Periodic polynomial regression analysis of urban driving characteristics

ArticleUrban driving characteristics with a focus on energy consumption have been tested in Riga on three main city streets with inflexible coordinated traffic lights control. The aim of this article is to investigate periodic polynomial regression analysis method to analyse car urban driving parameters’ change during weekday twenty-four hours to assess the influence of vehicle technologies on energy consumption in city driving, to map the energy demand on Riga city main street sections and to evaluate the traffic lights control on flow energetic characteristics. The tests have been done using GPS and OBD data loggers on a test car repetitively driven along a preplanned route at around-the-clock hours. A regression analysis using periodic polynomials was developed and applied to evaluate the traffic flow characteristics with a given time shift. It was concluded that using polynomial regression function, the polynomial order has to be at least seven although a visual conformation of good regression line to the measured data has to be checked especially with lower orders. To evaluate the traffic conditions at a given 20 minutes to one hour shift the application of regression function is limited for the periods with fast changing traffic flow, especially after the end of rush hours when the usability of regression line for the given data has to be checked individually for tested street sections

Experimental analysis of hydrotreated vegetable oil (HVO) and commercial diesel fuel blend characteristics using modified CFR engine

ArticlePerformance parameters of different commercial diesel fuels is a subject of interest for fuel consumers. Fuel retailer Neste recently introduced a new brand of WWFC 5th grade diesel fuel in Baltic market, consisting of diesel fuel and hydrotreated vegetable oil (HVO) blend. Fuel samples have been recently tested on chassis dynamometer, measuring wheel power and torque and in road conditions, measuring fuel consumption. Evaluation of fuel consumption and performance parameters in road or laboratory conditions may yield uncertain results due to complexity of modern automobile engine management and emission reduction systems. To better evaluate the combustion, fuel samples have been tested in modified CFR engine at various intake air pressure, temperature and compression ratio settings. Engine indicated performance parameters and combustion phasing of regular diesel fuel and diesel fuel-HVO blend are presented. Comparing to regular diesel fuel, fuel blend with HVO showed reduced apparent heat release rate (AHRR) during premixed combustion phase at low inlet air temperature and low compression ratio conditions, comparing to regular diesel fuel. Premixed combustion phase AHRR of diesel-HVO blend increased above AHRR of regular diesel fuel at higher inlet air temperature and higher compression ratio conditions. Diffusion controlled combustion phase AHRR of diesel-HVO blend increased above AHRR of regular diesel fuel at higher inlet air temperature, higher compression ratio conditions and supercharged air supply

Research on energy efficiency of pneumatic cylinder for pneumatic vehicle motor

Compressed gas is relatively expensive source of energy. When compressed gas is used for propelling of pneumatically driven vehicle, efficient gas utilization is favoured. Design and control strategy of pneumatic cylinder, with the emphasis on effective energy conversion is being discussed in this paper. Mathematical model, results of computer simulation and experimental work are provided and discussed. Experimental research is performed on the competition vehicle, equipped with pneumatically driven piston motor and instrumented. Relative significance of various geometric and control parameters of pneumatic cylinder on efficiency of energy conversion is presented

Valor de la Resonancia Nuclear Magnética en Ortopedia Oncológica

Presentamos nuestra experiencia preliminar sobre la utilidad diagnóstica de la Resonancia Nuclear Magnética (RM) en la evaluación pre- y postoperatoria de pacientes con tumores musculoesqueléticos. Se han revisado 21 pacientes con tumores caracterizados histológicamente. Del total, 10 casos eran sarcomas de partes blandas, 7 correspondían a tumores óseos y 4 eran metástasis óseas o recidivas locales. Las imágenes se obtuvieron mediante un sistema de RM de campo medio provisto de un imán superconductor operando a 0.5 Teslas. En todos los casos se obtuvieron imágenes T1 y T2, en los planos axial y coronal. Como norma se objetivó un excelente contraste entre la señal de la lesión y la de las estructuras normales adyacentes. Sólo en un caso, un osteosarcoma del extremo proximal del peroné, las imágenes de extensión a partes blandas vecinas resultaron ser negativas en la exploración quirúrgica. El análisis de los cambios de intensidad de la señal no permitieron distinguir la especificidad tisular del tumor, ni diferenciar lesiones benignas y malignas. En nuestra experiencia, la RM nos ha permitido un mejor diagnóstico anatómico de la extensión tumoral, facilitándonos la planificación quirúrgica que requieren las modernas técnicas reconstructivas en ortopedia oncológica.The preliminary experience using Magnetic Resonance imaging for pre- and post-operative assessment of orthopaedic oncologic patients is hereby reported. Twenty-one patients with histologically characterized bone and soft tissue tumors have been reviewed. Seventeen patients had primary musculoskeletal neoplasia: 10 had soft tissue sarcomas and 7 bone tumors. The remained 4 patients consisted of bone metastasis or local racidive. Magnetic resonance images were acquired using a superconductive magnet operating at 0.5 Tesla. T1- and T2-weighted transaxial and coronal images were obtained in all cases. An excellent contrast between the signal of the lesion and the normal adjacent structures was usually obtained. Only in one osteosarcoma of the proximal fibula, an extraosseous extension was presumed but not found during surgical resection. Changes in image intensity did not permit to identify tumor tissue specificity neither distinguish between benign and malignat lesions. In our experience, Magnetic Resonance shows a great advantage in order to determine tumor anatomical extension, providing a useful information for the surgical planning required by current reconstructive techniques in orthopaedic oncology

Losing a parent to cancer as a teenager: Family cohesion in childhood, teenage, and young adulthood as perceived by bereaved and non-bereaved youths.

OBJECTIVE: The aim of this study was to investigate levels of perceived family cohesion during childhood, teenage years, and young adulthood in cancer-bereaved youths compared with non-bereaved peers. METHODS: In this nationwide, population-based study, 622 (73%) young adults (aged 18-26) who had lost a parent to cancer 6 to 9 years previously, when they were teenagers (aged 13-16), and 330 (78%) non-bereaved peers from a matched random sample answered a study-specific questionnaire. Associations were assessed using multivariable logistic regression. RESULTS: Compared with non-bereaved youths, the cancer-bereaved participants were more likely to report poor family cohesion during teenage years (odds ratio [OR] 1.6, 95% CI, 1.0-2.4, and 2.3, 95% CI, 1.5-3.5, for paternally and maternally bereaved youths, respectively). This was also seen in young adulthood among maternally bereaved participants (OR 2.5; 95% CI, 1.6-4.1), while there was no difference between paternally bereaved and non-bereaved youths. After controlling for a number of covariates (eg, year of birth, number of siblings, and depression), the adjusted ORs for poor family cohesion remained statistically significant. In a further analysis stratified for gender, this difference in perceived poor family cohesion was only noted in females. CONCLUSION: Teenage loss of a parent to cancer was associated with perceived poor family cohesion during teenage years. This was also noted in young adulthood among the maternally bereaved. Females were more likely to report poor family cohesion. Our results indicate a need for increased awareness of family cohesion in bereaved-to-be families with teenage offspring, with special attention to gender roles.The Swedish Cancer Foundation [2008–758]; the Gålö Foundation; the Kamprad Family Foundation for Entrepreneurship; and the Mats Paulssons Stiftelse supported the research project

Bone defects following curettage do not necessarily need augmentation: A retrospective study of 146 patients

Background and purpose The natural pattern of bone healing in large bony defects following curettage alone as treatment of benign bone tumors around the knee is not well reported. We analyzed the outcome in 146 patients

Losing a parent to cancer as a teenager: Family cohesion in childhood, teenage, and young adulthood as perceived by bereaved and non-bereaved youths.

OBJECTIVE: The aim of this study was to investigate levels of perceived family cohesion during childhood, teenage years, and young adulthood in cancer-bereaved youths compared with non-bereaved peers. METHODS: In this nationwide, population-based study, 622 (73%) young adults (aged 18-26) who had lost a parent to cancer 6 to 9 years previously, when they were teenagers (aged 13-16), and 330 (78%) non-bereaved peers from a matched random sample answered a study-specific questionnaire. Associations were assessed using multivariable logistic regression. RESULTS: Compared with non-bereaved youths, the cancer-bereaved participants were more likely to report poor family cohesion during teenage years (odds ratio [OR] 1.6, 95% CI, 1.0-2.4, and 2.3, 95% CI, 1.5-3.5, for paternally and maternally bereaved youths, respectively). This was also seen in young adulthood among maternally bereaved participants (OR 2.5; 95% CI, 1.6-4.1), while there was no difference between paternally bereaved and non-bereaved youths. After controlling for a number of covariates (eg, year of birth, number of siblings, and depression), the adjusted ORs for poor family cohesion remained statistically significant. In a further analysis stratified for gender, this difference in perceived poor family cohesion was only noted in females. CONCLUSION: Teenage loss of a parent to cancer was associated with perceived poor family cohesion during teenage years. This was also noted in young adulthood among the maternally bereaved. Females were more likely to report poor family cohesion. Our results indicate a need for increased awareness of family cohesion in bereaved-to-be families with teenage offspring, with special attention to gender roles.The Swedish Cancer Foundation [2008–758]; the Gålö Foundation; the Kamprad Family Foundation for Entrepreneurship; and the Mats Paulssons Stiftelse supported the research project