A novel technique for the measurement of liquid viscosity

A novel technique for the measurement of liquid viscosity is presented. In this technique, a disk was driven by a constant speed dc shunt motor in the test liquid. The change in the motor current measured the viscosity. The change in motor current was measured using an instrumentation amplifier and the viscosity of the liquid was measured in terms of output voltage. The temperature of the liquid was controlled using a peltier cooler/heater and was measured using an AD590 two-terminal integrated circuit temperature sensor. The viscosity of vegetable oils (groundnut, palm, sunflower, coconut) in the temperature range from 20 °C to 60 °C were determined. The results thus found were similar to the results obtained from a Redwood viscometer. This technique is useful to measure viscosity of liquids.     

Influence of pore water chemistry on the swelling behavior of compacted clays

The influences of the exchange complex and pH of the solution used for cation saturation on Atterberg limits, compaction, and swelling potential of a compacted clay were investigated. The study involved transforming the exchange complex from a heterogeneous to a homogeneous one so that a frame of reference can be set for the clay behavior under such an ideal condition. The employed method for altering the exchange complex successfully yielded homo-ionic clay. The introduction of different species of cations gave rise to different particles associations. When introduced to the tested clay, potassium cations bond its particles with a rather strong bond (K-linkage), causing a drastic decrease in the specific area of the clay (about one-fourth of its untreated specific area), a decrease in the CEC, as well as a drastic decrease in the swell potential. For example, the swell pressure decreased from 1.87 kg/cm² for the untreated samples to 0.4 kg/cm² for the K-treated samples (under the same conditions). Also, the swell potential vs. time relationships can be modeled accurately using a rectangular hyperbola.     

Fast computation of accurate Zernike moments

Zernike polynomials are continuous orthogonal polynomials defined in polar coordinates over a unit disk. Zernike moment’s computation using conventional methods produced two types of errors namely approximation and geometrical. Approximation errors are removed by using exact Zernike moments. Geometrical errors are minimized through a proper mapping of the image. Exact Zernike moments are expressed as a combination of exact radial moments, where exact values of radial moments are computed by mathematical integration of the monomial polynomials over digital image pixels. A fast algorithm is proposed to accelerate the moment’s computations. A comparison with other conventional methods is performed. The obtained results explain the superiority of the proposed method.     

A three-phase symmetrical multistage Voltage multiplier

A three-phase symmetrical Cockcroft-Walton (CW) multistage voltage multiplier (VM) is proposed. It consists of one smoothing column and six oscillating columns. The oscillating columns are connected to three-phase power through center-tap transformers. The capacitors of the smoothing column are charged six times per cycle by six oscillating columns and are discharged six times through the load, unlike the conventional symmetrical VM in which they are charged and discharged twice per cycle. The three-phase symmetrical structure completely eliminates the first five harmonic components of load-generated voltage ripple. Theoretical analysis indicates that the proposed three-phase symmetrical CW-VM has one-third the voltage ripple and voltage drop of the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the proposed three-phase symmetrical CW-VM as well as of the conventional single-phase symmetrical CW-VM are presented. A comparison shows that the three-phase symmetrical CW-VM has significantly less voltage ripple, half the voltage drop, and a fourfold increase in output power over the conventional single-phase symmetrical CW-VM.     

STOPE‐based approach for e‐readiness assessment case studies

The STOPE‐based approach is used here for practical e‐readiness assessment case studies. The approach integrates and evaluates the various e‐readiness assessment issues, over its well‐structured domains: strategy, technology, organization, people, and environment. The case studies considered concern three Saudi organizations: a government organization, a bank, and a private sector company. The results obtained provide e‐readiness indicators that illustrate the strengths and weaknesses of each organization with regard to e‐readiness strategic development issues, information and communication technology (ICT) issues, management and organization issues, people issues, and environment issues within which the organization operates. The work shows how the approach can be practically used, and it also provides practical results that direct the organizations concerned toward enhancing their e‐readiness in response to the current trend of globalizing e‐business. Copyright © 2007 John Wiley & Sons, Ltd.     

Investigation into performance of deep excavation in sand covered karst: A case report

Performing deep excavations in karst regions is likely lead to geo-hazards, e.g. sinkholes, water ingress, and ground surface settlement. This case report presents the performance of a 16-m deep excavation in sand covered karst in Metro Line no. 9, Guangzhou, China. The performances during deep excavation, including lateral wall deflection, vertical wall movement, ground surface settlement, and settlement of adjoining buildings, were monitored and evaluated. Based upon the interpretation of the field measurements, the following major findings were obtained: (i) the lateral wall deflection and surface settlement measurements were smaller those cited in other case studies with similar geological conditions, (ii) both the grouting of the karst cavern and the use of the socket diaphragm wall panel dominated the performance of the deep excavation; (iii) the type of the founding structure could significantly affect the settlement development of the adjoining buildings. This case report provides insight into the design and construction of deep, narrow excavations in sand covered karst in a metropolitan environment.     

Way forward in meeting energy challenges in Pakistan

In this review the energy potential of Pakistan from hydro, coal, wind, solar and nuclear sources has been discussed. The new projects that are being commissioned on coal, wind, solar, hydel and nuclear-based technologies have also been mentioned. The review has also explored the future prospects of the country’s energy requirements. Pakistan has potential to produce 100,000?MW of electricity from Thar coal for 20 years, 56,000?MW of hydroelectricity, 150,000?MW of wind energy and ～50,000?MW from solar sources. The coal-fired power generation is expected to 11,500?MW in period 2017–2019. The country is moving in the right direction to cater its energy needs. However, there is a need to find local and foreign investment in the country to meet high energy demands in the country in future.     

Experimental investigation of a new type of interfacial instability in a reactive coextrusion process

This paper deals with the study of new interfacial instabilities, called “grainy” defects, in coextrusion process of reactive multilayer polymers. The main objective was to better understand this phenomenon since no help can be found in the literature. The fundamental approach from a micro‐scale to a macro‐scale involves the study of relationships between polymer structure, processing, and interfacial properties. The influence of these parameters on the generation of “grainy” defects during coextrusion has been assessed in correlation with physicochemical properties. Through this work, rheological properties and the interfacial morphology between tie and barrier layers have been investigated by shear stress relaxation experiments and transmission electronic microscopy, respectively. Depending on the reactive polymers, the interfacial coupling was found to significantly alter the stress relaxation behavior by extending the relaxation time and generating an interfacial roughness. Hence, relations between the copolymer architecture, the relaxation process, and the interfacial morphology were established in correlation with the generation of grainy defects in coextrusion process. POLYM. ENG. SCI., 55:2542–2552, 2015. © 2015 Society of Plastics Engineers     

pH‐Cleavable Nucleoside Lipids: A New Paradigm for Controlling the Stability of Lipid‐Based Delivery Systems

Lipid‐based delivery systems are an established technology with considerable clinical acceptance and several applications in human. Herein, we report the design, synthesis and evaluation of novel orthoester nucleoside lipids (ONLs) for the modulation of liposome stability. The ONLs contain head groups with 3′‐orthoester nucleoside derivatives featuring positive or negative charges. The insertion of the orthoester function in the NL structures allows the formation of pH‐sensitive liposomes. ONL‐based liposomes can be hydrolyzed to provide nontoxic products, including nucleoside derivatives and hexadecanol. To allow the release to be tunable at different hydrolysis rates, the charge of the polar head structure is modulated, and the head group can be released at a biologically relevant pH. Crucially, when ONLs are mixed with natural phosphocholine lipids (PC), the resultant liposome evolves toward the formation of a hexadecanol/PC lamellar system. Biological evaluation shows that stable nucleic acid lipid particles (SNALPs) formulated with ONLs and siRNAs can effectively enter into tumor cells and release their nucleic acid payload in response to an intracellular acidic environment. This results in a much higher antitumor activity than conventional SNALPs. The ability to use pH‐cleavable nucleolipids to control the stability of lipid‐based delivery systems represents a promising approach for the intracellular delivery of drug cargos.     

Propoxylated Fatty Thiazole,Pyrazole, Triazole,and Pyrrole Derivatives with Antimicrobial and Surface Activity

Lauric acid and propylene oxide were used to modify four biologically active heterocycles (thiazole, pyrazole, triazole, and pyrrole) to synthesize 17 new surfactants. The chemical structures of these surfactants were confirmed using infrared and ¹H, and ¹³C nuclear magnetic resonance (NMR) spectroscopy. The surfactants all show good surface activity, low critical micelle concentration (CMC) values, high cloud points, and tight interfacial packing. All showed antimicrobial activity on both bacteria and fungi. In addition, biodegradation testing demonstrated significant breakdown within seven days.