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1.
Accid Anal Prev ; 199: 107513, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38428244

RESUMO

The study presents a real-time safety and mobility assessment approach using data generated by autonomous vehicles (AVs). The proposed safety assessment method uses Bayesian hierarchical spatial random parameter extreme value model (BHSRP), which can handle the limited availability and uneven distribution of conflict data and accounts for unobserved spatial heterogeneity. The approach estimates two real-time safety metrics: the risk of crash (RC) and return level (RL), using Time-To-Collision (TTC) as conflict indicator. Additionally, a Risk Exposure (RE) index was developed to reflect the risk of an individual vehicle to travel through a corridor. In parallel, the mobility of corridor were assessed based on the highway Capacity manual methodology using real-time traffic data (Highway Capacity Manual, 2010). The study used a 440-hour AVs' dataset of a corridor in Palo Alto, California. After normalizing for each LOS representation in the dataset, LOS E was identified as the most hazardous operating condition with the highest average crash risk. However, the time spent under different operating condition would affect the safety of individual vehicles traveling through a road facility (i.e., vehicle's exposure time). Accounting for exposure time, the vehicle has the highest chance of encountering an extremely risky driving condition at intersections and segments under LOS D and E, respectively.


Assuntos
Acidentes de Trânsito , Veículos Autônomos , Humanos , Teorema de Bayes , Acidentes de Trânsito/prevenção & controle , Benchmarking , Viagem
2.
ACS Omega ; 8(50): 47440-47451, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38144106

RESUMO

In the oil and gas industry, gas flaring through flare stacks plays a critical role in safely and efficiently releasing and burning gases and other materials from pressure-relief and vapor-depressurizing systems. Gas flaring is a contentious and formidable environmental challenge, both regionally and globally. Its adverse impacts encompass pollution, contribution to global warming, and substantial economic losses. Shockingly, gas flaring squanders approximately 5% of the global gas supply, resulting in the annual production of over 350 million tons of CO2 gas. While alternatives to gas flaring exist, they are either undergoing investigation or currently lacking economic viability. Consequently, the development of a more efficient gas flaring system is imperative. In addition, the reliable and efficient operation of flares is paramount, as they are expected to function seamlessly over extended periods under various service conditions. In this paper, a novel gas flaring tip to address the limitations of existing flaring systems is introduced. This innovative tip features a distinctive configuration, incorporating a bullet-shaped device positioned atop the flare. This bullet device boasts four strategically placed apertures equipped with internal deflectors, facilitating the convergence of gases into a single vortex outlet at its apex. For operational flexibility, the bullet is affixed to the flare tip using a system of three springs, enabling it to elevate at a pressure of 2.0 psig and achieve full extension at 8 psig. This dynamic design harnesses the Coanda effect, promoting efficient oxygen utilization. The comprehensive evaluation of this tip spanned a wide range of gas capacities, 4.0 and 10.0 MMSCFD. In this analysis, parameters such as the fraction of heat radiated, transmissivity, atmospheric humidity level, solar radiation adjustment, ambient temperature, and horizontal wind velocity were factored. The evaluation included both theoretical analysis and experimental investigation. The theoretical analysis employed a simplified open pipe flare tip approach to predict thermal radiation levels around the tip using the Brzustowski and Sommer model. The experimental setup included equipment such as thermocouple thermometers, heat flux sensors, digital sound level meters, mass flowmeters, and portable flue gas analyzers. Throughout testing, thermal radiation levels, isopleths, noise levels, and flue gas composition were measured. The collected data were subsequently compared to predictions generated using the Brzustowski and Sommer model for identical gas flow rates, flare heights, and flare diameters. Due to technical challenges and safety concerns, flue gas composition was not available. The authors are exploring different alternatives to overcome these obstacles and data should be available in the near future. The resulting data of heat radiation and noise levels unequivocally demonstrate the superiority of the new tip when compared to conventional gas flaring systems. With its cost-effectiveness, smokeless operation, heightened efficiency, and cleaner flame characteristics, the authors, due to the groundbreaking design of this tip, strongly advocate its adoption as a means to mitigate the environmental impact of gas flaring.

3.
Arab J Urol ; 18(3): 181-186, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33029429

RESUMO

OBJECTIVE: To compare the management of large ureteric stones (>10 mm) with ureterorenoscopy (URS) and laser or pneumatic lithotripsy, and their associated costs. PATIENTS AND METHODS: Our prospective study followed the tenets of the Declaration of Helsinki and included 101 patients with large mid-ureteric stones eligible for URS and lithotripsy, and was conducted between January 2018 and August 2019. Patients were randomly divided into two groups: Group 1 had laser lithotripsy, while the Group 2 had lithotripsy using a pneumatic energy source. RESULTS: Operative time was significantly longer in cases using pneumatic lithotripsy (P < 0.001). The stone-free rate (SFR) on the first postoperative day was 94% and 92.5% for laser and pneumatic lithotripsy respectively, and there were no statistically significant differences in terms of early (day 1) or late (day 30) SFRs between the groups. Complications were classified according to the Clavien-Dindo Grading System, all complications were Grade

4.
J Egypt Soc Parasitol ; 45(2): 429-33, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26485863

RESUMO

Ambulant flexible cystoscopy is the standard procedure in the urological practice for follow-up of Ta-T1 urothelial carcinoma (UC) due to its ability to survey the bladder for a variety of indications. It is the principal means of diagnosis and surveillance of bladder tumors. The follow-up of patients treated for Ta-T1 UC is of great importance because of the high incidence of recurrence and progression of the disease, whereby patients with Ta-T1 UC undergo cystoscopy every three months. The aim of this study to evaluate the procedure of ambulant flexible cystoscopy in proper diagnostic follow-up of Ta-T1 UC, patient's acceptance in regard to pain tolerance, non-hospital stay and expenses. Twenty one patients (18 male and 3 female) were diagnosed before as Ta-T1 UC by rigid cystoscopy and transuretheral resection of bladder (TURB) lesion scheduled for follow up by flexible cystoscopy under local anesthesia using 20 ml 2% lidocain gel on an ambulatory bases. Comparison was done using a cohort of 32 patients who underwent the procedure of follow-up of Ta-T1 cystoscopy and TURB using rigid cystoscopy and resectoscope. Seventeen patients 80.9% (16 male and 2 female) proved to be bladder free from recurrent lesion, 4 patients {19.1 %} (3 males and one female) which revealed recurrent lesions in spite of that the urinary bladder was free in pelvic ultrasonography. Cold cup biopsy from the lesions sent for histopathological examination which revealed recurrence of the tumor in 3 patients (two patients with Ta and one patient T1. TURB was done to have complete resection in 4 patients, the histopathological examination revealed ulcerating mucosa and free lamina propria in 3 specimens, and T2 in the fourth specimen. Comparison between the 2 groups revealed more patient's acceptance for the flexible cystoscopy group as regard pain tolerance, non-hospital stay and expenses. Ambulatory flexible cystoscopy with 20 ml of 2% lidocaine gel anesthesia is tolerated well by patients, with advantage of no hospital stay in the regular follow up of Ta-T1 tumors, pain perception was accepted by all patient provided delayed cystoscopy after lidocaine-gel instillation.


Assuntos
Carcinoma/diagnóstico , Cistoscopia/efeitos adversos , Cistoscopia/métodos , Dor/etiologia , Neoplasias da Bexiga Urinária/diagnóstico , Idoso , Assistência Ambulatorial , Carcinoma/classificação , Carcinoma/patologia , Cistoscopia/economia , Cistoscopia/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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