Synthesis of Polyols for the preparation of biodegradable polyurethanes

Natural oils such as rapeseed oil do not contain the necessary chemical functionality (hydroxyl groups) required for the synthesis of the target biodegradable Polyurethane. The main aim of this work was to find an appropriate dihydroxylation reaction route to convert natural oils containing double bonds into polyols that can be used to produce biodegradable polyurethanes. We were particularly aiming for a low-cost process which could also be scaled up. Initial experiments were performed on model substrates containing double bonds (hexene and decatriene) to allow complete characterization of the compounds and consequently gain a more thorough understanding of the chemistry taking place. Several methods were investigated to find a suitable process to dihydroxylate alkenes and also to convert the unsaturated oils into polyols suitable for the preparation of polyurethanes. The permanganate and water system was suitable for the model compounds, but requiring a stoichiometriс amount of catalyst was a disadvantage for scale-up. The results of hydroxylation reaction of alkenes using hydrogen peroxide and formic acid were not encouraging. The results of hydroxylation reactions using phosphoric acid and hydrogen peroxide were quite encouraging. The reactions using natural oils were quite successful producing polyols with the hydroxide numbers of 187 and 164 for soyabean and rapeseed samples respectively. The method using organic peroxide, meta-сhlого perbenzoic acid (m-СРВА) was also encouraging. The (^1)Ή NMR analysis of the reaction of m-CPBA with the decatriene model compound revealed that m-CPBA selectively hydroxylates the internal double bonds. However, when natural oils, water and m-CPBA powder were mixed and stirred the reaction mixtures became dough like and were therefore difficult to manipulate

Grant-free Radio Access IoT Networks: Scalability Analysis in Coexistence Scenarios

IoT networks with grant-free radio access, like SigFox and LoRa, offer low-cost durable communications over unlicensed band. These networks are becoming more and more popular due to the ever-increasing need for ultra durable, in terms of battery lifetime, IoT networks. Most studies evaluate the system performance assuming single radio access technology deployment. In this paper, we study the impact of coexisting competing radio access technologies on the system performance. Considering \mathpzc K technologies, defined by time and frequency activity factors, bandwidth, and power, which share a set of radio resources, we derive closed-form expressions for the successful transmission probability, expected battery lifetime, and experienced delay as a function of distance to the serving access point. Our analytical model, which is validated by simulation results, provides a tool to evaluate the coexistence scenarios and analyze how introduction of a new coexisting technology may degrade the system performance in terms of success probability and battery lifetime. We further investigate solutions in which this destructive effect could be compensated, e.g., by densifying the network to a certain extent and utilizing joint reception

CONTRIBUTIONS OF THE MANAGEMENT SKILLS OF MANAGERS TO ORGANIZATIONAL CLIMATE ACCORDING TO THE OPINIONS OF EMPLOYEES WORKING IN DIRECTORATE OF YOUTH SERVICES AND PROVINCIAL DIRECTORATE OF YOUTH AND SPORTS

This study was conducted in order to reveal the effects of management skills of managers to organizational climate, according to the opinions of employees working in the Directorate of Youth Services and Provincial Directorate of Youth and Sports. The sample group of the study comprises of 73 randomly chosen employees from five cities (Elazığ: 17 employees, Diyarbakır: 10 employees, Gümüşhane: 14 employees, Isparta: 18 employees and Kırklareli: 14 employees). In order to collect the data for the study, “Contributions of Perceived Management Skills of Managers to Organizational Climate Scale”, which was developed by Akar (2006), was adopted. The Scale form consists of 4 subscales and a total of 30 matters. These are “Job Centeredness”, “Tolerance”, “Close Control” and “Contempt”. In the data analysis, frequency and percentage calculations were used. In terms of the mean points on the scale, determinant statistics, normality analysis, and homogeneity results were examined. Due to the inability of the data to present a normal distribution, in independent pair group comparisons, Mann-Whitney U test of non-parametric tests was adopted while Kruskal-Wallis H test was adopted in multiple group comparisons. The statistical meaningfulness degree Alpha (α) error rate was adopted as p<0.05. The following results were obtained as a result of the mentioned tests: No statistically significant difference was observed according to the sample group’s variables of marital status and educational level. In the “Job Centeredness” subscale of the scale, meaningful differences were observed in the professional seniority (0.041<p) and service time (0.039<p). In the “Tolerance” subscale, meaningful differences were observed in the variables of gender (0.012<p) and professional seniority (0.045<p). Furthermore, in the “Contempt” subscale, meaningful differences were observed in the variable of the place of duty (0.015<p).  Article visualizations

Aggregation and Closed-Form Results for Nonhomothetic CES Preferences

We provide four novel results for nonhomothetic Constant Elasticity of Substitution preferences (Hanoch, 1975). First, we derive a closed-form representation of the expenditure function of nonhomothetic CES under relatively flexible distributional assumptions of demand and price distribution parameters. Second, we characterize aggregate demand from heterogeneous households in closed-form, assuming that household total expenditures follow an empirically plausible distribution. Third, we leverage these results to study the Euler equation arising from standard intertemporal consumption-saving problems featuring within-period nonhomothetic CES preferences. Finally, we show that nonhomothetic CES expenditure shares arise as the solution of a discrete-choice logit problem

Hungry for Power: Historical Shifts of Energy Sources in Turkey and Italy

The aim of this paper is to analyze the role of the industrial revolution and the economic policies on the energy transition process of two developing Mediterranean countries: Turkey and Italy. Both countries not only have coast to Mediterranean, they also share a similar story in terms of their energy demands and industrialization in the interwar period. The study will analyze the period between the two world wars, considering the fact that times of war and depression most likely traumatize energy consumptions and economic growth and energy policies are constantly altered by wartime policies and constraints

Quality changes of spotless shad during storage at different conditions

KORAL, SERKAN/0000-0001-7424-2481; Kose, Sevim/0000-0001-6029-0458WOS: 000377012900006This study investigates the effect of using ice in combination with refrigeration on the sensory, physico-chemical and microbiological attributes of spotless shad during storage. Spotless shad kept in ice under refrigerated conditions had better sensory, physicochemical and microbiological quality as compared with control groups. the shelf life of samples kept at ambient temperature without ice was 2 days. Using ice and refrigeration only extended the shelf-life for 3 days and 4 days, respectively, while ice application with refrigeration further increased the shelf-life by 10 days. Physico-chemical and microbiological results usually supported sensory values. Histamine values were below EU (European Union) and FDA permitted levels for the shelf-life of fish

Ranolazine improved left ventricular diastolic functions and ventricular repolarization indexes in patients with coronary slow flow

IntroductionCoronary slow flow (CSF) is a condition commonly encountered during angiography. Recent studies have shown the adverse effects of CSF on left ventricular diastolic functions. CSF reportedly increases the novel ventricular repolarization parameters. Ranolazine is a preparation with a prominent anti-anginal activity that has positive effects on anti-arrhythmic and diastolic parameters. In this context, this study was carried out to investigate the effects of ranolazine on left ventricular diastolic functions and repolarization in patients with CSF.Material and methodsForty-six patients with CSF and 29 control subjects were included in the patient and control groups, respectively. Both groups received ranolazine for one month and were evaluated using 12–lead electrocardiography, conventional echocardiography, and tissue Doppler imaging at the baseline and after one month of ranolazine treatment.ResultsCorrected P, QT dispersion, and Tp-e interval values were significantly higher in the patient group than in the control group. There was a significant decrease in isovolumic relaxation time (IVRT) and deceleration time (DT) values after the ranolazine treatment compared to the baseline values in the patient group but not the control group. A significant increase was observed in the mean E and A velocities and the mean E/A ratio after the ranolazine treatment compared to the baseline values in the patient group. Additionally, there was a significant difference between the Tp-e interval and corrected P dispersion values measured after the ranolazine treatment compared to the baseline values in the patient group but not in the control group.ConclusionThis study's findings demonstrated that ranolazine positively affected impaired diastolic functions and repolarization parameters, particularly in patients with CSF

Adnexal Torsion: Difficulty in Diagnosis and Management

Aim:To investigate both the diagnostic value of Doppler-ultrasonography and factors influencing surgical intervention in patients with adnexal torsion (AT).Methods:We retrospectively examined medical records of 66 women with AT in a single center between January 2007 and December 2016.Results:Forty-three out of 66 patients (65.1%) with AT were correctly diagnosed preoperatively. On Doppler examination, reduced ovarian arterial blood velocity was observed in 39 patients (59.1%); and the sensitivity was 0.67. AT was diagnosed in 49 patients (74.2%) via laparotomy, and the number of patients who were subjected to radical treatment was higher than that of patients managed with conservative treatment (54.6% vs 45.4%). Although there was no difference in the surgical approaches (laparoscopy vs laparotomy) between the groups, age, gravidity, parity, body mass index, and ovarian cyst size were significantly lower in patients who were treated conservatively (p<0.05).Conclusion:The diagnostic value of Doppler examination for AT is limited and the decision for surgical management should not be delayed based on Doppler results. Early age, low gravidity, parity and body mass index, and small size of ovarian cyst on ultrasonography were indication for conservative treatment, whereas black-bluish macroscopic appearance had no influence on the preference towards the selection of treatment