Synthesis of Spirooxoindole Derivatives

This review summarizes the methods for preparing spirocyclic oxoindole derivatives in the past years until 2012 which are divided into several groups according to ring size of the fused spiroindoles

Recent Developments In Chemistry Of 1,3,4-Thiadiazoles

The methods of preparation, structure and biological activities of 1,3,4-thiadiazoles are reported

تحليل أداء الأنظمة الشمسية الكهروضوئية: دراسة حالة لمحطة الطاقة الشمسية الكهروضوئية في جامعة فلسطين التقنية

Performance ratio is one of the indicators used to describe the effectiveness of the PV systems. The sustainability of the PV system year after year as well as its reliability can be checked by measuring the performance ratio each year. This indicator will also enable us to carry out a comparison between the performances of different PV systems. In this paper, the performance ratios for five PV systems installed on the roof tops of some of PTUK university buildings have been calculated on monthly and yearly basis. The analysis has been carried out using the available data (energy production and solar irradiation) for the year 2019. It was found that the performance ratio has higher values for May and September in comparison with other months. On the other hand, its lowest values were obtained in winter months. This trend can be observed for all of the PV clusters on the five buildings. When taking into account the overall system, the highest value for the performance ratio was 0.89, which was for September, whereas its lowest value of 0.70 was obtained in January. The performance ratio, which was calculated on yearly basis for the overall system, was found to be 0.80. When considering each building separately, the lowest value was 0.44 for the “Services” building whereas the highest value was 0.94 for the Science buildin

The Penalty Clause in Jordanian Civil Law

The research is financed by the Deanship of Scientific Research and Graduate Studies in the Applied Science Private University Abstract The penalty clause was introduced as one of the solutions provided by the legislator to regulate the individual legal transactions. Most netting contract contains a penalty clause, particularly contracts that its implementation takes long time, as in the contracts for work and procurement contracts. However, the practice of this legal option is still confused with other legal options and weaknesses in the wording of its terms, transgression and misunderstanding of the scope and limits of the contractual assurance still remains. Therefore, the origin of the subject and the declaration of its true legal context should be examined through this study, which is based on the position of the Jordanian law and its judicial provisions in this regard. Keywords: Penalty clause, concepts, legal system, limits

Opportunistic Spectrum Sharing using Dumb Basis Patterns: The Line-of-Sight Interference Scenario

We investigate a spectrum-sharing system with non-severely faded mutual interference links, where both the secondary-to-primary and primary-to-secondary channels have a Line-of-Sight (LoS) component. Based on a Rician model for the LoS channels, we show, analytically and numerically, that LoS interference hinders the achievable secondary user capacity. This is caused by the poor dynamic range of the interference channels fluctuations when a dominant LoS component exists. In order to improve the capacity of such system, we propose the usage of an Electronically Steerable Parasitic Array Radiator (ESPAR) antenna at the secondary terminals. An ESPAR antenna requires a single RF chain and has a reconfigurable radiation pattern that is controlled by assigning arbitrary weights to M orthonormal basis radiation patterns. By viewing these orthonormal patterns as multiple virtual dumb antennas, we randomly vary their weights over time creating artificial channel fluctuations that can perfectly eliminate the undesired impact of LoS interference. Because the proposed scheme uses a single RF chain, it is well suited for compact and low cost mobile terminals