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To evaluate in the first stage, the efficiency of changing the nature and the length of diols on the properties of perfectly hard sequences polyurethanes (PU). In the second, the thermal properties of a new series of segmented PU with different concentrations of soft sequences were determined.

The synthesis of segmented PU has been realised in two stages known as the pre‐polymer method. Various compositions of PU were obtained by keeping the poly(tetramethylene glycol) – PTMG molecular weights constant, but varying its concentration. The products obtained were characterised by IR, NMR, gel permeation chromatography and studied by differential scanning calorimetry.

The level of phase segregation depends on several parameters, especially the nature of the soft segment and its average molecular weight, nature of the hard sequence and the number of hydrogen bonds established in the PU sequences.

The segmented PU obtained were synthesised from PTMG of number molecular weight 2,000. They could also be synthesised from PTMG of molecular weight 600, 1,000, 2,000, 4,000, etc. The effect of change of PTMG molecular weight on PU properties could also be studied.

Better understanding of the morphology of segmented PU and its effect in the practical domains.

Novel perfectly hard sequences PU have been synthesised and characterised. The effect of soft sequence nature and concentration on the phase segregation in these new series of segmented PU is discussed.

The purpose of this paper is to evaluate the effect of thiourea (TU) on corrosion resistance property for rolled and recrystallized E-34 microalloyed steels by using electrochemical polarization techniques.

To perceive the effect of TU on the corrosion inhibition efficiency, various concentrations of TU (from 1 × 10 − 4 to 1 × 10 − 2M) and different temperatures (20, 30 and 400°C) in 1N sulfuric acid are used.

It is found that TU has significant inhibition effect on corrosion process. Moreover, it reveals that both the inhibitor concentrations and temperatures have a strong influence on the corrosion prevention efficiency of inhibitor. Thermodynamics studies confirm that the inhibitor adsorption follows the Langmuir adsorption isotherm model.

To the best of the authors’ knowledge, it is the first work that has been disclosed the corrosion inhibitory effect of TU for recrystallized E-34 microalloyed steels in acidic media.

The purpose of this study is to determine the effect of olive cake (CO) on glycaemia and lipemia and lipid peroxidation and antioxidant enzymes activities in erythrocytes and tissues, in streptozotocin (STZ)-induced diabetic rats.

Diabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg BW). In total, 12 diabetic D rats, weighing 260 ± 20 g, were divided into two groups fed a casein diet supplemented (D-OC) or not (D) with OC (7.5 per cent), for four weeks.

In D-OC compared with D, glycaemia, total cholesterol and triglycerides values (−40 per cent; p = 0.007, 27 per cent; p = 0.007 and −27 per cent; p = 0.0019). In erythrocyte, liver, kidney, heart, muscle and brain, thiobarbituric acid reactive substances contents were respectively, (−19 per cent; p = 0.03, −32 per cent; p = 0.002, −20 per cent; p = 0.04, −68 per cent; p = 0.003, −74 per cent; p = 0.0003 and −38 per cent; p = 0.04). In erythrocyte, SOD, GSH-Px and CAT activities were respectively, (+14 per cent; p = 0.01, +74 per cent; p = 0.012 and +34 per cent; p = 0.0009). In the liver, kidney, heart and muscle, SOD activity was respectively, (+31 per cent; p = 0.004, +12 per cent; p = 0.038, +43 per cent; p = 0.001 and +23 per cent; p = 0.18). GSH-Px activity was respectively, (+121 per cent; p = 0.0009, 89 per cent; p = 0.0006, + 95 per cent; p = 0.008, +71 per cent; p = 0.02 and +26 per cent; p = 0.01), in the liver, kidney, heart, muscle and brain. Catalase activity was (+21 per cent; p = 0.008) in the liver, (+88 per cent; p = 0.0002 in the kidney, +53 per cent; p = 0,002 in the heart and 83 per cent; p = 0.00004 in the muscle).

In diabetic rats, OC reduces hyperglycaemia induced by STZ and attenuates triglyceridemia and cholesterolemia. This residue is able to decrease the oxidative stress by increasing the antioxidant enzymes activity in erythrocytes and tissues. The high contents of phytoconstituents present in OC are considered to be responsible for this effect.

The purpose of this paper is to exploit the multiple-Toeplitz matrices reconstruction method combined with quadratic spatial smoothing processing to improve the direction-of-arrival (DOA) estimation performance of coherent signals at low signal-to-noise ratio (SNRs).

An improved multiple-Toeplitz matrices reconstruction method is proposed via quadratic spatial smoothing processing. Our proposed method takes advantage of the available information contained in the auto-covariance matrices of individual Toeplitz matrices and the cross-covariance matrices of different Toeplitz matrices, which results in a higher noise suppression ability.

Theoretical analysis and simulation results show that, compared with the existing Toeplitz matrix processing methods, the proposed method improves the DOA estimation performance in cases with a low SNR. Especially for the cases with a low SNR and small snapshot number as well as with closely spaced sources, the proposed method can achieve much better performance on estimation accuracy and resolution probability.

The study investigates the possibility of reusing pre-existing designs for the DOA estimation of the coherent signals. The proposed technique enables achieve good estimation performance at low SNRs.

The paper includes implications for the DOA problem at low SNRs in communication systems.

The proposed method proved to be useful for the DOA estimation at low SNR.

The purpose of this systematic review and meta-analysis was to investigate the efficacy of propolis on glycemic indices in type 2 diabetic patients.

Web of science (ISI), Embase, Scopus and PubMed were systematically searched to find randomized controlled trials (RCTs) assessing the effects of propolis intake on glycemic controls in type 2 diabetic patients, from inception up to September 1, 2020. A random-effects model was used to pool weighted mean difference (WMD). Meta-regression was performed to detect the potential sources of inter-study heterogeneity.

Seven trials were included in the meta-analysis. Compared to controls, propolis intake significantly improved serum fasting blood sugar (FBS) (WMD = −13.62 mg/dl, 95% CI = [−23.04, −4.20], P = 0.005, I2 = 58.5%) and hemoglobin A1C (HbA1c) (WMD = −0.52%, 95% CI = [−0.86, −0.18], P = 0.002, I2 = 64.0%). In contrast, receiving propolis did not change serum insulin (WMD = −1.46 (uIU/ml), 95% CI = [−2.94, 0.02], P = 0.05, I2 = 75.0%) and homeostatic model assessment for insulin resistance (HOMA-IR) (WMD = −0.98 (%), 95% CI = [−2.00, 0.04], P = 0.06, I2 = 82.3%) compared to controls.

The present meta-analysis demonstrated that propolis intake significantly reduces serum FBS and HbA1c in diabetic patients but does not alter serum insulin and HOMA-IR. Further large-scale RCT’s are needed to approve these effects.

The purpose of this paper is to investigate the efficiencies of argon (Ar), oxygen (O₂) and O₂ followed by Ar (O₂→Ar) plasma treatments in terms of contaminant removal and wire bond interfacial adhesion improvement. The aim of this study is to resolve the “lifted ball bond” issue, which is one of the critical reliability checkpoints for light emitting diodes (LEDs) in automotive applications.

Ar, O₂ and O₂→Ar plasma treatments were applied to LED chip bond pad prior to wire bonding process with different treatment durations. Various surface characterization methods and contact angle measurement were then used to characterize the surface properties of these chip bond pads. To validate the improvements of Ar, O₂ and O₂→Ar plasma treatments to the wire bond interfacial adhesion, the chip bond pads were wire bonded and examined with a ball shear test. Moreover, the contact resistance of the wire bond interfaces was also measured by using four-point probe electrical measurements to complement the interfacial adhesion validation.

Surface characterization results show that O₂→Ar plasma treatment was able to remove the contaminant while maintaining relatively low oxygen impurity content on the bond pad surface after the treatment and was more effective as compared with the O₂ and Ar plasma treatments. However, O₂→Ar plasma treatment also simultaneously reduced high-polarity bonds on the chip bond pad, leading to a lower surface free energy than that with the O₂ plasma treatment. Ball shear test and contact resistance results showed that wire bond interfacial adhesion improvement after the O₂→Ar plasma treatment is lower than that with the O₂ plasma treatment, although it has the highest efficiency in surface contaminant removal.

To resolve “lifted ball bond” issue, optimization of plasma gas composition ratios and parameters for respective Ar and O₂ plasma treatments has been widely reported in many literatures; however, the O₂→Ar plasma treatment is still rarely focused. Moreover, the observation that wire bond interfacial adhesion improvement after O₂→Ar plasma treatment is lower than that with the O₂ plasma treatment although it has the highest efficiency in surface contaminant removal also has not been reported on similar studies elsewhere.

Large-scale organizational change, such as seen through mergers and acquisitions, CEO succession, and corporate entrepreneurship, sometimes is necessary in order to allow firms to be competitive. However, such change can be unsettling to existing employees, producing considerable uncertainty, conflict, politics, and stress, and thus, must be managed very carefully. Unfortunately, to date, little research has examined the relationships among change efforts, perceptions of political environments, and employee stress reactions. We introduce a conceptual model that draws upon sensemaking theory and research to explain how employees perceive and interpret their uncertain environments, the politics in them, and the resulting work stress, after large-scale organizational change initiatives. Implications of our proposed conceptualization are discussed, as are directions for future research.

This article explores the symbolic aspects of change agency on a learning platform designed to facilitate system-wide transformation in cancer care. A sensemaking–sensegiving perspective is adopted to analyze the construction of meaning in interaction between the leader of a regional cancer center, senior physicians, and an action research team in relation to patient-centered care. The analysis suggests that the physicians, as change agents, made sense of the vision from three quite distinct discourses in relation to the development effort. We argue that although meanings reconstructed in development initiatives may well be far from shared, this by no means implies that they are dysfunctional.

In this paper, we contribute to the understanding of how entrepreneurs can deploy their values to enable joint action of heterogeneous stakeholders. Such an understanding forms a critical endeavor to tackle grand challenges adequately. Building on sensegiving research, we conducted a single-case study of an entrepreneurial initiative that tackles gender inequality in Lebanon which has been successful in mobilizing heterogeneous stakeholders who ordinarily would not collaborate with each other. We find that the values of the founders were pivotal for the initiative’s success as those values activated latent values of stakeholders through processes of contextualization and enactment. We subsume these processes under the label value-driven sensegiving. As a result of value-driven sensegiving, heterogeneous stakeholders could make sense of the founders’ aspirational vision and the role they could play in it, which paved ways for tackling grand challenges collaboratively. Our study provides insights into the centrality of values for mobilizing heterogeneous stakeholders across boundaries. Therefore, it contributes to the body of work on sensegiving, societal grand challenges, and new forms of organizing.