A pilot study on particle emission from printer paper shredders

This project investigated airborne particle releases derived from paper shredding. The characteristics of these emissions have not been studied previously. The objective of this project was to characterize released particles in terms of particle size distribution, particle mass and number concentration, particle morphology and chemical composition, as well as the structure of paper fibers. A significant amount of paper particles were found in the close vicinity of an unenclosed paper shredder during shredding and the manual manipulation of shredded paper. The particle release from shredding using two types of printer paper, two types of shredders, and various shredding frequencies was measured inside the shredder basket. The particles released from paper shredding were found to be in the nanometer to micrometer size ranges, and the particles contained calcium and other metal elements. Manual stirring of shredded paper released the highest particle concentration as measured at the opening of the container. Shredding with 30-s intervals increased the duration of airborne particle release as compared to intermittent shredding. Multiple quantitative analyses were employed to evaluate released particles at various particle size ranges. Two real-time instruments which measured thoracic (<10 μm) and respirable (<4 μm) particle sizes showed comparable concentrations measured inside and outside of the shredder basket.

Copyright © 2017 American Association for Aerosol Research     

Effects of gamma irradiation on quality of Pakistani blood red oranges (Citrus sinensis L. Osbeck)

Effect of gamma irradiation and washing on physicochemical and sensory quality of blood red oranges was investigated. The citrus fruits were packed in cellophane bags and stored at room temperature for 42 days. Two gamma irradiation doses 0.25 and 0.5 kGy alone and in combination with washing were applied to the fruits. Weight loss decreased with gamma irradiation and increased with washing during storage. Acidity and ascorbic acid values were higher for the oranges irradiated at 0.5 kGy and minimum for the washed oranges. Generally, total soluble solids (TSS) increased during the storage period. However, washed samples had the highest concentration and 0.5 kGy-irradiated samples had the lowest TSS at the end of the storage period. Sensory quality qualify by appearance, odour and taste are decreased during storage in both treatments. However, the fruits were still acceptable by the trained observers. It can be inferred from this study that irradiation at 0.5 kGy or in combination with washing is an effective post-harvest technique in keeping the changes in physicochemical and sensory quality to a minimum level during storage.     

Influence of germination techniques on phytic acid and polyphenols content of chickpea (Cicer arietinum L.) sprouts

Influence of germination time and type of illumination on phytic acid and polyphenols of chickpea was investigated. With blue light illumination, a significant decrease (p < 0.01) in phytic acid content was observed, while all other illuminations had no effect on this parameter. Germination time up to 48 h significantly reduced (p < 0.01) the phytic acid content from 1.01% to 0.6% while beyond that time it increased significantly (p < 0.01) reaching the maximum value of 0.9% after 120 h which is still significantly lower than control (1.01%). A similar trend was observed for methanol extractable polyphenols as for phytic acid. It decreased significantly (p < 0.01) with 24 h and 48 h germination time while after that it increased significantly (p < 0.01) and the maximum value was noted with 120 h germination. Red light significantly diminished methanol extractable phenols as compared to dark, fluorescent, yellow and irradiation illuminations. Effect of germination time and type of illumination was highly significant (p < 0.01) for water and acidic methanol extractable phenols. Acidic methanol extractable phenols significantly increased (p < 0.01) from 0.055% to 0.14% within the first 24 h germination while beyond that it decreased significantly reaching the minimum value as for control. Germination under dark and irradiated chickpea seed enhanced the methanol extractable phenols content followed by fluorescent and yellow illuminations. Lowest values for methanol extractable phenols were noted for red followed by green and blue illuminations. Water extractable polyphenols decreased significantly with the increase in germination time. Significantly higher water extractable polyphenols content were noted under blue light germinating samples followed by irradiated samples and lower values for germination under yellow light.     

Micromechanical discrete element modeling of fiber reinforced polymer composites

An analytical model of mechanical behavior of carbon fiber reinforced polymer composites using an advanced discrete element model (DEM) coupled with imaging techniques is presented in this article. The analysis focuses on composite materials molded by vacuum assisted resin transfer molding. The molded composite structure consists of eight‐harness carbon fiber fabrics and a high‐temperature polymer. The actual structure of the molded material was captured in digital images using optical microscopy. DEM was developed using the image‐based‐shape structural model to predict the composite elastic modulus, stress–strain response, and compressive strength. An experimental case study is presented to evaluate the accuracy of the developed analytical model. The results indicate that the image‐based DEM micromechanical model showed fairly accurate predictions for the elastic modulus and compressive strength. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Security Requirement Management for Cloud-Assisted and Internet of Things—Enabled Smart City

The world is rapidly changing with the advance of information technology. The expansion of the Internet of Things (IoT) is a huge step in the development of the smart city. The IoT consists of connected devices that transfer information. The IoT architecture permits on-demand services to a public pool of resources. Cloud computing plays a vital role in developing IoT-enabled smart applications. The integration of cloud computing enhances the offering of distributed resources in the smart city. Improper management of security requirements of cloud-assisted IoT systems can bring about risks to availability, security, performance, confidentiality, and privacy. The key reason for cloud- and IoT-enabled smart city application failure is improper security practices at the early stages of development. This article proposes a framework to collect security requirements during the initial development phase of cloud-assisted IoT-enabled smart city applications. Its three-layered architecture includes privacy preserved stakeholder analysis (PPSA), security requirement modeling and validation (SRMV), and secure cloud-assistance (SCA). A case study highlights the applicability and effectiveness of the proposed framework. A hybrid survey enables the identification and evaluation of significant challenges.     

Green synthesis,characterisation and biological evaluation of plant‐based silver nanoparticles using Quercus semecarpifolia Smith aqueous leaf extract

The development of reliable and green methods for the fabrication of metallic nanoparticles (NPs) has many advantages in the field of nanotechnology. In this direction, the present work describes an eco‐friendly and cost‐effective protocol for the production of silver NPs (AgNPs) using an aqueous extract of Quercus semecarpifolia leaves. Different techniques were carried out for the characterisation of the synthesised AgNPs. The ultraviolet–visible spectroscopic analysis showed the highest absorbance peak at 430 nm. The particle size and structure were confirmed by scanning electron microscopy as well as transmission electron microscopy (TEM) analysis. From TEM imaging, it was revealed that the formed particles were spherical with an average size of 20–50 nm. The crystalline nature of the NPs was determined by X‐ray powder diffraction patterns. Thermogravimetry and differential thermal analysis were also evaluated by a temperature increment from 100 to 1000°C. Bio‐inspired synthesis of AgNPs was performed for their pharmacological evaluation in relation to the activities of the crude methanolic, n ‐hexane, chloroform, ethyl acetate, and aqueous extracts. Good cytotoxic activity was exhibited by the green‐synthesised AgNPs (77%). Furthermore, the AgNPs were found to exhibit significant antioxidant activity at 300 μg/ml (82%). The AgNPs also exhibited good phytotoxic potential (75%).Inspec keywords: scanning electron microscopy, toxicology, visible spectra, particle size, nanofabrication, nanomedicine, transmission electron microscopy, silver, ultraviolet spectra, differential thermal analysis, nanoparticles, X‐ray diffraction, botany, biochemistry, cellular biophysicsOther keywords: green synthesis, biological evaluation, plant‐based silver nanoparticles, reliable methods, metallic nanoparticles, eco‐friendly cost‐effective protocol, silver NPs, ultraviolet–visible spectroscopic analysis, highest absorbance peak, particle size, structure, transmission electron microscopy analysis, TEM imaging, crystalline nature, X‐ray powder diffraction patterns, differential thermal analysis, pharmacological evaluation, aqueous extracts, good cytotoxic activity, significant antioxidant activity, AgNPs exhibited good phytotoxic potential, bio‐inspired synthesis, Quercus semecarpifolia Smith aqueous leaf extract, scanning electron microscopy, thermogravimetry, crude methanolic, n‐hexane, chloroform, ethyl acetate, phytotoxic potential, haemagglutination activity, size 20.0 nm to 50.0 nm, wavelength 430.0 nm, temperature 100 degC to 1000 degC, Ag     

Association of education level with dialysis outcome

The impact of education on health care outcome has been studied in the past, but its role in the dialysis population is unclear. In this report, we evaluated this association. We used the United States Renal Data System data of end-stage renal disease patients aged 18 years. Education level at the time of end-stage renal disease onset was the primary variable of interest. The outcome of the study was patient mortality. We used four categories of education level: 0 = less than 12 years of education; 1 = high school graduate; 2 = some college; 3 = college graduate. Subgroups based on age, race, sex, donor type, and diabetic status were also analyzed. After adjustments for covariates in the Cox model, using individuals with less than 12 years of education as a reference, patients with college education showed decreased mortality with hazard ratio of 0.81 (95% confidence interval 0.69–0.95), P = 0.010. In conclusion, we showed that higher education level is associated with improved survival of patients on dialysis.     

Comparison of sprout quality characteristics of desi and kabuli type chickpea cultivars (Cicer arietinum L.)

Effect of germination time on comparative sprout quality characteristics (proximate composition, ascorbic acid, phytic acid, invitro protein digestibility, protein solubility and sensory properties) was investigated. Sprouting significantly increased (P<0.01) the moisture, crude protein, crude fat and ascorbic acid contents and decreased nitrogen free extract (NFE). Phytic acid was reduced (P<0.01) with sprouting, but more pronouncedly so in the case of Kabuli type (73% reduction) than in desi type (32% reduction). In-vitro protein digestibility (IVDP) and protein solubility improved significantly (P<0.01) with increase in sprouting time. The overall sensory scores increased with the first (24 h) sprouting interval and then decreased. However, the acceptability scores for both chickpea types remained within the acceptable range (>5.0). Although, organoleptically the desi type chickpea sprouts were preferred over Kabuli type, the nutritional improvement due to sprouting was more pronounced in Kabuli chickpeas than their desi counterparts. Due to overall superior sprout quality, the kabuli type was more suitable for sprouting purposes.