Fast pyrolysis of halogenated plastics recovered from waste computers

The disposal of waste computers is an issue that is gaining increasing interest around the world. In this paper, results from the fast pyrolysis in a fluidized bed reactor of three different waste computer monitor casings composed of mainly acrylonitrile-butadiene-styrene (ABS) copolymer and two different waste computer body casings composed of mostly poly(vinyl chloride) (PVC) type polymers are presented. Preliminary characterization of the waste plastics was investigated using coupled thermogravimetric analysis-Fourier transform infrared spectrometry (TGA-FT-IR). The results showed that the plastics decomposed in two stages. For the ABS-containing monitor casings, aromatic and aliphatic material were released in the first and second stages. The PVC-containing computer body casing samples showed a first-stage evolution of HCl and a second stage evolution of aromatic and aliphatic material and further HCl. In addition, each of the five plastics was fast-pyrolyzed in a laboratory-scale fluidized bed reactor at 500 °C. The fluidized bed pyrolysis led to the conversion of most of the plastics to pyrolysis oil, although the two PVC computer body cases produced large quantities of HCl. The pyrolysis oils were characterized by GC-MS and it was found that they were chemically very heterogeneous and contained a wide range of aliphatic, aromatic, halogenated, oxygenated, and nitrogenated compounds

Alkaline hydrothermal treatment of brominated high impact polystyrene (HIPS-Br) for bromine and bromine-free plastic recovery

A method to recover both Br and Br-free plastic from brominated flame retardant high impact polystyrene (HIPS-Br) was proposed. HIPS-Br containing 15% Br was treated in autoclave at 280℃ using water or KOH solution of various amounts and concentrations. Hydrothermal treatment (30 ml water) leads to 90% debromination of 1 g HIPS-Br but plastic is strongly degraded and could not be recovered. previous termAlkalinenext term hydrothermal treatment (45 ml or 60 ml KOH 1 M) showed similar debromination for up to 12 g HIPS-Br and plastic was recovered as pellets with molecular weight distribution close to that of the initial material. Debromination occurs at melt plastic/KOH solution interface when liquid/vapour equilibrium is attained inside autoclave (280℃ and 7 MPa in our experimental conditions) and depends on the plastic amount/KOH volume ratio. The antimony oxide synergist from HIPS-Br remains in recovered plastic during treatment. A pictorial imagination of the proposed debromination process is presented.</p

Monitoring of Buituri Slag Dump, Hunedoara County in Relation with Environmental Protection

Detailed analysis of appearance and relief evolution in mining areas cannot be done without mining engineering concepts. Over time, researchers around the world have responsibly been involved in this matter necessary for the development of society, also with obvious implications and repercussions over the quality of life. The purpose of the scientific research detailed in this paper comprises in monitoring the slag dump from Buituri, Hunedoara County using space geodetic technology. Slag dump is the result of steel production activities carried out under the steel factory Arcelor Mittal Hunedoara S.A., formerly known as the steel factory Hunedoara - Siderurgica S.A. Therefore it was decided to conduct monthly topographic measurements to monitor possible dynamic changes that may appear in the context of continuous exploitation of the above mentioned slag dump. Monitoring possible movements is performed by comparing transversal and longitudinal profiles drawn based on zero measurement carried out on 20.05.2011, with the ones obtained after processing of the monthly measurements realized throughout the years 2011, 2012, 2013, 2014, 2015 and 2016. Also, for observing the displacements, comparative charts or tables with records regarding coordinates differences are studied. The issue of measuring and graphic representation of settlements, horizontal linear movements and landslides for structures such as slag or sterile dumps, requires further studies and interdisciplinary research, creating links between specialists in the fields of terrestrial measurements science and geology

Storage Security in Cloud Computing: Data Auditing Protocols

Cloud computing has emerged as a necessity for hosting data on cloud servers so that information can be accessed and shared remotely. It was quickly adopted because it provides quality of service for various remotely available, easy-to-configure, and easy-to- use products, such as IaaS (Infrastructure as a Service) or PaaS (Platform as a Service). However, this new paradigm of data hosting brings new challenges. Some of the challenges related to the issue of security require independent audit services to verify the integrity of cloud-hosted data. With many end users and companies moving from on-premise to cloud models for their business, cloud data security is a critical concept that needs to be managed. First, we identify security requirements. Second, we look at potential solutions to ensure data integrity in cloud storage. Last, we propose a data auditing solution that can be used to detect corrupt data or file anomalies in the storage system

Comprehensive characterization of Napier grass as a feedstock for thermochemical conversion

Study on Napier grass leaf (NGL), stem (NGS) and leaf and stem (NGT) was carried out. Proximate, ultimate and structural analyses were evaluated. Functional groups and crystalline components in the biomass were examined. Pyrolysis study was conducted in a thermogravimetric analyzer under nitrogen atmosphere of 20 mL/min at constant heating rate of 10 K/min. The results reveal that Napier grass biomass has high volatile matter, higher heating value, high carbon content and lower ash, nitrogen and sulfur contents. Structural analysis shows that the biomass has considerable cellulose and lignin contents which are good candidates for good quality bio-oil production. From the pyrolysis study, degradation of extractives, hemicellulose, cellulose and lignin occurred at temperature around 478, 543, 600 and above 600 K, respectively. Kinetics of the process was evaluated using reaction order model. New equations that described the process were developed using the kinetic parameters and data compared with experimental data. The results of the models fit well to the experimental data. The proposed models may be a reliable means for describing thermal decomposition of lignocellulosic biomass under nitrogen atmosphere at constant heating rate

Study of the Influence of adding styrene-ethylene/butadiene-styrene in acrylonitrile-butadiene-styrene and polyethylene blends

This work studies the recovery of two grades of acrylonitrile butadiene styrene (ABS) contaminated with low-density polyethylene (LDPE), by adding styrene ethylene/butadiene styrene (SEBS). To simulate contaminated ABS, virgin ABS was mixed with 1, 2, 4, and 8% of LDPE and then extruded at 220°C. After this, the ABS with the highest percentage of LDPE (8%) was mixed with 1, 2, 4, and 8% of SEBS and then extruded. Different blends were mechanically, rheologically, optically, and dimensionally characterized to study how different percentages of LDPE and SEBS modify their properties. The results obtained show how the tensile strength, Young modulus, elongation, and impact strength linearly decrease as the LDPE amount increases, for both natural and black ABS. Through the addition of SEBS to contaminated ABS, it is possible to improve its impact strength and elongation values nearly to those of virgin ABS. However, its tensile strength and Young modulus show no improvement, and even show a slight reduction. Regarding the rheological properties, the LDPE contamination in ABS causes a remarkable decrease in viscosity, and adding SEBS to the blend lowers its viscosity even further for both natural and black grades. This reduction is not a negative aspect, but rather quite the reverse, as the more fluid the material, the easier the mold injection process becomes. POLYM. ENG. SCI., 54:1313 1324, 2014. © 2013 Society of Plastics EngineersContract grant sponsor: "Subdireccion de Investigacion, Desarrollo e Innovacion de la Universitat Politecnica de Valencia" to the research project: "la investigacion de sistemas ternarios aplicados a los materiales polimericos para la mejora de residuos de estireno," Ref.: 20091056 belonging to the research program primeros proyectos de investigacion; contract grant number: PAID 06-09.Peydro, MA.; Parres, F.; Navarro Vidal, R.; Sanchez-Caballero, S. (2014). Study of the Influence of adding styrene-ethylene/butadiene-styrene in acrylonitrile-butadiene-styrene and polyethylene blends. Polymer Engineering and Science. 54(6):1313-1324. https://doi.org/10.1002/pen.23680S13131324546Adrados, A., de Marco, I., Caballero, B. M., López, A., Laresgoiti, M. F., & Torres, A. (2012). Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste. Waste Management, 32(5), 826-832. doi:10.1016/j.wasman.2011.06.016Brebu, M., Bhaskar, T., Murai, K., Muto, A., Sakata, Y., & Uddin, M. A. (2004). Thermal degradation of PE and PS mixed with ABS-Br and debromination of pyrolysis oil by Fe- and Ca-based catalysts. Polymer Degradation and Stability, 84(3), 459-467. doi:10.1016/j.polymdegradstab.2004.02.003Maris, E., Aoussat, A., Naffrechoux, E., & Froelich, D. (2012). Polymer tracer detection systems with UV fluorescence spectrometry to improve product recyclability. Minerals Engineering, 29, 77-88. doi:10.1016/j.mineng.2011.09.016Ta?demir, M. (2004). Properties of acrylonitrile-butadiene-styrene/polycarbonate blends with styrene-butadiene-styrene block copolymer. Journal of Applied Polymer Science, 93(6), 2521-2527. doi:10.1002/app.20708Taşdem??r, M., & Karatop, Ş. (2006). Effect of styrene–isopren–styrene addition on the recycled polycarbonate/acrylonitrile–butadiene–styrene polymer blends. Journal of Applied Polymer Science, 101(1), 559-566. doi:10.1002/app.23555Li, B., Wan, C., Zhang, Y., & Ji, J. (2010). Blends of poly(2,6-dimethyl-1,4-phenylene oxide)/polyamide 6 toughened by maleated polystyrene-based copolymers: Mechanical properties, morphology, and rheology. Journal of Applied Polymer Science, 115(6), 3385-3392. doi:10.1002/app.30742Yin, N., Zhang, Y., Zhang, Y., Zhang, X., & Zhou, W. (2007). Preparation and properties of PC/SAN alloy modified with styrene-ethylene-butylene-styrene block copolymer. Journal of Applied Polymer Science, 106(1), 637-643. doi:10.1002/app.26681Peydró, M. A., Parres, F., Crespo, J. E., & Juárez, D. (2010). Study of rheological behavior during the recovery process of high impact polystyrene using cross-WLF model. Journal of Applied Polymer Science, 120(4), 2400-2410. doi:10.1002/app.33444Tiganis, B. ., Burn, L. ., Davis, P., & Hill, A. . (2002). Thermal degradation of acrylonitrile–butadiene–styrene (ABS) blends. Polymer Degradation and Stability, 76(3), 425-434. doi:10.1016/s0141-3910(02)00045-9Arostegui, A., Sarrionandia, M., Aurrekoetxea, J., & Urrutibeascoa, I. (2006). Effect of dissolution-based recycling on the degradation and the mechanical properties of acrylonitrile–butadiene–styrene copolymer. Polymer Degradation and Stability, 91(11), 2768-2774. doi:10.1016/j.polymdegradstab.2006.03.019Karahaliou, E.-K., & Tarantili, P. A. (2009). Stability of ABS compounds subjected to repeated cycles of extrusion processing. Polymer Engineering & Science, 49(11), 2269-2275. doi:10.1002/pen.21480Karahaliou, E.-K., & Tarantili, P. A. (2009). Preparation of poly(acrylonitrile-butadiene-styrene)/montmorillonite nanocomposites and degradation studies during extrusion reprocessing. Journal of Applied Polymer Science, 113(4), 2271-2281. doi:10.1002/app.30158Chang, T. C., & Faison, E. (2001). Shrinkage behavior and optimization of injection molded parts studied by the taguchi method. Polymer Engineering & Science, 41(5), 703-710. doi:10.1002/pen.10766Shen, C., Wang, L., & Li, Q. (2007). Optimization of injection molding process parameters using combination of artificial neural network and genetic algorithm method. Journal of Materials Processing Technology, 183(2-3), 412-418. doi:10.1016/j.jmatprotec.2006.10.036Tang, S. H., Tan, Y. J., Sapuan, S. M., Sulaiman, S., Ismail, N., & Samin, R. (2007). The use of Taguchi method in the design of plastic injection mould for reducing warpage. Journal of Materials Processing Technology, 182(1-3), 418-426. doi:10.1016/j.jmatprotec.2006.08.025Ganguly, A., Saha, S., Bhowmick, A. K., & Chattopadhyay, S. (2008). Augmenting the performance of acrylonitrile–butadiene–styrene plastics for low-noise dynamic applications. Journal of Applied Polymer Science, 109(3), 1467-1475. doi:10.1002/app.2805

Separation and recovery of materials from scrap printed circuit boards

Printed circuit boards from waste computers, televisions, and mobile phones were pyrolysed in a fixed bed reactor with the aim of separating and recovering the organic and metallic materials. A selection of printed circuit boards from each of the three waste classes was pyrolysed at 800°C and the pyrolysis products were analysed using GC-FID, GC-TCD, GC-MS, GC-ECD, ICP-MS, and SEM-EDX. The pyrolysis oils contained high concentrations of phenol, 4-(1-methylethyl)phenol, and p-hydroxyphenol, as well as bisphenol A, tetrabromobisphenol A, methyl phenols, and bromophenols. The pyrolysis oils also contained significant concentrations of organo – phosphate compounds and a number of tetrabromobisphenol A pyrolysis products were also identified. The pyrolysis residues were very fragile and the organic, glass fibre, and metallic fractions could easily be separated and the electrical components could easily be removed from the remains of the printed circuit boards. The ash in the residue mainly consisted of copper, calcium, iron, nickel, zinc, and aluminium, as well as lower concentrations of valuable metals such as gallium, bismuth, silver, and gold, silver was present in particularly high concentrations. Many other metals were also identified in the ash by ICP-MS and SEM EDX. The pyrolysis gases mainly consisted of CO2 and CO but all of the C1 – C4 alkanes and alkenes were present, as were some inorganic halogens

Is natural orifice specimen extraction surgery really safe in radical surgery for colorectal cancer?

Scop: Chirurgia rectală robotică este în prezent o procedură nouă pentru cancerele rectale. Extracția eșantionului cu orificiu natural transanal (NOSE) este o tehnică nouă de îndepărtare a specimenului din cavitatea abdominală prin anus, în loc de o incizie suplimentară după o intervenție chirurgicală colorectală laparoscopică sau robotică. Siguranța NOSE rămâne controversată. Acest studiu și-a propus să investigheze siguranța precoce a NOSE transanal în tratamentul cancerului de colon sigmoid și rectal superior din următoarele aspecte: caracteristici clinice și patologice, indicatori inflamatori și imunitari și complicații postoperatorii. Prezentare de caz: O femeie de 61 de ani, diagnosticată anterior cu cancer rectal, cu antecedente de 6 luni de hematochezie și alternanta diaree-constipatie. Diagnosticul de cancer rectal a fost pus pe baza biopsiei colonoscopice care a confirmat un nodul circumferenţial neregulat de adenocarcinom bine diferenţiat la 10 cm de marginea anală. Rezecția anterioară joasă asistata robotic, urmata de extracția specimenului transanal a fost efectuată după obținerea consimțământului informat. Procedura a fost efectuată cu succes și pacienta a avut o evolutie postoperatorie fără complicații. Diagnosticul patologic postoperator a evidențiat un adenocarcinom moderat diferențiat de 4x4x0,6 cm3 și margine circumferențiala libera. Concluzii: Rezectia de rect robotica plus extractia transanala a specimenului pentru cancerul rectal poate fi efectuata în siguranță și poate fi o abordare eficientă în contrast cu abordarea deschisă sau laparoscopică.Background: Robotic rectal surgery is currently a novel procedure for rectal cancers. Transanal natural orifice specimen extraction (NOSE) is a novel technique to remove the specimen from the abdominal cavity through the anus instead of an additional incision following laparoscopic or robotic colorectal surgery. The safety of NOSE remains controversial. This study aimed to investigate the early safety of transanal NOSE in the treatment of sigmoid colon and upper rectal cancer from the follow aspects: clinical and pathological characteristics, inflammatory and immune indicators and postoperative complications. Case presentation: A 61-year-old women, previously diagnosed with rectal cancer with came 6 months history of hematochezia and altered bowel habit. A diagnosis of rectal cancer was made in view of colonoscopic biopsy which confirmed an irregular circumferential lump of well differentiated adenocarcinoma at 10 cm from the anal verge. Robotic low anterior resection (LAR) plus transanal natural orifice specimen extraction (NOSE) was performed after obtaining informed consent. The procedure was performed successfully and the patient convalesced nicely without any complications. The postoperative pathological diagnosis revealed a 4x4x0.6 cm3 moderately differentiated adenocarcinoma and circumferential clearance. Conclusions: Robotic LAR plus transanal NOSE for rectal cancer can be performed safely and may be an effective approach in contrast to open or laparoscopic approach

The role of the frozen section examination in the diagnosis of the thyroid nodules

Universitatea de Medicină și Farmacie Victor Babeș Timișoara, România, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Diagnosticul diferențial preoperator sau intraoperator între leziunile tiroidiene benigne și maligne este de o importanță majoră pentru decizia chirurgicală intraoperatorie. Acest studiu analizează corelația dintre rezultatul examenului extemporaneu și rezultatul examinării histopatologice la parafină în cazul nodulilor tiroidieni. Material si metode: Acesta a fost un studiu retrospectiv asupra a 330 de cazuri cu patologie tiroidiană, operate în cadrul Clinicii 2 de Chirurgie a Spitalului Clinic Județean de Urgență Timișoara din 2011 până în 2014, la care s-au efectuat atât examen extemporaneu intraoperator (EXT) cât și examen histopatologic la parafină în cadrul Departamentului de Anatomo-patologie al aceluiași spital. Rezultate: Din cele 330 de cazuri studiate, examenul EXT a stabilit diagnosticul în 244 (73,9%) cazuri și la 86 (26.1%) cazuri diagnosticul a fost incert, cu o sensibilitate de 93,33%, specificitate de 95,81%, în timp ce precizia a ajuns la 95,66%. Două sute douazeci și nouă (84,8%) au fost tumori benigne, iar 15 (27,3%) au fost tumori maligne. La examenul histopatologic, din 86 cazuri incerte 51 (59,3%) au fost benigne, 30 (34,8%) maligne și 5 (5,8%) au ramas neclare. Concluzii: Rezultatele noastre cu metoda EXT sunt echivalente cu cele disponibile în literatura de specialitate cu specificitate, sensibilitate si precizie foarte bune. În cazul în care investigațiile preoperatorii evidențiază noduli unilaterali, EXT a fost util pentru decizia intraoperatorie între lobectomie și tiroidectomie totală, evitând lobectomia inutilă sau reintervenția.Introduction: Preoperative or intraoperative differential diagnosis between benign and malignant thyroid lesions is of utmost importance for the surgical intraoperative decision. This study analyses the correlation between the frozen-section result and the result of the histopathologic paraffin examination in cases of thyroid nodules. Material and methods: This was a retrospective study upon 330 cases with thyroid pathology, operated on in the 2nd Surgical Clinic of the Clinical County Emergency Hospital of Timisoara from 2011 to 2014, that had both intraoperative frozen-section (FS) and postoperative paraffin histologic examination performed by the Pathology Department of the same hospital. Results: Of 330 cases studied, FS examination set the diagnosis in 244 (73.9%) cases and no diagnosis (uncertain) in 86 (26.1%), with a sensitivity of 93.33%, specificity of 95.81%, while accuracy reached 95.66%. Two hundred twenty-nine (84.8%) were benign tumors and 15(27.3%) were malignant tumors. At the histopathologic examination, from 86 uncertain cases 51 (59.3%) were benign, 30(34.8%) malignant and 5 (5.8%) remained unclear. Conclusions: Our results with FS method are equivalent to those available in the literature with very good specificity, sensitivity and accuracy. In cases in which the preoperative investigations show unilateral nodules, FS was still useful for the intraoperative decision between lobectomy and total thyroidectomy, avoiding inutile lobectomy or reoperation

Thermal treatment of Himalayan balsam: Tar and biochar analysis

The practicality of Himalayan balsam as an alternative biomass material was considered throughout this investigation. However, due to the materials high-water content, thermal efficiency during pyrolysis was compromised as extra energy was required to remove free and bound water. A simple solution which involved drying at ambient temperature in air, significantly lowered the moisture content, (65% reduction) this resulted in an increase in the bulk density of the material and lowering the thermal energy input of the process. The thermal decomposition process at 300–400 °C generated petroleum like compound; a mixture of volatile aromatic, linear and branched alkanes, and therefore a possible source for replenishment of hydrocarbon-based fuel. The solid remaining carbon generated (~35% mass of dry material) termed biochar showed adsorption properties to rhodamine B dye. The level of activity was increased upon activation using phosphoric acid. The activated biochar could be a promising adsorbent used to remove aqueous organic compounds. The thermal treatment of Himalayan balsam has potential in generating useful products such as bio-fuels and biochar