Implementation of Double-Timing Pulse Interpolation Applied to Compact Piston Provers

This work presents an electronic circuit for double-timing pulse interpolation applied to compact piston provers (also referred as small volume provers). Compact provers are usually employed to prove meters with pulsed outputs. API and ISO standards [1,2] recommend a minimum of 10.000 pulses per run to obtain a resolution better than ± 0.01%. Since the volume of fluid displaced by a compact prover is relatively small, the number of pulses produced during a proving run is often considerably less than 10.000 pulses. Pulse interpolation techniques are commonly used to increase resolution and to diminish uncertainty during a proving run by estimating the fractional part of meter pulses within the time interval of the calibration. In this way, pulse interpolation techniques are essential to obtain accurate flow measurements and to allow the calibration of meters with compact provers. Our implementation uses a compact piston prover with an internal volume of 12 L and maximum flow capacity of 180 L/min. In order to implement the double-timing pulse interpolation method, we have used a Pentium D, 2.80 GHz installed with a 16-bit counter/timer board. Data acquisition and control software were written using VB .Net. An electronic circuitry was built to activate/deactivate counters gates, and to collect pulses. Some requirements and limitations of pulse interpolation techniques such as circuitry testing and pulse stability are also discussed in this work

Torsion of the gallbladder: a case report

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Comparison of different methods for liquid level adjustment in tank prover calibration

The adjustment of the liquid level during the calibration of tank provers with fixed volume is normally done by overfill but it can be done in different ways. In this article four level adjustment techniques are compared: plate, pipette, ruler and overfill adjustment. The adjustment methods using plate and pipette presented good agreement with the tank’s nominal volume and lower uncertainty among the tested methods.Indisponível

Torsion of the Gallbladder: Report of a Case

Torsion of the gallbladder is a rare entity that is difficult to diagnose preoperatively. The condition occurs most often in the elderly. Although its etiology is unknown, a constant finding is the presence of the gallbladder on a mobile mesentery (floating gallbladder). Torsion, or volvulus, of the gallbladder occurs when it twists axially, with the subsequent occlusion of bile and/or blood flow. Herein, a case of torsion of the gallbladder is presented where preoperative computed tomographic scan and laparoscopy were successfully used to diagnose and treat this condition without the usual requirement of open exploration. Given the possibility of laparoscopic cholecystectomy and the increasing incidence with which torsion of the gallbladder is being witnessed today, the importance of a preoperative computed tomographic scan is emphasized when there is a high index of clinical suspicion

Quantitative assessment of inter-observer variability in target volume delineation on stereotactic radiotherapy treatment for pituitary adenoma and meningioma near optic tract

<p>Abstract</p> <p>Background</p> <p>To assess inter-observer variability in delineating target volume and organs at risk in benign tumor adjacent to optic tract as a quality assurance exercise.</p> <p>Methods</p> <p>We quantitatively analyzed 21 plans made by 11 clinicians in seven CyberKnife centers. The clinicians were provided with a raw data set (pituitary adenoma and meningioma) including clinical information, and were asked to delineate the lesions and create a treatment plan. Their contouring and plans (10 adenoma and 11 meningioma plans), were then compared. In addition, we estimated the influence of differences in contouring by superimposing the respective contours onto a default plan.</p> <p>Results</p> <p>The median planning target volume (PTV) and the ratio of the largest to the smallest contoured volume were 9.22 cm³(range, 7.17 - 14.3 cm³) and 1.99 for pituitary adenoma, and 6.86 cm³(range 6.05 - 14.6 cm³) and 2.41 for meningioma. PTV volume was 10.1 ± 1.74 cm³for group 1 with a margin of 1 -2 mm around the CTV (n = 3) and 9.28 ± 1.8 cm³(p = 0.51) for group 2 with no margin (n = 7) in pituitary adenoma. In meningioma, group 1 showed larger PTV volume (10.1 ± 3.26 cm³) than group 2 (6.91 ± 0.7 cm³, p = 0.03). All submitted plan keep the irradiated dose to optic tract within the range of 50 Gy (equivalent total doses in 2 Gy fractionation). However, contours superimposed onto the dose distribution of the default plan indicated that an excessive dose 23.64 Gy (up to 268% of the default plan) in pituitary adenoma and 24.84 Gy (131% of the default plan) in meningioma to the optic nerve in the contours from different contouring.</p> <p>Conclusion</p> <p>Quality assurance revealed inter-observer variability in contour delineation and their influences on planning for pituitary adenoma and meningioma near optic tract.</p

Gross motor function in children with Congenital Zika Syndrome from Rio de Janeiro, Brazil.

Congenital Zika Syndrome (CZS) is characterized by many impairments especially in the central nervous system, potentially compromising neurodevelopment and causing significant morbidity in affected children. The aim was to assess gross motor function in children with CZS. This was a cross-sectional investigation nested within a prospective cohort study of children with CZS based in a Brazilian referral hospital in Rio de Janeiro. Between March/2017 and February/2018, we performed gross motor function assessments using the Gross Motor Function Classification (GMFCS) and the Gross Motor Function Measure (GMFM), estimating the mean and standard deviation of GMFM scores among GMFCS groups. The study sample included 72 children, with a median age of 13 months (7-25). Of these, 63 (87.5%) had severe motor impairment, 3 (4%) had moderate impairment, and 6 (8%) had mild impairment. The mean GMFM score for each group was respectively 11.6, 26.1, and 81.6, with statistically significant differences (p-value < 0.001). Severely affected children only achieved head control in the sitting posture when supported. Children with milder forms were able to develop walking skills.Conclusion: Most children with CZS have major motor disabilities and a poor prognosis. Better understanding of limitations and functionality in children with CZS can serve as a prognostic guide in their management. What is Known: • Severe motor impairment was present in 63 (87.5%) children with CZS. • The degree of neurological impairment was inversely associated with motor performance. What is New: • Microcephaly was more frequent among children with severe gross motor function impairment. • Children with CZS have major motor disabilities and a poor prognosis

3D bioactive composite scaffolds for bone tissue engineering

Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. Developing bioactive three-dimensional (3D) scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering (BTE). A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts. However, individual groups of materials including polymers, ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone. Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds. This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers, hydrogels, metals, ceramics and bio-glasses in BTE. Scaffold fabrication methodology, mechanical performance, biocompatibility, bioactivity, and potential clinical translations will be discussed