Search

In 2012 the City of Flagstaff partnered with researchers at the Dept. of Civil and Environmental Engineering at Northern Arizona University to successfully develop a mix design utilizing sludge derived from the manufacturing of recycled paper pulp sludge (PPS) and fly ash as a component of a landfill cap. This research has been extended to explore the addition of polymers to the mix of waste materials in order to optimize a design that would be suitable as a component for an EPA Subtitle D-approvable landfill liner. Cinder Lake Landfill (CLL) serves several communities in Northern Arizona and is managed by the City of Flagstaff. CLL does not have a reliable source of clay needed to construct a required landfill liner, which is necessary for the upcoming 108-acre landfill expansion. However, CLL receives approximately 80 tons of recycled PPS daily from the local tissue manufacturing plant. PPS is currently used as daily cover and was tested for use as part of a landfill cap, as noted above. Incorporating polymers in alternative materials such as PPS and fly ash has the potential to meet performance criteria and be approved by state and federal regulators, and has the potential to save the City millions of dollars over conventional composite liners of geomembrane and clay. Different mixtures of PPS, fly ash and three different polymers are currently being subjected to testing for the following: Water Content, Specific Gravity, Porosity, Organic Content, Atterberg Limits (plasticity), Proctor Compaction, Consolidation, California Bearing Ratio, Shear Strength, Gas Permeability, and Liquid Permeability. The optimal mixture of PPS and fly ash will be blended with a range of polymer concentrations. The goal is to find an optimal mix of PPS, fly ash, and polymer to achieve regulatory standards related to permeability, along with other desirable properties such as strength and flexibility. The optimum mixture(s) will then be subjected to field trials, scheduled to begin in 2016, in which test cells will be created at CLL. The liner will be constructed with the optimized mixture(s), and the cells will be operated as landfills for 1-2 years. Results from lab and field testing will be submitted to federal and state regulators for consideration as an alternative liner approach.

In this work, we investigate the influence of ZnO nanoparticles on the performance of paper-based humidity sensors. The sensors were developed on standard, commercial printing paper with laser-patterned gold interdigitated electrodes (IDE) and ZnO nanoparticles spin-coated by various sol-gels. Blank devices were used as reference sensors in an effort to elucidate the role of ZnO and the dependence of the device performance on the concentration of the sol-gels and the number of spin-coated layers. Resistive measurements were conducted at room temperature to evaluate the devices’ response on known relative humidity levels. Relatively fast rise and response times were observed even at room temperature, while all devices tested did not require refreshing procedures. The deposition of ZnO was found to affect the sensor response, resulting in reduced sensor signal, due to the blocking of water diffusion in the porous paper material.

In this work, the fabrication of Rochelle salt based piezoelectric structures is illustrated. Structures composed of paper and Rochelle salt are easily manufactured using simple processes. Both manufacturing and the material itself are environmental friendly. Additionally Rochelle salt is biocompatible. In the paradigm of a cleaner piezoelectric technology, the fabrication of active sensing or actuating devices is developed. Thus processing method, material and piezoelectric properties have been studied: (1) pure crystals are used as acoustic actuator, (2) properties of paper impregnated with Rochelle salt are detailed, (3) charge generation is demonstrated on the impregnated material. Actuating and sensing devices are reported in order to highlight the potential of this green piezoelectric material. © 2015 The Authors. Published by Elsevier Ltd.

The fabrication of a mechanically flexible piezoresistive load sensor is reported. Inkjet printing offers an inexpensive non-contact fabrication method for microelectronics. Herein we report the first direct fabrication of inkjet-printed graphene arrays, and apply them to electromechanical detection of force. The graphene ink was printed on a cantilever shape paper substrate. The results illustrated a linear resistance change with the applied forces. The force range, force resolution, and sensitivity were found to be 25 mN, 10 μN, and 1.2 mV/mN, respectively. In addition, graphite ink was also used as the sensing component in order to make a comparison between the piezoresistive effect of graphene and graphite ink. The results show that using graphene ink instead of graphite increases the force range and gauge factor of the sensor, which are two important designing factors. This sensor is inexpensive, simple to fabricate, lightweight, and disposable.

This paper is focuses modeling of the last part of the paper machine – the drying section. Paper is dried by letting it pass through a series of steam heated group of cylinders and the evaporation is thus performed by the latent heat of vaporization of the steam. The moisture in the paper is controlled by adjusting the set point of the steam presure controllers to the cylinders. There exist several incentives to focus on the performance of the moisture control. The time to perform a grade change is often limited by the moisture and shorter grade change time is directly correlated to economic profit. The plant model is identified periodically and the changes in its dynamic characteristics are observed. Periodic identification gives a great advantage over the conventional controller tuning methods, which uses the plant model at the nominal operating conditions. A variety of model structures are available to assist in modelling a system. Model for the drying process of Paper industry is established based on gathering 1000 groups of 2500 real-time sample data. Based on the collection of data, that was adapted to both the conventional and intelligent modelling process. Finally the suitable model is tuned with the suitable controller for optimal control of the drying process.

The aim of the study is to model and to simulate the thermal and electrical efficiencies of the cogeneration plant of a paper mill. The final purpose is the benefits optimization by adjusting production to the amount of energy to be sold. It is necessary to know it because the sale price goes down when the actual production of electrical energy does not match the scheduled power.

Remaining Life of the oil-immersed transformer is decided due to deterioration of the winding insulation paper (WIP). The DGA method is conventionally used to estimate the WIP deterioration status condition. This paper presented the four status conditions assessment of paper deterioration for oil-immersed transformer using fuzzy-logic (FL). In this paper the correlation between accumulated values of carbon dioxide (CO2) and carbon monoxide (CO) with insulation resistance in oil-filled power transformers is studied using FL. The authors have estimated the insulation paper deterioration condition using proposed method for 20 transformers or more. As a result, appropriate maintenance scenario can be planned.

Commercial inkjet-printers from manufacturers like Epson or Brother can be used for rapid prototype printing conductive traces onto paper or flexible PET substrates by using nanoparticle based dispersions. The surface coating of the substrate influences the attainable electrical conductivity and dielectric permittivity as well as the loss tangent, which are important parameters for developing inkjet-printed microwave circuits on paper substrates. For characterizing the permittivity conventional methods are using microstrip ring or microstrip transmission line resonators that require the printing of two electrically conductive layers. In the proposed paper, a novel method is introduced to determine the relative permittivity and loss tangent via a coplanar waveguide resonator realized on a single layer.

A piezoelectric based touch sensitive device has been successfully fabricated by screen printing silver (Ag) and polyvinylidene fluoride (PVDF) inks as conductive and piezoelectric materials, respectively, on paper substrate. X-ray diffraction (XRD) analysis was performed to verify the formation of β-phase crystals in the PVDF layer during the curing process. Voltages, as high as 0.22 V, were observed for human finger touch tests and a sensitivity of 0.3 V/N was obtained when varying forces ranging from 0.2 N to 1.4 N, in steps of 0.2 N, were applied on the printed device. The piezoelectric-voltage analysis demonstrated that the printed device can be used for both touch and force sensing applications.

Ever increasing user demands and development of modern communication technologies have led to the evolution of communication networks from 1st Generation (1G) network to 4G heterogeneous networks. Further, 4G with heterogeneous network environment will provide features such as, “Always Best Connected”, “Anytime Anywhere” and seamless communication. Due to diverse characteristics of heterogeneous networks such as bandwidth, latency, cost, coverage and Quality of Service (QoS) etc., there are several open and unsolved issues namely mobility management, network administration, security etc. Hence, Designing proficient mobility management to seamlessly integrate heterogeneous wireless networks with all-IP is the most challenging issue in 4G networks. Mobile IPv6 (MIPv6) developed by Internet Engineering Task Force (IETF) has mobility management for the packet-switched devices of homogeneous wireless networks. Further, mobility management of homogeneous networks depends on network related parameter i.e., Received Signal Strength (RSS). However the mobility management of heterogeneous networks, not only depends on network related parameters, but also on terminal-velocity, battery power, location information, user-user profile & preferences and service-service capabilities & QoS etc. Designing mobility management with all-IP, while, considering issues such as context of networks, terminal, user and services is the main concern of industry and researchers in the current era.

We study the evolution of deformation on a quasi 2D paper sample during fatigue and creep experiments. Paper is a fibrous material, sensitive to various parameters (humidity, temperature, history effect). As for many materials, the lifetime varies a lot. Basquin's law claims that the number of cycles at break in fracture tests has a power-law dependence on the external load amplitude; Monkman-Grant relationship predicts that lifetime is proportional to the minimum strain rate during creep. The main question is therefore: is it possible to predict the time-dependent rupture? We perform creep and cyclic tests on paper samples. The main tools of investigation are acoustic emission (AE) -based analysis and digital image correlation (DIC). Via the AE, one can follow the damage evolution in samples, like microcrack formation that releases elastic energy. The DIC instead works well as a tool to measure at great accuracy both global and local deformation fields. From these, local strain rates can be derived, which then can be used to understand the microscopic dynamics that lie behind a certain rheology or sample response. The issue is to predict the break by looking at the sample-to-sample variation and by comparing experiments.

Australia produces both black and brown coal and is the world's fourth largest producer of black coal, after China, USA and India. Australian underground coal mines operate under controlled safety codes. The establishment of the mine safety management system, including the 1994 outburst management plan, contributed to a significant improvement in mine safety leading to non-fatality in outburst related incidences since 1994. The management of outburst risk, as a part of the overall safety and health management system is described. Also discussed are the introduction of outburst threshold limit values and the desorption rate index which forms the basis for determining safe mining conditions along with the “Authority to Mine” process The measures taken and lessons learned from safe mining of Australia's outburst prone mines represent an opportunity for improved mining safety in other countries, such as China.. The role of the Australian Coal Association Research Program, which supports research in critical areas such as outburst risk control and management, is also discussed.

Because of world-wide persistent demand for cellulose man-made fibers suitable in textile processing and application and the predicted stagnation of cotton production, there is a strong need for innovative approaches to safeguard the future availability of dissolving pulps for cellulose fiber production. The paper will present the results of a national network project, which was focused on the development of an integrated process chain for the manufacturing of novel fabrics produced of man-made Lyocell fibers derived from organically grown hemp (OG hemp). The whole process line was established within the process studies starting from hemp cultivation, machine-aided harvesting and automatic peeling to isolate hemp bast stripes (HBS) from stems, pulp manufacturing and transfer into fibers by solution spinning up to processing to yarns and dyed and finished fabrics. More representative, the paper will specifically describe the transfer of almost free of shives extracted, retted hemp fibers and dried HBS into dissolving pulp by means of a specific adjusted pulp cooking process. The main challenges in that step were identification as well as practical development of suitable process approaches for degumming, DP adjustment and purification from contained light and heavy metal traces. Furthermore, the pulp had to be assessed for its usability in direct dissolution process. For that purpose dopes were prepared and characterized regarding optimal DP adjustment, the insoluble parts in dopes and the thermal dope stability at elevated temperatures. After identification and application of most favored process parameters the dissolved pulps could be converted into Lyocell fibers by solution spinning applying the most suitable dry-wet shaping procedure conditions. Manufactured fibers exhibit comparable properties in fineness, tensile strength, elongation and loop tenacity like common Lyocell fibers made of conventional wooden pulp. In project R&D activities obtained fibers had been further processed into yarns, fabrics and apparel demonstrators applying conventional processing parameter. The manufactured Lyohemp TM clothes offer excellent product qualities as well as wearing properties.

For successful management of construction projects and organizations, it is crucial to adopt effective management systems that can handle the various information and documents of project activities. Document Management System (DMS) is the system used to store, control, coordinate, process and/or retrieve documents whether it is in electronic or paper based format. This research aims at investigating existing electronic and paper based DMSs in a sample of small size contracting companies in Jordan. Interviews and questionnaire survey with contractors, contractors’ representatives and practitioners of DMSs in a number of small contracting companies were carried out to investigate and evaluate the components, processes, motivations and challenges of the existing and intended DMSs. Electronic formats of documents and files used in small contracting companies will be also investigated. The results of this research can help contracting companies to enhance their DMSs, and improve efficiency and performance of the processes of construction projects management.

To effectively promote the capacity of fire brigade to handle the building fire and improve the effect of building fire simulation training, a set of design procedure of simulation training module of building fire simulation training facility is proposed in this paper based on the theoretical calculation and according to the field investigation. Such procedure is capable to provide the training environment with the high degree of simulation and complete functions for the fireman and effectively promote the training effect.

Occupant safety evacuation in fires is a critical issue in public safety field. The evacuation process is divided into several stages and each stage can be influenced by various uncertain factors. Some factors were studied in this paper based on the Monte Carlo approach. The safety level affected by different factors and the sensitivity of sampling size were analysed according to the failure probability model of occupant evacuation. The results show that safety level of occupant evacuation in buildings can be evaluated by the failure probability model. When the population density is more than 0.8 pers/m2, the failure probability goes up rapidly with the fire growth rate increasing. Whether the fire is large or not, the population density have a great impact on the evacuation. Then the influencing degree on failure probability of different parameters are changeable in various conditions. In addition, when the sample capacity is large enough, the Monte Carlo simulation can be deemed accurate.

The paper presents the state-of-the-art concerning the current achievements in the field of 3D printing of buildings and building components. The 3D printing technologies, comparing to traditional techniques of constructing the buildings, could be considered as environmental friendly derivative giving almost unlimited possibilities for geometric complexity realizations. Two kinds of technologies were described in this paper with pointing to Contour Crafting as a promising technique that may be able to revolutionize construction industry in near future. Numerous advantages of this technology, such as reduction of the costs and time, minimizing the pollution of environment and decrease of injuries and fatalities on construction sites could be cited. Despite many advantages and hopes, some concerns are summarized in the conclusions, as the technology still has many limitations. A brief description of few examples of pioneering usage of 3D printing in construction industry are presented (Canal House in Amsterdam, WinSun company and printing application for building carried out by Skanska company). Creating a model that will be appropriate for 3D printers is possible in many different modelling programs. One of the most popular formats for sharing such models is STL format. In the paper sample models crated in Autodesk Inventor are shown, but also other tools suitable for preparing models for 3D printing are briefly discussed.

The paper is focused on degradation caused by microorganisms, a process called biodegradation, and on risks for human health caused by them. Bacteria and algae are the primary microorganisms on external building surfaces. These pioneer microorganisms have an enriched space of organic carbon, which is necessary for the growth of any subsequent microorganism which is often mold. Biodegradation is a synergic process of chemical reactions (chemical biodegradation) and physical effects of microbial bodies on building materials (biophysical degradation). The paper is a summary of the current state of art and knowledge in the field of biodegradation.

In this paper, a novel method with addition of graphene in diamond slurry is proposed to conduct CMP lapping of sapphire wafer. Two kinds of graphenes are added including graphene oxide (GO), reduced graphene oxide (RGO). Effect of three important processing parameters on material removal rate (MRR) and surface roughness is investigated, including graphene type, graphene weight fraction, and ultrasonication time. Weight fractions of various graphenes versus diamond slurry are controlled in the range from 0.5 to 2.0 wt%. Results indicate that addition of graphene in diamond slurry can significantly increase MRR of sapphire wafer. MRR of sapphire wafer is proportional to graphene weight fraction. At higher weight fraction, GO/diamond slurry leads to higher MRR than RGO/diamond slurry does. MRR by the pure diamond is 285.80 nm/min, while MRR by the diamond/GO(2.0wt%) with 48-hour ultrasonication is 832.1 nm/min. Surface roughness is inversely proportional to graphene weight fraction and proportional to graphene particle size. Ultrasonication is able to efficiently reduce graphene particle size. RGO/diamond slurry can result in lower surface roughness than GO/diamond slurry.

Activated Carbon (AC) is amorphous carbon which was obtained through carbonaceous material. AC has a large specific surface area, so it has good adsorption capacity for inorganic substances, organic substances and colloidal particles in the gas or solution. Annual consumption is huge. Corn stalks are the remnants of agricultural production. China is one of the countries with the largest straw production in the world, but straw has not been fully utilized for a long time. A large number of straws were discarded or burned, which will waste resources and cause environmental pollution. Corn stalks were selected as raw material, pyrophosphoric acid was selected as activator, and microwave irradiation method was used to study the preparation technology of corn stalk based activated carbon in this paper. The optimum conditions for the preparation of AC from corn stalks were determined by the orthogonal experiment. The optimum parameters for the preparation of AC by microwave heat activation in the laboratory stage were obtained. The concentration of pyrophosphate was about 45% (wt), the impregnation ratio was 1: 2, the impregnation time was 8 hours, the radiant power was 400W, and the activation time was 8 minutes.

Since all most all foods are hygroscopic, tend to shorten their shelf life by absorbing water vapour from the natural environment. This phenomenon is very badly affecting for the food security as well as in building resilience against calamities. To investigate this relationship a hygroscopic food product “Noodles” were taken and packed in LLDPE, OPP, Double laminate and triple laminate pouches and stored at 85% RH and 25°C. Samples were drawn weekly up to 14 weeks and determined increment of moisture content. Results were analyzed to determine co-relationship between storage time and moisture ingress and also to develop an equation “how long the Noodles can be kept safe” under different packaging materials by performing regression analysis. Result revealed that there is a strong positive co-relationship between moisture ingress and period of storage of noodles packed in LLDE, OPP, DL and TL packaging materials as coefficient of correlation ship were 0.89, 0.99, 0.98 and 0.99 respectively. The developed equations for the same order of the packing materials for maximum period of storage were y = 6.31 + 0.606x, y = 6.92 + 0.307x, y = 7.07 + 0.243x and y = 7.27 + 0.166x (y = period of storage, x = moisture content %). According to these equations Noodles can be stored safely for 12, 19, 28 and 42 weeks respectively in LLDE, OPP, DL and TL packaging materials.

Carbon dioxide, a byproduct of fossil-fuel combustion, is a greenhouse gas, which traps solar radiation in the atmosphere. This cause climate change and global warming issues. Biodiesel has gained increasing attention as an alternative to fossil fuels for reducing the greenhouse gas emissions from the transportation sector. Yellow oleander (Thevetia peruviana) grows extensively in gardens as a decorative tree throughout Sri Lanka. The plant is a potential source of feed stock for biodiesel production as it produces fruit with two seeds with higher oil content as 49.6% (db) and it is a non-utilized oil crop without any economic value. The objective of this study is to produce biodiesel by transesterifying using extracting oil and to determine its properties. Yellow oleander oil with proper free fatty acid limit was pretreated with NaOH as catalyst and anhydrous methanol amount as 20% of oil volume. The produced yellow oleander methyl ester was characterized. It was observed as gross calorific value as 37.74 MJ/kg (ASTM D 240), flash point of 118°C (ASTM D 93), Kinematic viscosity at 40°C of 5.96 mm2/s (ISO 3105:1976), specific gravity of 0.8874 (ASTM D 1298) and density at 15°C of 887 kg/m3. All the tested parameters are within the accepted limits of the biodiesel thus making it an alternate fuel as transportation fuel for diesel engines.

Recognizing the widespread of negative impact from the usage of fossil fuels, biodiesel has been explored to ensure the sustainability of the environment. Recently, microtube reactor has been widely studied for continuous synthesis of biodiesel production. Therefore, this paper is intended to investigate the transesterification of palm oil using micro- and milli-channel reactors. The research was conducted to study the effects of catalyst concentration (0.5-5.0 wt%) and residence time (60-180 s) for two different tube internal diameters of 1.6 and 0.58 mm. The results showed that the oil conversion and FAME yield are greatly influenced by the tube internal diameter, catalyst concentration and residence time. The effect of tube internal diameter may be attributed to mass transfer effect between oil and methanol phases. The microtube reactor achieved more than 95% at 4.5 wt% of catalyst concentration and 180 s of residence time. Besides, the ester content determined by GC-FID analysis is a good estimation to the FAME yield determined by HPLC analysis.

This paper presents the research results aimed at the assessment of the impact of the group composition of Kazakhstan and West Siberian heavy vacuum distillate on the yield and composition of the catalytic cracking products. The laboratory research was performed to determine the physical and chemical characteristics and group composition of two samples of the heavy vacuum distillate of Kazakhstan and West Siberian oil. The patterns of changing yield of wet gas, light and heavy gas oil, coke, and gasoline depending on the composition of the feedstock were established using mathematical model of catalytic cracking.

The directions of the ecological sustainability in printing reproduction are in the area of the application of the renewable and recycled raw materials, in the decrease of the energy consumption, the usage of the energy from the renewable sources and in the production without waste. This article presents the research results of voltage changes of the intermediate cylinder in indirect electrophotography with liquid toner on dirt count and area on handsheet made from fibers after prints pulping and flotation, brightness and effective residual ink concentration. Since on the indirect transfer of ElectroInk except the voltage of the intermediate cylinder also impacts temperature, its influence on the dirt count and area is showed. Uncoated and both side coated substrates were used for printing. The results show that changes in voltage of the intermediate cylinder in the printing affects the characteristics of pulped and floated fibers and dirt count and area on handsheets. Dominant factor of studied process is surface treatment of the printing substrate. Maximum efficiency of deinking flotation (87.7%) was observed on non coated paper print, at the voltage of the intermediate cylinder of 700V. The efficiency of deinking flotation on both sides coated paper prints in dependence on the voltage of the intermediate cylinder in most cases is below 10%. The results show that an increase in temperature of the intermediate cylinder increases dirt count and area on handsheetst after pulping prints under experimental conditions. Increased efficiency of flotation was found for print obtained at a lower temperature of the intermediate cylinder.

Most popular renewable energy source is biomass. The typical form of biomass is wood. Use of wood for fuel have long tradition in Slovakia. Between a normally trees in Slovakia belongs beech and spruce. This article deals with the energy properties of spruce (Picea Abies). On different parts of the tree have been performed experimental measurements. The measured results show that the parts of the tree have potential for to the next application and processing.