Evaluation of the effect of size reduction and thermal treatment on metal extraction from PCBs of mother board and digital video drive of desktop PC

The study aims at evaluating the effect of particle size and thermal treatment on printed circuit boards (PCBs) of Mother Board (MB) and DVD on metal extraction. Results show around 90-95% (w/w) and 35-40% (w/w) of total Al and Cu respectively, in CPU could be recovered by systematized disassembly. Remaining embedded Al and Cu require metallurgical or hydro-metallurgical processing. Cu extraction increases with size reduction. Thermal treatment of MB-PCB shows reduction in Cu extraction (23-38%) for all sizes in comparison without thermal treatment, while DVD-PCB showed surge in extraction after thermal treatment (41-141%) in comparison without thermal treatment

Deep vein thrombosis of the lower limbs: A retrospective analysis of doppler ultrasound findings

Background: Deep venous thrombosis (DVT) of lower limbs is one of the most common cause for the majority of deaths caused by pulmonary embolism. Many medical and surgical disorders are complicated by DVT. Most venous thrombi are clinically silent. B-mode and color Doppler imaging is needed for early diagnosis of DVT to prevent complications and sequalae of DVT. Aim and Objectives: The objectives of the following study were to evaluate the role of Doppler as an imaging modality in diagnosing DVT of lower limbs, to study the spectrum of findings on Doppler ultrasound in patients with DVT. Materials and Methods: Retrospective descriptive analysis of 78 patients of DVT diagnosed on Doppler. Results: Nearly 74% of the patients were males and 26% were females with majority belonging to fifth decade (26%). 75 (96.1%) cases showed unilateral while 3 (3.9%) cases showed bilateral lower limb involvement. In our study, predominant distribution of thrombus was found to be in above knee region with 69/78 (88.5%) patients having thrombus in the superficial femoral vein. Popliteal vein was involved in 54/78 (69.2%) patients. Complete thrombosis was observed in 54/78 (69%) cases, while partial thrombosis was observed in 24/78 (31%) cases. Subacute stage was seen in 42 cases (53.8%), acute stage in 23 cases (29.5%) while chronic stage in 13 cases (16.7%). 71 cases (91%) had multiple contiguous segmental involvement, whereas 7 cases (9%) had isolated vein involvement. Conclusion: Color Doppler is useful in diagnosing DVT in symptomatic and at risk patients and provides a non-invasive method of investigation. It is also helpful in evaluating the site, extent and stage of thrombus

Microbially assisted arsenic removal using Acidothiobacillus ferrooxidans mediated by iron oxidation

The aim of this investigation was to determine the efficiency of arsenic removal present in acidic water using the biochemical method in presence of Acidothiobacillus ferrooxidans bacteria and ferrous ions. The process includes the bio-oxidation of ferrous to ferric by bacteria with simultaneous conversion of arsenite to arsenate and its removal by chemical method. The experiments were carried out in shake flasks with or without A. ferrooxidans culture. The variables of the pH, temperature, cell density and initial concentration of ferrous ions in the growth medium of A. ferrooxidans bacteria were examined in the laboratory to determine how they affect the removal of arsenic. It was found that the maximum arsenic removal (80%–85%) occurred at ferrous ions concentration of 2 gL−1 at the temperature of 35 ◦C with the initial cell density of 3.66 × 107 cells/mL and initial pH value of 2.5 with 70%–75% bio-oxidation of ferrous ions. The results of scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses have confirmed the growth of bacteria and identify the nature of precipitate generated by the bacteria. The finding showed that arsenic can be removed considerably in this process in an efficient and greener way, but also removing efficiency was much more (<80%) in acidic wastewater. The ANOVA and LSD statistical analysis were performed to assess any significant differences occurred among the four different levels of each variable. This study verified that combination of bio-oxidation with filtration improves the removal efficiency of arsenic