Monte Carlo sensitivity analysis of vehicle suspension energy harvesting in frequency domain.

Regenerative shock absorbers (RSAs) have still not entered production lines despite the promising potentials in energy efficiency and emission reduction. Vibration energy harvesting from vehicle dampers has been replicating the dynamics of passive viscous dampers. An accurate frequency-based analysis of the harvestable energy and dynamics for vehicle suspensions under typical operating conditions is essentially needed for designing functional Vibratory Regenerative Dampers (VRDs). This paper proposes frequency-based parametrical bandwidth sensitivity analyses of both the vehicular suspension dynamics and energy harvesting potentiality in accordance with the Monte Carlo sensitivity simulations. This provides insights into which suspension parameter could highly broaden the harvestable power magnitude, which contributes positively to conceptualizing an efficient design of a wide broad-banded energy harvesting damper leading to improved harvesting efficiencies in different road conditions. The conducted sensitivity analysis included the change in both frequency and amplitude bandwidth of the dissipative damping power, body acceleration, dynamic tire load, and suspension deflection. During the sensitivity simulations, a 2-DOFs (degrees-of-freedom) quarter-car model is considered, being excited by harmonic excitations. The selected suspension parameters were normally randomized according to the Gaussian probability distribution based on their nominal values and a 30% SD (standard deviation) with respect to the uniformly randomized excitation frequency. The results inferred higher sensitivity change in the harvestable power bandwidth versus the excitation parameters, damping rate, and tire properties. Conversely, the harvestable power hardly broadened with respect to the body and wheel masses and the spring stiffness.

Dual Diagnosis and Suicide Probability in Poly-Drug Users.

OBJECTIVE: To determine the frequency of suicidal thoughts and suicidal probability among poly-substance abusers in Saudi population, and to examine the relation between dual diagnosis and suicidal thoughts. STUDY DESIGN: Case control study. PLACE AND DURATION OF STUDY: Al-Baha Psychiatric Hospital, Saudi Arabia, from May 2011 to June 2012. METHODOLOGY: Participants were 239 subjects, aged 18 - 45 years. We reviewed 122 individuals who fulfilled the DSM-IV-TR criteria of substance abuse for two or more substances, and their data were compared with that collected from 117 control persons. RESULTS: Suicidal cases were highly present among poly-substance abusers 64.75%. Amphetamine and cannabis were the most abused substances, (87.7% and 70.49%, respectively). Astatistically significant association with suicidality was found with longer duration of substance abuse (p < 0.001), using alcohol (p=0.001), amphetamine (p=0.007), volatile substances (p=0.034), presence of comorbid psychiatric disorders (dual diagnosis) as substance induced mood disorder (p=0.001), schizo-affective disorder (p=0.017), major depressive disorders (p=0.001), antisocial (p=0.016) and borderline (p=0.005) personality disorder. Suicidal cases showed significant higher scores (p < 0.001) of suicide probability scale and higher scores in Beck depressive inventory (p < 0.001). CONCLUSION: Abusing certain substances for long duration, in addition to comorbid psychiatric disorders especially with disturbed-mood element, may trigger suicidal thoughts in poly-substance abusers. Depression and suicide probability is common consequences of substance abuse.

Assessment of female sexual function in patients with psoriasis.

INTRODUCTION: Psoriasis has a major impact on sexual health due to the disfiguring skin lesions affecting self-image and self-esteem. However, this topic has not been fully explored. AIM: The study aims to assess sexual function in female patients with psoriasis. METHODS: This cross-sectional study included 52 sexually active female patients with psoriasis regardless of their age (group I) and 30 normal volunteers (who were age matched with the patients) who served as a control group (group II). Full history taking, general and systemic examination, including sexual history, together with clinical examination to evaluate the extent of skin disease using Psoriasis Assessment Severity Index (PASI) score and evaluation of sexual function using the Female Sexual Function Index (FSFI) Questionnaire, were done for all the subjects enrolled in the study. MAIN OUTCOME MEASURES: Correlation between PASI and FSFI domain scores was determined in matched groups using Pearson correlation. RESULTS: This study revealed a negative correlation between the PASI score and the overall sexual satisfaction in the studied group. Also, psoriatic female patients with genital psoriasis have more significantly impaired sexual function compared with either those without genital lesions or those with lesions elsewhere in the body. CONCLUSIONS: It is imperative to do full sexual and psychological assessment of psoriatic patients to improve outcomes and increase patients' compliance with treatment.