29 research outputs found
Binary Nematic Liquid Crystals Mixture with Enhanced Electro-Optics Properties for Photonic Applications
Purpose: In this work, we mix two simple nematic liquid crystals (NLCs) and investigated the binaryNLCs mixtures of 7CB/PCH5 of different mixing ratios.
Methodology: The pure liquid crystals 7CB and PCH5 and binary mixtures of them of high temperature stability were thermally analyzed by differential scanning calorimetry. The mixture 7CB/PCH5:30/70 wt% has the highest thermal stability with a nematic-isotropic (N-I) transition temperature at 50oC. The electrooptic properties of 7CB, PCH5, and the mixture 7CB/PCH5:30/70 wt% at room temperature were also investigated using an amplitude modulated electric signal (1 kHz - 100 Hz) by increasing diving peak voltage from 0 V to 10 V. The threshold volage is relatively reduced for the binary mixture in comparison to that value for PCH5. In comparison to the pure LCs, the mixture 7CB/PCH5:30/70 wt% has the fastest response times of values 2.36 ms total time response, 0.41 ms rise time, and 1.95 ms fall time. It has also the highest contrast ratio. Moreover, it has a maximum measured transmission that is higher than those for PCH5 and 7CB by about 17 % and 8%, respectively, at a field strength of 2V/mm.
Findings: The obtained results indicate that the electrooptic properties of PCH5 was improved when mixed with a proper ratio of 7CB, of lower cost, more stablity , and higher potential for photonic applications.
Unique Contriburibution to Theory, Practice and Policy: This expermental study shows that simply by mixing two relatively low cost NLCs materials, one of high thermal stability and low electro-optic properties with other one of low thermal stability and better electro-optic properties; this would improve the stability, response, and transmition of the binary mixture. If the a suitable driving method is applied, without doping with other orgnic or inorganic matrial
Value of α-smooth muscle actin and glial fibrillary acidic protein in predicting early hepatic fibrosis in chronic hepatitis C virus infection
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
The Egalitarian Principle of “Qist” as Lived Ethic: Towards a Liberational Tafsir
The Qur’anic term and principle of “qist”—generally defined as fairness, equity, and giving each his/her due share—occurs twenty-two times and forms a particular intentional discourse against social and economic privilege and against power in its various dimensions. These occurrences, their contexts, and fields of meaning demonstrate its distinctive place within the Qur’anic moral worldview, at the nexus between private virtue ethics and collective praxis. Qist is presented not merely as an abstract ideal, but as a specific, concrete social and economic goal for the marginalized and disempowered of any community. Especially in the domains of gender relations, poverty conditions, and authorial power, the divine injunction for applying equality in lived contexts becomes a call for liberation from “zulm” (injustice) and “taghut” (false deities). Can the examination of this concept and its affiliates form the basis for a scriptural theorization on an Islamic theology of social and economic justice, of resistance to tyranny and unjust constructions of privilege and superiority? Towards an answer to this inquiry, one can argue that qist directs attention to the practical ways of applying the overarching, comprehensive value of shari’ah, al-‘adl (justice), as well as to its defining features of collectivity and distributiveness
Comparative analysis of seasonal wind power using Weibull, Rayleigh and Champernowne distributions
Abstract Accurate statistical modeling of wind speed variability is crucial for assessing wind energy potential, particularly in regions with low wind speeds and significant calm hours. This study evaluates the Champernowne distribution as a novel model for wind speed analysis, comparing its performance with the two-parameter Weibull, three-parameter Weibull, and Rayleigh-Rice distributions. Wind speed data at 10 m hub height over three years (2021–2023) from Ben Guerir, Morocco, were analyzed using statistical metrics such as Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Bias Error (MBE), Coefficient of Determination (R2), Akaike Information Criterion (AIC), and Bayesian Information Criterion (BIC). The Champernowne distribution outperformed the other models across all metrics, achieving the lowest RMSE (0.00036), MAE (0.00022), AIC (650.52), and BIC (689.46), and the highest R2 (0.99998). Its ability to capture calm hours and extreme wind speeds provided more accurate power density estimates, with errors averaging 23%, compared to 33% and 42% for the Weibull and Rayleigh-Rice distributions, respectively. Despite low mean wind speeds (2.7 m/s), Ben Guerir’s ground-based power density ranged from 18 to 54 W/m2. The results suggest that conventional large-scale wind energy projects are unsuitable for Ben Guerir. Instead, small Vertical-Axis Wind Turbines (VAWTs) or alternative strategies should be considered. The Champernowne distribution’s robustness makes it a valuable tool for wind energy assessments, especially in regions with intermittent wind patterns, providing a foundation for more accurate modeling and energy planning
