack of systematization among the few methods used and discusses how these can be used to build a systematic and multifunctional evaluation model in order to utilize the information from different studies to build a knowledge base for the future. Copyright © 2001 John Wiley & Sons, Ltd.